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L.   B.    Cat.   No.   1 137 


John  James  Audubon  - 
1785-1851 

From  a  portrait  in  oil  by  George  P.  A.  Healy,  London,  1838. 

Courtesy  of  Mr.  Ruthven  Dcane. 


BIOLOGY 
IN      AMERICA 


R  .    T.     YOUNG 


WITH  MORE  THAN 
TWO  HUNDRED  ILLUSTRATIONS 


BOSTON 

RICHARD  G.  BADGER 

THE   GORHAM   PRESS 


Copyright,  1922,  by  Richauu  G.  Badger 


All   Rights  Reserved 


Made  in  the   United   States   of  America 


Press  of  J.  J.  Little  and  Ives  Company,  New  York,  U.   S.  A. 


•  LIBRARY 

fl,  C.  state  College 


To 

THE  MEMORY  OF 

MY  MOTHER 


11  J   11 


PREFACE 

To  the  "man  in  the  street"  the  biologist,  with  his  "bugs" 
or  his  ' '  germs, ' '  frequently  appears  as  a  harmless  but  equally 
useless  individual.  Thus  in  an  issue  of  the  "New  Republic," 
shortly  after  America's  entrance  into  the  world  war,  a  serio- 
comic writer  in  criticizing  the  action  of  President  Wilson  in 
appointing  a  committee  on  national  preparedness  from  the 
National  Academy  of  Sciences  says,  "I  doubt  if  any  other 
nation  ever  responded  to  the  prospect  of  war  with  a  scheme 
of  national  defense  which  included  a  Committee  on  Zoology 
and  Animal  Morphology." 

What  excuse  then  has  the  biologist  for  his  existence  ?  What 
can  he  say  for  the  ' '  truth  that  is  in  him ' '  ? 

When  half  a  century  ago  the  Austrian  monk,  Gregor 
Mendel,  was  "puttering"  over  his  sweet  peas  in  the  garden 
of  the  monastery  at  Briinn  in  the  Tyrol,  the  world  took  small 
notice  of  his  work,  little  realizing  that  he  was  laying  the 
foundation  stones  of  a  science  which  was  to  place  animal  and 
plant  breeding  on  a  scientific  basis,  and  teach  us  how  to  build 
a  better  race  of  man  himself.  When  the  English  army  sur- 
geon Ross  in  India  in  1898  was  studying  a  microscopic  organ- 
ism in  the  blood  of  the  owl,  he  could  not  foresee  that  his  work 
would  in  a  few  years'  time  virtually  abolish  malaria  in 
Ismailia  on  the  Suez  Canal,  where  in  1902  there  were  1548 
cases  in  a  population  of  about  6,000;  that  it  would  render 
possible  the  building  of  the  Panama  Canal,  and  convert 
Havana  into  a  health  resort. 

Of  what  particular  practical  importance  was  Harrison's 
discovery  that  a  bit  of  nerve  cord  transferred  from  a  tadpole 
to  a  drop  of  frog's  lymph  would  develop  nerve  fibres  there? 
Yet  Harrison's  method  of  making  that  discovery  has  opened 
to  science  an  entirely  new  field  in  the  study  of  tissue  growth, 
both  benign  and  malignant,  has  enabled  us  to  observe  the 
growth  of  the  cancer  cell,  and  determine  some  of  the  con- 
ditions of  that  growth,  and  may  some  day  lead  us  to  a  solu- 
tion of  the  cancer  problem. 

When  a  fish  embryo  is  developed  in  a  solution  of  magnesium 
chloride  it  gives  rise  to  various  malformations,  most  conspicu- 
ous of  which  is  the  ' '  cyclopean  eye. ' '  Of  what  possible  value 
to  a  workaday  world  is  such  a  discovery?     Very  little  in 

'  7 


8  Preface 

itself.  But  if  the  young  fish  can  be  distorted  into  all  sorts 
of  monstrous  shapes  by  chemical  treatment,  why  may  not  the 
monstrosities  observed  in  man,  some  of  which  are  not  neces- 
sarily fatal,  but  which  entail  on  their  victims  sorrow  and  suf- 
fering, be  due  to  a  similar  cause?  And  may  not  the  discovery 
of  the  cause  lead  to  its  control? 

But  the  primary  aim  of  science  is  not  utilitarianism.  Were 
this  so,  it  would  still  be  wearing  rompers  instead  of  seven 
league  boots.  It  is  a  commonplace  to  say  that  the  aim  of 
science  is  truth,  regardless  of  what  practical  value  such  truth 
may  have.  But  the  "man  in  the  street"  frequeiitly  fails  to 
realize  the  connection  between  purpose  and  accomplishment 
in  science.  Perha})S  never  has  this  relation  been  made  more 
clear  than  in  the  recent  war.  The  German  Government,  recog- 
nizing the  value  of  science  for  its  own  sake,  encouraged  it 
with  every  means  in  its  power,  and  the  German  university 
became  a  Mecca  for  scientific  students  throughout  the  world. 
England,  on  the  contrary,  was  more  interested  in  develop- 
ing good  cricketers  and  diplomatists  than  in  training  scien- 
tists, and  when  war  came  upon  her  "like  a  thief  in  the  night" 
she  found  herself  under  a  well-nigh  fatal  handicap. 

It  was  farseeing  statesmanship  which  led  President  Wilson 
to  call  for  a  council  of  national  defense  from  the  National 
Academy  of  Sciences  on  America's  entrance  into  the  war.  It 
would  have  been  still  farther  sighted  had  this  council  been 
established  long  years  ago. 

American  biology,  with  the  lusty  vigor  of  youth,  has  ad- 
vanced by  leaps  and  bounds  in  recent  years;  and  today  a 
wonderful  future  opens  before  it.  From  the  days  when  the 
early  naturalists  went  hand  in  hand  wuth  the  pioneer  into  the 
depths  of  our  great  forests,  crossed  the  boundless  prairie  and 
pierced  the  trackless  labyrinth  of  mountain  peak  and  canyon, 
to  the  present,  w'hen  the  names  of  American  biologists  stand 
throughout  the  world  as  synonyms  of  biological  progress,  their 
record  is  one  of  which  our  nation  and  the  world  may  well  be 
proud. 

It  is  in  the  hope  of  recording,  in  some  small  measure,  the 
story  of  this  progress  that  this  book  is  written.  Most  of  the 
facts  herein  recorded  have  already  appeared  in  the  many 
books  dealing  with  the  biological  problems  of  the  last  few 
years,  but  nowhere,  so  far  as  I  know,  has  a  brief,  compre- 
hensive and  simple  story  of  the  work  of  American  biologists 
been  told.  It  is  in  the  hope  of  presenting  such  a  story  that 
this  work  has  been  undertaken.  To  give  a  comprehensive  as 
well  as  simple  account  of  so  complex  a  field  as  biology  is, 
however,  far  from  easy,  A  full  account  of  so  wide  a  field 
would  require  many  volumes,  but  I  shall  attempt  to  touch  only 


Preface  9 

upon  th3  more  salient  points.  The  avoidance  of  technical 
terms  is  in  many  cases  impossible,  but  I  have  endeavored 
to  reduce  them  to  a  minimum. 

It  is  of  course  impossible  in  such  a  story  to  avoid  referring 
to  the  work  of  biologists  in  other  lands.  Nor  is  it  desirable. 
Science  is  not  bounded  by  political  and  racial  lines,  and  the 
work  of  American  biologists  can  only  be  appreciated  in  the 
light  of  what  their  colleagues  in  other  lands  have  been  doing. 
The  book  is,  however,  a  record  of  American  biology,  so  that 
reference  to  the  work  of  other  biologists  will  be  only  incidental 
to  the  main  trend  of  the  story. 

A  zoologist  should  perhaps  apologize  for  the  title,  since 
the  main  emphasis  will  naturally  fall  on  that  branch  of 
biology  with  which  he  is  most  familiar.  The  great  principles 
of  life,  however,  apply  equally  to  plants  and  animals,  and 
even  though  the  examples  which  illustrate  these  principles 
have  been  drawn  mainly  from  the  animal  world,  nevertheless 
the  title  will  be  justified  if  the  discoveries  recorded  are  those 
which  in  the  main  illustrate  the  laws  which  govern  plants 
aiid  animals  alike. 


The  writer  is  indebted  to  numerous  sources 
for  the  illustrations  and  quotations  found  in  this 
book.     Due  acknowledgment  for  each  is  made 

in  coimection  with  it. 

To  his  wife,  Ellen  F.  P.  Young,  and  sister, 
IMary  Farrar,  grateful  acknowledgment  is  due 
for  assistance  with  the  proof  and  index. 


CONTENTS 

CHAPTER  PAGE 

I.  Work  of  Early  Biologists.  Explorers  and  Travel- 
ers, Collectors,  Field  Naturalists  and  Museum 
Men.     Early  Surveys,  State  and  National       ...       19 

II.  Biological  Institutions  in  America.  Universities  and 
Colleges,  Museums,  Botanical  and  Zoological  Gar- 
dens, Biological  Stations  and  Endowed  Labora- 
tories    47 

III.  Descriptive    Biology.      Development    of    Plants    and 

Animals;  of  Sex  and  Sexual  Reproduction,  and  Al- 
teration OF  Generations.  The  Path  of  Vertebrate 
Evolution 88 

IV.  The  Story  of  the  Rocks.     Contribution  of  Paleon- 

tology TO  Evolution.    Rise  and  Fall  of  the  Faunas 

of  the  Past 116 

V.  Geographical  Distribution  of  Plants  and  Animals. 
Relation  Between  Organism  and  Environment. 
Methods  of,  and  Barriers  to  the  Spread  of  Plants 
and  Animals.  Plant  and  Animal  Societies.  Life 
Zones  op  North  America 151 

VI.  Experimental  Biology.  Preformation  in  a  New 
Dress,  Organization  of  the  Egg,  Regeneration  and 
Grafting,  Plastic  Surgery,  Tissue  Culture,  the 
Problem  of  Death,  and  Immortality  of  the  Cell    .     188 

VII.  Experimental  Biology  Continued.  The  Role  of  the 
Chromosomes  in  Inheritance.  Inheritance  of  Sex 
and  Sex-Linked  Characters 202 

VIII.  Experimental  Biology  Continued.  Influence  of  En- 
vironment IN  Determining  the  Development  of  Or- 
ganisms. Effects  of  Temperature,  Light,  Moisture, 
Chemicals,  and  Food  upon  the  Form  of  Animals  and 
Plants.     The  Control  of  Sex       219 

IX.  Experimental  Biology  Continued.  The  Factors  of 
Evolution:  Natural  Selection,  Mutation,  Ortho- 
genesis, Isolation,  Inheritance  of  Acquired  Char- 
acters. Experimental  Modification  of  the  Germ 
Cells 234 

X.  Experimental  Biology  Continued.  Mendelism  and 
the  Multiple  Factor  Hypothesis.  Human  Inherit- 
ance and  Eugenics 257 

XI.  Experimental  Biology  Continued.  Mechanism  Versus 
Vitalism.  Physico  -  chemistry  op  Vital  Processes, 
Metabolism  of  Animals  and  Plants 278 

11 


12  Contents 

CHAPTER  PAGE 

XII.  Experimental  Biology,  Mechanism  Versus  Vitalism 
Continued.  Tropisms,  Instincts  and  Intelligence. 
Hormones.     Artificial  Fertilization 301 

XIII.  Color  in  Nature.    Colors  of  Flowers  and  the  Inter- 

relation OF  Flowers  and  Insects.  Colors  of 
Animals  and  Their  Physico-chemical  Causes.  The 
Theories  of  Pjiotective  Coloration,  Warning  and 
Alluring  Colors,   Mimicry  and  Recognition  Marks     330 

XIV.  Aquatic  Biology.    Oceanography,  Life  of  the  Sea  and 

Its  I']nvikonment.  Biology  of  Inland  Waters. 
Methods  of  Studying  Aquatic  Life 349 

XV.  Economic  Biology.  Dependence  of  Man  upon  Nature. 
Ignorance  of  Nature  the  Cause  of  Economic  Loss. 
Conservation  and  Increase  of  Natural  Resources  .     385 

XVI.  Biology  and  Medicine.  Microscopic  Life  and  Its  Re- 
lation to  Human  Health.  The  Role  of  Animals  in 
Spreading  Disease.  Animal  Experimentation  and  Its 
Contributions  to  Human  Welfare.  The  New  Medi- 
cine, Safeguarding  the  Health  of  the  Nation     .     .     440 

XVII.   The  Outlook.     Some  Unsolved  Problems  of  Biology. 

Possibilities  of  Larger  Service 478 


ILLUSTRATIONS 

1     John  James   Audubon, Frontispieo 


e 


PAGE 


2  Alexander    Wilson       21 

3  Rafinesque       29 

4  Lewis  and  Clark,  Thomas  Jefferson,  Thomas  Nuttall     ...  35 

5  Louis  Agassiz 38 

6  James  Dwight  Dana,  Joseph  Leidy,  Edward  Drinker  Cope, 

Othniel  Charles   Marsh 41 

7  Asa    Gray 43 

8  Spencer  Fullerton  Baird 44 

9  The  Academy  of  Natural  Sciences  of  Philadelphia    ....  53 

10  The  American  Museum  of  Natural  History  in  New  York     .  54 

11  Blue  shark  and  school  of  young 55 

12  Duck  hawk  at  nest 56 

13  Florida   swamp 56 

14  Woolly  rhinoceros,  saiga  antelope  and  mammoth     ....  57 

15  Monarch  butterfly 58 

16  New  sources  of  aquatic  food 60 

17  The  U.  S.  National  Museum 61 

18  The  Now  York  Botanical  Gardens 64 

19  The  laurel  bank  in  the  Arnold  Arboretum 65 

20  The  "forest  primeval"  in  the  Arnold  Arboretum 66 

21  Marine  Biological  Laboratory  at  Woods  Hole,  Mass.     ...  68 

22  View  of  Woods  Hole 69 

23  Animal  community  of  a  New  England  wharf 70 

24  The  Station  for  Experimental  Evolution  of  the  Carnegie  In- 

stitution          74 

25  Desert  Botanical  Laboratory  of  the  Carnegie  Institution     .     .  75 

26  Old  shore  line  of  Salton  Sea 78 

27  Tortugas  Laboratory  of  the  Carnegie  Institution 82 

28  The  yacht  "Anton  Dohrn"  of  the  Carnegie  Institution    ...  83 

29  Types    of   Protozoa 90 

30  Types    of   Protozoa 91 

31  Lower  plant  life 93 

32  Amoeba   proteus 94 

33  Life  cycle  of  malarial  organism 97 

34  Phlox,  liverwort  and  moss 99 

35  Invertebrate   types 102 

36  Vertebrate  embryos 104 

13 


14  Illustrations 

FACE 

37  Head  of  lamprey,  and  sucker  showing  scars  made  by  lamprey  109 

38  Lungfish  and  fossil  shark,  Cladoselachc 112 

39  A    trilobite 117 

40  A   king  crab 117 

41  Ostracoderms 118 

42  Cestracion,  Polyterus  and  Hatteria 121 

43  Footprint   of  a  primitive  am[)liihi;in 122 

44  A    stcgoccphalan 123 

45  Landscape  of  the  coal-forming  period 124 

46  Dinosaur   tracks 126 

47  Brontosaurus        127 

48  Stegosaurus 128 

49  Triceratops 128 

50  Rhamphorhynchus       129 

51  Arc'ha'opteryx 131 

52  Hesperornis 132 

53  Part  of  feather,  showing  details 133 

54  Tooth  of  dinosaur  and  jaw  of  contemporary  mammal     .     .    .  137 

55  Opossum 138 

56  Spiny  ant-eater 139 

57  Uintatherium,  Coryphodon,  and  Dromocyon 141 

58  Eohippus 143 

59  The   tarsier 144 

60  The   saber-toothed   tiger 146 

61  Excavation  of  a  tar  pit  at  Rancho  La  Brea,  California  .     .     .  148 

62  Early  days  in  the  tar  pools  of  Southern  California     ....  149 

63  The  arctic  tern 152 

64  A  group  of  lichens 159 

65  A  glacial   pond 160 

66  Zoogeographical   realms 161 

67  Life  zones  of  North  America 162 

68  Profile  of  San  Francisco  Mountain,  showing  life  zones  .     .     .  163 

69  An  alpine  dwarf 164 

70  Pika,  or  Rocky  Mountain  hare 165 

71  Ptarmigan  in  summer  plumage 166 

72  Ptarmigan  in  autumn  plumage 166 

73  Ptarmigan  in  winter  plumage 167 

74  Clarke's   crow 167 

75  Timber  line  in  the  Rocky  Mountains 168 

76  Polar  bears 169 

77  Cariboo       169 

78  Musk   oxen 170 

79  Wolverine 170 

80  Canadian  zone  forest  in  Colorado 171 

81  Woodchuck 172 

82  Weasel 173 

83  Snowshoe  rabbit 173 


Illustrations  15 

PAGE 

84  Canadian  and   transition  zone   landscape 174 

85  Beaver 175 

86  Beaver  pond 176 

87  Cypress  swamp 177 

88  Cotton   rat 178 

89  Alligator 179 

90  Water  moccasin 179 

91  Burrowing    owl 180 

92  Prairie  dog 181 

93  Prairie  dog  at  burrow 181 

94  Horned  toad        183 

95  Kangaroo   rat 183 

96  Gila   monster       184 

97  California  big  trees 185 

98  Mountain    beaver 186 

99  Beroe 189 

100  Organ-forming  substances  in  the   egg 190 

101  Four-legged  tadpoles       195 

102  Combination  frog 196 

103  Reconstruction  of  wounded  soldier's  face 198 

104  A  piece  of  growing  tissue 199 

105  Mitosis  in  a  sea  urchin's  egg,  showing  chromosomes  ....  204 
1C6  Diagram  of  inheritance  of  size  in  sweet  peas 205 

107  Diagram   of  combinations^  of  three   pairs   of  chromosomes     .  206 

108  Photographs  of  chromosomes,  showing  sex  chromosomes  .     .  208 

109  Gynandromorph  fruit  flies 209 

110  Diagrams  showing  distribution   of  sex  chromosomes  in   ma- 

turation          211 

111  Fruit  flies,  showing  mutations 212 

112  Diagrams  showing  chromosomes  in  relation  to  sex  linkage     .  213 

113  Chromosome  map  showing  distribution  of  linked  characters 

in  the  fruit  fly 216 

114  Diagrams  of  chromosomes  in  the  fruit  fly  showing  result  of 

non-disjunction 217 

115  Influence  of  environment  on  plants 221 

116  Effect  of  diet  on  body  form  in  Amblystoma 225 

117  Scarlet  tanager  and  bobolink,  showing  sex  differences     .     .     .  226 

118  Cyclopean   fish 228 

119  Human  twin  monster 229 

120  Types  of  human  faces 229 

121  A   human   monster 230 

122  Moulted  skin  and  egg  case  of  daphnid 231 

123  Diagram  showing  pure  lines  in  beans 237 

124  Hooded   rats 238 

125  Mutation  in  (Enothera 239 

126  A  rumpless  fowl 240 

127  Diagram  showing  height  variation  in  man 241 


16  Illustrations 

PAGE 

128  Mutations  in  the  potato  beetle 247 

129  Deer    mouse 250 

130  Inheritance  of  color  in  the  four  o'clock 258 

131  Inheritance  in  Andalusian  fowl 259 

132  Inheritance  of  ear  length  in  rabbits 260 

133  Inheritance  in  guinea  pigs 261 

134  Diagrams  showing   Mendelian   inheritance   of   one,   two   and 

three  pairs  of  characters  respectively 262 

135  Hornless  cattle 267 

136  Diagram  showing  osmosis 279 

137  Effect  of  diet  on  man 288 

138  Effect  of  diet  on  dogs 291 

139  Pursuit  of  food  by  Amoeba 302 

140  Compass  plants  as  seen  from  different  positions 307 

141  Mimosa  or  sensitive  plant 308 

142  Sundew   leaf 309 

143  Sagging  in  a  stem 310 

144  Relative  amount  of  bending  in  stems  due  to  unequal  growth  311 

145  Effect  of  the  kinetic  drive  on  a  soldier 322 

146  Effect  of  the  kinetic  drive  on  the  tissues  of  the  body     .    .    .  323 

147  Sebright   poultry,   normal   and   castrated 326 

148  Relation  of  bee  and  flower 331 

149  Flatfish  photographed  on  different  backgrounds 334 

150  Protective  form  and  color  in  animals 335 

151  Leaf  insect 336 

152  Walking  stick  insects 336 

153  Dead  leaf  butterfly         337 

154  Imitation  of  an  orchid  by  a  mantis 338 

155  Skunk 339 

156  Porkfish        339 

157  Mimicry  of  monarch  by  viceroy  butterfly 340 

158  Biuiiblebee   mimicked  by   fly 340 

159  Mimicry  in  butterflies 341 

160  Mimicry  of  leaf  cutting  ant  by  tree  hopper 341 

161  Antelope 343 

162  Male  and  female  wood  ducks 344 

163  Sexual  difference  in  beetles 345 

164  Sexual  difference  in  fish 345 

165  The  "Albatross" 350 

166  A  radiolarian 352 

167  Deep  sea  fishes  on  a  light  background 354 

168  Deep  sea  fishes  on  a  dark  background 355 

169  Angler  fish   and   Chiasmodus 356 

170  Giant  squid  and  tentacle  marks 356 

171  Portuguese  man  of  war 357 

172  Vellela 358 

173  Sunfish  and  crustacean  larva 359 


Illustrations  17 

rAOF 

174  Salmon  at  hn^c  of  falls 362 

175  Leaping   salmon 362 

176  Sigsbee  sounding  machine  in   use  on  the  "Albatro.--.s"          .     .  364 

177  Bigelow  water  bottle        368 

178  Blake   deep  sea   trawl 369 

179  Tow-nets  in  use  on  the  "Albatross" .          .  371 

ISO  Jaws  of  whalebone  whale 373 

181  Hensen's  net        374 

182  Synura 378 

183  Gypsy  moths  and  caterpillars  on  trees 386 

184  Trees  stripped  by  gypsy  moth  caterpillars 386 

185  Alfalfa   field   ruined  by   mice 387 

186  Red-tailed    hawks        388 

187  Barn  owl     . 389 

188  Skulls    disgorged   by   barn    owls 389 

189  Meadow  mice 394 

190  Apple  tree  girdled  by  mice 395 

191  Cottontail  rabbit 397 

192  Brown   rat        399 

193  Gray   wolf   and    pups 401 

194  Ground  squirrel       401 

195  Pocket  gopher 402 

196  San  Jose  scale 403 

197  Mass  of  San  Jose  scales  on  tree  tnmk 404 

198  Apples  infested  with  San  Jose  scale 405 

199  Pitiful   ladybird   beetle 406 

200  Screw  worm   and   cattle   ticks 408 

201  Bamboo    grove 410 

202  Udo 411 

203  Udo  stem,  blanched        412 

204  Tung  oil  tree      .     , 413 

205  Fruit  of  tung  oil  tree 414 

206  Pistache  trees 415 

207  Indian  mango 416 

208  Date    plantation 417 

209  Bunch    of   dates 418 

210  Herd  of  buffalo       419 

211  Elk  in  Yellowstone  Park 420 

212  Egret  colony        421 

213  Group  of  fur  bearing  animals 423 

214  Otter       424 

215  Mink       424 

216  Seining  salmon        428 

217  Salmon   eggs 429 

218  Interior  of  salmon  hatchery 430 

219  Developing   fish       .     .     .    ' 431 

220  Seals  on  Pribilof  Islands 433 


18  Illustrations 

PAGE 

221  Glofliidiuia    larva        435 

222  Dianiorul-back  terrapin 437 

223  Carroll,  Lazcar  and  Rwd 451 

224  War  on  the  mosquito 454 

225  Trifhina    in   mviscle      .          462 

226  Tapcnvorni   of   man 463 

227  Hookworm       465 

228  Hookworm   (lisprnsar.v 468 

229  Hookworm  patient  before  and  after  treatment 469 


BIOLOGY 
IN   AMERICA 


BIOLOGY  IN  AMERICA 


CHAPTER  1 

Work  of  the  early  biologists.  Explorers  and  travelers,  col- 
lectors, field  naturalists  and  museuni  men.  Early  surveys, 
state  and  nationul. 

The  evolution  of  human  thought  parallels  that  of  the  indi- 
vidual mind.  Man  sees  first  the  effect  and  then  seeks  the 
cause.  The  falling  apple  pointed  the  way  to  the  discovery  of 
the  law  of  gravitation;  the  amber  wand,  when  rubbed  with  a 
bit  of  fur,  to  the  discovery  of  electricity,  and  the  "pebrin" 
disease  of  the  silkworm  to  the  modern  science  of  bacteriology. 
The  story  of  all  science  is  one  of  observation  of  phenomena, 
speculation  as  to  their  cause,  and  finally  the  determination 
'6f  cause  by  means  of  experiment.  The  recording  of  phe- 
nomena is  not  however  limited  to  any  given  sidentific  age, 
but  necessarily  goes  hand  in  hand  with  philosophy  and  experi- 
ment, forming  with  them  the  trinity  of  scientific  progress. 

It  is  but  imtural,  then,  that  the  early  history  of  biology  in 
'America  should  be  written  in  the  bold  characters  of  stirring 
adventure.  Across  the  sea  in  the  first  years  of  the  last  cen- 
tury came  adventurous  spirits,  keen-eyed  and  lusty  hearted, 
with  the  "call  of  the  wild"  in  their  souls.  Some  of  these, 
llfte  the  Scotch  peddler  Wilson,  and  the  eccentric  Audubon 
W&re  "ne'er  do  weels"  filled  wdth  the  primitive  instinct  of  the 
ii'dtead.  Others  were  men  of  high  station  in  the  Old  World, 
tike  Lucieii  Bonaparte,  nephew  of  the  great  imperialist,  who 
idame  to  'this  country,  like  their  humbler  comrades,  impelled 
by  a  spirit  of  scientific  adventure.  There  were  still  other 
naturalists  in  the  early  days  in  America,  like  the  Bartrams, 
Who  Were  natives  of  the  soil. 

'These  early  biologists  were  naturally  collectors  and  field 
Naturalists,  but  with  the  establishment  of  learneil  societies 
they  were  soon  joined  by  museum  men,  who  worked  up  the 
material  collected  in  the  field.  The  interest  of  these  latter, 
then  as  now,  was  primarily  in  classification  and  distribution, 
but  the  writings  of  the  field  naturalists  are  replete  with 
interesting  accounts  of  the  liomes  and  habits  of  the  animals 

10 


20  Biology  in  America 

and  plants  which  they  collected.  Oftentimes  collector  and 
classifier  were  the  same,  as  with  Baird,  Coues  and  many 
othei-s. 

On  tho  banks  of  the  Sehnylkill  River  in  Philadelphia  stands 
an  okl  stone  luansion,  over  whieh  the  pleasant  ivy  clambers, 
and  in  the  garden  round  about,  now  a  city  park,  are  still 
growing  many  of  the  plants  set  out  there  nearly  two  centuries 
ago  by  John  Bartram,  who  was  the  first  American  botanist 
of  note,  and  whose  garden,  laid  out  in  1728,  was  the  first 
botanical  garden  in  America.  His  old  rock  wine  press  is 
there  still,  from  which  the  host  provided  refreshment  for 
Washington,  Franklin,  Hancock,  Rittenhouse,  Morris  and 
many  others  whose  names  are  written  large  on  the  pages  of 
our  nation's  story;  and  to  his  home  also  came  many  notables 
from  abroad,  for  his  reputation  for  learning  and  hospitality 
was  well  known.  Bartram  acted  at  one  time  as  American 
botanist  to  George  III,  and  corresponded  with  Linmeus,  who 
considered  him  "the  greatest  natural  botanist  in  the  world,'' 
as  well  as  with  other  leading  European  naturalists  of  his  time, 
with  whom  he  exchanged  many  plants  for  the  books  which 
could  only  be  obtained  in  Europe.  Provided  with  independ- 
ent means,  he  made  extensive  journeys  through  eastern 
America,  from  Lake  Ontario  to  Florida,  in  search  of  plants, 
accounts  of  which  were  published  by  him,  as  well  as  several 
minor  papers  on  natural  history. 

Here  was  born  and  died  the  son,  William,  a  botanist  and 
ornithologist  of  note.  Like  his  father,  he  was  an  extensive 
traveler,  and  published  an  account  of  his  travels,  as  well  as 
a  list  of  American  birds,  w^hich  was  the  first  extensive  work 
on  American  ornithology. 

Over  the  counter  of  a  little  store  in  Louisville,  Kentucky, 
there  occurred  in  INIareh,  1810,  a  chance  meeting  between  two 
men  who  have  stamped  their  names  in  indelible  letters  on  the 
pages  of  American  Science.  They  were  Alexander  Wilson, 
the  Scotch  weaver,  and  John  James  Audubon,  the  French 
artist.  In  his  "Ornithological  Biography,"  Audubon  has 
given  us  an  interesting  account  of  tiiis  meeting  and  of  his 
impressions  of  his  co-worker  in  the  field  of  ornithology.  "One 
fair  morning,"  writes  Audubon,  "I  was  suri)rised  by  the 
sudden  entrance  into  our  conntiug-room  at  Louisville  of  Mr. 
Alexander  Wilson,  tlie  celebrated  author  of  the  American 
Ornithology,  of  whose  existence  I  had  never  until  that  moment 
been  apprise<l.  This  happened  in  ]\Iarch,  1810.  How  well 
do  I  remember  him  as  lie  tlien  walked  up  to  me!  His  long, 
rather  hooked  nose,  the  keenness  of  his  eyes,  and  his  promi- 
nent cheek-bones,  stamped  his  countenance  with  a  peculiar 
character.     His  dress,  too,  was  of  a  kind  not  usually  seen  in 


Early  Naturalists  21 

that  part  of  the  country ;  a  short  coat,  trousers,  and  a  waist- 
coat of  g-rey  cloth.  Ilis  stature  was  not  above  middle  size. 
He  had  two  volumes  under  his  arm,  and  .  .  .  immediately 
proceeded  to  disclose  the  object  of  his  visit,  which  was  to 
procure  subseiiptions  for  his  work.  ...  It  happened  that  he 
lodged  in  the  same  house  with  us,  but  his  retired  habits,  1 
thought,  exhibited  either  a  strong  feeling  of  discontent  or  a 


Alexander  Wilson 
From  a  painting  by  James  Craw. 
Courtesy  of  Mr.  Ruthven  Deanc. 

decided  melancholy.  The  Scotch  airs  which  he  played  sweetly 
on  his  flute  made  me  melancholy,  too,  aiul  I  felt  for  him. 
I  presented  him  to  my  wife  and  friends,  and  seeing  that  he 
was  all  enthusiasm,  exerted  myself  as  much  as  was  in  my 
power  to  procure  for  him  the  specimens  which  he  wanted. 
We  hunted  together,  and  obtained  bii'ds  which  he  had  never 
seen  before;  but,  reader,  I  did  not  subsci'ibe  to  his  work,  for, 
even  at  that  time,  my  collection  was  greater  than  his.  .  .  . 


22  Biology  in  Amrrica 

Some  time  elapsed.  {luii)ig  wliicli  1  iicvei-  heard  of  him,  or 
of  his  \v()i-k.  At  lengtli,  liaviiig-  oceasioii  to  go  to  Phihidel- 
I)liia,  I,  immediately  after  my  arrival  there,  iiuiuired  for  him, 
and  paiel  him  a  visit,  (but)  .  .  .  feeling,  as  1  was  forced  to 
do,  that  my  company  was  not  agreeable,  I  parted  from  him; 
and  after  that  1  never  saw  Iiim  again.  J>iit  judge  of  my 
astonishment  some  time  after  when,  on  reading  the  thirty- 
ninth  page  of  the  ninth  volume  of  Americcui  Orniihologij,  1 
found  in  it  the  following  paragraph: 

"  ']\Iarcli  28,  ]i)10.  1  bade  adieu  to  Louisville,  to  which 
place  I  liad  four  letters  of  reconnnendation,  and  was  taught 
to  expect  much  of  everything  there ;  but  neither  received  one 
act  of  civility  from  those  to  whom  1  was  recommended,  one 
subserilx-r,  nor  one  new  bird;  though  I  delivered  my  letters, 
ransacked  the  woods  repeatedlj^,  and  visited  all  the  characters 
likely  to  subscribe.  Science  or  literature  has  not  one  friend 
in  this  place.'  "  ^ 

Alexander  Wilson,  the  "father  of  American  ornithology," 
was  born  at  Paisley,  Scotland,  on  July  G,  1766.  lie  was  the 
son  of  a  weaver,  who,  together  with  liis  regular  trade,  com- 
bined farming,  distilling  and  smuggling.  Destined  by  his 
parents  for  the  church,  his  studies  in  this  direction  were  early 
terminated  by  various  vicissitudes  in  the  Wilson  family,  such 
avs  the  advent  of  a  step-mother  and  sundry  children,  and  the 
young  Wilson  became  a  weaver  apprentice,  from  which  pur- 
suit his  raml)ling  propensities  soon  diverted  him  into  the 
paths  of  the  peildler  and  poacher.  Indulging  himself  in  a 
little  fun  at  the  expense  of  the  master  weavers  during  a  trade 
dispute,  he  paid  i)enance  therefor  with  a  brief  sojourn  in 
jail,  after  which  he  emigrated  to  America  in  1794.  Here  he 
earned  a  precarious  living  as  peddler,  printer,  and  school 
teacher,  the  latter  profession  seeming  to  have  stood  as  high 
in  ])ublic  esteem  then  as  now,  until  he  nuide  the  acquaintance 
of  the  younger  Bartram  and  the  engraver  Lawson,  under  whose 
advice  and  encouragement  he  gave  himself  up  to  his  passion 
for  natural  history  and  learned  to  draw  the  objects  of  his 
search.  lie  now  devoted  liimself  to  the  preparation  of  his 
"American  Ornithology,"  in  the  course  of  which  he  roamed 
the  wilderness  of  the  then  West,  crossing  the  Alleghanies, 
sailing  down  the  Ohio,  sleeping  under  the  stars  or  in  the  fron- 
tiersman's "shack."  In  the  course  of  these  journeys  "in 
search,"  as  he  says,  "of  birds  and  subscribers,"  he  made  tlie 
acquaintance  of  Audubon  in  the  iiuinner  above  described. 
The  first  volume  of  his  work  appeared  in  1808  and  six  others 
followed  prior  to  his  early  death  in  1813,  as  the  result  of 

*Aiutubon's    Ornithological    Biograpliy,    quoted    in    "Life    of    Audu- 
bon," pp.  22-24. 


Early  Naturalists  23 

hardship  and  exposure  incurred  while  seeking  the  birds  he 
loved  so  well. 

To  the  careful  observation  of  the  scientist,  Wilson  joiueil 
the  literary  enthusiasm  of  poet  and  nature  lover.  His  account 
of  the  passenger  pigeon  is  full  of  fascinating  interest. 

"In  descending  the  Ohio  by  myself  in  the  month  of  Feb- 
ruary, 1  often  rested  on  my  oars  to  contemplate  their  aerial 
manoeuvres.  A  column  eight  or  ten  miles  in  length  would 
appear  from  Kentucky,  high  in  air,  steering  across  to  Indiana. 
The  leaders  of  this  great  body  would  sometimes  gradually 
vary  their  course,  until  it  formed  a  large  bend  of  more  than 
a  ndle  in  diameter,  those  behind  tracing  the  exact  route  of 
their  predecessors.  This  would  continue  sometimes  long  after 
both  extremities  were  beyond  the  reach  of  sight;  so  that  the 
whole,  with  its  glittery  undulations,  marked  a  space  on  the 
face  of  the  heavens  resembling  the  windings  of  a  vast  and 
majestic  river.  When  this  bend  became  very  great,  the  birds, 
as  if  sensible  of  the  unnecessary  circuitous  course  they  were 
taking,  suddenly  changed  their  direction ;  so  that  what  was 
in  column  before  became  an  immense  front,  straightening  all 
its  indentures  until  it  swept  the  heavens  in  one  vast  and  in- 
finitely extended  line.  Other  lesser  bodies  also  united  with 
each  other  as  they  happened  to  approach,  with  such  ease  and 
elegance  of  evolution,  forming  new  figures,  and  varying  these 
as  they  united  or  separated,  that  I  was  never  tired  of  contem- 
plating them.  Sometimes  a  hawk  would  make  a  sweep  on  a 
particular  part  of  the  column,  from  a  great  height,  when 
almost  as  quick  as  lightning  that  part  shot  downwards  out 
of  the  common  track ;  but  soon  rising  again,  continued  advanc- 
ing at  the  same  height  as  before.  This  intiection  was  con- 
tinned  by  those  behind,  who  on  arriving  at  this  point  dived 
down  almost  perpendicularly  to  a  great  depth,  and  rising, 
followed  the  exact  path  of  those  that  went  before.  As  these 
vast  bodies  passed  over  the  river  near  me,  the  surface  of  the 
water,  which  was  before  smooth  as  glass,  appeared  marked 
with  innumerable  dimples,  occasioned  by  the  dropping  of  their 
dung,  resembling  the  commencement  of  a  shower  of  large 
droi)s  of  rain   or  hail. 

"Happening  to  go  ashore  one  charming  afternoon  to  pur- 
chase some  milk  at  a  house  that  stood  near  the  river,  and  while 
talking  with  the  people  within  doors,  I  was  suddenly  struck 
with  astonishment  at  a  loud  rushing  roar,  succeeded  by  in- 
stant darkness;  which  on  the  first  moment  I  took  for  a  tor- 
nado, about  to  overwhelm  the  house  and  everything  around 
in  destruction.  The  people,  observing  ray  surprise,  coolly 
said,  'It  is  only  the  pigeons;'  and  on  running  out,  I  beheld  a 
flock  thirty  or  forty  yards  in  width  sweeping  along  very  low, 


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« 

24  Biology  in  America 

between  the  house  and  the  mountain  or  height  that  formed 
the  second  bank  of  the  river.  These  continued  passing  for 
more  than  a  quarter  of  an  hour,  and  at  length  varied  their 
bearing  so  as  to  pass  over  the  mountain,  behind  which  they 
disappeared  before  tlie  rear  came  up." 

And  these  lines  from  his  verses  to  the  bluebird  are  full  of 
the  sweet  freshness  of  the  out-of-doors,  and  bring  back  to  our 
minds  the  days  of  our  care-free,  bare-foot,  boyhood: 

"Then  loud-piping  fi'ogs  make  the  marshes  to  ring; 

Then  warm  glows  the  sunshine,  and  fine  is  the  weather; 
The  blue  woodland  tiowers  just  beginning  to  spring, 

And  spicewood  and  sassafras  budding  together:" 

"The  slow  lingering  schoolboys  forget  they'll  be  chid, 
While  gazing  intent  as  he  warbles  before  them 
In  mantle  of  sky-blue,  and  bosom  so  red, 
That  each  little  loiterer  seems  to  adore  liim."^ 

A  charming  picture  of  Wilson  has  been  given  us  by  James 
Lane  Allen  in  his  "Kentucky  AVarbler, "  where  we  see  him, 
traveling  twelve  hundred  miles  on  foot  through  the  wilder- 
ness to  visit  Niagara  Falls  and  reaching  "home  'mid  the  deep 
snows  of  winter  with  no  soles  to  his  boots."  And  again  as 
he  sets  forth  on  his  solitary  voyage  down  the  Ohio : 

"...  It  is  the  twenty-fourth  of  February :  the  river,  swol- 
len with  the  spring  flood,  is  full  of  white  masses  of  moving 
ice.  .  .  .  They  warned  him  of  his  danger,  urged  him  to  take 
a  rower,  urged  him  not  to  go  at  all.  Those  who  risked  the 
passage  of  the  river  floated  down  on  barges  called  Kentucky 
arks,  or  in  canoes  hollowed  each  out  of  a  single  tree,  usually 
the  tulip  tree,  which  you  know  is  very  common  in  our  Ken- 
tucky woods.  But  to  mention  danger  was  to  make  him  go  to 
meet  it.  He  would  have  no  rower,  had  no  money  to  hire  one, 
had  he  wished  one.  He  tells  us  what  he  had  on  board :  in  one 
end  of  the  boat  some  biscuit  and  cheese,  a  bottle  of  cordial 
given  him  by  a  gentleman  in  Pittsburgh,  his  gun  and  trunk 
and  overcoat;  at  the  other  end  himself  and  his  oars  and  a 
tin  with  which  to  bail  out  the  skifit",  if  necessary,  to  keep  it 
from  sinking  and  also  to  use  as  his  drinking-cup  to  dip  from 
the  river. 

"That  February  day— the  swollen,  rushing  river,  the 
masses  of  white  ice — the  solitary  young  boatnum  borne  away 

» Quotations  from  the  "Passenger  Pigeon"  and  the  "Bluebird"  in 
the  "American  Ornithology." 


Eaiiy  Naturalists  25 

to  a  new  world  on  his  great  work :  his  heart  expanding  with 
excitement  and  joy  as  he  lieaded  toward  the  unexplored  wil- 
derness of  the  Mississippi  Valley. 

"Wondrous  experiences  were  his:  from  the  densely  wooded 
shores  there  would  reach  him  as  he  drifted  down  the  whistle 
of  the  red  bird — those  first  spring  notes  so  familiar  and  so 
welcome  to  us  on  mild  days  toward  the  last  off  February. 
Away  off  in  dim  forest  valleys,  between  bold  headlands,  lie 
saw  the  rising  smoke  of  sugar  camps.  At  other  openings  on 
the  landscape  grotesque  leg  cabins  looked  like  drg-houses  un- 
der impending  mighty  mountains.  His  rapidly  steered  skiff 
passed  flotillas  of  Kentucky  arks  heavily  making  their  way 
southward,  transporting  men  and  women  and  children — the 
moving  pioneers  of  the  young  nation  :  the  first  river  merchant- 
marine  of  the  new  world ;  carrying  horses  and  plows  to  clear- 
ings yet  to  be  made  for  homesteads  in  the  wilderness ;  trans- 
porting mill-stones  for  mills  not  yet  built  on  any  wilderness 
stream.   .  .  . 

"He  records  what  to  us  now  sounds  incredible,  that 
on  March  fifth  he  saw  a  flock  of  parrokeets.  Tliink  of  parro- 
keets  on  the  Ohio  River  in  March !  .  .  .  Once  he  encountered 
a  storm  of  wind  and  hail  and  snow  and  rain,  during  which 
the  river  foamed  and  rolled  like  the  sea  and  he  had  to  make 
good  use  of  his  tin  to  keep  the  skift'  baled  out  till  he  could  put 
in  to  shore.  The  call  of  wild  turkeys  enticed  him  now  toward 
the  shore  of  Indiana,  now  toward  the  shore  of  Kentucky,  but 
before  he  reached  either  they  had  disappeared.  His  first 
night  on  the  Kentucky  shore  he  spent  in  the  cabin  of  a  squat- 
ter and  heard  him  tell  tales  of  bear-treeing  and  wildcat-hunt- 
ing and  wolf-baiting.  All  night  wolves  howled  in  the  forests 
near  by  and  kept  the  dogs  in  an  uproar ;  the  region  swarmed 
with  wolves  and  wildcats  'black  and  brown.' 

"On  and  on,  until  at  last  the  skiff*  reached  the  rapids  of  the 
Ohio  at  Louisville  and  he  stepped  ashore  and  sold  his  frail 
savior  craft,  which,  at  starting,  he  had  named  the  Orni- 
thologist. The  Kentuckian  who  bought  it  as  the  Ornithologist 
accepted  the  droll  name  as  that  of  some  Indian  chief.  He 
soon  left  Louisville,  having  sent  his  baggage  on  by  wagon, 
and  plunged  into  the  Kentucky  forest  on  his  way  to  Lexing- 
ton.^ 

After  Wilson's  death,  the  remaining  volumes  of  his  work 
were  completed  by  his  friend,  Charles  Lucien  Bonaparte,  the 
Prince  of  Cannino  and  nephew  of  Napoleon,  who  in  early 

*  From  the  ' '  Kentucky  Warbler, ' '  pp.  82-88,  by  i>eriiiission  of  the 
author  and  Doubleday,  Page  and  Co. 


26  Biology  in  America 

life  came  to  America,  where  he  gained  reputation  as  an  or- 
nithologist. 

Tlie  other  of  these  two  remarkable  men,  while  an  American 
by  birth,  was  Frencii  by  parentage  and  education.  Born  in 
Louisiana  in  1780,  his  family  shortly  lifter  removed  to  the 
estate  of  Aux  Cayes  in  St.  Domingo,  where  his  mother  was 
killed  in  the  insurrection  of  the  blacks  in  1791,  his  father,  with 
tlie  chihlreii,  escaping  to  France,  where  he  remarried,  entrust- 
ing tlie  tutelage  of  his  children  to  their  step-mother.  She 
was  an  easy  mistress  and  the  young  Audubon  was  reared  in  an 
atmosphere  of  indulgent  plenty.  AVith  more  foresight  than  his 
wife,  the  boy's  father  insisted  on  his  education,  originally 
intending  him  for  a  maritime  or  engineering  career.  Tlie  tine 
arts  were  not,  however,  neglected  in  his  education,  music  and 
drawing  being  included  in  his  studies,  the  latter  under  the 
famous  French  artist,  David.  His  studies,  however,  did  not 
prevent  many  rambles  into  the  country,  from  which  he  "re- 
turned loaded  with  objects  of  natural  history,  birds'  nests, 
birds'  eggs,  specimens  of  moss,  curious  stones,  and  other  ob- 
jects attractive  to  his  eye."  Audubon  also  began  in  his  early 
boyhood  to  draw  birds,  completing  sketches  of  two  hundred 
specimens. 

Finding  his  son's  interest  fixed  upon  other  than  maritime 
or  military  pursuits,  the  father  sent  him  to  America  to  super- 
intend his  estate  of  iMill  Grove  on  the  I'erkiomen  Creek  near 
Philadelphia,  where  in  Audubon's  own  words,  he  found  a 
"blessed  spot"  and  where  "hunting,  fishing  and  drawing  oc- 
cupied my  evpi-y  moment,  cares  I  knew  not  and  cared  nothing 
for  them."  Here,  too,  he  met  his  future  wife,  Lucy  Bake- 
well,  the  daughter  of  an  P^nglish  gentleman,  residing  on  an 
adjoining  estate. 

Before  his  marriage,  Audubon  returned  for  a  year  t(i 
France,  where  he  served  for  a  brief  time  as  a  midshipman  in 
the  French  navy,  and  where  he  met  a  young  man  named 
Rosier,  who  later  became  his  partner  in  his  business  ventures 
in  America. 

Subsequent  to  Audubon's  return  to  America  the  future 
partners  essayed  a  business  apprenticeship  in  New  York, 
which  Audubon  signalized  by  the  loss  of  several  hundred 
l)ounds  in  speculation;  Rosier  similarly  losing  considerable 
money.  His  connncrcial  enterprises,  however,  did  not  pre- 
vent Audubon  from  devoting  himself  to  his  favorite  pursuits, 
which  caused  such  a  disagreeable  odor  in  liis  rooms  that  \\h 
neighbors  demanded,  through  a  constable,  an  abatement  of 
the  nuisance ! 

Leaving  New  York,  Audubon  journeyed  to  Louisville,  where 
he  invested  the  proceeds  of  the  sale  of  the  Mill  Grove  prop- 


Early  Naturalists  27 

erty    in    Ijushioss   with    Rosier   and   where   lie    shortly    after 
brought  his  wife. 

Space  does  not  permit  us  to  follow  all  the  wanderings  of 
this  brilliant,  but  eccentric  man.  His  various  business  ad- 
ventures were  foreordained  to  failure,  and  from  comfort,  it' 
not  opulence,  he  and  his  ever  brave  and  loyal  wife  were  soon 
reduced  to  penury,  Audubon  earning  a  meagre  penny  by 
giving  lessons  in  drawing,  music,  fencing  and  dancing,  while 
his  wife  acted  as  governess  in  a  private  family. 

His  roving  life  in  a  new  and  sparsely  settled  country  was 
full  of  wild  and  interesting  experiences  which  are  vividly 
depicted  in  his  journal.  His  account  of  an  Indian  swan  hunt 
in  Tennessee  gives  us  a  lively  picture  of  the  abundance  of 
wild  life  in  America  in  the  early  daj^,  and  some  idea  of  the 
cause  of  its  rapid  disappearance. 

"The  second  morning  after  our  arrival  at  Cash  Creek, 
while  I  was  straining  my  eyes  to  discover  whether  it  was 
fairly  day  dawn  or  no,  I  heard  a  movement  in  the  Indian 
camp,  and  discovered  that  a  canoe,  with  half  a  dozeii  squaws 
and  as  many  hunters,  was  about  leaving  for  Tennessee.  I 
had  heard  that  there  was  a  large  lake  opposite  to  us,  where 
immense  flocks  of  swans  resorted  every  morning,  and  asking 
permission  to  join  them,  I  seated  myself  on  my  haunches  in 
the  canoe,  well  provided  with  ammunition  and  a  bottle  of 
whisky,  and  in  a  few  minutes  the  paddles  were  at  work, 
swiftly  propelling  ns  to  the  opposite  shore.  I  was  not  much 
surprised  to  see  the  hunters  stretch  themselves  out  and  go  to 
sleep.  On  landing,  the  squaws  took  charge  of  the  canoe, 
secured  it,  and  went  in  search  of  nuts,  while  we  gentlemen 
hunters  made  the  best  of  our  way  through  thick  and  thin  to 
the  lake.  Its  muddy  shores  were  overgrown  with  a  close 
growth  of  cotton  trees,  too  large  to  be  pushed  aside,  and  too 
thick  to  pass  through  except  by  squeezing  yourself  at  every 
few  steps;  and  to  add  to  the  ditficulty,  every  few  rods  we 
came  to  small  nasty  lagoons,  which  one  must  jump,  leap,  or 
swim,  and  this  not  without  peril  of  broken  limbs  or  drowning. 

''But  when  the  lake  burst  on  our  view  there  were  the  swans 
by  hundreds,  and  white  as  rich  cream,  either  dipping  their 
black  bills  in  the  water,  or  stretching  out  one  leg  on  its  sur- 
face, or  gently  floating  alone.  According  to  the  Indian  mode 
of  hunting,  we  had  divided  and  approached  the  lagoon  from 
different  sides.  The  moment  our  vidette  was  seen,  it  seemed 
as  if  thousands  of  large,  fat,  and  heavy  swans  were  startled, 
and  as  they  made  away  from  him  they  drew  towards  the 
ambush  of  death  ;  for  the  trees  had  hunters  behind  them,  whose 
touch  of  the  trigger  would  carry  destruction  among  them. 
As  the  first  party  fired,  the  game  rose  and  flew  within  easy 


28  Biology  in  America 

distance  of  the  party  on  the  opposite  side,  when  they  again 
fired,  and  I  saw  the  water  covered  with  birds  floating  with 
tlieir  backs  dowjiwards,  and  tlieir  heads  sunk  in  the  water, 
and  tlieir  legs  kicking  in  the  air.  "When  the  s])ort  was  over 
we  counted  more  than  tifty  of  these  beautiful  biixls,  whose 
skins  were  intended  for  the  ladies  in  Europe.  There  were 
plenty  of  geese  and  ducks,  but  no  one  condescended  to  give 
them  a  shoot.  A  conch  wa.s  sounded,  and  after  a  while 
the  squaws  came  dragging  the  canoe,  and  collecting  the  dead 
game,  which  was  taken  to  the  river's  edge,  fastened  to  the 
canoe,  and  before  dusk  we  were  again  landed  at  our  camping 
ground.  1  had  heard  of  sportsmen  in  England  who  walked 
a  whole  day,  and  after  firing  a  pound  of  powder  returned  in 
great  glee  bringing  one  partridge ;  and  I  could  not  help  won- 
dering Avhat  they  would  think  of  the  spoil  we  were  bearing 
from  Swan  Lake." 

His  picture  of  the  Mississippi  in  flood  is  wonderfully  im- 
pressive. 

"I  have  floated  on  the  Mississippi  and  Ohio  when  thus 
swollen,  and  have  in  different  places  visited  the  submerged 
lands  of  the  interior,  propelling  a  light  canoe  by  the  aid  of  a 
paddle.  In  this  manner  I  have  traversed  immense  portions 
of  the  country  overflowed  by  the  waters  of  these  rivers,  and 
particularly  whilst  floating  over  the  iMississippi  bottom  lairds 
I  have  been  struck  with  awe  at  the  sight.  Little  or  no  current 
is  met  with,  unless  when  the  canoe  passes  over  the  bed  of  a 
bayou.  All  is  silent  and  melancholy,  unless  when  the  mourn- 
ful bleating  of  the  hemmed-in  deer  reaches  your  ear,  or  the 
dismal  scream  of  an  eagle  or  a  heron  is  heard,  or  the  foul  bird 
rises,  disturbed  by  your  approach,  from  the  carcass  on  which 
it  was  allaying  its  craving  appetite.  Bears,  cougars,  lynxes, 
and  all  other  quadrupeds  that  can  ascend  the  trees,  are  ob- 
served crouched  among  their  top  branches;  hungry  in  the 
midst  of  abundance,  although  they  see  floating  around  them 
the  animals  on  which  they  usually  prey.  They  dare  not  ven- 
ture to  swim  to  them.  Fatigued  by  the  exertions  which  they 
have  made  in  reaching  dry  land,  they  will  there  stand  the 
hunter's  fire,  as  if  to  die  by  a  ball  were  better  than  to  perish 
amid  the  waste  of  waters.  On  occasions  like  this,  all  these 
animals  are  shot  by  hundreds." 

In  his  journeys  Audubon  fell  in  with  many  interesting 
characters.  One  of  these  was  the  naturalist  Rafinesque.  Dur- 
ing Audubon's  residence  in  Kentucky,  Rafinesque  visited 
him,  presenting  a  letter  of  introduction  in  which  he  was 
described  as  an  "odd  fish"  as  yet  undescribed  in  published 
works.  Audubon's  innocent  inquiry  as  to  where  the  *'odd 
fish"  was,  led  to  much  amusement  and  a  cordial  entente 


Early  Naturalists 


29 


between  the  two.  "His  attire,"  writes  Audubon,  "struek  me 
as  exceedingly  remarkable.  A  long  loose  coat  of  yellow  nan- 
keen, much  the  worse  for  the  many  rubs  it  had  got  in  its 
time,  and  stained  all  over  with  the  juice  of  plants,  hung 
loosely  about  him  like  a  sack.  A  waistcoat  of  the  same,  with 
enormous  pockets,  and  buttoned  up  to  the  chin,  reached  below 
over  a  pair  of  tight  pantaloons,  the  h)wer  parts  of  which  were 
buttoned  down  to  tlie  ankles.  His 
beard  was  as  long  as  I  have  known 
my  own  to  be  during  some  of  my 
peregrinations,  and  his  lank  black 
hair  hung  loosely  over  his  shoul- 
ders. His  forehead  was  so  broad 
and  prominent  that  any  tyro  in 
phrenology  would  instantly  have 
pronounced  it  the  residence  of  a 
mind  of  strong  powers.  His  words 
impressed  an  assurance  of  rigid 
truth,  and  as  he  directed  the  con- 
versation to  the  study  of  the  natu- 
ral sciences,  I  listened  to  him  with 
great  delight.  He  requested  to  see 
my  draAvings,  anxious  to  see  the 
plants  I  had  introduced  besides  the 
birds  I  had  drawn.  Finding  a 
strange  plant  among  my  drawings, 
he  denied  its  authenticity ;  but  on 
my  assuring  him  that  it  grew  in  the  neighborhood,  he  insisted 
on  going  off  instantly  to  see  it. 

"When  I  pointed  it  out  the  naturalist  lost  all  command 
over  his  feelings,  and  behaved  like  a  maniac  in  expressing  his 
delight.  He  plucked  the  plants  one  after  another,  danced, 
hugged  me  in  his  arms,  and  exultingly  told  me  he  had  got,  not 
merely  a  new  species,  but  a  new  genus. 

"He  immediately  took  notes  of  all  the  needful  particulars 
of  the  plant  in  a  note-book,  which  he  carried  wrapt  in  a  water- 
proof covering.  After  a  day's  pursuit  of  natural  history 
studies,  the  stranger  was  accommodated  with  a  bed  in  an  attic 
room.  We  had  all  retired  to  rest ;  every  person  I  imagined 
was  in  deep  slumber  save  myself,  when  of  a  sudden  I  heard  a 
great  uproar  in  the  naturalist's  room.  I  got  up,  reached  the 
place  in  a  few  moments,  and  opened  the  door;  when,  to  my 
astonishment,  I  saw  my  guest  running  naked,  holding  the 
handle  of  my  favorite  violin,  the  body  of  which  he  had  bat- 
tered to  pieces  against  the  walls  in  attempting  to  kill  the  bats 
which  had  entered  by  the  open  window,  probably  attracted  by 
the  insects  flying  around  his  candle.    I  stood  amazed,  but  he 


Eafinesque 
From  Popular  Science  Monthly. 
Copy    furnished    hy    Conrad 


Lantern 
Chicago. 


Slide    Company, 


30  Biology  in   A))irrira 

contiiuu'd  ,jmni)ing  and  riiniiiii<i::  rouiul  and  round,  until  \\v 
was  fairly  exhausted,  when  he  begged  me  to  procure  one  of  the 
aninuils  for  Iniu,  as  he  felt  eonvinccd  they  belonged  to  a  'new 
species.'  Although  1  was  convinced  of  tlu;  contrary,  1  took  up 
the  bow  of  my  demolished  Cremona,  and  administering  a  smart 
tap  to  each  of  the  bats  as  it  came  up,  soon  got  specimens 
enough.  The  war" ended,  I  again  bade  him  good-night,  but 
could  not  help  observing  the  state  of  the  room.  It  was  strewed 
with  plants,  which  had  been  previously  arranged  with  care. 

"lie  saw  my  regret  for  the  havoc  that  had  been  created,  but 
added  that  he  would  soon  put  his  plants  to  rights — after  ho 
had  secured  his  new  specimens  of  l)ats. "* 

Rafinesque  was  a  marked  example  of  the  combination  of 
brilliance  with  eccentricity;  his  career,  filled  with  striking 
contrasts  of  light  and  shade,  forms  one  of  the  most  pathetic 
pictures  in  American  science.  Born  in  Constantinople, 
of  Franco-German  parentage,  traveler,  zoologist,  botanist, 
chemist,  geographer,  archaeologist,  historian,  philosopher, 
economist  and  poet,  professor  in  Transylvania  ITniversity  at 
Lexiiigton,  Kentucky,  medalist  of  the  Geographical  Society  of 
Paris,  associate  and  correspondent  of  many  of  the  leading 
scientists  of  his  day,  dying  at  last  in  penury,  unbefriended 
and  alone  in  his  garret  home  in  Philadelphia  ;  his  very  corpse 
seized  by  his  landlord  for  sale  to  the  dissecting  room,  rescued 
by  friends  and  buried  in  an  obscure  burial  ground,  now  in  the 
heart  of  the  great  city;  his  course  was  marked  by  flashes  of 
brilliance,  but  ended  in  obscurity  and  gloom. 

Like  many  another  Rafinesque  was  ahead  of  his  generation. 
When  he  submitted  to  the  Academy  of  Natural  Sciences  in 
Philadelphia  a  paper  describing  two  genera  of  fossil  jellyfish, 
it  was  rejected  as  unworthj^  of  publication,  such  a  thing  as  a 
fossil  jellyfish  being  considered  an  impossibility  in  those  days. 
He  had  clearly  in  mind  the  idea  of  evolution  at  a  time  when 
the  doctrine  of  the  fixity  of  species  was  firmly  entrenched  in 
men's  minds.  In  the  title  page  of  his  poem  on  "The  World  or 
Instability, ' '  published  in  1836,  he  writes : 

"If  Solomon  did  say,  that  nothing  new 
Under  the  sun  was  seen,  'tis  not  (piite  true: 
Since  we  contend  that  every  hour  and  day 
Brings  novelties,  with  changes  due  array. 
Whatever  had  a  birth  must  change  sustain, 
Unsteady  ever  be ;  but  not  in  vain : 
Enjoying  life  must  die  to  live  again, 
In  after  lives  perfection  to  attain." 

*  The  foregoing  quotations  are  from  Audubon's  diary  in  Buchanan's 
"Life  of  Audubon." 


Early  Naturalists  31 

Living  a  lonely  life,  embittered  by  disappointment,  with  the 
memory  of  a  faithless  wife  behind  him,  and  the  ever  elusive 
will-o'-the-wisp  of  ungi-atified  ambition  before  him,  it  is  no 
wonder  that  his  disposition  became  soured  and  that  he  some- 
times indulged  in  caustic  criticism  of  his  fellows,  winning  him 
their  enmity  and  embittering  his  own  life  all  the  more. 

Despite  his  financial  failures  Audubon  seems  never  to  have 
lost  heart  in  his  ambition  to  publish  his  studies  and  drawings 
of  the  birds  of  America,  And  in  this  ambition  he  was  en- 
couraged and  materially  aided  by  his  ever  loyal  wife.  In  the 
furtherance  of  this  project  he  visited  Philadelphia  in  1824, 
where  he  met  many  men  prominent  in  scientific  and  artistic 
circles.  Among  them  were  Lucien  Bonaparte,  Le  Sueur,  the 
ichthyologist,  Murtrie,  the  conchologist.  Sully,  the  artist  and 
many  others.  Of  his  meeting  with  Titian  Peale,  the  artist- 
naturalist,  he  speaks  in  the  following  bitter  words : 

"Showed  all  my  drawings  to  Titian  Peel,  who  in  return 
refused  to  let  me  see  a  new  bird  in  his  possession.  This  little 
incident  fills  me  with  grief  at  the  narrow  spirit  of  humanity, 
and  makes  me  Avish  for  the  solitude  of  the  woods. ' '  ^ 

Fighting  his  way  through  repeated  failure  and  discourage- 
ment, and  with  the  aid  of  his  ever  faithful  wife,  Audubon 
was  finally  enabled  to  reach  England  and  to  obtain  the  funds 
necessary  to  the  publication  of  his  monumental  work,  the 
"Birds  of  America." 

Publication  of  a  book  in  those  days  was  a  different  matter 
from  what  it  is  at  present.  There  were  no  publishers  willing 
to  incur  the  financial  risk  of  printing  and  illustrating  so  costly 
a  work  as  the  ' '  Birds  of  America. ' '  For  the  author  then,  with- 
out independent  means,  it  was  necessary  to  secure  enough 
subscriptions  in  advance  to  defray  the  costs  of  publication. 
He,  of  necessity,  became  his  own  book  agent.  To  this  end,  as 
well  as  to  supervise  the  preparation  of  the  elaborate  colored 
engravings  illustrating  his  work,  Audubon  made  several  trips 
abroad,  visiting  both  England  and  France,  where  his  merit 
as  naturalist  and  artist  gained  him  ready  entrance  into  the 
highest  circles  of  art  and  learning. 

.  Audubon  was  accompanied  on  his  visit  to  France  by  his 
friend  Swainson,  one  of  the  prominent  ornithologists  of  the 
time,  and  later  one  of  the  authors  of  the  "Fauna  boreali- 
Americana,"  descriptive  of  the  natural  history  of  northern 
North  America,  studied  by  Richardson,  naturalist  to  Sir  John 
Franklin's  exploring  parties.  Swainson 's  reputation  indeed 
was  greater  than  Audubon's  at  this  time,  as  he  was  known  in 
France,  where  the  latter,  prior  to  his  visit,  had  not  been 
heard  of. 

'Locus  Citatus.  . 


32  Biology  in  Amrn'ra 

In  tlie  interims  between  his  journeys  to  England,  Audubon 
Avas  l)usy  ill  liis  search  for  liirds  and  also  iiiaimiials,  visiting 
aiiiong  other  places,  Labrador  aiul  Fh^rida,  and  liiially  making 
his  last  expedition,  that  up  the  Missouri  Kiver  to  the  mouth  of 
the  Yellowstone,  primaril\-  to  collect  material  for  his  "Quad- 
rupeds of  America,"  one  volunie  of  which  was  published 
before  his  deatii,  and  tlie  other  two,  by  his  sons,  Victor  and 
John,  subserpient  thereto. 

In  the  early  morning  of  dan.  27,  1851,  in  tlie  country  home 
of  "JMinniesland"  on  the  hanks  of  the  Iliidson,  there  passed 
away  the  pi-emier  of  America's  early  pioneers  in  science. 
Today  towering  apartment  houses,  and  a  splendid  driveway, 
look  down  on  "Minniesland,"  but  his  work  lives  after  him 
and  his  spirit  pulses  still  in  the  "Audubon  Societies"  through- 
out our  land. 

Both  of  Audubon's  sons  followed  in  their  father's  foot- 
steps as  naturalists  and  artists,  and  were  early  associated 
with  him  in  his  ornithological  work,  and  later  in  his  work  on 
the  "Quadrupeds,"  in  the  course  of  which  the  younger  of 
the  sons,  John,  visited  both  Texas  and  California,  making  the 
journey  overland  in  search  of  specimens  of  natural  histoiy. 

Following  the  Louisiana  Purchase  in  1803,  both  public  and 
private  interest  awakened  in  the  unknown  resources  of  the 
vast  territory  beyond  the  Missouri  and  its  head  waters.     An 
expedition  to  visit  this  region,  cross  the  Rockies  and  descend 
the  Columbia  to  its  mouth  was  early  planned  by  President  Jef- 
ferson, under  the  leadership  of  his  secretary  Captain  Merri- 
wether  Lewis,  accompanied  by  Francois  Andre  Michaux,  a 
French  botanist  visiting  America  under  the  auspices  of  the 
French     government.       ]\Iichaux    had    traveled     extensively 
through  eastern  North  America  on  botanical  explorations,  the 
result  of  which  were  his  "Flora  boreali- Americana,"  and  his 
' '  North  American  Sylva. ' '    Before  this  plan  could  be  executed, 
however,  he  was  recalled  liy  his  government  to  Fi-ance.    Noth- 
ing daunted  by  failure  Jeti'erson  i)lanned  a  second  expedition, 
and  in  3  804-5  Captains  Tjewis  and  ('lark  of  the  IT.  S.  Army 
crossed  the  continent  via  the^  Missouri  and  Columbia  Rivers. 
On   this  (>x|)edi1ioii   they  collected  voluminous  scientific  data 
dealing  in  ])art  with  the  natural  history  of  the  region  trav- 
ersed. 

It  is  worth  while  at  this  point  to  glance  for  a  moment  at 
the  scientific  work  of  that  remarkably  versatile  man,  Thomas 
Jelferson,  a  man  Avho  in  many  respects  was  the  i)rototype 
of  that  other  statesman-naturalist  who  has  so  recently  de- 
l)arted  from  iis.  Jefferson's  interests  were  very  broad. 
Astronomer,  ])hysicist,  engineer,  anatomist,  geologist,  zoolo- 
gist,  botanist,   palaioutologist,   litterateur,   educator,   lawyer, 


Early  Naturalists  33 

farmer,  economist  and  statesman,  he  indeed  was  a  man  of  far 
vision  and  high  achievement,  dreamer  of  dreams  and  doer  of 
deeds.  Writing  in  the  "Magazine  of  American  History"  for 
April,  1885,  Mr.  Frederic  N.  Luther  says  of  him : 

...  In  Febrnaiy,  1801,  when  Congress  was  vainly 
trying  to  untangle  the  difficulties  arising  from  the  tie  vote 
between  Jefferson  and  Burr,  when  every  politician  at  the 
capital  was  busy  with  schemes  and  counter-schemes,  this  man, 
whose  political  fate  was  balanced  on  a  razor's  edge,  was 
corresponding  with  Dr.  Wistar  in  regard  to  some  bones  of  the 
mastodon  which  he  had  just  procured  from  Shawangunk, 
Ulster  County.  Again  in  1808,  when  the  excitement  over  the 
embargo  was  highest,  when  every  day  brought  fresh  denuncia- 
tions of  him  and  his  policy,  he  was  carrying  on  his  pahTonto- 
logical  studies  in  the  rooms  of  the  White  House  itself.  .  .  . 
Never  for  a  moment,  however  apparently  absorbed  in  other 
work,  did  he  lose  his  warm  sympathy  with  nature." 

It  is  amusing  to  read  on  the  other  hand  the  tribute  which 
his  studies  called  forth  from  Bryant,  then  thirteen  years  old. 

"Go,  wretch,  resign  the  Presidential  chair, 
Disclose  thy  secret  measures,  foul  or  fair. 
Go,  search  with  curious  eyes  for  horned  frogs, 
'Mid  the  wild  wastes  of  Louisianian  bogs ; 
Or,  where  the  Ohio  rolls  his  turbid  stream. 
Dig  for  huge  bones,  thy  glory  and  thy  theme." 

One  of  Jefferson's  scientific  contemporaries  was  Buffon,  the 
French  evolutionist.  Buffon  had  an  idea  that  the  animals  of 
the  new  world  are  smaller  than  their  near  relatives  in  the  old, 
and  that  domesticated  types  are  degenerating  in  the  former  as 
compared  with  the  same  types  in  the  latter.  These  conten- 
tions were  refuted  by  Jefferson,  who  exported  to  Paris  speci- 
mens of  several  of  our  large  animals  as  evidence  of  his 
contentions.  As  a  result  Buffon  wrote  to  Jefferson,  "I  should 
have  consulted  you,  Sir,  before  publishing  my  'Natural  His- 
tory,' and  then  I  should  have  been  sure  of  my  facts." 

Jefferson  was  one  of  our  pioneer  plant  importers.  While 
minister  to  Paris  he  sent  to  America  large  numbers  of  seeds 
and  plants  of  various  sorts.  Most  of  these  were  failures, 
among  them  the  olive,  the  cork  oak  and  the  caper.  With  rice 
however  he  was  more  successful.  Noting  the  gi-eat  demand 
for  this  cereal  during  Lent  in  France,  and  noting  further  the 
small  importations  of  American  as  compared  with  Italian 
rice,  he  set  about  discovering  the  reason,  and  soon  a.scertained 
that  it  was  due  to  the  superior  quality  of  the  latter  grain. 
In  those  days  importation  of  plants  from  one  country  to 


34  Biology  in  America 

another  was  (liffifult,  owinj;  to  the  selfish  Jack  Horner  policy 
of  keopiiifi:  all  the  ])liiins  at  home.  Jefferson  however  visited 
Italy  and  carrie<l  off:  successfully  some  pockets  full  of  rice, 
which  he  sent  to  tlie  Charleston  planters,  and  from  which 
have  develop(Hl  the  rice  crops  of  the  South  today. 

Among  Jeil'erson's  important  contrihutions  to  biology  were 
his  discovery  of  the  remains  of  a  giant  sloth  in  the  mountains 
of  Virginia,  which  bears  his  name  and  which  is  mentioned 
elsewhere  in  this  book ;  his  discovery  of  the  bones  of  the 
mastodon  in  Ulster  County,  N.  Y.,  and  his  account  of  the  nat- 
ural history  of  Virginia,  published  in  his  notes  on  that  state. 

In  1810  an  expedition  fitted  out  by  John  Jacob  Astor  set 
out  for  the  Columbia,  which  reached  the  infant  village  of 
Astoria  near  its  mouth  on  February  15,  1812,  after  suffering 
untold  hardships  in  the  wilderness.  On  this  expedition  were 
two  naturalists,  both  Englishmen;  one,  John  Bradbury  sent 
out  by  the  Botanical  Society  of  Liverpool  to  collect  American 
plants;  and  the  other,  Thomas  Nuttall,  the  ornithologist,  and 
botanist,  who  was  traveling  independently.  They  accom- 
panied it  for  several  hundred  miles  above  St.  Louis,  but 
returned  before  the  main  party  crossed  the  Rocky  Mountains. 
Later  Bradbury  visited  several  of  the  central  western  states, 
the  results  of  all  his  journeys  being  interestingly  recorded  in 
his  "Travels  in  the  Interior  of  America."  Nuttall 's  travels 
also  took  him  along  the  shores  of  the  Great  Lakes  into  Wis- 
consin, down  the  Mississippi  to  St.  Louis,  up  the  Arkansas 
River  and  finally  in  company  with  the  naturalist  Townsend, 
across  the  continent  to  the  Columbia,  whence  he  returned 
east  by  the  Hawaiian  Islands  and  Cape  Horn.  On  this  expedi- 
tion they  traveled  with  the  party  of  Mr.  Nathaniel  J.  Wyeth 
of  Boston,  who  in  1833  made  a  well  conceived  but  ineffectual 
attempt  to  recover  for  the  United  States  the  trade  lost  when, 
twenty  years  previously,  Astoria  passed  into  the  hands  of  the 
"Northwest  Company,"  a  Canadian  company  and  rival  of  the 
"Hudson  Bay  Company"  for  the  trade  of  the  Northwest. 

In  1819-20  Major  Stephen  H.  Long,  from  whom  one  of  the 
most  inspiring  peaks  in  the  Rocky  Mountains  takes  its  name, 
made  an  expedition  under  the  direction  of  the  War  Depart- 
ment to  the  Rocky  Mountains.  He  was  accompanied  on  this 
expedition  by  Thomas  Say,  the  conchologist  and  entomologist, 
and  Edwin  James,  a  botanist  and  geologist.  Say  also  accom- 
panied Long  on  his  survey  of  the  Great  Lakes  region  and  the 
valleys  of  the  upper  Mississippi  and  Red  River  as  far  as  Lake 
Winnipeg. 

The  life  of  the  far  West  in  the  days  when  the  pioneers  blazed 
their  trails  for  civilization  and  science  through  its  wildernesses, 
was  one  to  appeal  to  the  hardy  and  adventurous.    Its  virgin 


Above,  William  Clark  Above,  Merriwether  Lewis 

Below,  Thomas  Jefferson  Below,  Thomas  Nuttall 

Copies  supplied  hy  Handy,  photo. 


35 


36  Biology  in  America 

wilds  too  offered  a  rich  reward  to  the  scientific  explorer.  Its 
dangers  and  hardships  however  presented  an  effective  barrier 
to  all  but  the  most  resolute  and  dauntless.  Vivid  pictures  of 
this  life,  with  its  fascinating  beauty  and  danger,  the  intense 
rivalry  of  the  different  fur  companies,  the  savage  attack  and 
wanton  ravage  of  the  lurking  Indians,  the  midnight  revel 
about  the  roaring  camp  tire,  the  g^nnes  and  frolics,  feuds  and 
friendships  of  men  without  rcsti-aiut ;  the  challenge  of  the 
chase,  the  elk's  whistle  and  the  howling  wolf,  the  magnificence 
of  boundless  plain,  of  towering  peak  and  roaring  river,  the 
glory  of  the  sunset  and  the  starlit  sky  and  the  terror  of  the 
tempest,  have  been  drawn  for  us  by  many  writers,  especially 
Irving  in  his  "Astoria"  and  "Captain  Bonneville";  and  the 
journals  of  these  early  adventurere  are  as  full  of  enthralling 
interest  as  they  are  of  historical  and  scientific  information. 

In  the  early  days  of  American  exploration,  adventurous 
eyes  were  turned  to  the  frozen  north,  and  in  the  Elizabethan 
age  of  English  glory  her  mariners  penetrated  the  frozen  seas 
as  far  as  latitude  72°  N.,  leaving  a  record  of  their  daring  in 
the  names  of  Frobisher's  and  Davis'  Straits.  In  the  following 
century.  Sir  Henry  Hudson  explored  the  bay  which  bears  his 
name,  and  perished  upon  its  inhospitable  waters.  A  shorter 
route  to  India,  through  the  Northwest  Passage,  was  one  of  the 
motives  of  these  early  voyages.  It  was  on  this  quest  that  the 
famous  voyages  of  Ross  and  Parry  were  made,  early  in  the 
last  century. 

In  1819-22  Sir  John  Franklin,  who  had  been  second  in 
command  of  Buchan  's  polar  expedition  of  the  preceding  year, 
undertook  the  exploration  of  the  Canadian  Coast  bordering 
the  Arctic  Sea.  On  this  expedition  he  was  accompanied  by 
Richardson  as  surgeon  and  naturalist,  whose  name  was 
destined  to  become  famous  in  the  annals  of  early  American 
biology.  The  party  left  York  Factory  on  Hudson  Bay  on  Sep- 
tember 9,  reaching  Cumberland  House  on  October  23,  where 
they  wintered.  The  following  year,  greatly  handicapped  by 
lack  of  provisions,  Franklin  and  his  party  pushed  northward 
to  Fort  Enterprise,  where  they  spent  the  second  winter,  and 
in  the  summer  descended  the  Coppermine  River  to  the  Arctic 
Sea,  whose  coast  they  explored  as  far  as  Bathurst  Iidet.  On 
the  return  to  Fort  Enterprise  the  party  suffered  untold  hard- 
ships, a  glimpse  of  which  may  be  obtained  from  Franklin's 
own  narrative.  The  fifth  of  September,  without  food  or  fire, 
was  spent  in  bed,  while  a  raging  storm  covered  them  with 
several  inches  of  snow.  "Our  sufferings  (writes  Franklin) 
from  cold,  in  a  comfortless  canvas  tent  in  such  weather,  with 
the  temperature  at  20°,  and  without  fire,  will  easily  be 
imagined ;  it  was,  however,  less  than  that  which  we  felt  from 


Early  Naturalists  37 

hunger."  Living  largely  on  lichens,  they  were  fortunate 
enough  to  kill  a  musk  ox  on  the  tenth.  ' '  To  skin  and  cut  up 
the  animal  was  the  work  of  a  few  minutes.  The  contents  of 
its  stomach  were  devoured  upon  the  spot;  raw  intestines  which 
were  next  attacked,  were  pronounced  by  the  most  delicate 
amongst  us  to  be  excellent."  Finally  when  Fort  Enterprise 
was  reached  it  was  found  deserted  and  provisionless !  Here 
Franklin  and  his  men  spent  several  weeks  awaiting  succor 
from  Fort  Providence,  to  which  a  few  of  the  party  had  pushed 
on  for  help ;  subsisting  meantime  on  lichens,  and  bits  of  skin 
and  bones  from  the  refuse  heaps  of  the  preceding  winter. 
They  were  so  weak  that  even  when  game  appeared,  none  of 
them  were  able  to  go  after  it.  "We  saw,"  continues  Franklin, 
"a  herd  of  reindeer  sporting  on  the  river,  about  half  a  mile 
from  the  house ;  they  remained  there  a  long  time,  but  none  of 
the  party  felt  themselves  strong  enough  to  go  after  them,  nor 
was  there  one  of  us  who  could  have  fired  a  gun  without 
resting  it. "  *^  Finally,  early  in  November,  relief  came  from 
Fort  Providence,  enabling  the  party  to  reach  Fort  Chipewyan, 
where  they  wintered,  returning  to  York  Factory  the  following 
summer.  Such  were  the  surroundings,  and  such  the  men,  in 
which,  and  by  whom  American  biology  was  made. 

Richardson  also  accompanied  Franklin  on  a  subsequent 
expedition  in  1825,  together  with  Drummond,  another  nat- 
uralist, to  Great  Bear  Lake  and  down  the  ^Mackenzie  River 
to  its  mouth,  whence  one  party  under  Franklin  explored  the 
coast  to  the  westward,  while  another  under  Richardson  went 
some  nine  hundred  miles  eastward.  In  1848-9  Richardson 
was  in  charge  of  one  of  the  expeditions  sent  in  search  of 
Franklin,  who  never  returned  from  his  fateful  voyage  of  1845. 
In  the  course  of  this  search  he  further  explored  the  coast 
between  the  mouths  of  the  Mackenzie  and  Coppermine  Rivers. 

The  natural  history  results  of  Richardson's  explorations 
were  embodied  in  liis  vohimes  of  the  "Fauna  boreali- Ameri- 
cana," published  with  tlie  assistance  of  the  ornithologist, 
Swainson,  and  the  entomologist,  Kirby. 

Beginning  with  1830  and  for  many  years  subse(iuent 
thereto,  different  states  organized  surveys  of  their  natural 
resources.  Of  still  greater  value,  however,  to  natural  science 
were  the  various  government  surveys  leading  up  to  the  Pacific 
Railroad  Surveys  and  those  of  the  territories,  and  finally 
culminating  in  1879  in  the  establishment  of  the  U.  S. 
Geological  Survey, 

"Quoted  from  Wright,  "The  Great  Wliite  Nortli,"  \>\>.  Sd-S,  l)y  jicr- 
mission  of  the  Maemillan  Company. 


38 


Biology  in  America 


While  these  surveys  were  primarily  topographical  and 
geological  in  purpose,  they  were  usually  accompanied  by 
naturalists,  whose  duty  it  was  to  investigate  and  report  upon 
the  wild  life,  both  plant  and  animal,  of  the  region  visited,  and 
to  them  much  of  our  knowledge  of  the  natural  history  of  the 
United  States  is  due. 

Of  prime  importance  in  the  work  of  these  naturalists  were 
the  discoveries  of  the  paliEontologists.  The  western  plains 
and  mountains  constitute  a  veritable  storehouse  of  buried 
treasure,  and  the  pick  and  shovel  of  the  paUeontologist  un- 
covered here  a  large  part  of  the  material  for  writing  the 
history  of  ancient  life. 

These  were  days  too  when  it  was 
lint  impossible  for  one  man  to  cover 
an  extensive  field  of  science.  Tlius 
we  find  the  elder  Agassiz  equally 
famed  as  a  geologist  and  zoologist, 
and  Dana,  the  noted  geologist,  i)ro- 
tVssor  at  Yale  from  1850  to  1890, 
writing  a  monumental  work  on  the 
Z()oi)hytes  and  Crustacea  of  the 
Wilkes  Exploring  Expedition  ;  Cope, 
master  not  onl}'  of  vertebrate 
palaeontology  but  of  modern  fishes, 
am])hibia  and  reptiles  as  well,  and 
Lcidy,  botanist,  mineralogist,  geolo- 
gist, paleontologist,  parasitologist, 
protozoologist  and  comparative 
anatomist. 

A  notable  event  in  American 
science  was  the  advent  of  Louis 
Agassiz  in  1846.  Born  in  1807  at  the  little  town  of  Motiers  in 
Switzerland,  the  son  of  a  clergyman,  he  early  displayed  that 
love  of  natural  history,  which  made  him  famous.  Champion 
fencer  and  jolly  comrade,  as  well  as  gifted  student,  his  uni- 
versity days  at  Zurich,  Heidelberg  and  Munich  found  him  a 
leader  among  his  fellows  and  his  room  in  Munich  dubbed 
by  them  "The  Little  Academy."  His  scientific  work  early 
attracted  the  attention  of  Humboldt  and  Cuvier,  who  gave 
him  all  possible  assistance  in  his  career.  While  professor 
of  natural  history  in  the  University  of  Neuchatel,  Agassiz 
gained  world  wide  fame  by  his  studies  in  zoology,  palaeon- 
tology, and  especially  on  the  glaciers  of  the  Alps.  In  1846  he 
came  to  America,  where  he  remained  until  his  death  in  1873. 
During  most  of  this  time  he  was  professor  of  natural  history 
at  Harvard,  where  he  gathered  about  him  a  group  of  men  and 


Louis  Agassiz 
From  Popular  Science  Moiitlily 

Copy  furnished  ty  Con/rod 
Lantern  Slide  Company, 
Cliicago. 


Early  Naturalists  39 

sent  them  forth  to  become  leaders  of  biology  in  America. 
Indeed,  it  was  as  teacher,  rather  than  as  investigator,  that 
Agassiz's  influence  was  most  widely  felt.  Possessed  of  a 
compelling  personality,  remarkable  diction  and  inspiring 
enthusiasm,  he  left  an  impress  upon  biology  in  this  country 
that  can  never  be  effaced.  He  was  the  founder  of  the  Museum 
of  Comparative  Zoology  of  Harvard  University,  while  his 
summer  school  at  Penikese  in  1873  was  the  forerunner  of 
biological  stations  in  America.  A  disciple  of  Cuvier,  he  was 
ever  an  ardent  champion  of  his  views  and  an  opponent,  albeit 
a  warm  personal  friend  of  Darwin. 

Pupil  of  Agassiz  at  Neuchatel,  and  later  his  co-worker  in 
America,  was  Girard,  who  prepared  the  report  on  the  reptiles 
of  the  Wilkes  expedition.  Girard  was  better  known,  however, 
for  his  work  on  flslies,  in  the  course  of  which  he  studied  much 
of  the  material  collected  by  the  U.  S.  Surveys. 

While  exploring  naturalists  were  busy  gathering  the  un- 
known fruits  of  our  virgin  fields  and  forests,  their  colleagues 
in  the  dim  and  dusty  rooms  of  museum  and  college  were  no 
less  busy  in  making  known  the  results  of  their  harvests.  Dr. 
Joseph  Leidy,  a  Philadelphia  physician,  professor  of  anatomy 
at  the  University  of  Pennsylvania  and  later  professor  of 
natural  history  at  Swarthmore  College,  was  one  of  the  most 
noted  of  these  early  college  and  museum  men.  He  is  a  striking 
example  of  the  "all  around"  naturalist  of  the  early  days,  his 
writings  embracing  a  wealth  of  subjects  of  both  extinct  and 
living  animals,  and  ranging  from  the  unicellular  animals  to 
man.  Of  his  notable  works  one  of  the  earliest  was  his  account 
of  the  fossils  from  the  "bad  lands"  of  Nebraska,  collected  by 
one  of  the  surveys  of  the  then  (1850)  Northwest  Territory, 
conducted  by  the  geologist,  David  Day  Owen,  under  the 
direction  of  the  U.  S.  Treasury  Department. 

Colleagues  of  Leidy  in  the  study  of  the  fossils  brought  back 
from  the  West  by  the  government  surveys,  and  by  exploring 
parties  sent  out  by  museums  and  colleges,  were  two  men 
whose  names  stand  in  the  front  rank  of  our  palaeontologists — 
Othniel  Charles  Marsh  and  Edward  Drinker  Cope. 

As  professor  of  palaeontology  at  Yale,  Marsh  inaugurated 
in  1870  a  series  of  scientific  expeditions  into  the  Western 
States,  the  results  of  which  were  the  splendid  collections  of 
vertebrate  fossils  of  Yale  and  the  U.  S.  National  Museum,  and 
the  stores  of  information  about  the  pre-historic  life  of  our  con- 
tinent which  Marsh  gave  to  the  world  and  which  soon  made 
him  famous.  His  earlier  expeditions  were  undertaken  and 
largely  supported  by  himself,  but  after  the  organization  of  the 
U.  S.  Geological  Survey  in  1879,  he  became  connected  with  it 


40  Biology  in  America 

as  pala?ontologist  and  thereafter  worked  under  its  auspices. 
His  expeditions  took  him  into  the  western  plains  country  and 
the  Rocky  ^louiitains,  where  lie  discovered  the  reinarkalile 
birds  witli  teeth,  lles})erornis  and  Iclitliyornis,  and  a  host  of 
dinosaurs,  the  lizard-like  reptiles,  many  of  them  giants  of  the 
animal  world,  whose  bones  have  been  unearthed  in  such 
numliers  on  our  western  plains,  and  are  now  reposing  in  so 
many  museums  both  here  and  abroad,  and  whose  biographies 
fill  so  many  ponderous  volumes  on  the  shelves  of  our  libraries. 
Here  too  he  collected  a  series  of  skeletons  of  fossil  horses 
which  has  fnrnislied  one  of  tlie  strongest  evidences  for  evolu- 
tion knuwji,  and  which  served  to  recast  the  views  regarding 
the  descent  of  the  horse  which  were  current  at  that  time. 
In  1876  when  Huxley  visited  America,  he  spent  a  week  with 
Mai'sh  inspecting  his  collections  of  fossils  at  Yale.  Huxley 
was  at  this  time  preparing  to  deliver  a  lectui'e  in  New  York 
on  the  evolution  of  the  horse,  and  as  a  result  of  his  study 
of  the  Yale  collections  this  lecture  was  largely  rewritten. 
When  ]\Iarsh  had  brought  out  box  after  box  of  specimens  to 
illustrate  various  points  in  their  discussion,  Huxley  finally 
turned  to  him  and  said,  "I  believe  you  are  a  magician; 
whatever  I  want,  you  conjure  it  up." 

As  a  further  result  of  this  conference  Huxley  predicted 
the  discovery  of  the  then  unknown  five-toed  ancestor  of  the 
horse,  and  sure  enough,  less  than  two  months  later  Professor 
Marsh  ' '  dug  up ' '  the  renowned  Eohippus  in  the  Eocene  strata 
of  the  West. 

Cope,  one  of  the  most  indefatigable,  brilliant  and  versatile 
of  American  biologists,  was  born  and  died  in  Philadelphia. 
When  a  young  man  he  served  as  professor  of  natural  science 
in  Haverford  College,  later  becoming  connected  with  the 
government  surveys  of  the  territories  under  AVheeler  and 
Hayden.  For  several  years  he  was  curator  of  the  Academy 
of  Natural  Sciences  of  Philadelphia,  and  finally  professor  of 
geology  in  the  University  of  Pennsylvania.  In  the  literature 
of  modern  fishes,  and  especially  of  reptiles  and  amphibians, 
Cope's  work  will  ever  be  classic,  but  it  was  chiefly  in  the 
field  of  vertebrate  palaeontology  that  he  became  famous.  As 
a  member  of  government  surveys  and  the  Philadelphia 
Academy  his  work  on  the  fossil  vertebi-ates  of  the  AVest  was 
both  able  and  voluminous,  and  contributed  largely  not  aloiie 
to  his  own  fame,  but  to  that  of  the  institutions  which  he 
represented.  As  illustrative  of  American  idealism,  a  trait 
for  which  our  people  have  not  hitherto  received  due  credit, 
it  is  both  pleasant  and  stimulating  to  think  of  Cope  on  his 
deathbed  putting  the  finishing  touches  on  his  report  upon 


Above,  James  D wight  Dana  Above,  Joseph  Leidy 

Below,   Edward  Drinker  Cope        Below,  Othniel  Charles  Marsh 
Cuurtt'sy  oj  Dr.  Qeo.  P.  Merrill. 


41 


42  Biology  in  America 

the  fossils  of  the  Port  Kennedy  cave,  then  recently  discovered 
on  the  Schuylkill  River  near  Philadelphia. 

But  if  the  labors  of  Leidy  and  his  colleagues  were  actuated 
by  high-spirited  and  idealistic  love  of  science,  they  were  none 
the  more  free  from  the  comedy  of  petty  selfishness.  Ever 
eager  to  forestall  the  others  in  the  announcement  of  their 
"finds"  they  occasional!}^  made  ludicrous  mistakes  through 
their  haste  in  publication.  On  one  occasion  Cope  got  hold 
of  some  bones  of  an  ancient  reptile  from  Kansas.  The  ani- 
mal's head  was  missing  and  certain  other  bones  which  are 
usually  included  in  the  skeleton  of  any  orthodox  beast,  but 
Cope  in  his  enthusiasm,  and  apparently  in  a  state  of  headless- 
ness  resembling  his  subject,  described  them  under  the  dignified 
title  of  Elasmosaurus  platyurus.  But  Leidy,  ever  keen  to 
detect  a  slip  on  the  part  of  an  opponent,  made  a  more  care- 
ful examination  of  the  defunct  and  announced  an  error  in 
the  epitaph  which  Cope  had  written,  as  the  remains  belonged 
to  a  different  creature  altogether,  namely  Enaliosaurus, 
Cope's  mistake  being  due  to  having  reversed  the  animal  end 
for  end,  and  imagined  a  head  where  the  tail  rightfully  be- 
longed. 

In  his  early  recollections  of  Leidy,  Marsh  and  Cope,  Osborn 
says  that  "whereas  in  Leidy  we  had  a  man  of  the  temper  of 
an  exact  observer,  Cope  was  a  man  who  loved  speculation; 
if  Leidy  was  the  natural  successor  of  Cuvier,  Cope  was 
the  follower  of  Lamarck,  a  man  of  remarkable  inventive  genius. 
.  .  .  Marsh  .  .  .  was  a  comparative  anatomist  of  a  high 
order,  and  had  a  genius  for  appreciating  what  might  be  called 
the  most  important  thing  in  science.  He  always  knew  where 
to  explore,  where  to  seek  the  transition  stages,  and  he  never 
lost  the  opportunity  to  point  out  at  the  earliest  possible  mo- 
ment the  most  significant  fact  to  be  discovered  and  dissemi- 
nated. .  .  . 

"I  had  the  pleasure  of  knowing  Leidy  slightly  and  of  a 
long  personal  ac(|uaintanee  with  Marsh ;  I  knew  Cope  very 
intimately.  .  .  .  On  one  memorable  occasion  when  I  visited 
his  house  he  pulled  out  a  drawer  of  his  black  walnut  work- 
table,  where  he  always  sat  and  wrote  his  papers,  and  brought 
out  a  packet  carefully  done  up  in  paper  and  twine,  saying, 
'Osborn,  here  are  some  records  that  you  have  never  seen 
before.'  I  said,  'Well,  what  are  they?'  He  replied,  'These 
are  my  ]\Iarshiana,  here  is  everything  relating  to  the  mistakes 
which  that  man  Marsh  has  made;  and  when  the  time  comes, 
Osborn,  I  am  going  to  launch  this  on  the  world.'  Well,  he 
did ;  the  bombshell  was  exploded  in  due  time,  and  this  great 
mass  of  information  regarding  the  supposed  incapacity  of 
Marsh  was  spread  on  the  pages  of  the  "New  York  Herald"  in 


Early  Naturalists 


43 


one  of  its  Sunday  issues.  The  very  next  Sunday,  however, 
Marsh,  who,  it  appears,  had  likewise  been  accumulating 
a  private  stock  of  Copeiana,  proved  with  equal  success 
that  Cope's  life  was  one  long  string  of  errors  from  first  to 
last. 

"Heredity  makes  strange  bedfellows.  It  is  only  by  the 
most  extraordinary  combination  of  personal  characteristics 
that  we  find  among  scientific  men  of  the  greatest  capacity, 
such  strange  mixtures  of  personal  qualities  side  by  side  with 
genius."  ^ 

Possibly  it  was  some  of  these  early  rivalries  which  prompted 
Bret  Harte  's  classic  little  gem  of  comedy,  ' '  The  Society  upon 
the  Stanislow." 

A  pathetic  figure  among  the  makers  of  American  science  is 
Lesquereux,  the  Swiss  botanist,  and  associate  of  Louis  Agassiz, 
He  was  born  in  the  province  of 
Nenchatel,  Switzerland,  in  1806, 
emigrating  to  America  in  1848. 
His  interest  was  at  first  in  living 
plants,  but  he  later  devoted  himself 
almost  entirely  to  a  study  of  fossil 
forms.  After  coming  to  America 
he  was  connected  with  several  state 
surveys,  and  later  with  the  terri- 
torial surveys  under  Hayden.  His 
work  on  the  coal  forming  plants  of 
Pennsylvania,  Ohio,  Illinois,  and 
Arkansas  served  chiefly  to  make  his 
reputation.  He  worked  nnder 
peculiar  disadvantages,  being  but  a 
poor  master  of  English,  and  becom-  ^^^  Gray 

ing  deaf  at  an  early  age.     He  once  From  Popular  Science  Monthly. 
said   of  himself,   "My   deafness   cut        copy    furnished    by    Oonrad 

me  off  from   everything   that  lay         cMca'^o   ^^^^  company. 
outside   of  science.    I   have   lived 

with  nature,  the  rocks,  the  trees,  the  flowers.    They  know  me. 
I  know  them.    All  outside  are  dead  to  me. ' '  ® 

It  is  in  connection  with  these  early  surveys  that  we  first 
meet  with  the  names  of  many  men  famous  in  the  annals  of 
American  science,  who  are  still  living,  or  have  but  recently 
passed  away — Jordan,  the  ichthyologist,  and  more  recently  the 
philosopher  and  apostle  of  pacifism,  Coulter,  the  botanist, 
Gilbert,  the  ichthyologist,  Scudder,  the  entomologist,  Coues, 
the  ornithologist,  and  Asa  Gray,  premier  botanist  of  America, 
and  author  of  the  well-known  manual  of  American  plants. 

'"'  Proceedings  of  the  Academy  of  Natural  Sciences,"  1912,  p.  xxxiv. 
•Locus  citatua. 


44  Biology  in  Ayncrica 

Here  too  Ave  meet  with  Sir  Josepli  Hooker,  director  of  the  Kew 
Gardens,  Eiifjlaiid.  l^arwiu's  elder  brother  in  science,  and  the 
man  wlio,  with  I^yell,  Ihe  freolo<rist.  was  more  than  any  other 
responsible  for  tlie  publication  of  the  "Orifjin  of  Species." 

In  the  introduction  to  his  scholarly  an<l  at  the  same  time 
interestinpr  work  "A  History  of  Lan(l  IMammals  in  the  West- 
ern HtMuispliere, "  Professor  Scott  tells  us  tluit  "One  afternoon 
in  June,  1876,  three  I'rinccton  uu(lcr<2:ra(luates  were  lying 
under  the  trees  on  the  canal  bank,  making  a  languid  pretence 
of  preparing  for  an  examination.  Suddeidy,  one  of  the  trio 
rcuuirked  :  'I  have  been  reading  an  old  nuigazine  article  which 
describes  a  fossil-collecting  ex])edition  in  the  West;  why  can't 
we  get  up  something  of  the  kind?'  The  others  replied,  as 
with  one  voice,  '  We  can ;  let 's  do  it. '  This  seemingly  idle 
talk  was,  for  Osborn  and  myself,  a  momentous  one,  for  it 
completely  changed  the  careers  which,  as  we  then  believed, 
had  been  mapped  out  for  us.  The  random  suggestion  led 
directly  to  the  first  of  the  Princeton  pahpontological  expedi- 
tions, that  of  1877,  which  took  us  to  the  "Bad  Lands"  of 
the  Bridger  region  in  southwestern  Wyoming."®  In  this 
trivial  incident  lay  the  germ  of  the  collections  of  vertebrate 
fossils  of  Princeton  University,  and  the  American  Museum  of 
Natural  History,  and  led  to  many  of  the  most  imporant 
palaeontological  discoveries  in  the  world. 

Next  to  Audubon,  Agassiz  and  Gray,  no  name  is  more 
prominent  in  the  early  annals  of  American  biology  than  that 
of  Spencer  Fullerton  Baird.  In  his  early  career  Baird  was 
professor  of  the  natural  sciences  in  Dickinson  College, 
becoming  assistant  secretary  of  the  Smithsonian  Institution 
in  1850.  While  in  this  position  he  founded  the  National 
Museum  and  prepared  the  monumental  reports  upon  the 
mammals  and  birds  collected  by  the  several  Pacific  Railroad 
surveys  during  the  decade  of  the  fifties.  On  the  latter  reports 
he  was  assisted  by  the  well-known  ornithologists,  John  Cassin 
(of  Pliiladelphia)  and  Geo.  N.  Lawrence  (of  New  York). 
He  was  also  joint  author  with  Brewer  and  Ridgway  of  the 
splendid  "History  of  American  Birds,"  published  from  1874 
to  1884. 

T^aird  was  tlie  Nestor  of  economic  zoology  in  America. 
Tlirough  his  activity,  aided  hy  otiier  scientists  and  fish  cul- 
turists  throughout  the  United  States,  the  U.  S.  Fish  Commis- 
sion was  established  in  1874,  and  he  was  appointed  its  com- 
missioner, a  post  wliich  he  tilled  without  salary  for  a  number 
of  years.  Tlie  organi/ation  of  this  great  institution,  whose 
work  is  briefly  mentioned  in  another  chapter,  we  owe  to 
Professor  Baird. 

"Quoted  by  permission  of  the  Macmillan  Company. 


Early  Naturalists 


45 


A  hundred  years  ago  the  scientific  thought  of  America  was 
as  firmly  rooted  in  the  belief  in  the  fixity  of  species  as  was 
that  of  Europe.  American  colleges  were  almost,  if  not 
entirely,  presided  over  by  doctors  of  divinity,  and  there  was 
even  a  feeling  in  many  quarters  against  the  sciences,  especially 
of  geology,  as  tending  to  unsettle  the  belief  of  the  young  in 
the  Mosaic  account  of  creation ;  and  yet,  even  so  early  as 
1833  there  appears  to  have  been  an  underlying  current  of 
unrest  present  in  the  minds  of  some,  for  in  the  second  Amer- 
ican edition  of  "Bakewell's  Geology,"  published  in  this  year, 
under  the  editorship  of  Silliman, 
the  lawyer,  chemist  and  geologist, 
who  was  professor  of  chemistry  and 
natural  science  at  Yale,  we  read 
"Any  attempt  to  disprove  the 
truth  or  genuineness  of  the  Penta- 
teuch, and  Genesis  in  particular,  is 
wholly  superfluous,  and  quite  aside 
from  any  question  that  can  in  this 
age  be  at  issue  between  geologists. 
No  geologist  at  the  present  day 
erects  any  system  upon  the  basis 
of  the  scripture  history."  The 
editor  however  accepted  the  Mosaic 
account  as  true  and  endeavored  to 
bring  it  into  accordance  with  the 
geological  record.  In  the  first 
edition  of  the  same  work  published 
four  years  earlier,  Silliman  con- 
sidered the  discoveries  of  geology 
as     consistent     with     the     bH:)lical 

story,  stating  that  "respecting  the  deluge,  there  can  be  but  one 
opinion  .  .  ,  geology  fully  confirms  the  scripture  history  of 
that  event. ' '  ^"  Archaic  as  these  views  appear  today,  they  show 
none  the  less  the  leaven  that  was  beginning,  slowly,  yet  none 
the  less  surely,  to  work  in  men's  minds,  preparing  them  for 
the  acceptance  of  the  gospel  of  truth.  The  anti-Darwinian 
attitude  in  America  was  supported  largely  by  the  influence 
of  Louis  Agassiz,  who,  in  spite  of  his  personal  friendship  for 
Darwin,  was  ever  his  bitter  opponent  in  the  arena  of  science. 
But  Darwin  found  an  equally  powerful  champion  in  Asa  Gray, 
the  botanist,  and  colleague  of  Agassiz  on  the  Harvard  College 
faculty.  Darwin  had  met  Gray  on  a  visit  of  tlie  latter  to 
England,  some  years  before  the  i^ublication  of  the  "Origin 
of  Species,"  and  in  its  preparation  he  frequently  consulted 

^"Merrill,   "Contributions  to   the  History  of  American   Geology," 
Eep.  U.  S.  N.  M.,  1904,  pp.  292  and  317. 


Spencer  Fullerton   Baird 
First  U.  S.  Fish  Commissioner. 

Courtesy  of  the  U.  S.  Bureau 
of  Fisheries. 


in 


46  Biology  m  America 

him.  Gray,  on  his  part,  staunchly  supported  Darwin  in  the 
bitter  attack  which  was  launched  against  him  after  the 
appearance  of  his  work,  although  he  was  unable,  on  account 
of  his  religious  views,  to  accept  it  in  its  entirety.  Ilis  opinion 
of  Darwin's  work  is  evidenced  in  a  letter  to  Hooker  written 
in  1860.  "It  is  done  in  a  masterly  manner.  It  might  well 
have  taken  twentj^  years  to  produce  it.  It  is  crammed  full 
of  most  interesting  matter  .  .  .  au<l  .  .  .  makes  out  a  better 
case  than  I  had  supposed  possible.  .  .  .  Tell  Darwin  all  this. 
...  As  I  have  promised,  he  and  you  shall  have  fair  play 
here."" 

In  science,  as  in  every  other  field  of  human  endeavor,  it  is 
the  individual  who  counts  most  in  progress.  Nevertheless 
the  individual  works  most  effectively  in  co-operation  with  his 
fellows.  And  so  in  the  development  of  American  science 
organization  has  been  a  powerful  factor. 

About  1840  there  was  organized  the  Society  of  American 
Naturalists  and  Geologists,  which  in  1848  was  expanded  into 
the  American  Association  for  the  Advancement  of  Science, 
which  has  a  present  membership  of  over  12,000,  divided  into 
twelve  sections  and  having  twenty-six  societies  affiliated  with 
it,  several  of  which  are  organized  in  biology.  The  annual  con- 
vocation of  this  Association  and  its  affiliated  societies  during 
Christmas  week  serves  as  a  "get-together"  meeting,  and  is 
a  splendid  stimulus  to  scientific  work. 

Fragmentary  as  is  the  foregoing  account  of  the  rise  of 
biology  in  America,  it  nevertheless  shows  us  something  of  the 
men  who  were  pioneers  in  this  great  field,  their  endeavors  and 
achievements,  their  friendships  and  their  petty  jealousies; 
it  gives  us  a  glimpse  of  the  major  trends  of  biological  research 
and  may  serve  perchance  as  a  background  for  the  later  history 
of  biology,  its  institutions,  its  discoveries  and  theories,  which 
is  to  follow. 

"Darwin's  "Life  and  Letters,"  p.  238.     D.  Appleton  and  Company. 


CHAPTER  II 

Biological  institutions  in  America.  Universities  and  colleges, 
museums,  botandcal  and  zoological  gardens,  biological 
stations  and  endowed  laboratories. 

Biology's  service  to  the  world  has  been  rendered  under 
many  auspices,  chief  of  which  has  been  the  college  and  the 
university.  Harvard  College  was  the  first  of  these  to  be 
established  in  America.  No  sooner  were  the  early  colonists 
of  Massachusetts  Bay  domiciled  in  the  wilderness  than  they 
began  to  think  of  education,  not  only  for  their  own  sons,  but 
also  for  those  of  their  savage  neighbors,  hoping  doubtless  to 
convert  them  to  civilization  as  readily  as  they  turned  the  forest 
into  fertile  fields  of  grain. 

Amidst  the  struggle  for  existence  with  savage  men  and 
barren  nature,  in  the  face  of  privation,  hardship,  danger  and 
death;  while  ''the  sounding  aisles  of  the  dim  woods  rang" 
not  alone  to  "the  anthem  of  the  free"  but  also  to  the  war- 
whoop  of  the  Indian,  and  the  gleam  of  burning  thatch  lit  up 
"the  depths  of  the  desert  gloom;"  the  pilgrim  fathers  forgot 
not  posterity  while  thinking  of  themselves,  and  in  the  midst 
of  the  wilderness  established  institutions  of  freedom,  religion 
and  learning. 

"About  midnight  we  heard  a  great  and  hideous  cry,  and 
our  Sentinell  called,  Arme,  Arme !  So  we  bestirred  our  selues 
and  shot  off  a  couple  of  Muskets,  and  noyse  ceased ;  we  con- 
cluded, that  it  was  a  company  of  Wolues  or  Foxes,  for  one 
told  vs,  hee  had  heard  such  a  noise  in  New-found-land.  About 
fine  a  clocke  in  the  morning  wee  began  to  be  stirring,  and 
two  or  three  which  doubted  whether  their  Peeces  would  goe 
off  or  no,  made  tryall  of  them,  and  shot  them  off,  but  though 
at  nothing  at  all. 

"After  Prayer  we  prepared  our  selues  for  brek-fast,  and 
for  a  journey,  and  it  being  now  the  twilight  in  the  morning, 
it  was  thought  meet  to  carry  the  things  downe  to  the  Shallop : 
some  sayd,  it  was  not  best  to  carry  the  Armour  downe,  others 
sayd,  they  would  be  readier;  two  or  three  sayd,  they  would 
not  carry  theirs,  till  they  went  themselues,  but  mistrusting 
nothing  at  all :  as  it  fell  out,  the  water  not  being  high  enough, 
they  layd  the  things  downe  vpon  the  shore,  &  came  vp  to  brek- 

47 


4S  Biolofjif  in   A))Krlca 

fast.  AiKuii',  ill!  \  poll  a  sudden,  we  licai'd  a  {xrcat  &  strangle 
(*!-y,  wliicli  we  knew  to  he  the  saiiie  voycos,  tlioiigli  tlioy  vai'i(Ml 
tlit'ir  notes.  One  of  oiu'  ('oiiij)any  hoiiifi:  al)i'oa(l  came  niiniiufij 
iu,  and  eryod  Thoy  ar  men.  Indians,  Indians;  and  withall, 
tlu'ir  airows  camo  flying  amongst  vs,  onr  men  ran  out  witli 
all  sjx'cd  to  reeovor  their  amies,  as  hy  tlie  good  Providence 
of  God  they  did.  In  the  meane  time,  Captainc  IMiles  Standish, 
liaviiig  a  snaphanee  ready,  made  a  shot,  and  after  liim  an- 
other; after  they  two  had  shot,  other  of  vs  were  ready,  but 
lie  wisht  vs  not  to  slioot,  lill  we  eonhl  take  ayme,  for  we 
knew  not  what  need  we  shouki  liaue,  &  there  were  fourc  only 
of  vs,  which  had  their  armes  there  redie,  and  stood  before  the 
open  side  of  our  Baricado,  which  was  first  assaulted ;  they 
thought  it  l)est  to  defend  it,  least  the  enemie  should  take  it 
and  our  stutt'e,  and  so  haue  the  more  vantage  against  vs; 
our  care  was  no  lesse  for  the  Shallop,  but  we  hoped  all  the 
rest  would  defent  it ;  we  called  vnto  them  to  know  how  it 
was  with  them,  and  they  answered,  AVell,  AVell,  every  one, 
and  be  of  good  courage:  we  heard  three  of  their  Peeces  goe 
off,  and  the  rest  called  for  a  fire-brand  to  light  their  matches ; 
one  tooke  a  log  out  of  the  fire  on  his  shoulder  and  went  and 
carried  it  vnto  tliem,  which  was  thought  did  not  a  little  dis- 
courage our  enemies.  The  cry  of  our  enemies  was  dreadfull, 
especially,  Avhen  our  men  ran  out  to  recover  their  Armes, 
their  note  was  aftei-  this  manner,  Woath  woach  ha  ha  hach 
woach :  our  men  were  no  sooner  come  to  their  Armes,  but  the 
enemy  were  ready  to  assault  them. 

"There  was  a  luslie  nmn  and  no  whit  lesse  valiant,  who  was 
thought  to  bee  their  Captaine,  stood  behind  a  tree  within 
halfe  a  musket  shot  of  vs,  and  there  let  his  arrowes  fly  at  vs; 
he  was  scene  to  shoote  three  arrowes,  which  were  all  avoyded, 
for  he  at  whom  the  first  arrow  was  aymed,  saw  it,  and  stooped 
downe  and  it  flew  over  him,  the  rest  were  avoyded  also:  he 
stood  three  shots  of  a  IMusket,  at  length  one  tooke  as  he  sayd 
full  ayme  at  him,  after  which  he  gaue  an  extraordinary  cry 
and  away  they  went  all ;  wee  followed  them  about  a  quarter 
of  a  mile,  but  wee  left  sixe  to  keep  our  Shallop,  for  we  were 
carefull  of  our  businesse:  then  wee  shouted  all  together  two 
severall  times,  and  shot  off  a  couple  of  muskets  and  so 
returned :  this  wee  did  that  they  might  see  wee  were  not 
afra^^d  of  them  nor  discouraged. 

"Tims  it  pleased  God  to  vanquish  our  Enemies  and  giue 
vs  deliverance. ' '  ^ 

(January  23,  1697) 

"T  attempted,  this  Day,  the  Exercises  of  a  secret  Fast  before 
the  Lord.    But  so  extremely  cold  was  the  weather,  that  in  a 

>"  Journal  of  the  Pilgrims  of  Pljonouth,"  1620,  pp.  44-46. 


Biological  Institutions  49 

ward  Room,  on  a  great  Fire,  the  Juices  forced  out  at  the  End 
of  short  Billets  of  Wood,  by  the  Heat  of  the  Flame,  on  which 
they  were  laid,  yett  froze  into  Ice,  at  their  coming  out.  This 
Extremity  of  the  Cold  caused  mee  to  desist  from  the  purpose, 
which  I  was  upon;  because  I  saw  it  impossible  to  serve  the 
Lord,  without  such  Distraction  as  was  inconvenient. 


<  ( I 


(January  11,  1719-20) 
Tis  dreadful  cold.     My  Ink-glass  in  my  Standish  is  froze 
&  splitt,  in  my  very  stove.    My  Ink  in  my  very  pen  suffers  a 
congelation :  but  my  witt  much  more. "... 

"Sabbath,  Jan.  24,  1686,  Friday  night  and  Satterday  were 
extream  cold,  so  that  the  Harbour  frozen  up,  and  to  the 
Castle.  This  day  so  cold  that  the'  Sacramental  Bread  is 
frozen  pretty  hard,  and  rattled  sadly  as  broken  into  the 
plates. — Samuel  Sewall. 

"Lord's  Day,  Jan.  15,  1715-6.  An  Extraordinary  Cold 
Storm  of  Wind  and  Snow.  Blows  much  worse  as  coming 
home  at  Noon,  and  so  holds  on.  Bread  was  frozen  at  the 
Lord 's  Table.  .  .  .  Though  twas  so  Cold,  yet  John  Tuckerman 
was  baptised.  At  six  a-clock  my  ink  freezes  so  that  I  can 
hardly  write  by  a  good  fire  in  my  Wive 's  Chamber.  Yet  was 
very  comfortable  at  Meeting.     Laus  Deo. — Samuel  Sewall. ' '  ^ 

Such  was  the  cradle  of  higher  education  in  America. 

In  1636  the  Colony  Court  "agreed  to  give  £400  towards  a 
schoole  or  collidge,"  which  in  1637  was  located  at  Cambridge 
and  later  received  its  name  from  its  first  patron,  the  Rev. 
John  Harvard,  who  died  in  Charlestown  in  1638,  leaving  one 
half  of  his  estate  (about  £800)  and  his  library  to  the  infant 
college.  The  first  of  the  buildings  erected  was  known  as  "The 
Indian  Collidge"  with  rooms  for  twenty  youthful  savages, 
several  of  whom  attended,  but  only  one  of  whom  graduated 
from  it.  History  repeats  itself  in  the  case  of  many  of  the 
"youthful  savages"  within  its  walls  today.  Here  the  first 
college  text-books  were  printed,  including  the  Apostle  Eliot's 
translation  of  the  Bible  into  the  Indian  language,  primers, 
grammars,  tracts,  etc.  It  is  possible  that  the  missionary  spirit 
of  the  founders  of  the  college  was  not  a  wholly  disinterested 
one,  since  many  of  its  funds  were  obtained  abroad  for  the 
express  purpose  of  converting  the  heathen;  or  in  more 
materialistic  terms,  making  a  bad  Christian  out  of  a  good 
savage. 

Harvard  College  was  followed  by  William  and  Maiy's 
College  (1692),  Yale  (1700),  Princeton  (1746),  the  University 

'Hanscom,  "The  Heart  of  the  Puritan,"  pp.  29-30,  210.  By  permis- 
sion of  the  Macmillan  Company, 


50  Biology  in  America 

of  Pennsylvania  (1749),  and  King's  College  (now  Columbia 
University)  in  1754.  These  early  colleges  and  their  succes- 
sors, prior  to  the  early  part  of  the  last  century,  were  sup- 
ported mainly  by  private  funds,  given  largely  in  the  form  of 
endowments;  but  since  1837,  when  the  University  of  Michigan 
Avas  founded,  most  of  the  states  maintain  universities  at  public 
expense.  The  private  institutions  have  been,  almost  exclu- 
sively supported  by  religious  societies,  even  some  of  the  great 
universities,  which  today  are  non-sectarian,  such  as  Harvard, 
Yale  and  Princeton,  having  been  originally  established  on  a 
religious  basis. 

The  early  instruction  in  our  colleges  and  universities  was 
strictl}'^  classical.  The  appointment  of  Benjamin  Silliman  as 
professor  of  chemistry  and  natural  science  at  Yale  in  1802, 
therefore  marks  an  epoch  in  the  history  of  American  educa- 
tion. It  is  interesting  to  note  that  the  young  professor,  at 
the  time  of  his  appointment  but  twenty-three  years  of  age, 
was  a  lawyer  by  profession,  with  no  knowledge  whatever  of 
the  sciences  he  was  to  teach.  He  says  of  his  appointment  that 
it  ''was  of  course  the  cause  of  wonder  to  all,  and  of  cavil  to 
political  enemies  of  the  college.  Although  I  persevered  in 
my  legal  studies  ...  I  soon  after  the  confidential  communi- 
cation of  President  Dwight  (informing  him  of  his  probable 
appointment)  obtained  a  few  books  on  chemistry  and  kept 
them  secluded  in  my  secretary,  occasionally  reading  in  them 
privately.  This  reading  did  not  profit  me  much.  Some  gen- 
eral principles  were  intelligible,  but  it  became  at  once  obvious 
to  me  that  to  see  and  perform  experiments  and  to  become 
familiar  with  many  substances  was  indispensable  to  any 
progress  in  chemistry,  and  of  course  I  must  resort  to  Phila- 
delphia, which  presented  more  advantage  to  science  than  any 
other  place  in  our  country."  ^ 

As  Yale  was  the  pioneer  in  breaking  away  from  "the  tra- 
ditions of  the  elders,"  and  establishing  a  professorship  in 
science,  so  too  was  it  the  pioneer  in  establishing  soon  after- 
ward (1824)  a  distinct  organization  or  school,  the  Sheffield 
Scientific  School,  for  scientific  instruction.  In  1847  a  similar 
organization  (the  Lawrence  Scientific  School)  was  established 
at  Harvard,  and  soon  the  teaching  of  science  in  American 
colleges  and  universities  was  placed  on  an  equal  footing  with 
that  of  art  and  letters.  At  the  present  time  indeed  science, 
tried  alike  in  the  fires  of  war  and  the  sunshine  of  peace, 
stands  preeminent,  both  in  education  and  in  industry. 

Biology  in  American  schools  owes  its  birth  primarily  to 
Agassiz  and  Gray,  colleagues  on  the  Harvard  faculty  at  the 

'  Merrill,  * '  Contributions  to  the  History  of  American  Geology, ' '  after 
G.  P.  Fisher,  "Life  of  B.  Silliman,"  p.  215. 


Biological  Institutions  51 

middle  of  the  last  century.  After  the  impelling  influence  of 
these  two  great  teachers,  it  has  made  a  lusty  growth.  In  early 
days  the  college  professor  was  supposed  to  be  as  many  sided 
as  the  country  "school  marm"  of  the  present  day  and  genera- 
tion. No  man  was  sufficiently  well  educated  to  occupy  a 
professor's  chair  unless  he  was  an  authority  in  at  least  two 
major  sciences,  while  the  idea  of  a  professor  confining  liis 
attention  to  a  single  branch  of  one  of  these  sciences  was 
unheard  of.  Today  all  our  great  universities  have  two  en- 
tirely separate  departments  of  l^iology  (botany  and  zoology) 
each  with  a  staff  of  from  five  to  ten  or  more  members,  each 
one  of  whom  has  in  charge  his  own  particular  branch  of  the 
subject.  To  appreciate  the  multiplicity  of  modern  science 
one  need  but  turn  to  any  recent  program  of  a  scientific  society 
where  the  papers  are  arranged  by  subjects.  Thus  at  the  1921 
meeting  of  the  American  Society  of  Zoologists  there  were 
papers  presented  in  the  following  branches  of  zoology :  embry- 
ology, cytology,  parasitology^  evolution,  genetics,  ecology,  dis- 
tribution, general  physiology,  and  comparative  anatomy.  The 
average  college  catalog  contains  such  a  "feast  of  fat  things" 
as  to  impair  the  digestion  of  even  the  most  voracious  of  stu- 
dent "sharks." 

But  with  the  passing  of  the  "good  old  days"  when  every 
college  "prof"  was  supposed  to  be  a  "walking  encyclopedia" 
has  come  a  far  more  exacting  age  for  teacher  and  investigator 
alike,  for  modern  standards  of  success  demand  of  both  a  far 
more  encyclopedic  knowledge  of  science,  than  was  expected 
of  their  forbears.  The  inter-relations  of  the  many  branches 
of  science,  and  their  intimate  dependence  one  upon  the  other,, 
demands  a  much  more  extensive,  and  withal  exact  knowledge 
of  their  subject  on  the  part  of  biologists  today,  than  was 
needed  in  the  past.  Especially  is  this  true  in  the  field  of 
experimental  biology,  which  has  made  such  remarkable  strides 
in  the  last  two  decades,  and  which  employs  as  its  handmaidens 
its  sister  sciences  of  chemistry  and  physics.  Today  indeed 
chemistiy  and  biology  are  united  in  the  new  science  of  bio- 
chemistry, one  which,  for  possibility  of  discovery  of  the  most 
elusive  secrets  of  nature,  gives  more  promise  than  any  other 
field  of  scientific  quest  and  conquest. 

With  this  ever  increasing  specialization  and  complexity  of 
biology  (and  the  same  is  no  less  true  of  other  sciences)  have 
come  ever  increasing  demands  for  equipment  on  the  means 
of  our  higher  institutions  of  learning.  Time  was  when  the 
biological  laboratory  was  considered  equipped  if  it  possessed 
a  few  old  microscopes,  hand  lenses  and  dissecting  instruments, 
a  little  glassware,  a  few  chemicals  and  some  pickled  caricatures 
of  things  which  were  once  alive.    Today  the  work  shop  and 


52  Biology  in  America 

class  room  of  the  well  equipped  biologist  contains  not  only 
the  most  modern  microscopes  (the  instrument  par  excellence 
of  biological  research)  but  microtomes  for  cutting  sections 
of  microscopic  material  down  to  a  twenty-five  thousandth  of 
an  inch  in  thickness;  electrically  controlled  incubators,  where 
cultures  of  microscopic  organisms  and  growing  tissues  can 
be  held  within  one  degree  F.  of  any  desired  temperature; 
electrically  driven  centrifuges  running  at  speeds  of  from  three 
to  four  tliousand  revolutions  per  minute;  projection  appa- 
ratus for  projecting  pictures,  microscopic  preparations,  and 
even  living  animals  themselves  upon  the  demonstration  screen, 
or  drawing  board ;  apparatus  for  taking  photographs  of  these 
preparations  at  magnifications  of  from  one  to  two  thousand 
diameters;  delicate  balances  for  weighing  down  to  a  twenty- 
five  thousandth  of  an  ounce  or  less,  and  hot  houses  and 
aquaria  where  living  material  for  study  may  be  always  avail- 
able. 

Such  is  some  of  the  more  common  apparatus  of  the  biolog- 
ical laboratory.  In  laboratories  devoted  exclusively  or  pri- 
marily to  research,  such  as  those  at  Woods  Hole,  Cold  Spring 
Harbor  and  elsewhere,  reference  to  which  will  be  made  below, 
apparatus  of  a  special,  and  often  costly  type  is  usually  found 
in  addition  to  the  more  common  equipment  outlined  above. 

The  biological  laboratory  of  college  or  university  is  not 
however  a  separate  institution  especially  devoted  to  biology, 
but  merely  a  part  of  a  larger  institution  dedicated  to  the  dis- 
semination and  advance  of  all  knowledge.  Yet  it  is  through 
this  channel  that  the  greatest  contributions  to  biology  have 
thus  far  come.  In  considering  biological  institutions  however 
we  are  primarily  interested  in  those  devoted  exclusively  to 
this  science,  including  our  museums,  government  and  endowed 
laboratories,  and  others  of  similar  character. 

The  early  history  of  biology  in  America  was  as  we  have 
seen  closely  associated  with  the  museums.  From  their  mem- 
bers in  many  instances  went  forth  the  collectors  who  accom- 
panied the  early  explorers  into  virgin  forests,  across  trackless 
prairies  and  through  the  wild  defiles  of  mountain  fastnesses. 
And  it  was  to  the  museums  that  these  collectors  returned  to 
study  and  describe  the  treasures  whicli  they  had  found. 

Numerous  as  are  the  splendid  natural  history  museums 
in  America,  space  limits  us  to  a  brief  consideration  of  but 
three,  as  typical  of  the  achievements  of  American  science  in 
this  field.  Of  our  larger  museums,  especially  those  devoted 
primarily  to  natural  history,  the  earliest  established  was  the 
Academy  of  Natural  Sciences  in  Philadelphia.  The  dawn  of 
the  year  1812  was  darkened  by  the  cloud  of  war  which  hung 
low  over  America,    The  one  amusement  house  in  Philadelphia, 


Biological  Institutions 


53 


the  old  Walnut  Street  Theatre,  was  seldom  open,  and  the 
city's  youth  were  wont  to  gather  in  tavern  and  oyster  house 
to  discuss  the  momentous  events  of  the  times.  Under  circum- 
stances such  as  these  a  few  young  men  who  were  interested 
in  natural  history  met  at  the  home  of  one  of  their  number  on 
January  25,  1812,  for  the  organization  of  a  society  whose  pur- 
pose, according  to  the  minutes  of  the  meeting,  should  be  "the 
rational  disposition  of  otherwise  leisure  moments."  Their 
collections  at  this  time  comprised  "a  few  insects,  corals  and 


The  Acadkmy  of  Natural  Sciences  of  Philadelphia,  1912 
From   the   Academy   "Proceedings." 

shells,  a  dried  toad  fish,  and  a  stuffed  monkey."  From  this 
primitive  beginning  has  come  the  great  institution  which  has 
contributed,  perhaps  more  than  any  other  factor,  to  making 
Philadelphia  one  of  the  homes,  as  it  was  the  birthplace  of 
American  biology.  In  the  early  years  of  the  last  century 
Philadelphia  was  the  Mecca  of  American  biologists.  From 
here  Alexander  Wilson  started  on  his  ornithological  travels. 
Hither  came  Audubon,  seeking  support  for  the  "Birds  of 
America,"  and  through  the  generosity  of  Edward  Harris,  a 
Philadelphian,  he  was  enabled  to  nud^e  his  journey  up  the 
Missouri  River.  Lucien  Bonaparte,  who  continued  the  work 
of  AVilson,  after  the  latter 's  death,  was  for' a  time  resident  at 


54 


Biology  in  America 


Philadelphia.  The  early  naturalist  explorers,  Say,  Nuttall 
and  Townsend,  were  associated  with  the  Academy  at  Phila- 
delphia, two  of  whose  members  accompanied  the  famous 
Wilkes  Expedition  to  the  Antarctic.  The  Academy  was  as- 
sociated also  with  the  early  Arctic  expeditions  under  Kane 
and  Hayes,  while  Peary's  Greenland  expedition  of  1891  was 
conducted  under  its  auspices.  Many  are  the  names  famous 
in  the  annals  of  American  biology  which  have  been  associated 
with  the  Academy  of  Natural  Sciences,  Leidy,  Cope,  Cassin, 
Bachman,  Le  Sueur,  Gill,  Osborn  and  a  host  of  others. 

The  collections  of  the  Academy,  descendants  of  the  stuffed 
monkey  and  the  dried  toad  of  its  founders,  have  grown  to 
occupy  the  first  rank  among  biological  exhibits  in  America. 
While  they  are  surpassed  in  size  and  display  by  those  of  the 
American  Museum  of  Natural  History  and  the  tj.  S.  National 


4'm^imM^ 


The  American  Museum  of  Natural  History  in  New  York 
Courtesy  of  the  Museum. 

Museum,  for  reference  purposes  along  certain  lines  they  are 
second  to  none  in  the  world.  Its  library  too  is  one  of  the 
best  in  America  in  biology,  '  especially  in  the  works  of 
the  early  writers.  Pioneer  among  American  museums  the 
Academy  of  Natural  Sciences  of  Philadelphia  has  blazed  many 
a  trail  for  biologists  into  the  unknown. 

It  would  indeed  be  difficult  to  assign  a  premier  place  to 
any  one  museum  of  natural  history  in  America,  but  were  one 
to  undertake  such  a  thankless  task,  his  choice  would  be  likely 
to  fall  on  the  American  Museum  of  Natural  History  in  New 
York  City,  which  in  breadth  of  purpose,  in  the  extent  and 
value  of  its  collections,  and  in  its  scientific  achievements  is 
second  to  none  in  this  country.  Founded  in  1869  it  now 
occupies  a  $4,000,000  structure  in  Central  Park,  which  was 
built  and  is  maintained  by  the  city,  while  the  expense,  of  the 
collections  and  investigations  is  provided  for  by  an  endow- 
ment, by  dues  of  members  and  by  private  contributions. 


Biological  Institutions 


55 


Truly  may  it  be  said  of  the  American  Museum  that  its 
"lines  have  gone  forth  throughout  all  the  earth,  and  its  (men) 
to  the  ends  of  the  world."  From  frigid  pole  and  torrid 
equator,  from  rain-soaked  forest  and  from  sun-baked  desert, 
from  Andean  height  and  Amazonian  jungle  have  come  the 
treasures,  which  constitute  today  one  of  the  finest  exhibits  of 
natural  history  in  the  world.  To  attempt  any  adequate  ac- 
count of  the  Museum  and  its  work  in  this  place  would  be  out 
of  the  question,  but  brief  mention  may  be  made  of  a  few  of 
its  more  important  features. 

The  progress  of  American  palaeontology,  outlined  in  another 
chapter  is  largely  due  to  the  Museum,  and  its  splendid  col- 


The  Blue  Shark  with  School  op  Young 

Photograph  of  a  group  in  the  American  Museum  of  Natural  History 
in  New  York. 

Courtesy  of  the  Museum. 

lection  of  fossil  vertebrates  bears  witness  to  the  story  of  the 
past,  which  its  investigations  have  revealed. 

Until  comparatively  recent  years  we  have  been  accustomed 
in  our  museums  to  display  case  after  case  and  row  upon  row 
of  more  or  less  indifferently  stuffed  specimens,  with  jar  after 
jar  of  ''pickled"  snakes  and  turtles  and  case  upon  case  of 
pinned  butterflies  and'  moths.  But  no  hint  was  there  of  the 
activities  and  home  of  the  living  thing.  Today  our  best 
museums,  largely  under  the  inspiration  of  the  American 
Museum,  are  exhibiting  groups  of  birds  and  mammals,  rep- 
tiles, fish  and  other  forms,  illustrating  their  homes  and  lives 
in  Nature's  setting.  Here  one  finds  for  example  the  duck 
hawks,  with  their  nest  and  young  perched  among  the  rocks 


The  Home  of  the  Ducit  Hawk  in  the  Hudson  Palisades 

l^hotoyrapli  of  :i  gioup   in  the  Aineiican   Museum  of   Natural  History 

in   New   Voik. 

Conrtcxii   of  ihc   Munvum. 


A  Florida  Swamp 
Photogra})!!  of  a  reptile  group  in  the  American  Museum  of  Natural 

History  in  New   York. 

Courtesy  of  the  Museum. 

56 


Biological  Institutions 


57 


of  the  Palisades,  with  their  great  walls  painted  in  the  back- 
ground and  the  lovely  Hudson  flowing  at  their  base.  There 
is  the  reedy  border  of  a  lake  from  central  Oregon  filled  with 
the  wild  fowl  and  their  nests.  Another  exhibit  shows  a  bit 
of  a  Florida  cypress  swamp,  with  alligators  of  various  ages 
and  the  mother  guarding  the  nest  in  which  the  young  are 
hatching  from  the  eggs.  Here  too  are  shown  many  species 
of  snakes,  and  amphibians,  all  modeled  in  wax  and  colored 
from  living  specimens.  Yet  another  group  illustrates  the  blue 
shark  with  a  school  of  young  among  the  sargassum  weed  of  the 
Gulf  Stream,  while  still  another  displays  an  oak  tree  in  leaf 
with  its  branches  covered  by  hosts  of  the  beautiful  monarch 
butterfly  as  it  appears  when  migrating. 

A  unique  feature  in  the  Museum's  exhibit  is  Darwin  Hall 


The  Game  of  the  '  *  Men  of  the  Old  Stone  Age  ' ' 

The  woolly  rhinoceros,  with  the  saiga  antelope  and  mammoth  in  the 
distance. 

Copyrighted  ty  the  American  Museum  of  Natural  History. 

wherein  are  displayed  groups  of  invertebrate  animals  illus- 
trating the  evolution  of  this  portion  of  the  animal  kingdom 
from  the  Protozoa  to  the  ascidians.  Among  the  former  are 
models  of  disease  producing  types  such  as  the  organisms 
causing  malaria  and  the  deadly  African  sleeping  sickness. 
Here  too  are  wax  and  glass  models  of  the  Malaria  mosquito, 
reproducing  with  wonderful  delicacy  even  such  minute  parts 
as  the  bristles  on  its  body.  The  work  of  man  in  molding  the 
form  of  animals  to  his  will  is  illustrated  by  cases  of  pigeons 
and  other  domestic  animals,  while  the  results  of  modern 
research  in  heredity  are  shown  among  other  ways  in  the 
offspring  of  a  pair  of  rats,  and  in  a  demonstration  of  the 
inheritance  of  color  in  the  four  o'clock. 

In  the  Hall  of  the  Age  of  Man  is  depicted  by  painting  and 
model  the  story  of  the  "Men  of  the  Old  Stone  Age"  as  they 
lived  in  their  cavern  homes  and  hunted  with  implements  of 


Monarch  Butterflies 

Photofjraiili  of  a  group  in  the  American  Museum  of  Natural  History 
in  New  York. 

Courtesy ^0}  the  Museum. 


58 


Biological  Institutions  59 

flint  the  woolly  rhinoceros,  the  mammoth,  mastodon  and  royal 
bison,  which  roamed  the  world  when  the  glaciers  held  much 
of  the  northern  hemisphere  within  their  grasp. 

But  the  mere  exhibition  of  nature 's  wonders  is  by  no  means 
the  only,  or  even  the  primary  function  of  the  American 
Museum.  The  discovery  of  her  workings  and  her  secrets  is 
fundamental  to  their  demonstration  in  its  halls.  And  so 
with  the  gathering  of  material  for  its  exhibits  has  gone  hand 
in  hand  the  gathering  and  publication  of  information  relative 
thereto,  much  of  which  is  rehearsed  in  other  chapters  of  this 
book.  The  spread  of  knowledge  through  research,  publica- 
tion and  exhibition  is  the  comprehensive  function  of  every 
museum.  As  further  illustration  of  this  function  is  the  work 
of  the  public  health  department  of  the  Museum,  whose  pur- 
pose can  best  be  stated  in  the  words  of  its  curator.  Its  plan 
is  to  "present  a  fairly  comprehensive  picture  of  the  life  of 
man  as  an  animal,  his  place  in  the  general  scheme  of  natural 
history,  his  relations  to  his  geographical  and  meteorological 
surroundings,  the  parasites  which  cause  his  diseases,  and  the 
animals  and  plants  which  serve  him  for  food  and  clothing. 
The  plan  .  .  .  giving  a  survey  of  the  cycle  of  human  life,  its 
dangers  and  its  safeguards,  complete  enough  to  satisfy  the 
curiosity  of  the  ordinary  man  and  to  teach  him  what  he  needs 
to  know  in  order  to  keep  sound  and  well,  is  an  extensive 
one.  ..."  In  partial  fulfilment  of  this  plan  the  department 
has  installed  exhibits  of  the  disposal  of  sewage  and  garbage, 
the  water  supply  of  cities,  its  relation  to  rainfall  and  the 
ways  of  safeguarding  it  from  pollution;  the  composition  of 
water  and  the  microscopic  organisms  which  it  contains.  Some 
of  the  exhibits  in  this  department  are  a  series  of  models 
of  different  sorts  of  bacteria,  models  of  insect  carriers  of 
disease,  the  flea,  louse,  yellow  fever  mosquito  and  the  house- 
fly. The  mosquito  exhibit  shows  among  other  things  the 
condition  of  the  French  hospitals  in  Panama,  as  compared 
with  those  installed  by  the  Americans,  the  life  history  of 
mosquitoes  and  methods  of  combating  them  by  oiling,  drain- 
age, fumigation,  etc.  The  department  also  maintains  a  grow- 
ing collection  of  living  bacteria  including  hundreds  of 
different  varieties,  from  which  were  sent  out  in  1918  over 
3,000  cultures  free  of  charge  to  laboratories  throughout  the 
country. 

During  the  Great  War  the  Museum  aided  in  the  food  con- 
servation movement  by  the  preparation  of  a  food  exhibit 
illustrating  the  character  of  food,  its  use  in  human  metabolism, 
the  adjustment  of  the  daily  ration  to  meet  the  increasing  cost 
of  living,  and  showing  some  new  and  as  yet  little  used  sources 
of  food,  such  as  seaweeds,  snails,  mussels,  cuttle  fish,  etc. 


60 


Biology  in  Ama'ica 


Sueli  in  brief  arc  a  few  of  the  activities  of  this  splendid 
institution. 

One  of  tlie  best  additions  to  the  architecture  of  the  new 
"Washington  is  tlie  buildin<j:  of  the  National  Museum  located 
on  the  "IMall"  or  park,  which  stretches  westward  from  the 
Capitol  to  the  Potomac  River.  The  building  is  a  simple,  but 
imposing  structure  of  white  granite  and  so  arranged  as  to 
provide  the  greatest  amount  of  floor  space  possible  in  the 


IS'ew  iSouRCES   OF  Aquatic  Food,   Kelp,  Snails,   Mussels  and  Squid 

Photograph  of  a  group  in  the  American  Museum  of  Natural  History 
in  New  York. 

Courtesy  of  the  Mu^'^eum. 


area  covered.  Here  are  housed  the  natural  history  and  an- 
thropological collections  of  the  U.  S.  Government,  whose 
formation  was  begun  by  the  Wilkes  exploring  expedition 
around  the  world  in  1838-1842. 

In  18-46  the  Smithsonian  Institution  was  established  by 
act  of  Congress  in  accordance  with  the  will  of  the  English 
mineralogist  James  Smithson,  who  left  an  estate  of  about  a 
half  million  dollars  to  the  United  States  for  the  "increase 
and  diffusion  of  knowledge  among  men."  This  act  made  the 
National  Museum  a  part  of  the  Smithsonian  Institution.  The 
early  collections  of  the  government  were  augmented  partly 


Biological  Institutions 


61 


through  the  personal  efforts  of  Professor  Baird,  the  then  as- 
sistant secretary  of  the  Institution,  and  partly  througli  the  ef- 
forts of  the  scientists  wlio  accompanied  the  ji'overmneiit  sur- 
veys sent  out  about  the  middle  of  the  last  century.  Professor 
Baird  awakened  the  interest  of  officers  of  the  army  and  navy, 
fishermen,  fur  traders,  private  explorers  and  members  of  the 
Hudson's  Bay  and  Western  Union  Telegraph  Companies  in 
the  collection  of  natural  history  objects,  and  in  this  way  a 
large  amount  of  valuable  material  was  secured  by  the 
Institution.     Since  its  establishment  the   National   Museum 


The  U.  S.  National  Museum 

One  of  the  architectural  features  of  the  new  Washington. 

Courtesy  of  the  Museum. 


has  become  the  regular  repository  of  the  splendid  collections 
made  by  the  U.  S.  Biological  Survey,  the  Bureau  of  Fisheries, 
the  Bureaus  of  Animal  and  Plant  Industry,  and  the  U.  S. 
Geological  Survey.  IMuch  material  has  also  been  gathered 
through  the  expeditions  of  the  Smithsonian  Institution  itself. 

The  ethnological  exhibits  of  the  Museum  are  perhaps  its 
finest  productions,  but  it  has  many  beautiful  groups  of  birds 
and  mammals  as  well,  and  a  splendid  collection  of  fossils. 

Its  research  work  and  resultant  publications  are  largely 
technical,  consisting  of  the  monographing  and  description  of 
groups  and  species  of  animals  and  plants  in  its  collections. 

One  of  its  important  educational  features  is  the  distribution 


62  Biology  in  America 

of  duplicate  sets  of  specimens  to  schools  and  colleges  through- 
out the  country.  It  also  fills  an  important  place  as  a  conven- 
tion center,  not  only  for  the  scientific  societies  of  Washington, 
but  for  national  and  international  gatherings  as  well. 

Another  group  of  biological  institutions  are  the  zoological 
and  botanical  gardens  and  aquaria,  upon  the  possession  of 
one  or  more  of  which  nearly  every  city  of  any  size  in  America 
prides  itself. 

Established  primarily  for  purposes  of  display,  some  of 
these  institutions  have  performed  a  much  more  important 
service  in  adding  to  our  knowledge  of  the  animals  and  plants 
which  they  contain.  A  brief  account  of  a  few  of  them  will 
serve  to  illustrate  their  place  in  American  biologj'. 

A  leader  in  this,  as  in  other  lines  of  science,  Philadelphia 
established  a  zoological  garden  as  early  as  1859.  Along  the 
banks  of  the  Schuylkill  River  in  Fairmount  Park  are  housed 
the  extensive  collections  of  the  Zoological  Society,  which  are 
supported  in  part  by  the  city,  in  part  by  memberships  and 
partly  by  paid  admissions  to  the  garden.  The  grounds  of  the 
Society  and  its  financial  means  are  too  small  to  admit  of 
either  the  best  enclosures  for  its  animals  or  their  proper 
scientific  study.  It  furnishes  considerable  material  however 
to  the  Academy  of  Natural  Sciences  of  Philadelphia,  and 
maintains  a  pathological  laboratory  for  the  study  of  diseases 
infecting  its  stock. 

In  1807  the  United  States  built  a  fort  called  the  Southwest 
Battery,  and  later  Castle  Clinton,  on  the  lower  end  of  Man- 
hattan Island,  from  which  this  section  of  New  York  has 
derived  its  name  of  "the  Battery."  In  1823  it  was  given 
to  the  city  for  an  amusement  hall  known  as  Castle  Garden, 
which  welcomed  several  presidents  and  other  distinguished 
visitors,  including  the  Hungarian  patriot,  Kossuth ;  and  its 
walls  frequently  echoed  the  wonderful  notes  of  Jenny  Lind. 
From  1855  to  1890  over  7,500,000  immigrants  passed  through 
its  doors.  In  1896  it  became  a  public  aquarium,  passing  in 
1902  under  the  control  of  the  New  York  Zoological  Society, 
which  was  chartered  in  1895.  While  the  housing  and  equip- 
ment of  the  aquarium  are  wholly  inadequate,  it  nevertheless 
maintains  one  of  the  largest  and  best  aquaria  of  both  salt 
and  fresh  water  fishes  in  the  world. 

The  Zoological  Society  maintains  gardens  in  Bronx  Park, 
in  New  York,  which  have  in  a  few  years  joined  the  ranks  of 
the  leading  zoological  gardens  of  the  world,  and  share  with 
the  National  Zoological  Park  in  Washington  the  first  place 
for  institutions  of  this  kind  in  America. 

The  old  style  zoological  garden  was  an  animal  prison 
where  animals  large  and  small  were  confined  in  cages  just 


Biological  Institutions  63 

large  enough  to  permit  them  to  turn  around  easily,  and 
where  the  "convicts"  dragged  out  a  miserable  existence  for 
a  few  years  until  relieved  by  death,  seldom  leaving  offspring 
to  inherit  their  unhappy  fate.  Today,  in  gardens  such  as 
those  in  New  York  and  Washington,  the  animals  are  kept, 
as  far  as  may  be,  in  large  open  enclosures,  where  they  can 
live  under  as  nearly  natural  conditions  as  possible.  Under 
such  conditions  they  are  healthy  and  contented  and  frequently 
rear  families. 

But  the  New  York  Zoological  Society  has  not  confined 
itself  solely  to  the  show  business.  Its  studies  of  wild  life 
have  been  its  most  valuable  contributions  both  to  science  and 
popular  education,  and  today  our  inhabitants  of  land  and 
sea,  our  dwellers  in  forest,  field,  and  lake  and  river  are  be- 
coming objects  of  familiar  acquaintance  through  the  writings 
of  Hornaday,  Ditmars  and  Townsend,  as  well  as  through  the 
splendid  collections  at  the  "Bronx"  and  the  "Battery"  in 
New  York  City. 

A  recent  and  important  enterprise  of  the  Society  is  the 
Tropical  Research  Station  at  Kalacoon,  near  Georgetown,  in 
British  Guiana,  with  C.  W.  Beebe,  curator  of  birds  at  the 
New  York  Zoological  Park,  as  its  director.  The  object  of 
this  station  is  a  study  of  life  in  the  tropical  jungle,  with 
the  more  ample  equipment  of  the  permanent  laboratory 
taking  the  place  of  the  scanty  means  of  the  exploring 
naturalist,  through  whose  labors  our  knowledge  of  tropical 
life  has  thus  far  mainly  been  acquired.  The  recent  estab- 
lishment of  this  station,  with  its  more  or  less  improvised 
equipment,  has  not  led  to  any  large  results  thus  far,  although 
a  number  of  delightful  essays  by  the  director  recently  pub- 
lished under  the  title  of  "Jungle  Peace"  form  a  distinct 
^.ontribution  both  to  literature  and  to  popular  science. 

The  first  botanical  garden  in  America  was  that  of  John 
Bartram  in  Philadelphia,  to  which  brief  reference  has  been 
made  in  the  previous  cliapter. 

One  of  the  pioneer  figures  in  American  botany  was  Geo. 
Engelmann,  the  St.  Louis  botanist-physician,  contemporary 
of  Gray  at  Harvard  and  Torrey  at  Columbia.  Engelmann 
had  a  friend  in  Henry  Shaw  the  wealthy  merchant  and  lover 
of  plants.  During  his  extensive  travels  in  Europe  Shaw 
formed  the  idea  of  a  botanical  garden  at  his  country  place 
on  the  outskirts  of  St.  Louis.  From  Engelmann  he  obtained 
advice  and  encouragement,  and  through  him  started  a  library 
and  herbarium.  Upon  Engelmann 's  death  in  1885  Mr.  Shaw 
founded  the  Henry  Shaw  School  of  Botany  in  Washington 
University  and  in  it  established  the  Engelmann  professorship 
in  memory  of  his  friend  and  tutor.     On  Mr.  Shaw's  death 


64 


Biology  in  America 


the  garden  passed  into  tlic  hands  of  a  board  of  trustees  to  be 
administered  as  a  public  garden  and  a  research  school  of 
botany. 

On  this  foundation  has  risen  the  Missouri  Botanical  Garden 
of  the  present,  with  its  splendid  conservatories  and  her- 
barium; its  library  containing  among  thousands  of  modern 
botanical  works  some  of  the  rarest  of  those  dealing  with  the 
earliest  studies  on  the  exploration  of  plant  and  animal  life 
in  America ;  and  its  research  laboratory  where  the  faculty 
and   graduate   students    of   botany    in    the    university    may 


A  Glimpse  of  the  New  York  Botanical  Garden 
Courtesy  0/  the  Garden. 


prosecute  their  studies.  The  popular  conception  of  a 
botanical  garden  as  that  of  a  museum  of  living  plants  for 
display  purposes  is  admirably  realized  in  the  arboretum  and 
conservatories  of  the  garden,  while  the  less  popular,  but  far 
more  important  function  of  research  is  equally  well  per- 
formed in  its  well  equipped  laboratories.  The  field  of 
activity  covered  by  the  garden  is  limited  only  by  the  bounds 
of  botanical  knowledge.  No  problem  is  too  abstruse  or  too 
practical  for  its  attention.  In  all  of  its  educational  features, 
in  display  as  well  as  in  research,  the  Garden  occupies  one  of 
the  most  important  places  in  American  botany. 


Biological  Institutions 


65 


Similar  in  conception  to  the  Missouri  Botanical  Garden 
is  the  New  York  Botanical  Garden  in  the  Bronx  Park  in 
New  York  City,  which  was  established  in  1891  through  the 
initiative  of  the  Torrey  Botanical  Club,  which  takes  its  name 
from  one  of  its  founders,  the  pioneer  botanist,  John  Torrey, 
who,  like  others  of  his  early  colleagues,  was  well  versed  in 
other  sciences  than  that  in  which  he  earned  his  reputation. 
Commencing  his  career  as  a  physician  he  subsequently 
became  professor  of  the  natural  sciences  at  West  Point,  the 


A  View  of  the  Arnold  Arboretum  with  Bank  of  Laurel  on  the  Left 

Courtesy  of  Professor  Sargent. 


College  of  Physicians  and  Surgeons,  the  College  of  the  City 
of  New  York,  Princeton  and  Columbia,  and  was  for  many 
years  assay er  in  the  New  York  assay  office.  On  Torrey  fell 
the  duty,  among  others,  of  working  up  the  collections  of 
plants  gathered  by  the  many  exploring  expeditions,  which 
at  this  time  were  pushing  the  frontier  of  America  out 
through  the  trackless  west. 

On  the  outskirts  of  Boston  is  one  of  the  most  beautiful 
and  unique  collections  of  plants  in  the  world.  The  Arnold 
Arboretum   is   the   joint   product   of   Boston   and   Harvard 


A  Bit  of  the  "Forest  Primeval" 

A  hemlock  grove  in  the  Arnold  Arboretum. 

Courtesy  of  Professor  Sargent. 


m 


Biological  Institutions  67 

University.  It  was  established  about  fifty  years  ago  by  a 
gift  of  $100,000  by  James  Arnold  of  New  Bedford,  and  the 
setting  apart  of  a  tract  of  some  200  acres  by  joint  arrange- 
ment between  the  city  and  the  university.  It  forms  at  the 
same  time  a  part  of  the  splendid  park  system  of  Boston,  and 
a  "museum  of  living  trees."  Here  are  gathered  together 
trees  and  shrubs  from  temperate  climes  in  all  the  world,  the 
old  New  England  hemlocks,  a  bit  of  the  "forest  primeval" 
of  the  Pilgrim  fathers,  the  firs  and  spruces  of  the  Rocky 
Mountains,  the  oaks  of  England,  the  cedars  of  Lebanon,  and 
the  funereal  cypress  of  China,  with  roses  and  cherries  from 
far  away  Japan. 

In  the  arrangement  of  the  grounds  formality  has  been 
thrown  to  the  winds.  AVell  trimmed  lawns,  rows  of  trees 
and  flower  beds  with  square  corners  have  been  subordinated 
to  Nature's  beautiful  carelessness  in  the  planning  of  the 
gardens.  And  yet  through  all  the  apparent  disorder,  there 
runs  an  orderly  arrangement  whereby  related  plants  are 
brought  together,  and  each  family  of  tree  and  shrub  has  its 
own  appointed  place  in  the  general  plan. 

Under  the  direction  of  Professor  Sargent,  head  of  the  Ar- 
boretum, has  been  developed  a  museum,  library  and  herbarium 
containing  specimens  of  the  wood  of  all  American  trees, 
showing  its  structure  when  cut  with  or  across  the  grain,  and 
when  polished  or  smooth.  There  are  records  also  of  the 
physical  character  of  different  woods,  their  specific  gravity, 
heat  value,  amount  of  ash,  etc.  The  herbarium  contains  a 
collection  of  woody  plants  from  all  parts  of  the  world,  while 
the  libraiy  is  one  of  the  best  collections  on  trees  in  existence. 

From  the  Arboretum  have  come  Professor  Sargent 's  ' '  Silva 
of  North  America,"  a  classic  on  American  trees.  Here  too  was 
written  his  "Forest  Flora  of  Japan,"  the  result  of  extended 
travel  and  research  in  that  country.  As  author  of  the  report 
on  our  forests  in  the  tenth  census,  the  director  of  the  Arbor- 
etum brought  to  the  notice  of  the  people  of  the  United  States 
their  wonderful,  but  rapidly  vanishing  timber  resources,  and 
paved  the  way  for  the  development  of  forest  conservation  and 
the  establishment  of  our  forest  reserves. 

The  Arboretum  also  has  served  as  pioneer  and  guide  in  the 
establishment  of  botanical  gardens  elsewhere,  both  private 
and  public,  aiding  notably  in  the  development  of  the  New 
York  Botanical  Garden.  JMany  new  importations  from 
abroad  have  been  tested  here,  including  those  of  commercial 
as  well  as  artistic  value.  Of  these  might  be  mentioned  among 
many  others,  the  tung  oil,  lacquer,  pistachio  and  hardy  rul)her 
trees  of  China,  brought  from  the  Celestial  Kingdom  by  the 


68 


Biology  in  America 


indefatigable  and  hardy  explorer  of  the  Arboretum,  Mr.  E.  H. 
Wilson. 

Devoted  to  the  study  of  biology,  both  here  and  abroad,  are 
numerous  institutions  or  biological  stations,  which  have,  and 
are  exercising  a  wonderful  influence  upon  its  growth. 

An  exact  definition  of  a  biological  station  is  impossible. 
The  term  is  generally  referred  however  to  institutions,  apart 
from  college  laboratories,  dealing  usually  with  aquatic  biology 
and  often  operating  only  a  part  of  the  year,  but  such  a 
definition  is  by  no  means  exclusive. 


The  Main  Building  of  the  Marine  Biological  Laboratory  at  Woods 

Hole,  Mass. 

This  is  porliaps  the  leading  center  of  biology  in  America  and  one  of 
the  foremost  in  the  world.  There  gather  here  each  summer  many  of  the 
leading  biologists  from  all  parts  of  the  United  States;  and  in  it  have 
been  made  some  of  the  most  important  discoveries  in  biology. 

In  America  the  seed  from  which  biological  stations  have 
sprung  was  the  primitive  laboratory  of  Louis  Agassiz  at 
Penikese,  conducted  during  the  summer  of  1873 ;  where  in  an 
old  barn,  with  the  twittering  swallows  flying  in  and  out 
beneath  the  eaves,  and  from  whose  open  door  a  glimpse  of 
cloud-flecked  sky  and  foam-flecked  sea  could  be  seen  across 
the  heather,  this  great  student-teacher  gathered  a  little  band 
of  enthusiasts  to  catch  the  fire  of  his  imagination  and  carry 
it  throughout  the  land.    Anointed  with  the  spirit  of  the  master 


Biological  Institutions 


69 


this  little  group  of  apostles  went  forth  to  spread  his  teach- 
ings across  America,  and  a  Jordan  and  a  Brooks  have  passed 
the  torch  to  their  students,  and  they  in  turn  to  others  in  an 
ever  widening  circle  of  living  truth. 

The  laboratory  at  Penikese  was  abandoned  the  following 
year  owing  to  the  death  of  Agassiz,  but  a  worthy  successor 
was  soon  to  follow  in  the  Marine  Biological  Laboratory  at 
Woods  Hole,  which  was  founded  in  1888  by  Professor  Alpheus 
Hyatt  of  Boston,  and  a  group  of  naturalists  and  their  friends. 


Woods  Hoi^,  Mass. 
In  the  middle  background  is  the  ' '  Fish  Hawk, ' '  and  to  the  right  the 
buildings  of  the  U.  S.  Bureau  of  Fisheries.    In  the  foreground  is  the  sea 
bottom,  with  a  group  of  its  inhabitants. 

Courtesy  of  the  American  Museum  of  Natural  History. 

For  many  years  the  work  at  Woods  Hole  was,  and  to  a 
large  extent  still  is  conducted  in  flimsy  wooden  buildings,  of 
the  cheapest  sort  of  temporary  construction.  But  in  1914 
through  the  generosity  of  Chas.  R.  Crane,  the  patron  saint 
of  the  laboratory,  a  substantial  and  commodious  building  was 
erected,  which  is  well  furnished  with  modern  equipment  in 
biology. 

A  detailed  account  of  the  work  at  Woods  Hole  would 
require  several  volumes  in  itself,  and  is  out  of  the  question 
here,  but  its  principal  results  are  mentioned   elsewhere  in 


70 


Biology  in  America 


connection  with  the  general  account  of  biological  progress  in 
America.  Its  character  has  been  as  varied  as  that  of  the  men 
who  have  conducted  it,  a  list  of  whose  names  would  include 


Typical  Wharf  Pile  Community  of  the  New  England  Coast 

Submerged  timbers  form  the  home  of  a  wide  variety  of  sessile  animals 
including  sponges,  hydroids,  sea  anemones,  barnacles,  mussels  and  sea 
squirts.  The  immobility  of  the  anemones  and  hydroids,  and  their  deli- 
Rate  flower-like  habit,  led  the  great  Greek  naturalist,  Aristotle,  to  give 
the  name  of  zoophytes  (animal  plants)  to  these  and  similar  forms.  It 
was  such  surroundings  as  this  which  attracted  Agassiz  to  Penikese. 
Courtesy  of  the  American  Museum  of  Natural   History. 

the  leaders  of  American  biology  from  the  Atlantic  to  the 
Pacific  and  from  Canada  to  the  Gulf  of  Mexico. 

Woods  Hole  may  well  be  called  the  ' '  Naples  of  America, ' ' 
the  Mecca  to  which  in  ever  increasing  numbers  biologists 
make  pilgrimage  each  year.     Who  that  has  been  there  does 


Biological  Institutions  71 

not  carry  away  with  him  a  memory  and  an  inspiration?  A 
memory  of  the  "hole"  with  its  foaming  eddies,  of  the  "eel- 
pond"  with  its  landing  stage  and  launches,  and  the  "stone 
building"  where  the  genial  head  of  the  supply  department 
presides  over  an  incongruous  medley  of  flopping  dogfish,  five- 
rayed  starfish  and  bristling  sea  urchins,  which  the  "Caya- 
detta"  has  just  brought  in  from  the  fish  trap  in  Buzzard's 
Bay,  or  dredged  from  the  rocky  bottom  of  Vineyard  Sound. 
A.  memory  of  wind  swept  heath,  where  the  song  sparrow 
rears  it  brood,  of  gently  curving  beach,  white  shining  in  the 
summer's  sun;  of  rocky  headlands,  where  the  seaweeds  grow 
and  the  sea  anemone  clings  fast  to  its  home  uncovered  by  the 
falling  tide ;  of  the  lighthouse  on  the  point  and  the  buoy 
with  its  never  silent  bell ;  of  white  sails  upon  the  Sound,  and 
the  dim  shores  of  Martha's  Vinej^ard  fading  into  the  soft 
gray  blue  of  the  summer  haze  and  sky.  An  inspiration  of 
the  bigness  of  things,  of  all  there  is  to  do  and  the  joy  of  doing, 
of  knowledge  sought  for  the  sake  of  knowing,  a  touch  of  the 
fire  from  the  altar  of  Penikese,  lit  by  the  hand  of  Agassiz, 
the  master. 

Fast  following  the  pioneer  of  biological  stations  in 
America  came  a  number  of  lesser  stations,  at  first  along  the 
Atlantic  seaboard,  and  later  in  the  Mississippi  Valley,  on  the 
shores  of  the  Pacific,  and  in  the  Rocky  Mountains.  These, 
for  the  most  part,  have  been  merely  summer  schools  conducted 
in  conjunction  with  the  department  of  biology  in  some  college 
or  university.  In  some  however  notably  La  Jolla,  Calif., 
Havana,  111.,  and  Casco  Bay,  Me.,  the  emphasis  has  'been 
placed  upon  research,  and  much  original  work  of  great  value 
has  been  done.  The  first  of  these,  under  the  title  of  the 
Scripps  Institution  for  Biological  Research,  because  of  the 
generous  patronage  of  a  wealthy  La  Jolla  family,  is  an 
adjunct  of  the  Department  of  Zoology  of  the  University  of 
California.  In  the  earlier  years  of  its  existence  it  was,  so  to 
speak,  a  traveling  laboratory,  occupying  temporary  quarters 
at  various  points  on  the  California  Coast  and  finally  locating 
permanently  at  La  Jolla.  The  Scripps  Institution  is  one  of 
the  few  biological  stations  in  the  country  whose  physical 
equipment  is  adequate  to  the  work  it  tries  to  do.  The 
laboratory  building  is  simple,  almost  to  harshness  in  its 
architecture,  in  fitting  harmony  with  the  barren  landscape 
round  about ;  but  its  interior  appointments  and  equipment  are 
very  complete.  Its  principal  etforts  thus  far  have  been 
directed  to  the  study  of  the  smaller  marine  animals  or 
plankton  of  the  southern  California  Coast,  and  the  factors 
in  their  environment  which  determine  their  distribution,  but 
attention  has  also  been  turned  in  recent  years  to  certain  land 


72  Biology  in  America 

animals  (wood  mice  of  the  genus  Peromyscus)  and  the 
influence  of  climate  on  their  evolution.  The  Seripps  Institu- 
tion is  probably  unique  among  similar  institutions  in  America 
in  the  enlistment  of  both  private  and  public  agencies  in  its 
support.  Recently  the  legislature  of  California  has  con- 
tributed substantially  to  it  and  this  in  spite  of  the  fact  that 
its  work  is  avowedly  of  a  purely  scientific  character,  and  that 
no  attempt  has  been  made  to  arouse  interest  under  the 
specious  plea  of  some  practical  end  to  be  gained  at  some 
future  time. 

"Two  years  ago  when  the  first  allotment  was  made  by  the 
state  to  the  university  for  the  institution,  and  this  year  when 
an  increase  was  asked,  representatives  of  the  state  visited 
the  institution,  went  over  with  the  scientific  staff  and  business 
manager  in  considerable  particularity  the  work  being  prose- 
cuted, and  were  unequivocally  assured  that  the  problems 
under  investigation  are  all  first  and  foremost  scientific,  and 
that  only  some  of  them  might  be  expected  to  have  a  money 
value  to  the  state. 

"Great  emphasis  was,  however,  laid  by  the  men  of  the  insti- 
tution on  the  two  facts  that  all  increase  of  knowledge  of 
nature  is  capable  of  being  made  useful  to  the  people  of  the 
commonwealth  in  one  way  and  another,  either  for  their 
enlightenment  or  pleasure  or  material  gain ;  and  that  the 
institution  holds  itself  under  as  much  obligation  to  make  its 
discoveries  utilizable  in  some  form  as  it  does  to  prosecute  the 
investigations  themselves.  .  .  .  From  what  California  has 
done  toward  maintaining  the  Lick  Observatory  through  a 
considerable  term  of  years,  and  is  now  doing  for  the  Seripps 
Institution,  the  conclusion  seems  justified  that  the  state  is 
definitely  committed  to  the  principle  of  state  aid  to  scientific 
research,  even  though  such  research  has  no  direct  and  primary 
industrial  aims.  In  discussing  these  matters  with  officials,  I 
stoutly  contend  that  in  the  long  run  about  the  most  telling 
criterion  of  success  of  popular  government  will  be  the  extent 
to  which  it  contributes  to  the  highest  development,  spiritual 
and  physical,  of  the  naturally  best  endowed  persons  who  live 
under  and  who  participate  in  such  government.  The  facts 
and  reasonings  that  can  be  presented  in  support  of  this 
proposition,  particularly  those  touching  the  question  oi 
leadersliip  in  scientific  discovery,  seem  to  appeal  with  special 
force  to  men  grappling  earnestly  with  the  practical  problems 
of  government  for  a  modern  community. 

"Experience  strongly. inclines  me  to  the  view  that  the  seri- 
ous dereliction  of  our  national  and  several  state  governments 
in  the  support  of  scientific  investigation  is  chargeable  quite  as 


Biological  Institutions 


73 


much  to  scientific  men  themselves  as  to  government  officers 
and  the  people  at  large. ' '  * 

Surely  it  is  cause  for  congratulation  to  science  in  general, 
and  to  this  institution  and  its  director  in  particular,  when 
our  strictly  practical  legislators  can  be  made  to  see  the  value 
to  the  state  of  science  for  its  own  sake. 

In  addition  to  the  Scripps  Institution  several  other 
laboratories  have  been  privately  endowed  within  recent  years. 
Apart  from  the  Marine  Biological  Laboratory  at  Woods 
Hole,  which  is  of  much  longer  standing,  these  laboratories 


^Ml^l^^^l^^.. 

'----^ 

1 

i,..-, ,; — ,-,..  ,„ 

•     .rT%^ 

^^K^SS^^^B^K^^BBttBBB 

. 

• 

Buildings  of  the  Station  for  ExPERiiiENfAL  Evolution  of  the  Car- 
negie Institution  at  Cold  Spring  Harbor,  L.  I. 

Here  are  being  conducted  important  researches  into   the  laws  of  in- 
heritance in   plants  and   animals,   and   in   conjunction   with   this   station 
the  Eugenics  Record  Office  is  laying  the  foundation  for  an  intelligent 
treatment  of  marriages  and  the  breeding  of  a  better  human  race. 
After  Davenport.     Year  Book  of  the  Carnegie  Institution  for  19Vf. 


have  contributed  more  to  biology  than  all  other  biological 
stations  in  America  combined,  and  their  promise  for  the 
future  is  correspondingly  greater.  These  are  the  three 
biological  laboratories  of  the  Carnegie  Institution  and  its 
Department  of  Embryology,  and  the  Rockefeller  Institute 
for  Medical  Research.  It  is  true  that  the  latter  is  primarily 
a  medical  institution,  as  its  name  implies,  but  the  intimate 
association  of  medicine  with  biology,  and  the  fact  that  one  of 
its  departments  is  devoted  exclusively  to  biology,  entitles  it 
*Eitter  in  "Science/'  Vol.  XLII,  1915,  p.  245-246. 


74  Biology  in  America 

to  consideration  here.  The  Wistar  Institute  of  Anatomy  in 
Philadelphia,  and  the  Bussey  Institution  of  Harvard  Univer- 
sity should  also  be  included. 

Tlie  three  Carnegie  stations  are  known  respectively  as  the 
"Department  of  Experimental  Evolution"  at  Cold  Spring 
Harbor,  L.  I.,  the  "Department  of  Botanical  Research"  at 
Tucson,  Ariz.,  and  the  "Department  of  Marine  Biology"  on 
tlie  Dry  Tortngas  Keys  oft'  the  Florida  Coast.  These  were 
all  established  between  1903  and  1906,  shortly  after  the  found- 
ing of  the  Institution  by  Mr.  Carnegie.  The  first  of  these 
is,  as  its  name  implies,  devoted  to  a  study  of  evolution  and 
its  twin  sister,  or  better,  its  right  hand,  heredity.  As  early 
as  1617  Francis  Bacon  advocated  an  institution  for  studying 
evolution  experimentally,  but  not  until  the  early  years  of 
the  twentieth  century  was  his  suggestion  realized.  Its  major 
w^ork  has  been  the  study  of  inheritance  in  many  kinds  of 
animals  and  plants,  the  influence  of  external  factors,  such 
as  alcohol,  light,  etc.,  upon  the  structure  and  evolution  of 
animals,  the  influence  of  selection  in  evolution,  the  role  of  the 
chromosomes  in  inheritance,  and  the  underlying  factors  of 
sex. 

The  physical  equipment  of  an  institution  such  as  this 
emphasizes  the  specialization  of  biology  today,  and  its 
dependence  upon  other  sciences.  Apart  from  the  usual 
apparatus  of  the  biological  laboratory  and  the  extensive  pens 
and  stabling  required  for  housing  the  stock,  there  is  an 
artificial  cave  with  aquaria  for  studies  upon  cave  animals,  a 
well  equipped  chemical  laboratoiy,  and  constant  temperature 
rooms  arranged  in  pairs,  one  pair  for  dry  and  one  for  moist 
air,  so  that  experimental  animals  can  be  kept  in  warm  or  cold, 
dry  or  moist  chambers. 

The  site  of  the  station  and  the  adjoining  laboratory  of  the 
Brooklyn  Institute  of  Arts  and  Sciences  are  the  picturesque 
shores  of  Cold  Spring  Harbor,  a  long  narrow  inlet  from  Long 
Island  Sound.  On  the  opposite  shore  is  tiie  straggling  little 
village  of  the  same  name,  which  in  days  gone  by  was  one  of 
the  whaling  ports  of  Long  Island. 

Perhaps  the  most  important  outcome  of  the  station's  work 
has  been  the  Eugenics  Record  Office,  established  at  Cold 
Spring  Ifarl)or  in  1910,  through  the  generosity  of  Mrs.  E.  H. 
Harriman.  The  function  of  the  Ofifice  is  the  recording  of 
human  inheritance,  to  the  ultimate  end  of  gaining  greater 
knowledge  tliereof,  which  may  lead  to  its  improvement.^  It 
collects  recoi'ds  of  family  traits,  which  records  are  kept  in  a 
sextuple  card  index  of  persons,  traits  and  localities;  enabling 
an  investigator  to  readily  trace  a  given  trait  in  both  the 
families  and  the  localities  of  its  occurrence,  to  determine  the 


Biological  Institutions 


75 


families  and  traits  occurring  in  any  locality,  and  finally  to 
find  the  location  of  a  given  family  and  the  traits  peculiar  to 
it.  The  Office  has  extensive  collaboration  with  charitable  and 
penal  institutions  throughout  the  country,  by  means  of  which 
it  obtains  very  valuable  data  regarding  the  occurrence  and 
inheritance  of  many  defects  in  man,  both  mental  and  physi- 
cal ;  and  finally  it  conducts  a  training  school  for  workers  in 
human  inheritance,  with  a  view  to  preparing  them  for  service 
in  such  institutions. 

Baked    in    the    scorching   rays    of    the    Arizona    sun    lies 
Tumamoc  Hill,  the  Hill  of  the  Turtle  in  the  Navajo  tongue. 


Desert     Botanical  Laboratory 

The  deserts  of  Arizona  have  been  invaded  by  the  biologist,  offering 
as  they  do  a  specially  attractive  field  for  studies  of  the  influence  of 
environment  on  both  animals  and  plants.  At  this  station  of  the  Carnegie 
Institution  of  Washington  at  Tucson,  Arizona,  many  important  discov- 
eries have  been  made  as  to  how  plants  adapt  themselves  to  a  desert 
environment. 

Courtesy  0/  the  Bureau  of  Commerce  of  Tucson. 

On  its  slopes,  covered  with  the  rocky  debris  of  some  convul- 
sion of  the  earth  long  past,  grows  the  giant  cactus,  gaunt  and 
misshapen  by  day,  spectral  and  weird  by  night.  Its  summit 
overlooks  a  tumbled  junk  heap  of  hills  and  hollows  suggestive 
of  the  thought  that  the  Creator  became  hurried  at  the  last 
moment  and  did  not  have  time  to  put  the  finishing  touches 
on  the  wilderness.  At  its  foot  lies  the  Santa  Cruz  Valley 
with  the  city  of  Tucson,  and  across  the  valley,  sharply  out- 
lined against  the  deep  azure  of  the  desert  sky,  rise  the  bold 
commanding  shapes  of  the  Santa  Catalina  Mountains,  with 


7fi  Biology  in  America 

the  lure  of  the  forest  and  its  cold  fresh  streams  within  their 
depths. 

Ilerc  has  the  Desert  Lahoratory  of  the  Carnegie  Institution 
found  its  home  in  a  long,  low  stone  building  on  the  summit  of 
Tumamoc  Hill,  with  an  adjoining  greenhouse,  and  a  small 
photo-chemical  laboratory  nearl)y.  Tlic  efforts  of  the  Depart- 
ment have  been  devoted  to  a  study  of  deserf^  conditions  and 
their  effect  upon  the  plant  life  of  the  region.  In  conjunction 
with  a  small  branch  laboratory  at  Carmel,  near  Monterey, 
California,  extensive  studies  have  been  carried  on  upon  the 
influence  of  climate  on  the  form  of  plants.  Various  species 
of  plants  have  been  transplanted  from  their  cool,  moist  home 
in  the  Santa  Catalina  Mountains  to  the  experimental  gardens 
at  Tucson,  and  vice  versa,  and  interchanged  between  the 
Arizona  Desert  and  the  cool,  dani])  California  Coast  Avith 
consequent  marked  changes  in  their  form.  In  order  to  see 
how  "the  other  half"  of  the  plant  world  lives,  expeditions 
have  been  sent  to  the  Sahara  Desert,  and  the  tropical  forests 
of  Jamaica.  Studies  on  the  revegetation  of  the  Salton  Sea 
area  have  been  carried  on  for  several  years.  This  is  a  brackish 
water  lake  in  southern  California,  originally  over  400  square 
miles  in  extent,  which  was  formed  in  1905  by  the  overflow 
of  the  Colorado  River  through  an  irrigation  canal  leading  to 
the  Imperial  Valley.  In  the  arid  climate  of  southern  Cali- 
fornia this  lake  has  fallen  to  about  one-half  its  original  depth 
of  84  feet,  leaving  wide  stretches  of  lake  bottom  exposed, 
where  new  vegetation  may  arise.  From  such  studies  much 
can  be  learned  as  to  the  development  of  plant  life  in  our  arid 
southwest. 

At  one  time  Great  Salt  Lake  extended  over  a  much  wider 
area  than  now,  reaching  an  extent  of  nearly  20,000  square 
miles,  and  a  depth  of  1,000  feet,  as  can  be  determined  by  the 
old  shore  lines  on  the  mountain  slopes  in  northwestern  IJtah. 
To  this  greater  Great  Salt  Lake  the  name  of  Lake  Bonneville 
has  been  given,  from  the  doughty  captain,  whose  wanderings 
in  the  far  west  have  been  so  picturesquely  portrayed  by 
Irving  in  his  "Captain  Bonneville."  To  the  southwest  of 
Lake  Bonneville  stretched  the  wide  expanse  of  Lake  Lahontan, 
named  from  the  explorer  La  Hontan.  In  the  heyday  of  their 
existence,  following  the  retreat  of  the  ice  of  the  Glacial  period, 
these  lakes  received  a  copious  supply,  but  Nature  early  put 
into  effect  some  "bone  dry  laws"  in  this  region,  and  now  the 
site  of  Lake  Lahontan  is  an  arid  waste  clothed  in  sage  brush 
and  cactus  and  inhabited  by  the  coyote,  prairie  dog,  burrow- 
ing owl,  rattlesnake  and  horned  toad,  with  here  and  there  a 

'The  term  "desert"  as  applied  to  this  region  is  a  misnomer;  arid 
tableland  or  steppe  would  be  better. 


Biological  Institutions  77 

lonely,  but  optimistic  ranchman  and  a  few  salt  ponds,  rem- 
nants of  its  former  glory;  while  Great  Salt  Lake  is  but  a 
vestige  of  its  former  self. 

Today  one  may  find  in  Salton  Sea  a  repetition  of  the  story 
of  Lakes  Bonneville  and  Lahontan,  while  on  its  shores  Nature 
is  showing  us  how  she  clothes  the  desert. 

We  are  all  familiar  with  the  "oldest  inhabitant"  and  we 
enjoy  listening  to  him  as  he  smokes  his  pipe  and  conjures  up 
memories  of  the  past  through  the  curling  wreaths  of  blue 
smoke,  but  we  are  wont  to  be  a  bit  skeptical  when  he  tells 
us  of  the  ''old-fashioned  New  England  winter,"  when  fences 
presented  no  barriers  to  the  sleighs,  and  the  farmer  had  to 
tunnel  through  snow  in  the  morning  to  reach  the  barn,  and 
feed  his  cattle.  But  now  comes  the  scientist  to  the  aid  of 
the  "oldest  inhabitant"  and  tells  us  that  after  all  climates, 
like  peoples,  do  change,  and  that  the  pictures  of  the  "good 
old  days"  may  not  be  as  highly  colored  as  we  sometimes  fancy 
them  to  be.  To  gain  his  information  Professor  Ellsworth 
Huntington  of  Yale  has  quite  rightly  gone  to  the  "oldest 
inhabitants"  of  America,  dwellers  of  the  forest,  some  of  whom 
were  living  at  the  time  of  Moses,  and  were  creatures  of 
antiquity  in  the  days  of  Jesus  Christ.  To  most  of  us  indeed 
the  Sequoia,  or  California  "big  tree,"  is  a  veritable  Sphinx, 
a  creature  of  the  past  whom  we  revere  both  for  its  lordly 
mien  and  its  great  antiquity,  but  one  with  whom  we  cannot 
hold  converse.  But  Professor  Huntington  has  learned  to  read 
the  "riddles  of  the  Sphinx"  and  in  his  monogi'aph  on  the 
"Climatic  Factor"  he  has  told  us  its  story.  Each  year's 
growth  of  a  tree  leaves  its  mark  upon  its  stem  in  the  form  of 
a  ring  of  wood,  so  that,  not  only  does  the  stem  give  us  a 
record  of  the  age  of  the  tree,  but  also  of  the  amount  of  each 
year's  growth,  which  is  measured  by  the  thickness  of  the  ring. 
From  a  study  of  the  stumps  of  many  fallen  trees,  Professor 
Huntington  has  reached  conclusions  relative  to  the  "fat 
years,"  when  the  trees  made  a  good  growth,  and  the  "lean 
years"  of  the  past,  when  growth  was  slight.  But  the  amount 
of  growth  of  a  tree  depends  upon  the  amount  of  moisture 
which  it  receives,  and  thus  Professor  Huntington  has  deter- 
mined the  relative  amounts  of  annual  rainfall  for  several  thou- 
sand years  in  the  past. 

But  not  alone  in  the  trunks  of  the  big  trees  can  the  story 
of  the  past  be  read.  In  the  waters  and  the  old  shore  lines  of 
lakes  may  a  record  too  be  found.  The  water  of  every  river 
contains  a  certain  amount  of  dissolved  substances,  washed 
from  the  land  by  rain,  which  finds  its  way  as  "run-off"  into 
the  rivers.  Thus  through  countless  ages  has  the  ocean 
acquired  its  salt,  the  contribution  of  land  to  sea.    When  a  lake 


78 


Biology  in  America 


has  both  inlet  and  outlet,  its  water  is  being  continually 
changed,  and  consequently  it  contains  nearly  the  same  amount 
of  salt  from  year  to  year.  But  if  a  change  of  climate  occurs, 
sg  that  evaporation  exceeds  precipitation,  the  lake  begins  to 
shrink,  its  outlet  is  lost  and  the  salts  which  are  carried  into 
the  lake  by  its  tributary  rivers  accumulate,  and  a  little  inland 
sea  is  formed.  Thus  have  arisen  the  various  salt  lakes  and 
inland  seas  such  as  the  Caspian,  the  Dead  Sea  and  Great  Salt 
Lake.  If  now  we  measure  the  amount  of  w^ater  carried  by 
the  tributary  rivers  of  a  closed  lake,  and  determine  the  amount 
of  salts  cai'i-i(^d  by  them,  wo  cnii  estimate  the  number  of  j-ears 


Shore  op  Salton  Sea,  Showing  Old  Lake  Level  ix  Background 
The  character   of  the   beaches   of   extiuct   lakes   gives   a   ckie   to   the 
weather  of  the  past. 

After  MacDougal. 

required  for  the  lake  to  acquire  its  present  degree  of  saltiness 
since  the  time  when  it  had  an  outlet.  Such  measurements  are 
at  best  approximate,  due  largely  to  the  fact  that  when  rain- 
fall was  greater  the  rivers  carried  a  greater  amount  of  salt 
than  they  do  at  present,  but  Avhen  compared  with  the  testi- 
mony of  the  old  shore  lines,  they  furnish  a  means  for 
determining  probably  to  within  50  or  100  years  the  periods 
of  heavy  and  light  rainfall  in  the  past. 

These  ancient  lake  beaches  can  often  be  traced  for  miles 
with  the  greatest  ease.  When  a  lake  maintains  the  same  level 
for  a  number  of  years  it  leaves  an  unmistakable  record  "on 
the  sands"  or  gravels  ''of  time"  in  a  clear-cut  beach  or 
terrace,  where  the  waves  have  undermined  and  cut  away  the 


Biological  Institutions  79 

banks,  and  the  stronger  the  wave  action,  the  more  ch-arly 
marked  will  the  terrace  be.  AVhen,  on  the  other  hand,  llic 
lake  is  receding;,  the  terraces  will  be  wanting  or  ill-deliiicd, 
and  the  shores  gradually  sloping.  Thus  a  series  of  terraces, 
in  an  old  lake  basin,  with  intervening  slopes,  means  a  suc- 
cession of  alternating  wet  and  dry  periods  in  the  past,  during 
the  former  of  which  the  water  supply  was  sufficient  to  main- 
tain the  lake  at  a  constant  level,  while  during  the  latter  the 
level  was  steadily  falling.  Still  further  evidence  may  be 
obtained  from  submerged  forests.  The  bottom  of  Stump 
Lake,  N.  Dak.,  at  one  time  part  of  the  much  larger  glacial 
lake,  Minnewaukon,  was  years  ago  covered  by  a  forest,  as  is 
evidenced  by  the  stumps,  many  (f  which  are  still  lying 
on  the  old  lake  bottom,  now  being  exposed  by  the  progressive 
shrinkage  of  the  lake  from  excessive  evaporation.  This 
forest  contained  trees  probably  very  similar  to  those  at  present 
growing  about  the  lake  shore.  Thus,  within  comparatively 
recent  times,^  Stump  Lake  was  successively  part  of  a  con- 
siderable body  of  water,  then  dry  land  (at  least  in  part,  the 
extent  of  the  submerged  forest  not  being  known)  for  a  suffi- 
ciently long  period  to  allow  of  the  growth  of  forest  trees  of 
considerable  size;  again  it  became  a  lake  submerging  the 
forest  and  now  for  the  second  time  it  is  disappearing.  This 
evidence  is  borne  out  by  terraces  beneath  the  present  lake 
level  and  by  piles  of  boulders  in  the  lake  which  show  evidence 
of  the  work  of  ice  in  their  formation. 

And  so  Professor  Huntington  and  his  colleagues  have 
called  npon  Pyramid  and  Winnemucca  Lakes,  in  western 
Nevada,  remnants  of  the  old  glacial  Lake  Lahontan,  and 
Owens  and  Mono  Lakes  in  California  to  testify ;  and  their 
evidence  has  supported  that  of  the  "big  trees,"  and  the  words 
of  earth  and  tree  have  in  their  turn  been  verified  by  the  pages 
of  history.  According  to  the  evidence  it  is  about  2,000  years 
since  these  lakes  had  an  outlet,  so  that  during  the  Christian 
era  they  have  been  gradually  shrinking,  oscillating  up  and 
down  with  the  varying  rainfall  of  the  centuries. 

"The  lakes  do  more  than  indicate  a  change  of  climate 
within  two  or  three  thousand  years.  They  also  show  that  the 
change  has  been  highly  irregular.  This  is  proved  by  a  large 
number  of  strands  lying  below  the  level  of  the  outlets,  and 
by  the  way  in  which  these  vary  in  character  and  in  the  extent 
to  which  they  have  been  covered  by  fresh  detritus  washed 
down  from  the  mountains.  At  Owens  Lake  there  are  four 
series  of  strands.  These  apparently  correspond  to  the  four 
chief  periods  when  the  climate  has  grown  moist  as  shown  by 
the  growth  of  the  big  trees.  ,  .  .  Fortunately,  Owens  Lake 

*  Since  the  Glacial  Epoch. 


80  Biology  in  America 

lies  only  fii'ty  miles  east  of  the  region  where  the  trees  were 
measured.  The  general  climatic  fluctuations  of  both  districts 
are  the  same.  The  uppermost  strand,  the  huge  gravel  beach 
at  the  level  of  tlic  outlet,  must  date  from  about  the  time  of 
Christ,  for  both  the  chemical  evidence  and  the  trees  point  to 
this  conclusion.  A  series  of  similar,  but  much  smaller 
beaches  at  lower  levels  record  the  approach  of  a  dry  period 
during  which  the  lake  fell  to  a  low  level  whose  exact  position 
cannot  be  determined.  Judging  by  the  trees  this  must  have 
culminated  about  650  A.D.  During  this  period  gravels  were 
washed  in  by  mountain  streams  and  deposited  in  what  are 
known  as  fans,  or  low,  flattened  cones,  which  may  be  several 
miles  long.  These  covered  the  old  strands  in  many  places, 
and  extended  far  below  their  level  to  the  diminished  lake. 

"Next  the  waters  rose  again,  but  not  halfway  to  their 
former  level.  They  formed  two  small  strands,  2iot  gravelly 
like  their  predecessors,  but  faint  and  sandy  as  if  the  winds 
were  weak.  They  must  date  from  about- 1000  A.D.,  when  the 
trees  indicate  a  wet  period,  for  they  are  younger  than  the 
gravel  fans  of  the  preceding  dry  time.  The  next  phase  of 
the  lake  was  a  dry  period,  which  was  most  extreme  about 
1250  A.D.  More  gravels  were  then  deposited,  and  the  fact 
that  they  cover  the  preceding  strands  and  extend  to  a  much 
lower  level  shows  that  the  lake  then  stood  low,  as  would  be 
expected  from  the  trees. 

"The  next  high  period  of  the  lake,  about  1350  A.D.  accord- 
ing to  the  trees,  is  unusually  interesting.  The  water  did  not 
reach  so  high  a  level  as  formerly,  because  the  rainy  period 
was  short,  but  it  formed  a  large,  high  beach  of  gravel  quite 
different  from  the  preceding  beaches.  This  seems  to  indicate 
great  storminess,  a  condition  which  is  also  suggested  by  the 
fact  that  the  growth  of  the  trees  at  this  time  increased  more 
rapidly  than  at  any  other  period  for  nearly  3000  years.  In 
Europe  during  the  same  century,  unprecedented  storms 
caused  great  floods  in  France,  while  the  severity  of  the  waves 
was  so  intense  as  to  break  through  beaches  and  sand  dunes, 
and  convert  large  marshy  areas  into  portions  of  the  sea  along 
the  coasts  of  Holland  and  Lincolnshire.  During  the  winters 
the  rivers  froze  to  an  unheard-of  degree,  and  three  or  four 
times  men  and  animals  passed  from  Germany  to  Sweden  on 
the  solid  ice  of  the  Baltic  Sea,  an  occurrence  unknown  in  our 
day.  In  England  the  summers  were  so  rainy  that  the  average 
yield  of  grain  diminished  disastrously.  In  self-defense  many 
landowners  gave  up  gta in-raising,  and  turned  their  attention 
to  sheep  and  cattle.  Distress  and  discontent  were  the  inevit- 
able result  among  the  peasants.  Far  away  in  central  Asia 
the  Caspian  Sea  and  the  lake  of  Lop  Nor  both  rose  with  great 


Biological  histihitions  81 

rapidity  between  1300  and  1350  A.D.  Thus  from  California 
to  China  evidence  of  various  kinds  unites  to  indicate  that 
during  the  fourteenth  century  there  occurred  a  short  period 
of  unusual  stormiuess.  Such  conditions,  if  intensified  and 
prolonged,  would  probably  cause  the  accumulation  of  enor- 
mous glaciers. ' '  ^ 

Professor  Huntington's  studies  on  the  influence  of  climate 
upon  human  life  form  one  of  the  most  interesting  and  valuable 
contributions  to  history  of  recent  years.  He  has  shown  for 
example  that  the  wonderful  civilization  of  the  Mayas  in 
Guatemala  and  Yucatan,  in  a  region  where  today  death  stalks 
through  the  jungle  and  human  energy  is  at  its  lowest  ebb,  is 
explicable  on  the  hypothesis  of  a  different  climate  in  these 
regions  in  past  years,  an  hypothesis  supported  by  his  evidence 
obtained  from  lake  and  tree.  He  has  similarly  traced  the 
histoiy  of  man  in  Asia  and  Europe  and  likewise  discovered 
there  the  profound  influence  of  nature  upon  his  ways. 
These  climatic  changes  appear  to  be  in  some  way  determined 
by  solar  activity  as  evidenced  by  the  number  of  "sun  spots." 
But  these  most  interesting  hypotheses  would  lead  us  too  far 
aside  from  our  proper  path  were  we  to  pursue  them  further. 

Much  of  Professor  Huntington's  work  was  carried  on 
through  the  Department  of  Botanical  Research,  and  his 
results  are  among  the  most  interesting  and  valuable  of  its 
contributions  to  science. 

On  a  small  tract  of  land  in  the  Santa  Cruz  Valley  belonging 
to  the  Department  are  the  experimental  gardens,  where  for 
a  number  of  years  Professor  Tower  of  the  University  of  Chi- 
cago has  been  conducting  his  experiments  on  the  potato 
beetles,  reference  to  which  is  made  elsewhere.  In  the  physico- 
chemical  laboratory  extensive  investigations  are  in  progress 
on  the  physical  and  chemical  factors  involved  in  the  process 
of  photosynthesis ;  or  the  work  of  the  sun  through  the  chloro- 
phyl  of  the  green  plant  in  taking  the  raw  materials  of  earth 
and  air  and  Avater  and  constructing  from  them  the  starches 
and  the  sugars  which  the  plant  uses  as  its  food.  Many  other 
are  the  activities  of  the  Department  which  occupies  a  unique 
and  indispensable  place  in  American  research. 

Surrounded  by  the  blue  waters  of  the  tropical  sea, 
scorched  by  the  sun,  deluged  by  the  torrential  rains  and 
swept  by  the  cyclones  of  the  tropics  lie  a  string  of  little 
islands  off  the  southern  extremity  of  the  coast  known  as  the 
Florida  Keys.  On  one  of  the  gi-oups,  named  by  the  early 
Spaniards,  from  the  abundance  of  their  aboriginal  inhabitants, 
the  sea  turtles,  the  Dry  Tortugas,  is  located  the  Department 

^Huntington,  "Civilization  and  Climate,"  pp.  235-7.  By  permission 
of  the  Yale  University  Press. 


82 


Biology  in  America 


of  Marine  Biology  of  the  Carnegie  Institution.  Surrounded 
by  coral  reefs,  where  lurk  the  countless  denizens  of  the 
southern  seas,  in  a  healthful  environment,  and  with  the 
resources  of  the  Carnegie  Institution  behind  it,  the  Tortugas 
laboratory  has  enjoyed  a  situation  unique  in  the  histoiy  of 
biology.  How  well  it  has  profited  by  this  opportunity  e^an 
best  be  told  by  the  results  which  it  has  produced,  many  of 
which   are   referred   to    in    other   chapters   without    especial 


The  Garden  of  the  Tortugas  Laboratory 

Much  has  been  done  to  render  this  wind-swept  isle  a  spot  of  beauty. 
The  coral  reefs  surrounding  these  islands  abound  in  tropical  plants  and 
animals,  many  of  great  beauty  and  all  of  fascinating  interest. 
Courtesy  of  Dr.  A.  G.  Mayer,  Director  of  the  Latoratory. 


reference  to  the  source  whence  they  have  come.  It  would  be 
impossible  in  this  place  to  mention  these  results  in  detail,  or 
even  to  single  out  those  of  seemingly  most  importance.  No 
general  line  of  research  has  been  pursued,  the  only  limiting 
conditions  being  that  the  researches  should  be  devoted  to 
problems  of  tropical  life. 

In  addition  to  the  local  researches  of  the  laboratory,  visits 
have  been  made  in  its  staunch  little  ship,  the  "Anton  Dohrn," 
to  distant  regions,  through  the  Caribbean  Archipelago,  to 
Jamaica,  Porto  Rico,  and  even  to  the  Great  Barrier  Reef  of 


Biological  Institutions 


83 


Australia,  to  study  how  the  world  is  made,  at  least  that  part 
of  it  contributed  by  corals. 

While  our  knowledge  of  the  structure  of  the  human  body  is 
more  complete  than  that  of  any  other  animal,  our  information 
regarding-  the  beginnings  of  man  is  extremely  fragmentary. 
As  a  matter  of  fact  our  knowledge  of  man's  earliest  stages 
is  a  blank.  The  reasons  for  this  state  of  affairs  are  sufficiently 
evident.     For  many  years  anatomists  have  been  striving  to 


The  Yacht,  "Anton  Dohrn, "  of  the  Carnegie  Station  on  the  Tor- 

TUGAs  Islands 

Named    after   the    founder   and    life-long    head    of    the    world-famous 
station  at  Naples,  Italy. 

Courtesi/   of  Dr.  A.  O.   Mayer,  Director  of  the   Tortufjas  Station. 


supply  the  deficiencies  in  our  knowledge  by  collecting  human 
embryos  and  fetuses,  and  one  of  the  leaders  in  this  eifort  was 
the  late  Professor  ]\lall  of  Johns  Hopkins  University.  In  the 
course  of  many  years  Professor  Mall  brought  together  some 
2,000  embryos  and  fetuses,  and  his  studies  of  them  have 
thrown  light,  not  so  much  on  the  unknown  stages  of  human 
development,  as  upon  many  curious  malformations  in  man, 
which  are  apt  to  occur  in  the  material  which  the  anatomist 
secures,  and  knowledge  of  the  causes  of  which  are  of  the  high- 


84  Biology  in  America 

est  importance  in  our  efforts  toward  the  making  of  a  better 
human  race. 

In  1913  this  work  was  taken  over  by  the  Carnegie  Institu- 
tion and  organized  in  its  Department  of  Embryology,  which 
was  under  Professor  Mall's  direction  until  his  death  in  1917, 
and  since  then  has  been  conducted  by  his  successor,  Dr.  Geo.  L. 
Streeter.  The  work  of  the  department,  while  not  limited  to 
human  development,  has  that  as  its  focal  point. 

When  Dr.  Casper  Wistar  was  teaching  anatomy  at  the  Uni- 
versity of  Pennsylvania  in  the  early  part  of  the  last  century, 
and  discussing  with  President  Jefferson  the  bones  of  the  mas- 
todon which  the  latter  had  discovered  in  Shawangunk  County, 
N.  y.,  he  little  foresaw  the  institution  which  the  future 
was  to  raise  upon  the  foundation  he  was  laying.  The  col- 
lection of  anatomical  specimens  which  he  gathered  has  since 
grown  into  the  splendid  museum  of  the  Wistar  Institute  in 
Philadelphia,  founded  by  Dr.  Wistar 's  grand-nephew  in  1892. 
While  the  Institute  was  established  primarily  as  a  home  for 
the  W^istar  Museum,  its  usefulness  has  far  outgrown  the  func- 
tion of  mere  display.  In  research,  and  especially  as  a  center 
for  dissemination  of  its  results  through  scientific  journals,  it 
tills  a  place  unique  in  American  science. 

While  its  researches  have  been  largely  of  a  technical  char- 
acter, chiefly  upon  the  nervous  system,  they  form  the  basis 
for  future  investigations,  which  are  likely  to  prove  of  the 
highest  importance  to  man.  The  rat  has  been  used  as  the 
experimental  subject  for  these  researches.  For  this  purpose 
the  Institute  maintains  a  rat  colony  of  many  thousand 
individuals,  and  from  April,  1917,  to  April,  1919,  it  furnished 
thirty-five  thousand  rats  to  government  and  other  laboratories, 
or  one  rat  every  thirty-five  minutes  during  this  period.  A 
comparison  of  the  growth  of  the  body  as  a  whole,  of  the 
nervous  system  and  of  twenty  other  organs  in  rat  and  man, 
has  shown  a  general  similarity  in  both  animals,  if  comparison 
be  made  at  the  same  relative  stage  of  development  in  both. 
The  rat  grows  approximately  thirty  times  as  fast  as  man  and 
lives  approximately  one-thirtieth  as  long  a  life  (three  years). 
The  rat  is  weaned  at  twenty  days,  man  at  fifteen  months 
while  the  development  of  the  nervous  system  is  approximately 
the  same  at  this  age  (i.e.  when  weaned)  in  both  animals.  Simi- 
lar studies,  both  of  the  nervous  system  and  of  other  organs, 
have  given  similar  results.  The  rat  furthermore  is  almost  as 
omnivorous  as  man,  and  requires  much  the  same  food  con- 
stituents to  keep  him  healthy. 

If  then  the  growth  of  the  nervous  system  in  the  rat  can 
be  increased  for  example  by  exercise  or  retarded  by  poor 
food,  we  may  logically  expect  similar  results  in  man.     To 


Biological  Institutions  85 

solve  these  problems  the  Institute  is  beginning  a  series  of 
studies  upon  man  in  the  training  school  for  the  Feeble 
Minded  at  Vineland,  N.  J.,  where  records  are  being  made  of 
the  growth,  behavior,  and  clinical  history  of  some  four  hun- 
dred inmates.  In  conjunction  with  this  work  post-mortem 
examinations  will  help  to  explain  human  behavior  in  terms 
of  the  structure  of  human  tissues,  both  normal  and  diseased ; 
while  continued  studies  of  the  rat  will,  it  is  hoped,  throw 
further  light  upon  the  influence  of  an  animal's  surroundings 
on  its  structure  and  activities. 

The  effect  of  inbreeding  in  plants  and  animals  is  at  present 
but  little  understood.  The  general  belief  is  that  its  results 
are  highly  injurious  to  ths  offspring.  In  some  species  of 
plants  however  we  find  special  devices  of  nature  to  insure 
self-fertilization,  and  the  results  of  inbreeding  various  kinds 
of  domestic  animals  and  plants  are  by  no  means  uniform  in 
showing  its  harmful  character.  It  has  been  stated  that  among 
the  Ptolemies  and  the  Incas  marriage  of  brother  and  sister 
frequently  occurred,  while  in  ancient  Persia  the  marriage  of 
parent  and  child  was  permitted. 

Hence  the  studies  which  Dr.  King  has  been  carrying  on  at 
the  Institute  for  several  years  upon  the  effect  of  continued 
inbreeding  on  the  growth,  health,  fertility  and  sex  ratio  of 
animals,  are  of  peculiar  interest.  As  a  result  of  these  studies, 
which  are  the  most  extensive  hitherto  made,  Dr.  King  finds 
that  mating  of  brother  and  sister  rats  for  thirty  generations 
produces  no  ill  effect  upon  fertility  and  general  health  of  the 
offspring,  provided  the  best  animals  are  selected  for  breeding. 

One  of  the  most  important  and  interesting  researches  of  the 
Institute  has  been  its  studies  on  the  refractive  index  of  the 
blood  serum,  which  has  been  shown  to  differ,  not  only  at 
different  ages,  but  also  under  differing  conditions  of  health 
and  disease.  Thus  blood  from  persons  afflicted  with  syphilis, 
tuberculosis,  cancer  or  Bright 's  disease,  has  each  its  own 
characteristic  index;  and  the  method,  which  is  very  simple, 
gives  promise  of  being  a  very  valuable  aid  in  the  diagnosis 
of  disease. 

In  the  publication  of  journals  the  Institute  performs  one 
of  its  greatest  services  to  biology.  The  publication  of  such 
journals,  with  their  limited  circulation,  is  always  difficult 
financially;  but  by  systematizing  and  standardizing  its 
methods  for  several  of  them  the  Institute  has  been  able  to 
reduce  the  expense  of  publication  to  a  minimum,  while  at  the 
same  time  increasing  their  circulation  and  widening  their 
influence  throughout  the  world.  In  1919  nearly  five  thousand 
copies  of  five  journals  were  distributed  to  libraries  and  in- 
dividuals in  virtually  every  country  in  the  world,  at  a  net 


86  Biology  in  America 

expense  of  only  about  $6,000  annually.  In  addition  to  this  it 
publishes  a  card  index  with  a  brief  abstract  of  every  article 
published  in  its  journals  as  well  as  in  several  published  else- 
wliere. 

In  190]  there  was  established  in  New  York  City  an  institu- 
tion unique  in  character  and  destined  to  do  more  in  alleviating 
human  suffering  than  any  other  institution  in  America.  While 
the  Rockefeller  Institute  was  founded  primarily  for  medical 
research,  its  department  of  experimental  biolog:y  under  the 
direction  of  Jacques  Loeb  is  devoted  to  the  study  of  biology 
pure  and  simple,  and  is  furnishing  biologists  with  an  ample 
supply  of  food  for  thought  as  well  as  controversy.  Its  de- 
partments of  physiology,  bacteriology  and  protozoology  have 
also  made  invaluable  contributions  to  biological  science.  In 
the  field  of  medicine  proper  the  unique  feature  of  the  institu- 
tion is  a  splendid  hospital,  in  charge  of  a  staff  of  highly 
trained  experts,  the  majority  of  whom  are  devoting  their 
entire  time  to  this  work,  concentrating  their  efforts  at  any 
given  time  on  special  diseases  and  with  the  resources  of  the 
experimental  laboratory  at  their  command. 

Thus  far  the  diseases  selected  have  been  of  common 
occurrence,  including  some  of  the  worst  scourges  of  man,  such 
as  infantile  paralysis,  syphilis,  pneumonia  and  spinal  menin- 
gitis. Bulletins  are  issued  at  intervals  by  the  director  of  the 
hospital  informing  physicians  of  the  diseases  selected  for 
study  at  any  given  time. 

Patients  are  admitted  to  the  hospital  from  all  classes  of 
people,  rich  and  poor  alike,  without  charge.  In  some  cases 
however  wealthy  patients  have  been  permitted  to  donate 
money  to  the  hospital  in  recognition  of  their  indebtedness  for 
its  services.  But  although  the  services  of  the  institution  are 
freely  given,  and  while  its  primary  function  is  the  study  of 
disease,  the  right  of  the  patient  to  receive  the  best  possible 
treatment  is  fully  recognized,  and  no  one  on  entering  the 
Institute  surrenders  in  any  way  his  right  to  such  treatment. 

An  important  feature  of  the  Institute's  work  is  the  publi- 
cation of  the  "Journal  of  Experimental  Medicine,"  which  is 
one  of  the  leading  medical  journals  in  this  country,  and  in- 
cludes in  its  pages  much  material  of  primarily  biological  in- 
terest as  well. 

In  addition  to  its  studies  upon  human  diseases  the  Institute 
maintains  a  department  of  animal  pathology  at  Princeton, 
N.  J.,  where  animal  diseases  are  being  investigated. 

There  are  many  other  institutions  in  America  devoted  to 
the  study  of  special  diseases,  such  as  the  Henry  Phipps  Insti- 
tute of  Philadelphia  for  the  study  of  tuberculosis  and  the 
Barnard  Free  Skin  and  Cancer  Hospital  of  St.  Louis.    Their 


Biological  Institutions  87 

work  however  is  primarily  medical  in  character,  and  limits 
of  space  prohibit  further  mention  of  it  here. 

On  a  fine  old  estate  in  Forrest  Hills,  a  suburb  of  Boston,  at 
one  time  the  residence  of  the  late  Benjamin  Bussey,  is  the. 
Bussey  Institution,  an  adjunct  of  the  department  of  botany 
and  zoology  in  Harvard  University,  where  much  of  the  pioneer 
work  in  genetics  in  America  has  been  done.  Forest  conserva- 
tion and  increase,  and  insect  control  also  form  part  of  its 
program.  The  purpose  of  Mr.  Bussey,  the  founder  of  the 
institute,  was  to  support  the  teaching  of  agriculture  at 
Harvard.  His  funds  are  now  being  devoted  almost  wholly 
to  research  in  subjects  fundamental  thereto,  reference  to 
some  of  which  is  made  in  other  chapters. 

A  fourth  class  of  institutions  which  have  contributed  in  no 
small  measure  to  the  great  structure  of  American  biology, 
are  the  biological  bureaus  of  the  U.  S.  Government — 
the  Bureau  of  Fisheries,  of  Animal  and  Plant  Industry,  of 
the  Biological  Survey  and  of  Entomology;  but  inasmuch  as 
their  work  has  been  mainly  along  economic  lines,  it  may  be.st 
be  discussed  in  another  chapter. 

In  these  few  pages  have  been  briefly  sketched  the  history 
and  scope  of  American  biological  institutions.  Much  has  of 
necessity  been  omitted,  but  it  may  be  that  enough  has  been 
given  to  outline  the  extent  to  which  wealth  and  human  effort 
have  been  expended  in  this  broad  and  fertile  field. 


CHAPTER  III 

Descriptive  hiologij.  Development  of  plmits  and  animals;  of 
sex,  and  sexual  reproduction,  and  alternation  of  genera- 
tions.    The  path  of  vertebrate  evolution. 

Science  as  we  have  seen  is  cosmopolitan  and  impossible 
of  limitation  by  geographic  lines.  Especially  is  this  true  of 
descriptive  biology.  With  the  increasing  specialization  of 
modern  science  it  is  to  a  certain  extent  possible  for  one  man 
or  a  group  of  men  to  work  out  more  or  less  independently 
some  particular  problems  or  group  of  problems  of  far-reach- 
ing interest  and  importance.  Thus  our  knowledge  of  animal 
reactions  we  owe  largely  to  Jennings,  Rhumbler,  Mast  and 
Loeb;  the  physiology  of  digestion  immediately  calls  to  mind 
the  epochal  work  of  Pavlov,  while  Chittenden's  researches 
have  made  scientific  nutrition  matter  of  household  knowledge. 
The  new  science  of  genetics  we  owe  largely  to  the  work  of 
Bateson,  Punnett,  Cuenot,  Castle,  Davenport  and  Morgan, 
while  the  structure  and  function  of  the  cell,  have  been  in  great 
part  unraveled  by  the  skillful  touch  of  Wilson  and  Boveri. 
To  a  certain  extent  this  is  likewise  true  of  purely  descriptive 
biology.  Amphioxus  and  the  name  of  Willey  are  indissolubly 
linked  together  in  our  minds ;  the  oyster  has  been  exhaustively 
studied  by  Brooks,  the  alligator  by  Reese,  the  Ascidians  by 
Ritter  and  the  crayfish  by  Andrews.  We  have  the  splendid 
researches  of  Allen,  Merriam  and  Stone  on  the  classification, 
distribution  and  habits  of  birds  and  mammals;  those  of  Jor- 
dan, Dean  and  Eigenmann  on  fishes,  of  Mayer  on  Medusae  and 
of  hosts  of  other  specialists  on  various  groups  of  animals  and 
plants;  while  the  names  of  Osborn,  Cope  and  Scott  will  ever 
be  associated  with  the  extinct  life  of  ages  long  gone  by. 
Many  of  these  studies  however  are  of  but  small  value  in 
themselves.  Information  as  to  the  structure,  classification  and 
distribution  of  a  given  organism  or  group  of  organisms,  gives 
us  comparatively  little  information  as  to  the  great  laws  of  life, 
except  in  so  far  as  these  facts  are  correlated  with  similar  facts 
relative  to  other  groups  of  organisms,  whereas  the  research 
in  physiology  (using  this  term  in  its  broadest  sense)  of  a  single 
man,  may  lead  to  discoveries  of  profound  and  far-reaehing 

88 


Descriptive  Biology  89 

significance.  And  thus  it  comes  to  be  that  the  whole  fabric 
of  morphology,  or  the  science  of  form,  is  a  mosaic  of  individual 
bits  of  knowledge,  some  greater,  some  less,  but  none  of  great 
importance  except  when  considered  in  relation  to  all  the 
others.  Of  what  particular  interest  for  example  is  the  dis- 
covery of  a  connecting  ligament  between  the  arteries  which 
supply  the  lungs  and  those  which  supply  the  trunk  in  higher 
vertebrates,  apart  from  the  existence  of  a  functional  blood 
vessel  representing  this  ligament  in  some  of  their  more  lowly 
aquatic  cousins  (the  lungfishes  and  Amphibia)  ?  Or  how 
can  the  parts  of  a  flower  be  understood  without  a  knowledge 
of  the  process  of  reproduction  in  the  ferns  and  mosses  ? 

To  follow  adequately  the  course  of  descriptive  biology  in 
America  would  carry  us  too  far  afield,  and  into  paths  wherein 
many  of  us  perchance  would  not  care  to  wander.  "We  may 
however  trace  in  a  few  words  some  of  the  main  lines  of 
morphological  research,  noting  the  discoveries  to  which  they 
have  led  and  the  problems  which  still  confront  us. 

Since  Darwin's  epoch-making  work,  the  golden  thread  of 
evolution  has  linked  together  the  labors  of  morphologist  and 
physiologist  alike,  and  the  efforts  of  the  former  have  centered 
around  the  genealogies  of  living  things.  What  have  been  the 
lines  of  ascent  from  the  one-celled  animals  and  plants  to  those 
of  many  cells?  Are  animals  and  plants  of  common  ancestry 
or  do  they  belong  to  two  distinct  groups  of  living  things,  each 
with  its  own  origin?  What  has  been  the  origin  of  the  germ 
layers  and  the  ccelome  in  animals,  and  how  have  those  of  many 
segments  become  modified  to  those  of  few?  How  can  sexual 
be  related  to  non-sexual  forms,  and  hermaphroditic  to  those 
of  separate  sex  ?  AVhat  is  the  origin  of  alternation  of  genera- 
tions, and  how  has  the  non-sexual  gained  so  great  an  ascend- 
ency over  the  sexual  form  in  higher  plants  ?  These  are  a  few 
of  the  great  questions  which  the  morphologist  has  to  answer. 
In  this  solution  however  he  must  call  to  his  aid  the  experi- 
menter, for  after  all  observation  and  experiment  are  but  two 
phases  of  the  same  science,  working  together  toward  a  common 
end. 

All  living  things  may  be  divided  into  the  two  great  groups 
of  the  one,  and  the  many-celled,  the  Protozoa  and  Protophyta 
on  the  one  hand,  and  the  Metazoa  and  Metaphyta  on  the 
other.  Each  many-celled  animal  or  plant  begins  its  career 
as  a  single  cell,  containing  within  itself  all  the  possibilities 
of  the  adult  plant  or  animal.  So  too  does  the  one-celled 
organism  contain  the  possibility  of  evolution  into  a  new 
creation  of  beings  yet  unknown.  Most  of  these  lowly  creatures 
to  be  sure  have  deviated  from  the  straight  and  narrow  path 


90 


Biology  in  America 


whicli  leads  to  high  estate,  and  have  wandered  off  into  byways 
of  specialization,  some  of  which  may  perchance  cause  their 
undoing  and  lead  to  their  extinction. 

If  one  go  to  any  wayside  pool  or  pond,  gather  a  handful  of 
weeds  and  allow  them  to  stand  in  a  laboratory  jar  for  a  few 
days^  he  will  soon  have  a  new  creation  at  his  hand,  a  little 
world  of  swarming  life,  tense  with  the  keen  struggle  for 
existence.  Here  he  will  find  dwarfs  and  giants,  the  tiny 
"monad"  and  the  sac-like  Bursaria  which  reaches  the  rela- 


Protozoan  Types 
1,  Dileptus;  2,  Traehelophyllum ;  3,  Bursaria.     After  Conn, 


tively  enormous  size  of  one-twelfth  of  an  inch;  and  all  the 
bizarrerie  of  evolution  running  riot.  One  sliaped  like  a  rib- 
bon, yet  others  like  cornucopias  or  bells,  and  still  others  with 
long,  extensile  necks,  veritable  giraffes  of  the  microscopic 
world.  One  great  group  of  Protozoa,  the  eiliates,  derives  its 
name  from  the  delicate  rapidly  beating  processes  or  cilia  which 
cover  the  animals,  and  by  means  of  which  they  move  so 
rapidly  through  the  water  as  to  drive  many  an  amateur 
microscopist  to  drink,  in  desire  at  least,  if  not  in  practise. 
In  many  of  these  the  cilia,  instead  of  being  uniformly  dis- 
tributed over  the  body,  are  limited  to  definite  areas.     Occa- 


'^m/':< 


Protozoan  Types 

1,  Paramcecium;  2,  Coleps;  3,  Didinium  feeding  on  ParanKTN'ium; 
4,  Clathrulina;  5,  a  monad;  6,  Volvox;  7,  Stentor;  S,  Htylonichia; 
9,  Peridinium;  10,  Ceratium. 

Figs.  2  and  8  after  Conn;  4  after  Leidy;  5  and  7  after  Edmondson; 
9  modified  from  Schilling  after  Huitfeld-Kaas;  and  10  after  Laukcster; 
the  rest  original;  3  from  a  j)reparation  by  Powers. 


91 


92  Biology  in  America 

sionally  thoy  form  one  or  more  rings  about  the  body,  wbile 
again  they  are  condensed  into  several  long  flexible  processes 
by  means  of  which  the  animal  crawls  abont  over  the  weeds 
or  bottom.  Still  others  possess  long  slender  spines,  which  may 
either  have  no  apparent  use,  or  may  serve  as  springing  organs, 
the  animal  lying  still  for  a  time  and  then  suddenly  starting 
to  roll  and  tniiilile  abont  as  though  possessed  of  a  veiy  devil 
of  unrest. 

Yet  another  great  group  of  Protozoa,  the  flagellates,  derive 
their  name  from  the  flagella  or  whip-like  processes  by  means 
of  which  they  swim.  Most  Protozoa  are  actively  motile,  but 
some  are  attached  by  stalks,  either  singly  or  in  branching 
groups.  These  are  sometimes  fixed,  and  sometimes  furnished 
with  delicate  muscle  fibrils,  which  contract  suddenly  when  the 
animals  are  disturbed. 

Usually  naked,  some  Protozoa  are  enclosed  in  cases  or  shells. 
One  lives  in  a  tube,  with  a  lid  Avhich  -closes  as  the  animal 
retracts,  and  opens  as  it  expands.  Many  of  these  shells  are 
of  great  beauty  and  complexity.  The  infusorian  Coleps  bears 
a  shell  comprised  of  numerous  plates  arranged  in  circles 
around  the  body,  the  flagellate  Peridinium  has  a  delicately 
sculptured  shell  of  twenty-one  plates  and  Ceratium  is  en- 
closed in  a  shell  bearing  long,  horn-like  processes.  But  the 
most  remarkable  development  of  shells  is  found  in  the 
Foraminifera  and  Radiolaria,  whose  remains  form  so  large 
a  part  of  the  ooze  covering  the  bottom  of  the  sea,  and  which 
have  produced  valuable  deposits  of  building  stone  and  chalk 
in  the  past. 

Many  Protozoa  have  developed  primitive  organs  of  diges- 
tion, excretion  and  respiration,  while  some  have  contractile 
fibrils  in  the  outer  layer  of  the  body,  which  serve  as  primitive 
muscles.  Yet  others  have  the  suggestion  of  eyes  in  the  form 
of  pigment  spots,  which  doubtless  are  responsive  to  light. 

In  these  early  differentiations  of  structure  we  have  forecast 
for  us  the  conditions  in  the  Metazoa  or  many-celled  animals 
with  their  special  organs  and  corresponding  "division  of 
labor"  or  work  which  these  organs  have  to  do. 

Not  alone  in  structure  are  many  Protozoa  highly  specialized. 
In  manner  of  life  they  vary  widely.  Many  of  them  are 
exclusively  marine,  others  inhabit  only  fresh  waters,  while 
still  others  may  be  found  in  fresh  and  brackish  water  alike. 
Mostly  free  living,  a  few  have  developed  the  habit  of  com- 
mensalism,  or  close  association  with  some  other  organism. 
The  ciliates,  Triehodina  and  Kerona,  are  usually  found  gliding 
over  the  surface  of  the  fresh  water  polyp  Hydra.  The  Radio- 
laria harbor  symbiotic  algffi,  by  means  of  which  the  synthesis 
or  construction  of  carbohydrates  is  possible,  after  the  manner 


Descriptive  Biology 


93 


of  tlip  green  plant.  Yet  others  contain  within  tliemselves  the 
magic  chlorophyl,  whose  beautiful  green  delights  our  eyes  in 
the  early  verdure  of  the  spring,  and  by  whose  means  Nature 
performs  her  wonderful  chemistry,  converting  carbon  dioxide 
and  water  into  sugar,  which  plants  and  animals  alike  may 
use  as  food.  Many,  notably  the  Sporozoa  and  some  flagel- 
lates, are  parasitic,  and  in  some  cases  are  the  cause  of  plagues 
of  man  and  beast. 

In  the  world  of  the  little  as  well  as  in  that  of  the  great, 


Lower  Plant  Life 

1,  Spirogyra;  2,  desmids;  3,  a  diatom. 

1  and  3  original,  3  from  a  preparation  by  Elmore,  2  from  Needham  & 
Lloyd's  "Life  of  Inland  Waters,"  Comstock  Publishing  Company. 

we  find  the  role  of  the  hunter  and  the  hunted.  Usually  it  is 
the  smaller  fry  which  are  the  victims,  but  sometimes  it  is  they 
which  take  the  hunter's  part,  attacking  and  destroying  animals 
much  larger  than  themselves.  Chief  among  these  is  Didin- 
ium,  a  little  creature  about  1/150  inch  in  length  with  a  bor- 
ing proboscis  by  means  of  which  it  attacks  and  engulfs  other 
Protozoa  from  three  to  six  times  as  large  as  itself.  The  cus- 
tomary daily  ration  of  this  little  gourmand  is  one  or  two 
Paramoecia,  but  when  especially  hungry  it  may  consume  as 
many  as  four  or  five  of  these  animals. 

As  protection  against  their  insatiable  foes  many  Protozoa 


94 


Biology  in  America 


have  developed  structures  known  as  trielieysts.  or  secretions 
contained  in  the  surface  protopUisra,  wliieh  when  ejected  form 
a  mass  of  tangled  threads  and  serve  as  an  abattis  to  repel  the 
attacker. 

Among  the  unicellular  plants  also  high  degrees  of  special- 
ization occur,  which  are  represented  mainly  by  variations  in 
general  body  form,  by  development  of  shells,  filaments  and 
spines,  and  by  changes  in  chromatophores  and  nuclei.     Typ- 


Amceba  Pkoteus,  One  of  the  Most  Primitive  Types  of  Life 

Photograph  of  a  model  in  the  American  Museum  of  Natural  History 
in  New  York. 

Courtesy   0/  the   Museum. 

ically  spherical  or  ovate  in  form  the  algae  may  become  linear, 
club-shaped,  discoid,  spiral  or  crescentic,  while  the  shell  mark- 
ings of  desmids  and  diatoms  are  among  the  most  delicate  and 
beautiful  objects  of  microscopical  study. 

The  chromatophores  or  chlorophyl  carriers  of  the  algffi  are 
one  of  their  most  specialized  features.  In  its  simplest  form 
the  chromatophore  is  disk-  or  plate-like,  but  it  varies  from  the 
more  generalized  form  to  the  specialized  star-shaped,  spiral 
or  netted  ones.     Typically  possessing  but  a  single  nucleus, 


Descriptive  Biology  95 

the  algas  may  have  many  or  none.  In  the  latter  condition, 
shown  by  the  bacteria  and  blue-green  algaB  the  nucleus  prob- 
ably consists  of  numerous  granules  scattered  throughout  the 
cell. 

While  the  majority  of  unicellular  organisms  show  a  more 
or  less  high  degree  of  specialization,  there  are  a  few  which 
still  remain  more  nearly  in  what  was  undoubtedly  the  primi- 
tive condition  and  which  may  therefore  be  regarded  as  pos- 
sessing greater  possibilities  of  advance  to  higher  types.  Such 
among  animals  is  the  Amoeba,  while  among  plants  the  most 
primitive  are  the  Protococcacea'.  The  minute  flagellate  forms 
known  by  the  non-committal  term  of  "monads"  are  undoubt- 
edly however  very  close  to  the  bottom  of  the  ladder  of  life, 
and  it  is  quite  possible  that  they  represent  the  starting  point 
for  both  animals  and  plants.  Whether  these  primitive  forms 
are  very  ancient,  representing  the  direct  descendants  of  the 
original  progenitors  of  living  things,  or  whether  they  are 
recent,  and  represent  one  of  many  evolutions  of  living  from 
lifeless  matter  is  an  interesting  problem  for  speculation,  but 
one  offering  small  possibilities  of  solution  with  our  present 
knowledge.  In  view  of  the  great  variability  of  most  forms 
of  life  the  likelihood  of  any  group  of  organisms  persisting  with 
but  little  change  throughout  biologic  time  seems  most  improb- 
able. But  on  the  other  hand  we  have  no  evidence  of  the 
origin  of  living  from  lifeless  matter  at  the  present  time,  and 
we  know  further  that  some  forms  of  the  present  day  (i.  e. 
Spirifer,  one  of  the  Brachiopoda)  are  indistinguishable  save 
in  minor  characters  from  their  representatives  of  the  Cam- 
brian period,  which  may  have  lived  some  four  hundred  mil- 
lions of  years  ago. 

Among  both  the  Protozoa  and  Protophyta  are  many  species, 
in  which  the  cells  instead  of  remaining  distinct  are  grouped 
in  colonies.  In  many  of  these  the  association  is  loose  and 
indefinite,  the  group  increasing  in  size  for  an  indefinite  time 
and  finally  breaking  up  to  form  other  groups.  This  is  espe- 
cially true  of  the  numerous  filamentous  algae,  but  is  also  true 
of  other  algae  and  Protozoa.  In  some  however  notably  in  the 
Volvocaceae  the  size  and  the  number  of  cells  comprised  in  the 
colony  is  more  or  less  definite,  foreshadowing  the  conditions 
in  the  many-celled  animals  and  plants. 

Among  both  unicellular  plants  and  animals  reproduction 
occurs  typically  by  simple  cell  division.  At  the  time  of  divi- 
sion the  parent  cell  loses  its  identity  but  does  not  die,  con- 
tinuing to  live  in  its  two  descendants.  The  theoretical 
possibilities  of  increase  of  these  microscopic  forms  are  beyond 
our  powers  of  imagination.  According  to  Professor  Morgan, 
a  protozoan  Stylonichia  "produced  in  6Y2  days  a  mass  of 


9G  Biology  in  America 

protoplasm  wcigliingr  one  kilogram.  At  the  end  of  30  days, 
at  the  same  rate,  the  number  of  kilo<j;rams  would  be  1  fol- 
lowed by  44  zeros,  or  a  mass  of  protoplasm  a  million  times 
larger  than  the  volume  of  the  sun."  ^ 

But  in  many  of  these  forms  another  process  of  reproduction 
has  developed,  wherein  two  cells,  or  in  any  event  two  luielei 
play  a  part,  a  process  known  as  conjugation  or  fertilization. 
A  simple  example  will  illustrate  this.  If  a  single  individual 
of  the  ciliate  Paramo^cium  be  placed  in  a  suitable  culture  fluid 
it  will  divide  rapidly,  forming  in  a  few  days  a  countless 
progeny.  After  a  time  if  one  examine  a  drop  of  the  culture 
he  will  likely  find  some  of  the  individuals  united  in  pairs. 
They  remain  thus  united  for  possibly  24  hours,  after  which 
they  separate  and  each  resumes  its  rapid  multiplication. 
Briefly  told,  what  happens  during  their  union  is  as  follows : 
Paramecium  contains  two  nuclei,  a  larger,  or  macronucleus 
and  a  smaller,  or  micronucleus."  The  latter  divides  three 
times  and  several  of  the  parts  thus  formed  disappear,  but 
two  remaining.  Of  these  one,  the  larger,  remains  quiescent, 
while  the  other  migrates  across  the  protoplasmic  bridge  unit- 
ing the  two  animals  and  fuses  with  the  quiescent  nucleus  in 
the  other  cell.  This  fusion  nucleus  then  divides  several  times, 
some  of  the  daughter  nuclei  enlarging  to  form  new  macro- 
nuclei  which  are  distributed  to  the  daughter  cells,  the  old 
macronucleus  having  disappeared  in  the  meantime.  Some 
of  the  daughter  nuclei  degenerate,  w^hile  one  remains  to  form 
a  new  micronucleus.  We  have  here  probably  the  beginnings 
of  sex  as  indicated  in  the  difference  of  size  and  activity  of 
the  two  micronuclei,  which  fuse  with  each  other  during  the 
cell  union.  Externally  however  sexual  difference  between 
the  cells  is  not  evident. 

The  meaning  of  this  process  is  not  clear.  It  has  been  sup- 
posed to  have  a  rejuvenating  influence  upon  the  cells  taking 
part  in  it,  but  this  interpretation  is  i-endered  doubtful  by 
recent  experiments  of  Professor  Jennings  at  Johns  Hopkins, 
who  suggests  that  it  is  rather  a  means  of  producing  variation 
and  thus  leading  to  evolution. 

The  union  of  similar  gametes  or  reproductive  cells  is  com- 
mon among  the  alga>.  Frecpiently  these  cells  bear  cilia  and 
are  motile,  while  the  ordinary  form  is  non-motile.  In  some 
cases  a  slight  difference  in  size  between  the  conjugating 
gametes  is  suggestive  of  the  differentiation  between  egg  and 
sperm  cell  of  higher  forms. 

*  These  figures  are  given  by  Morgan  in  "Heredity  and  Sex."  He 
disclaims  responsibility  however  for  tho  mathematical  computation  in- 
volved. 

'  There  may  be  one  or  two  of  these  latter. 


Descriptive  Biology 


97 


A  still  further  stage  in  sex  development  is  shown  by  a 
distinct  difference  in  size  and  activity  of  the  copulating  cells. 
The  malaria  organism  multiplies  asexually  in  the  blood  cells 
of  its  host.  After  a  time,  under  conditions  not  well  under- 
stood, some  of  the  malarial  cells  enlarge.  If  now  the  patient 
is  bitten  by  one  of  the  Anopheles  mosquitoes,  which  transmit 
the  disease,  some  of  these  enlarged  cells  remain  quiescent, 
forming  the  female  cells  in  the  mosquito's  stomach,  while 
others  cast  off  a  number  of  small  active  filaments  or  male 
cells.     These  latter  then  unite  with  or  fertilize  the  former, 


;©  «5' ©I 


Life  Cycle  of  the  Malarial  Organism 

a,  parasite  in  red  blood  corpuscle;  b  and  c,  spore  formation;  d,  female, 
and  e,  male  cells,  which  are  uniting  at  f ;  g,  sporozoites  in  cyst;  h,  sporo- 
zoite  free;  i,  ameboid  parasite  developed  from  h,  prepared  to  enter  red 
blood  corpuscle,  j.     Original. 

and  from  their  union  a  large  number  of  minute  motile  cells 
or  "sporozoites"  are  formed,  by  which  the  asexual  cycle  is 
repeated  when  the  infected  mosquito  bites  a  new  victim. 

Yet  a  further  and  final  step  in  sex  differentiation  among 
the  unicellular  forms  is  found  in  Volvox,  an  organism  which 
is  on  the  fence,  so  to  speak,  between  Protozoa  and  Protophyta ; 
and  which  forms  a  bone  of  contention  between  the  botanists 
and  zoologists,  each  claiming  ownership  to  it.  Volvox  is  a 
hollow  spherical  group  of  cells,  numbering  in  some  cases  over 
20,000,  and  reaching  a  diameter  of  1/25  of  an  inch.  The  cells 
carry  a  pair  of  cilia  each,  by  means  of  which  the  organism  is 


98  Biology  in  America 

au  active  swimmer.  Tliey  also  contain  elilorophyl,  enabling 
it  to  manufacture  its  own  food,  so  that  physiologically  it  is 
a  plant,  but  in  respect  to  the  possession  of  cilia,  and  a  red  eye 
spot  which  is  sensitive  to  light,  it  resembles  more  nearly  an 
animal.  Its  reproduction  is  partly  asexual  and  partly  sexual. 
In  the  former  method,  some  cells  multiply  to  form  sec- 
ondary colonies,  which  lie  in  the  cavity  of  the  mother  colony 
and  tinally  break  tlirough  its  wall  to  form  new  colonies.  In 
the  latter,  certain  large  cells  lacking  cilia  are  ditferentiated 
as  eggs,  while  other  cells  divide  to  form  a  varying  number 
of  motile  sperms.  Fertilization  results  in  the  formation  of 
a  resting  cell  or  "zygote,"  which  after  a  period  of  inactivity 
develops  into  a  new  colony. 

In  definiteness  of  form,  close  association  of  cells  and  espe- 
cially in  the  differentiation  of  sexual  cells,  Volvox  stands  as 
a  stepping  stone  between  the  unicellular  types  with  their 
typically  asexual  reproduction  and  the  many-celled  forms 
which  typically  reproduce  by  fertilization.  In  yet  another 
respect  does  Volvox  approach  the  higher  types.  Some  species 
are  hermaphroditic,  producing  both  eggs  and  sperms  in  the 
same  colony,  while  in  others  the  two  sexes  are  lodged  in 
separate  individuals.  There  are  many  other  forms,  both 
single-celled  and  colonial,  which  resemble  animals  in  having 
flagella  and  eye-spots,  and  plants  in  possessing  chlorophyl. 
Sometimes  it  is  only  the  reproductive  cells  which  have  all 
of  these  features,  the  ordinary  cells  being  typical  alga^  with 
chlorophyl  but  neither  flagella  nor  eye-spots.  It  is  passible 
that  the  "monads,"  to  which  reference  has  already  been  made, 
have  developed  chlorophyl,  giving  rise  to  the  plant  kingdom, 
on  the  one  hand ;  and  have  assumed  an  ameboid  form,  pro- 
ducing the  animal  kingdom  on  the  other.  This  is  suggested 
by  the  occasional  occurrence  of  flagellates  which  are  either 
ameboid  at  all  times,  or  may  assume  an  ameboid  form  at 
certain  times  in  their  life  cycle. 

Through  the  entire  series  of  plants  from  the  lowest  to  the 
highest  runs  a  curious  phenomenon  known  as  alternation  of 
generations,  or  the  alternate  succession  of  sexual  and  asexual 
methods  of  reproduction.  How  many  of  us  stop  to  think 
when  we  pluck  a  violet  or  smell  a  rose  that  the  flower  was 
not  made  to  delight  our  eye  or  nose,  but  has  developed  as  a 
means  for  the  perpetuation  and  increase  of  its  kind?  And 
how  does  the  flower  perform  its  function?  Hidden  away  at 
its  center,  where  but  few  of  us  ever  see  them,  are  the  female 
organs  or  ovaries,  bearing  at  their  summits  little  processes 
known  as  styles,  which  end  in  small  expansions,  the  stigmas. 
Surrounding  the  ovaries  are  a  ring  of  delicate  filaments,  the 
stamens,  each  bearing  at  its  tip  a  sack,  the  anther.     In  the 


Descriptive  Biology 


99 


anther  the  pollen  grains  are  formed,  and  these  when  ripe 
are  scattered  by  the  wind  or  carried  by  insects  to  another 
flower,  where,  lighting  upon  its  stigmas,  they  germinate  and 
send  fine  tubes  down  through  the  styles  to  reach  the  ovaries 
at  their  base.  Through  these  tubes  pass  the  male  nuclei 
formed  within  the  pollen  grain,  which  unite  with  the  female 
nuclei  within  the  ovaries,  the  pollen  tube  representing  the 
last  remnant  of  the  body  of  the  sexual  plant  in  lower  forms. 
Similarly  there  are  contained  within  the  ovary,  beside  the 


r 


Eeproduction  of  Plants 

Left:  A  phlox  blossom  showing  flower  parts.  Ca,  calyx;  eo,  corolla; 
sta,  stamens;    sti,  stigma;    sty,  style.     Original. 

Right:  Alternation  of  generations  in  1,  fern,  showing  the  sexual  form 
or  prothallus  bearing  the  asexual  fern,  fe;  and  2,  moss,  showing  the 
spore  capsule,  c. 

female  nucleus,  several  nuclei,  which  represent  the  body  of 
the  female  sexual  plant  in  mosses  or  in  ferns. 

The  moss  plant  is  the  sexual  form,  which  bears  the  egg  and 
sperm  producing  organs.  From  the  egg,  after  fertilization 
in  the  ovary  springs  a  slender  stalk  bearing  a  capsule  at  its 
summit.  When  this  is  ripe  it  bursts,  casting  forth  the  tiny 
spores,  which  generating  give  rise  in  turn  to  the  sexual  moss 
plant.  Similar  conditions  obtain  in  the  liverworts.  In 
these  forms  therefore  the  gametjophyte  or  sexual  plant  is 
the  chief  generation,  the  sporophyte  or  asexual  form  the 
smaller,  secondary  one. 

In  ferns  the  reverse  is  the  ease.     If  one  examine  the  under- 


100  Biology  in  America 

side  of  an  ordinary  fern  leaf  he  will  find  its  edges?  pimpled 
with  rows  of  little  brown  capsules  somewhat  smaller  than  a 
pin  head,  which  on  bursting  scatter  to  the  wind  a  fine  brown 
dust.  This  consists  of  the  spores,  which  after  germination 
produce  a  leaf-like  body,  the  prothalhis,  about  a  quarter  of 
an  inch  in  diameter.  This  is  the  gametophyte,  which  bears 
the  sexual  organs.  It  grows  only  in  moist  places,  moisture 
being  necessary  for  the  transfer  of  the  sperm  to  the  (^^^. 
From  the  fertilized  egg  develops  the  sporophyte  or  ordinary 
fern  plant,  tlius  completing  the  cycle  in  the  life  of  the  fern. 

Alternation  of  generations  also  occurs  in  some  algffi.  Here 
it  is  the  gametophyte  which  is  the  conspicuous  plant,  the 
sporophyte  being  usually  a  smaller  structure. 

Passing  upward  from  the  lower  to  the  higher  plants  we 
see  then  the  sporophyte  progressively  increasing  and  the 
gametophyte  decreasing  in  importance. 

While  alternation  of  generations  is  characteristic  of  plants 
it  occure  occasionally  among  the  many-celled,  as  well  as  in 
unicellular  animals.  Many  of  the  delicate  and  beautiful  jelly- 
fish, with  which  any  observant  visitor  to  the  seashore  is 
familiar,  are  the  sexual  phase  of  the  life  cycle  of  an  animal 
whose  asexual  form  consists  of  an  attached  series  of  disks, 
which  in  the  course  of  development  separate  from  one  another 
to  form  the  sexual  form  or  medusa.  In  certain  marine  worms 
(Polycha^ta)  also  alternation  of  generations  occurs.  The 
anterior  part  of  the  body  does  not  develop  sex  organs,  while 
posteriorly  the  worm  divides  into  several  part ;,  whi.-h  becom- 
ing sexually  mature  separate  from  the  parent  stock  to  form 
the  sexual  generation.  In  some  of  the  curious  "sea  squirts" 
or  tunicates  also  this  process  is  found. 

The  tunicates  derive  their  name  from  the  mantle  or  tunic 
surrounding  the  body.  Some  are  fixed,  and  others  free  swim- 
ming as  adults;  while  in  the  former  the  animal  is  frequently 
free-swimming  as  a  larva.  The  name  of  "sea  squirt"  is 
derived  from  the  habit  of  the  fixed  forms  of  squirting  out  a 
stream  of  sea  water  when  touched. 

The  larva  of  the  fixed  forms  is  totally  different  from  the 
adult  and  the  true  relationships  of  the  latter  could  not  be 
understood  were  it  not  for  the  existence  of  the  former.  This 
is  a  tadpole-like  animal  with  a  long  tail  through  which  runs 
a  supporting  rod,  the  notochord.  At  the  anterior  end  of  the 
animal  is  an  adhesive  disk  by  means  of  which  it  attaches 
itself  at  the  time  of  metamorphosis.  The  wall  of  the  pharynx 
is  perforated  by  a  number  of  openings  or  gill  slits  which  lead 
into  a  waste  chamber  or  atrium  opening  to  the  exterior  by 
a  pore.  Dorsal  to  the  pharynx  is  a  nervous  mass  or  primitive 
brain,  and  between  the  two  a  small  duct  opening  into  the 


Descriptive  Biology  101 

former  which  is  known  as  the  ''sub-neural  gland,"  and  has 
been  compared  to  the  vertebrate  hypophysis,  which  is  part 
of  the  pituitary  body  or  gland  attached  to  the  base  of  the 
brain,  one  of  those  problematic  organs  of  "internal  secretion" 
which  is  playing  so  large  a  i^art  in  medicine  today.  The 
larva  swims  actively  by  means  of  its  long  tail,  but  at  metamor- 
phosis the  latter  is  lost  together  M'ith  its  supporting  rod  or 
notoehord,  and  the  animal  abandons  the  wandering  ways  of 
youth  and  settles  down  to  its  future  monotonous  existence. 

In  those  tunicates  in  which  an  alternation  of  generations 
occurs,  the  asexual  form  gives  rise  by  budding  to  a  colony 
of  "zooids"  which  more  or  less  directly  produce  the  sexual 
animals. 

The  meaning  of  this  strange  and  interesting  life  history 
remains  for  the  future  to  disclose.  Until  we  understand  the 
underlying  significance  of  sex,  it  is  hopeless  to  attempt  to 
solve  the  ri<ldle  of  alternation  of  generations.  In  our  attempt 
to  find  an  answer  to  both  of  these  two  great  questions  of 
biology,  the  experimental,  rather  than  the  purely  morpho- 
logical method  gives  the  greater  promise  of  success.  There 
is  already  at  hand  evidence  to  show  that  the  appearance  of 
sexual  reproduction  can  be  to  a  certain  extent  at  least  con- 
trolled by  experiment.  Details  regarding  such  experiments 
may  be  postponed  however  to  a  later  chapter. 

The  most  likely  interpretation  of  alternation  of  genera- 
tions however  is  that  it  is  a  "device"  of  Nature  to  increase 
the  spread  of  the  species  and  thus  enhance  its  chances  of 
survival.  It  occurs  typically  in  attached  forms  such  as  most 
plants,  and  the  hydroids,  Polyzoa  and  some  tunicates  among 
animals,  while  in  those  marine  worms  in  which  it  occurs  the 
asexual  generation  often  lives  a  retired  and  inactive  life  in 
the  recesses  of  some  rocky  shelter,  only  the  sexual  generation 
swimming  freely  at  the  surface  of  the  sea.  It  obviously 
increases  the  chances  of  distribution  of  a  fixed  form  to  have 
a  sexual  free-swimming  form  which  may  carry  the  repro- 
ductive cells  and  scatter  them  far  and  wide.  A  difficulty  in 
such  an  interpretation  however  is  that  in  some  of  these  forms 
the  sexual  generation  is  not  free-swimming  but  attached  to 
the  asexual  one.  This  may  of  course  be  a  degenerate  con- 
dition. 

In  the  case  of  the  plants  on  the  other  hand,  it  is  the  asexual 
form  with  its  numerous  spores,  which  is  most  important  in 
the  distribution  of  the  species,  these  spores  being  readily 
carried  by  the  wind  and  thus  better  suited  to  spreading  a 
land  form,  than  the  flagella-])eariiig  sperms,  which  recpiire 
water  for  their  distribution. 

Among  the  Protozoa  alternation  of  generations  frequently 


Invertebrate  Types 

1,  Hydra;  2,  earthworm;  3,  a  troehopliore  larva;  4,  a  rotifer;  5,  Ba- 
lanoglossus;  6,  Trochosphara;  7,  Aiiipliioxus;  8,  a  tunicate;  9,  Bonellia; 
10,  a  fresh  water  annelid  reproducing  by  fission.  Fig.  3,  from  Korsehelt 
and  Heider  after  Hatsehek;  4,  from  K.  &  H.  after  A.  Agassiz ;  6,  from 
K.  &  H.  after  .Semper;  9,  from  Doncaster;  the  others  are  original,  9 
from  a  preparation  by  Powers.  Fig.  1,  i,  intestine ;  m,  mouth ;  t,  ten- 
tacles. Fig.  2,  c,  crop;  ce,  coelome;  g,  gizzard;  i,  intestine;  m,  mouth; 
n,  nerve  cord;  np,  nephridium  (kidney)  ;  sv,  seminal  vesicles;  sr,  seminal 
receptacles;  ph,  pharynx.  Figs.  3  &  4,  a,  anus;  ev,  contractile  vesicle  or 
bladder;  e,  excretory  duct;  i,  intestine;  m,  mouth;  mx,  niastax  (grind- 
ing pharynx)  ;  pr,  pre-oral,  and  po,  post-oral  ciliated  rings;  pg,  pharyn- 
geal glands;  s,  stomach;  o,  ovary.  Fig.  6,  c,  cloaca;  e,  excretory  duct; 
m,  mouth;  mu,  muscle;  pr,  pre-oral,  and  po,  post-oral  ciliated  rings; 
o,  ovary;   pg,  pharyngeal  gland. 

102 


Descriptive  Biology  103 

occurs,  especially  in  the  parasitic  forms.  Here  the  production 
of  numerous  spores  undoubtedly  increases  the  distribution  of 
the  organism,  but  the  meaning  of  the  sexual  phase  in  the  life 
cycle  is  as  obscure  as  is  that  of  sexual  reproduction  among 
living  things  in  general.  The  whole  problem  of  reproduction, 
in  all  its  manifold  phases  is  one  of  the  most  perplexing  which 
biology  has  to  solve. 

In  the  majority  of  animals  the  sexes  are  distinct,  but  in 
some,  notably  flat  worms,  annelids,  some  molluscs,  etc.,  they 
are  found  in  the  same  individual,  which  is  then  known  as  an 
hermaphrodite  from  Hermaphroditus,  the  Son  of  Hermes  and 
Aphrodite,  who  became  joined  in  one  body  with  the  nymph 
Salmacis.  How  comes  it  that  in  some  animals  we  find  distinct 
sexes,  while  in  others,  not  distantly  related  to  them,  they  are 
united  ?  Here  again  we  are  face  to  face  with  one  of  Nature 's 
inscrutable  mysteries.  A  possible  clue  is  found  however  in 
the  fact  that  in  animals  of  separate  sex,  the  early  stages  of 
the  sex  organs  may  be  apparently  "indifferent,"  that  is, 
neither  male  nor  female,  becoming  differentiated  into  either 
sex  as  development  proceeds.  Even  though  sex  may  be,  as 
we  shall  see  later,  predetermined  in  the  fertilized  egg,  never- 
theless all  the  essential  parts  of  both  male  and  female  may 
develop  in  the  embryo.  Furthermore,  there  are  many  in- 
stances, some  of  which  will  be  mentioned  in  another  chapter, 
of  so-called  "sex  intergrades"  where  the  animal  or  plant  may 
be  predominantly  of  one  sex  and  yet  show  some  of  the 
characteristics  of  the  opposite  sex ;  and  further,  when  the  sex 
glands  cease  to  function,  either  from  disease,  removal  or  old 
age,  certain  characters  of  the  opposite  sex  may  appear,  as 
noted  in  a  later  chapter. 

Apparently  then  the  hermaphroditic  condition  is  primitive 
and  the  bisexual  one  derived,  through  suppression,  but  not 
loss  in  either  sex  of  the  characters  peculiar  to  the  opposite  sex. 

But  why  this  differentiation  has  occurred  and  the  advantage 
thereof  we  do  not  know. 

Passing  from  the  unicellular  to  the  multicellular  animals 
or  Metazoa  we  find  one  of  the  simplest  of  the  latter  in  a 
little  creature  which  strangely  enough  beai*s  the  name  of  the 
many-headed  monster,  Hydra.  Its  body  consists  of  two  layers 
of  cells  and  contains  a  primitive  digestive  cavity  with  a 
mouth,  which  is  surrounded  by  several  tentacles,  giving  the 
animal  its  fanciful  resemblance  to  the  horrid  monster  of 
fabled  story.  The  space  between  the  layers  contains  an  almost 
negligible  jelly  and  the  muscle  processes  of  cells  lying  in  the 
two  layers. 

From  Hydra  the  next  step  in  advance  is  very  uncertain. 
The  reader  may  best  be  spared  the  mental  contortions  neces- 


104 


Biology  in  America 


sary  to  follow  the  feats  of  the  imagination  performed  by  the 
morphologists  in  leaping  the  gap  between  Hydra  and  higher 
animals.  Suffice  it  to  say  that  an  imaginary  ancestor  has 
been  created  to  serve  as  the  starting  point  of  the  latter,  from 
which  these  have  diverged,  each  upon  its  several  way.- 


A  Series  of  Vertebrate  Embryos 

I,  II,  III,  1st,  2n(l,  aiul  Hid  stage.  From  Eomanes  "Darwin  and 
After  Darwin." 

By   permission    of    tlit:   Open    Court   PuMisliin§    Company 

If  one  compare  a  series  of  the  early  stages  of  animals,  which 
in  the  adult  form  are  widely  different  from  one  another,  he 
may  find  it  difficult  or  impossible  to  tell  them  apart.  The 
embryos  of  fish,  frog,  bird  and  mammal  are  almost  identical 
with  one  another  at  a  certain  stage  of  development. 

■  The  above  statement  must  not  be  interpreted  as  an  oversight  of 
the  higher  coelenterates  and  the  ctenophores.  But  even  taking  a 
ctenophore  as  a  "jumping  off  point"  there  is  still  a  wide  and  as 
yet    unfathomed    abyss    to    cross. 


Descriptive  Biology  105 

Man  begins  his  life  as  a  single  cell,  corresponding  to  the 
protozoan  stage  of  evolution.  Later  lie  consists  of  two  layers 
of  cells,  corresponding  to  a  greatly  moditied  Hydra.  Then 
he  possesses  three  "germ  layers"  and  numerous  segments  like 
a  worm,  from  which  stage  he  passes  to  that  in  which  he  has 
gills  like  a  fish,  and  later  on  a  tail  and  coat  of  hair  like  a 
monkey.^  These  and  many  other  facts  of  like  nature  have 
led  to  the  law  that  the  development  of  the  individual  is  a 
replica  in  miniature  of  the  development  of  the  race,  a  law 
which  has  been  much  abused  by  its  friends  no  less  than  by 
its  enemies.  While  this  principle  is  unquestionably  sound  it 
must  not  be  pushed  too  far.  In  its  main  features  the  develop- 
ment of  the  individnal  does  reproduce  that  of  the  race,  but 
in  all  its  details  certainly  not.  At  no  time  in  his  development 
does  man  ever  resemble  an  adult  fish,  but  there  are  certain 
stages  in  development  which  are  common  to  both ;  man  in  his 
earliest  stages  having  certain  fish-like  features. 

To  follow  the  trail  of  animal  evolution  through  the  develop- 
ment of  the  individual  calls  for  all  the  cunning  of  a  biological 
Sherlock  Holmes.  Nature  has,  as  it  were,  cleverly  concealed 
her  footsteps,  and  made  many  a  false  move  to  throw  the 
pursuer  off  the  track.  But  her  trail,  is  there  and  can  be 
followed  if  we  have  the  necessary  acumen  and  patience. 

In  the  development  of  many  worms,  molluscs,  echinoderms, 
tunicates  and  other  invertebrates  there  occur  certain  larval 
forms  known  as  trochophores.  All  trochophore  larv^  are  by 
no  means  alike,  but  all  have  the  same  general  plan  of  struc- 
ture, and  the  presence  of  these  larva;  in  the  development  of 
so  many  different  groups  of  invertebrates  has  led  to  a  belief 
in  an  ancestral  "trochophore"  from  which  these  groups  have 
radiated,  like  the  spokes  about  the  hub  of  a  wheel. 

Very  closel.y  resembling  in  many  respects  the  trochophore 
larva  is  the  group  of  rotifers  or  "wheel  animalcules"  so  called 
because  of  the  circles  of  rapidly  beating  cilia  leading  to 
the  mouth,  which  in  their  activity  resemble  the  motion  of 
a  wheel,  and  by  means  of  which  the  rotifer  obtains  its  food 
and  swims  through  the  water.  One  of  these,  Trochospha^ra, 
resembles  the  trochophore  larva  in  its  general  form  so  closely, 
as  to  have  misled  some  biologists  into  the  belief  that  this  was 
an  ancestral  type,  and  that  the  rotifers  were  the  hub  of  the 
animal  universe.  But  the  absence  of  a  body  cavity  renders 
such  an  interpretation  more  than  doubtful,  the  rotifers  hav- 
ing more  likely  been  shoved  off  onto  a  side  track  from  the 
main  branches  of  evolution,  where  they  stand,  nearly  related 

*  This  does  not  mean  of  course  fully  developed  gills,  tail  and  hair, 
but  their  beginnings  may  be  seen.  If  the  development  of  a  lish 
or  a  mammal  were  arrested  at  a  certain  stage  these  organs  would 
not  be  better  developed  in  them  than  in  man. 


106  Biology  in  America 

to  the  ancestral  form,  but  not  in  tlie  direct  line  of  evolution 
of  any  of  tlie  liiglu'r  tyi)es  of  animals. 

J*rogres.sijif^  upward  from  our  ancesti'al  tioehophore,  we 
come  to  forms  whose  geiu'ral  ])hin  of  structure  is  that  of  a 
double  cylinder,  somewhat  fiattened  along  one  axis,  with  two 
sides  alike  giving  it  bilateral  symmetry,  and  the  upper  or 
dorsal  differentiated  from  the  lower  or  ventral  surface.  The 
anteri'or  end  of  this  cylinder  is  dift'erentiated  as  a  head,  with 
mouth,  sense  organs  and  primitive  brain,  while  the  posterior 
end  lacks  sense  oi-gans  and  contains  an  anus.  The  outer  wall 
of  this  double  cylinder  is  made  up  of  "skin"  and  muscles, 
the  inner  is  the  wall  of  the  digestive  tract,  with  a  body 
cavity  or  ca4ome  between.  The  cylinder  is  further  divided 
into  rings  or  segments,  each  of  which  bears  one  or  more  pairs 
of  appendages  for  locomotion. 

Of  such  a  form  the  annelid  worm,  of  which  the  common 
angle  worm  is  an  example,  is  typical,  and  from  here  onward 
in  our  progress  to  the  vertebrates  and  man  we  are  on  surer, 
though  still  insecure  footing.  The  annelid  or  annulate  is  as 
its  name  indicates  a  series  of  joints  or  rings,  all  more  or 
less  alike,  wdiich  are  very  numerous  in  the  typical  form,  but 
in  the  more  specialized  groups  are  greatly  reduced.  In  fact, 
evolution  from  the  annelid  upward  consists  very  largely  in 
the  concentration  and  specialization  of  these  segments.  While 
the  annelids  are  probably  not  to  be  regarded  as  the  direct 
ancestors  of  the  vertebrates,  their  general  plan  of  structure, 
with  a  cfplome  and  a  segmented  body,  is  fundamental  to  that 
of  all  higher  types,  even  though  it  may  be  greatly  modified 
in  some. 

The  origin  of  the  vertebrates  is  still  shrouded  in  the  mist 
of  hypothesis  and  dispute,  and  indeed  may  ever  remain  so, 
since  their  invertebrate  ancestors  probably  no  longer  exist. 
Nevertheless  a  clue  to  their  origin  .  may  be  found  in  the 
tunicates  described  above  and  in  a  little  animal  with  a  big 
name,  Balanoglossus,  or  the  acorn-tongue.  This  is  a  worm- 
like creature  living  in  bui-rows  in  the  mud  or  sand  of  the  sea 
bottom  near  low  tide  level,  and  in  its  development  passing 
through  a  trochophore  stage.  The  anterior  end  is  marked  by 
a  contractile  and  very  sensitive  proboscis,  from  the  shape  of 
which  the  animal  dei'ives  its  name,  behind  which  is  a  collar 
region,  which  in  turn  is  followed  by  the  trunk.  Between  the 
proboscis  and  collar  opens  the  ventral  mouth  which  leads  into 
the  pharynx,  which  is  perforated  by  a  large  number  of  paired 
openings  to  the  exterior,  the  gill  slits.  Uorsal  to  the  mouth 
is  a  diverticulum  of  the  pharynx  which  projects  into  the  pro- 
boscis, and  which  Bateson  has  identified  as  the  notochord. 
The  nervous  system  presents  features  of  peculiar  interest. 


Descriptive  Biology  107 

Its  primitive  character  is  evidenced  by  the  superficial  net 
work  of  nerve  fibres  extending  all  over  the  body,  and  resem- 
bling- in  these  respects  the  nervous  system  of  a  sea  anemone. 
Along  the  mid-dorsal  and  mid-ventral  lines  this  network  is 
thickened  to  form  definite  nerve  cords,  thus  relating  the 
animal  to  the  invertebrates  with  their  ventral  nerve  cord  on 
the  one  hand  and  on  the  other  to  the  vertebrates,  whose 
central  nervous  system  is  dorsal.  This  latter  resemblance  is 
still  further  enhanced  by  the  hollow  character  of  the  dorsal 
cord  in  the  collar  region  (at  least  in  young  animals)  and  its 
separation  from  the  surface  and  deeper  situation  in  the  body 
in  this  region.  The  dorsal  and  ventral  cords  are  joined  by 
a  ring  surrounding  the  pharynx  at  the  base  of  the  collar 
similar  to  that  of  an  annelid. 

There  are  then  certain  points -of  fundamental  importance 
which  are  common  both  to  the  tunicate  and  Balanoglossus, 
and  to  the  vertebrates.  These  are  the  notochord,  the  gill  slits 
and  the  dorsal  nerve  cord.  The  opposite  position  of  the 
mouth  in  the  two  former  (dorsal  in  the  tunicate  and  ventral 
in  Balanoglossus)  introduces  an  element  of  uncertainty,  and 
indeed  the  origin  of  the  vertebrate  mouth  is  a  question  of 
great  difificulty.  It  is  improbable  that  vertebrates  can  claim 
either  the  tunicate  or  Balanoglossus  as  a  direct  ancestor.  In 
fact  "direct  ancestors"  in  the  animal  world  are  at  a  premium. 
In  the  very  nature  of  the  case,  if  living  things  are  labile  and 
not  stabile,  this  must  be  so.  Otherwise  all  organisms  would 
become  "stand  patters"  and  evolutionary  progress  cease. 
But,  regardless  of  direct  ancestry,  both  of  the  organisms  dis- 
cussed show  distinct  vertebrate  affinities  and  indicate  the  way 
which  the  latter  have  gone  in  their  advance. 

Further  on  the  path  of  vertebrate  development  stands  yet 
another  sign  post  to  mark  the  way.  Burrowing  in  the  sand 
of  shallow  seas  throughout  temperate  and  tropical  regions 
is  a  little  fish-like  animal  about  two  inches  in  length,  which 
on  account  of  its  shape  has  been  named  Amphioxus,  or  pointed 
at  both  ends.  Its  world  wide  distribution  in  the  face  of  its 
inadequate  means  of  dispersal,  and  its  comparatively  slight 
specific  differentiation,  suggest  that  it  is  both  a  very  ancient 
and  very  conservative  sort  of  creature. 

Running  from  tip  to  tip  of  the  body  extends  a  stiff  rod 
which  serves  as  a  skeleton  and  aids  it  in  its  rapid  burrowing 
in  the  sand.  The  body  is  marked  by  numerous  V-shaped  lines, 
indicating  the  divisions  between  the  segments  into  which  the 
muscles  are  divided.  Just  dorsal  to  the  notochord  is  the  hollow 
nerve  cord  from  which  paired  nerves  run  to  various  parts  of 
the  body.  Along  this  nerve  cord  are  distributed  numerous 
little  spots  of  pigment,  which  probably  give  the  animal  its 


108  Biology  in  America 

extreme  sensitiveness  to  Ijnjlit,  to  avoid  which  it  quickly  with- 
draws into  its  burrows  in  the  sand.  At  the  anterior  end  of 
the  body  arc  a  number  of  delicate  fingers  or  tentacle-like 
processes  surrounding  the  mouth,  wiiich  is  ventral  in  position 
and  which  opens  into  the  pharynx,  whose  walls  are  perforated 
by  numerous  gill  slits,  opening  into  a  common  branchial  cham- 
ber or  atrium.  These  are,  briefly  put,  the  principal  features 
of  this  very  curious  and  interesting  little  creature.  In  com- 
mon with  the  vertebrates  it  has  a  hollow,  dorsal  nerve  cord, 
a  notocliord  and  gill  slits,  w^hile  the  absence  of  vertebrae  and 
of  anything  resembling  jaws,  and  its  extensive  segmentation 
relate  it  to  invertebrates.  Its  organization  is  however  dis- 
tinctly more  vertebrate  in  character  than  is  that  of  either  the 
tunicate  or  Balanoglossus. 

The  first  of  the  vertebrates  proper  however  are  the  cyclo- 
stomes,  so  named  from  their  circular  mouths,  which  lack  jaws. 
They  include  both  marine  and  fresh  water  forms  and  are 
dangerous  parasites  of  fish,  attaching  themselves  to  the  latter 
by  means  of  the  suctorial  mouth,  and  rasping  away  the 
scales  with  their  powerful  tongue,  armed  with  numerous  horny 
teeth,  and  sucking  the  blood  and  soft  tissues  until  their  victim 
is  destroyed.  The  hagfish  Bdellostoma  of  the  California 
coast  is  an  example.  This  is  an  eel-like  creature  which  is 
persona  non  grata  to  the  Chinese  fishermen,  entangling  their 
nets  and  destroying  their  fish.  One  individual  in  a  pail  of 
water  will  quickly  convert  it  into  a  jelly-like  mass  due  to 
the  abundant  slime  secreted.  In  these  animals  we  find  the 
first  typically  vertebrate  structure,  namely  the  vertebral 
column^  incorrectly  called  the  "back  bone,"  since  it  is  not 
necessarily  bony,  Ibut  may  consist  of  cartilage,  and  in  some 
instances  is  not  a  continuous  structure  at  all,  but  consists 
merely  of  a  series  of  disconnected  cartilaginous  pieces,  par- 
tially surrounding  the  nerve  cord  at  the  base  of  which  lies 
the  notochord.  Whether  or  not  the  cyclostomes  are  primitive 
or  degenerate  types  is  a  bone  of  contention  among  zoologists. 
In  their  i)rimitive  vertebiu',  persistent  notochord,  extensive 
segmentation  of  nerves  and  muscles  and  numerous  gills  their 
primitive  character  is  clearly  indicated ;  but  in  their  suctorial 
mouth,  and  poorly  developed  eyes  there  is  evidence  of  degen- 
eration, correlated  perhaps  with  their  parasitic  habits. 

Not  until  we  reach  the  true  fishes  do  we  find  fully  developed 
the  vertebrate  plan  of  structure,  with  a  complete  vertebral 
colunm  built  around  and  replacing  the  degenerating  notochord, 
and  surrounding  the  nerve  cord;  with  paired  upper  and  lower 
jaws  and  paired  fins,  and  a  fully  developed  brain  case  or 
skull.  The  origin  of  most  of  these  structures  is  shrouded  in 
mystery,    and   unless   paleontology   comes   to    our    aid,    re- 


A.     Mouth  of  Lamprey 
fSliowing  the  rasping  tongue  and  toothed  liood. 

B.  Sucker  With  Scars  Madk  by  Lamprey 

From   Surface,  "The   Lampreys   of   Contr.il   New    York,"'    in   Bulletin 
U.  S.  Fish  Commission  for  1897. 


109 


110  Biology  in  America 

vealing  new  links  in  the  ehain  of  life,  it  is  likely  ever  to 
remain  so.  How  arose  the  vertehrate  mouth  and  jaws,  through 
what  steps  has  the  skull  evolved,  how  have  the  paired  fins  and 
their  sueeessoi-s,  the  limbs,  developed?  These  are  some  of 
the  problems  with  which  the  student  of  vertebrate  develop- 
ment has  to  stiiiggle. 

Is  the  vertebrate  mouth  a  modified  invertebrate  one,  and  if 
so  is  it  derived  from  the  dorsal  mouth  of  the  tunicate  or  the 
ventral  one  of  Bahinoglossus,  or  was  it  made  anew  when  the 
vertebrate  was  fashioned  in  Nature's  work  shop?  Are  the 
jaws  new  structures,  swi  generis,  or  are  they  second-hand  gill 
bai's  employed  by  Nature  for  the  purpose  because  they  were 
the  handiest  structures  she  could  find? 

A  possible  clue  to  this  question  is  found  in  the  peculiar 
development  of  the  anterior  end  of  Amphioxus.  When  the 
mouth  of  this  animal  first  appears  it  is  not  in  its  final  position 
in  the  median  plane  of  the  body,  but  tilted  far  up  on  the  left 
side,  while  vice  versa  the  first  gill  slits  make  their  appearance 
on  the  right  side  and  secondarily  are  shifted  over  .to  the  left. 
This  larval  asymmetry  would  be  produced  by  any  force  twist- 
ing the  anterior  end  from  left  to  right;  i.  e.,  in  the  opposite 
direction  to  that  in  which  the  clock  hands  move.  But  if,  as 
the  result  of  such  a  twisting,  the  mouth  is  carried  over  to  the 
left  side  its  original  position  must  have  been  dorsal.  Now 
what  evolutionary  change  could  have  produced  such  a  twist- 
ing? In  the  early  stages  of  the  larva  the  notochord  does  not 
reach  the  tip  of  the  body,  only  later  extending  there.  Further- 
more, neither  in  the  tunicate  lai'\'a  nor  in  Balanoglossus  does 
it  extend  to  the  tip  of  the  body.  If,  in  correlation  with  the 
burrowing  habit  of  the  animal,  the  notochord  extended  forward 
in  the  course  of  evolution,  thereby  stiffening  the  anterior  end 
of  the  body,  and  aiding  the  animal  to  wriggle  through  the 
sand,  the  tendency  would  be  to  displace  the  anterior  organs, 
and  among  them  the  mouth.  Such  an  assumption  seems  very 
reasonable.  If  correct,  then  the  mouth  of  Amphioxus  must 
originally  have  been  dorsal,  and  if  this  animal  represents  a 
primitive  vertebrate  type,  then  the  vertebrate  mouth  must 
originally  have  had  this  position,  secondarily  migrating  to 
the  ventral  side.  But  what  of  the  origin  of  the  jaws  which 
are  such  characteristic  features  of  all  vertebrates  above  the 
cyclostomes  ? 

As  we  have  already  seen  a  characteristic  feature  of  all 
higher  animals  is  their  segmentation.  This  is  seen  in  many 
parts  of  the  body, — muscles,  nerves,  blood  vessels,  gills,  etc. 
We  have  further  seen  that  one  phase  of  advance  is  the  reduc- 
tion in  number  of  these  segments  and  their  specialization,  or 
modification  for  the  performance  of  other  work  than  that 


Descriptive  Biology  HI 

which  they  were  originally  called  upon  to  do.  In  Ampliiuxus 
and  the  protocordates  (timicates,  Balanoglossus)  the  number 
of  gills  is  large,  occasionally  reaching  as  many  as  180  pairs  in 
the  former.  In  the  cyclostomes  the  number  varies  from  six 
to  fourteen  while  in  higher  fishes  the  number  is  typically 
five,  varying  from  three  to  seven.  In  land  vertebrates  gills 
are  absent  in  the  adult,  but  occur  more  or  less  developed  in 
the  embryo,  even  man  himself  at  one  stage  of  his  existence 
showing  indications  of  them,  a  heritage  from  some  remote 
fish-like  ancestor.  In  their  disappearance  have  these  gills 
left  any  traces  behind  them  ?  There  are  some  undoubted  rem- 
nants of  the  gills  and  their  associated  structures,  and  others 
which  can  be  so  interpreted  only  with  great  doubt.  Of  the 
former  may  be  mentioned  the  spiracle  in  fishes,  an  opening 
from  the  pharynx  to  the  exterior  just  back  of  the  head.  In 
land  vertebrates  this  becomes  the  cavity  of  the  middle  ear, 
which  is  closed  externallv  by  the  tympanum  and  internally 
communicates  with  the  pharynx  by  means  of  the  Eustachian 
tube.  The  delicate  ear  bones,  which  transmit  the  vibrations 
of  the  tympanum  to  the  inner  ear,  are  probably  in  part 
derived  from  the  first  gill  arch,  while  from  the  other  arches 
develop  the  hyoid  bone  and  some  of  the  laryngeal  cartilages. 
The  blood  vessels  and  nerves  supplying  the  gills  of  the  fish 
are  also  in  some  cases  directly  modified  to  form  other  nerves 
and  vessels  in  the  land  vertebrate.  If  then,  gill  arches  have 
been  so  markedly  reduced  in  number  and  can  be  so  profoundly 
changed  as  to  form  parts  of  the  organs  of  hearing  and  of 
speech,  why  may  they  not  also  have  been  changed  to  form 
even  more  distant  parts?  Hence  the  origin  of  jaws,  paired 
fins  and  fin  supports  or  girdles  have  been  attributed  by  some 
theorists  to  former  gill  bars,  while  even  the  lungs  have  been 
derived,  according  to  one  theory,  from  a  pair  of  gill  clefts. 

While  there  is  but  little  evidence  for  the  latter  theories, 
the  former  is  not  an  unreasonable  one.  The  position  and 
arrangement  of  the  jaws  is  such  that  they  can  be  readily  com- 
pared to  a  pair  of  gill  arches  united  below  and  hinged  in 
the  middle  to  form  the  upper  and  lower  jaws.  Furthermore, 
the  arrangement  of  the  nerves  supplying  the  jaws  is  very 
similar  to  that  of  those  which  supply  the  gill  arches. 

For  the  origin  of  the  paired  fins  of  fishes  we  have  a  more 
likely  theory  in  that  of  the  paired  fin  fold.  The  vane  of  the 
fish  extends  discontinuously  along  the  median  dorsal  line  from 
head  to  tail,  and  ventrally  is  represented  by  the  anal  or 
ventral  fins,  between  tail  and  anus.  Anterior  to  the  anus  we 
find  the  paired  fins  occupying  varying  positions  in  different 
fish.  According  to  the  paired  fin  fold  theoiy  the  ancestral 
fish  possessed  a  continuous  median  fin,   extending  dorsally 


112 


Iliology  in  America 


from  hoad  to  tail  and  veiitrally  as  far  as  the  arms,  where  it 
divid'd  In  pass  forward  aloiip:  the  sides  as  a  pair  of  folds 
to  the  liead.  Sueh  a  condition  we  aelnally  iind  in  Ainplii- 
oxus,  wlii'e  the  fossil  shark  ( 'ladoselache  possessed  paired 
fins  placed  exactly  as  we  shonld  expect  them  to  be  had  they 
been  derived  fiom  snch  hypothetical  fin  folds.  In  the 
Jai)anese  goldfish  the  anal  fins,  which  are  ordinarily  single, 
are  paired,  as  would  happen  if  the  paired  folds  extended 
further  back  than  nsnal. 

These  folds  are  supposed  to  have  acted  as  balancing:  organs 
originally,  but  later  they  became  stiengtliened  at  their 
anterior  and  posterior  ends  while  their  middle  parts  dropped 


til&IXtfc.-. 


(Above)     A  Lung  Fish 
Frtini  I'irsson  juid  ydiuclicrt 's  Geology,  by  perniissiou  of  John  Wiley 
&  Sons. 

(Below)     Cladoselache 

A  fossil  shark,  whose  paired  fins  give  evidence  of  the  origin  of  these 
structures  from  a  pair  of  continuous  fin  folds.  From  Dean 's  ' '  Fishes, 
Living  and  Fossil,"  by  permission  of  the  Macmillan  Company. 

out  and  the  parts  remaining  were  modified  to  form  the  paired 
fins  of  the  modern  fish. 

The  origin  of  the  vertebrate  limb  is  shrouded  in  the  mists 
of  the  past.  Whence  it  came,  and  how,  we  may  never  know ; 
for  there  are  as  yet  no  links  to  connect  the  fin  of  the  fish 
with  the  limb  of  the  amphibians.  True  it  is  that  the  impress 
of  a  foot  has  been  found  in  Pennsylvania  in  sandstone  rocks 
of  the  Devonian  period,  when  fishes  were  the  dominant  types 
of  life;  which  is  supposed  to  have  been  made  by  some  lowly 
ancestor  of  the  amphibians.  This  represents  only  the  foot 
however  and  tells  us  little  or  nothing  as  to  the  origin  of  the 
limb  as  a  whole.  Various  hypotheses  have  been  advanced  to 
take  the  place  of  facts,  but  about  the  most  that  can  be  said 
for  any  of  them  is  that  they  are  hypotheses,  and  one  is  per- 


Descriptive  Biology  113 

haps  as  good  as  another.  The  conditions  of  the  earth  and  its 
climate  under  which  the  amphibians  arose  are  considered  in 
the  following  chapter,  but  their  earliest  history  is  still  a 
blank. 

One  of  the  most  difficult,  but  withal  interesting  problems 
of  vertebrate  morphology  is  the  origin  of  the  head.  The 
ancestral  vertebrate  lacked  a  head.  How  have  its  descendants 
acquired  one?  This  question  involves  in  the  first  place  one 
fundamental  to  all  evolution.  Is  an  organ  developed  because 
it  is  used,  or  is  it  used  because  it  is  developed?  While  this 
question  has  ever  been  a  terra  incognita  in  biology  we  know 
at  least  that  fonn  and  function  go  hand  in  hand.  This  is 
the  corner  stone  of  adaptation  and  survival.  The  animal  is 
a  beautifully  adjusted  mechanism,  in  most  cases  built  for 
forward  movement.  The  anterior  end  is  the  one  which  first 
meets  with  changes  in  the  animal's  surroundings.  Here  food 
is  taken  and  danger  encountered.  Hence  the  development 
at  this  end  of  a  mouth  and  of  special  sense  organs.  In  cor- 
relation with  the  development  of  these  parts,  there  is  a 
corresponding  development  of  a  brain  or  enlarged  and  spec- 
ialized portion  of  the  central  nervous  system,  for  receiving 
the  nerves  coming  from  the  organs  of  special  sense,  and  for 
sending  out  nerves  controlling  various  parts  of  the  body.  En- 
largements of  the  central  nerve  cord  are  not  limited  to  the  an- 
terior end  of  the  body.  In  the  segmented  worms  and  in  arthro- 
pods for  example  there  are  many  such  enlargements  or  ganglia, 
one  for  each  segment  of  the  body,  and  when  several  of  these 
segments  are  combined  into  one,  as  occurs  in  the  latter  group, 
notably  in  insects  and  crustaceans,  the  ganglia  also  fuse  to 
form  compound  structures.  In  the  vertebrates,  in  corre- 
spondence with  the  development  of  paired  fins  or  limbs,  there 
are  enlargements  of  the  spinal  cord  opposite  the  latter,  which 
in  some  cases  may  even  exceed  the  brain  itself.  Thus  the 
enormous  dinosaur  Stegosaurus  had  a  "brain"  in  the  sacral 
region  controlling  the  hind  limbs  which  was  larger  than  that 
in  the  head. 

With  the  development  of  mouth,  sense  organs  and  brain 
there  is  a  corresponding  development  of  parts  to  enclose, 
protect  and  operate  them.  The  development  of  jaws  which 
operate  the  mouth  has  already  been  briefly  mentioned,  as 
have  also  the  changes  experienced  by  the  gill  arches  in 
the  land  vertebrates.  The  most  difficult  questions  of  head 
development  concern  the  brain  case  and  especially  the 
muscles. 

The  German  anatomist  Oken  sought  to  solve  the  problem 
of  the  brain  case  very  simply  by  supposing  that  Nature  had 
enlarged  and  shaped  three  of  the  anterior  vertebrae  for  this 


114  Biology  in  America 

purpose,  but  this  primitive  theory  has  long  since  been  laid 
to  rest.  Ail  tliat  we  know  of  the  major  part  of  the  skull 
is  that  as  the  eyes,  ears,  nose  and  brain  develop  the  sur- 
rounding? tissue  molds  itself  1o  lit  them,  forming  hard  parts 
(cartilage  and  bone)  as  a  firm  support  and  protection.  But 
there  are  occasionally  found  some  curious  bones  at  the  base 
of  the  skull  or  occiput  which  strongly  suggest  that  the  verte- 
bra; may  after  all  liave  had  something  to  do  in  the  building 
of  the  skull,  or  at  least  a  part  of  it. 

Of  world-Mdde  distribution,  with  representatives  in  South 
America,  Africa,  and  Australia  is  a  group  of  fishes  known  as 
the  lungfishes,  which  prol)cil)ly  re]n'esent  a  connecting  link 
between  fishes  and  Amphibia.  In  their  cartilaginous  skeleton, 
and  in  their  notochord,  which  persists  in  the  adult,  they  are 
very  primitive  types,  while  lungs  and  certain  other  features 
mark  them  as  far -advanced  along  the  path  of  evolution. 
These  fishes  live  in  pools  which  dry  up  wholly  or  in  part 
during  the  dry  season  and  are  filled  again  in  times  of  abun- 
dant rain.  Both  lungs  and  gills  appear  to  be  used  for  res- 
piration even  when  the  pools  are  full  of  water.  But  when 
the  pools  begin  to  dry  up  in  summer  and  the  water  becomes 
foul  with  decaying  vegetation,  the  ability  to  breathe  air  saves 
the  fish  from  suffocation.  Some  species  during  the  dry  season 
settle  comfortably  into  the  mud,  retaining  communication 
with  the  outer  world  by  means  of  a  hole  in  the  mud,  at  the 
•bottom  of  which  they  lie.  Here  they  breathe  air,  resuming 
the  gill  habit  when  the  rainy  season  once  more  replenishes 
their  pools.  In  these  fishes  there  is  a  "cranial  rib"  attached 
to  the  base  of  the  skull  somewhat  resembling  the  true  ribs 
of  the  fish  and  suggesting  that  a  vertebra  bearing  this  rib 
has  been  united  with  the  skull. 

The  cyclostome  skull  forms  but  an  incomplete,  basket-like 
frame  work  for  the  brain  and  does  not  extend  behind  the  ear, 
leaving  the  ninth  and  tenth  nerves  outside,  which  in  higher 
fishes  become  enclosed  in  the  skull.  When  Ave  come  to  the 
land  vertebrates,  the  reptiles,  birds  and  mammals,  this  process 
of  inclusion  of  nerves  within  the  skull  goes  a  step  further 
and  we  find  twelve  instead  of  ten  nerves  issuing  from  the 
skull.  AVhile  this  process  of  telescoping  as  it  were  the  head 
end  of  the  animal  is  going  on  many  of  the  nerves  and  muscles 
are  being  crowded  out,  while  others  are  so  modified  as  to  bear 
but  little  resemblance  to  their  former  selves.  Evidence  of 
the  loss  of  nerves  and  muscles  in  the  evolution  of  the  verte- 
brate head  may  be  found  in  the  presence  of  more  numerous 
nerves  and  muscles  in  this  region  in  adult  cyclostomes  than 
are  found  in  the  adults  of  the  jawed  vertebrates,  and  espe- 
cially in  the  development  of  the  latter,  where  a  varying  num- 


Descriptive  Biology  115 

ber  of  nerve  and  muscle  rudiments  appear  in  the  embryo, 
which  disappear  in  the  adult. 

The  modifications  which  nerves  and  muscles  undergo  in 
evolution  are  perhaps  nowhere  more  beautifully  shown  than 
in  the  evolution  of  the  muscles  and  nerves  of  the  human  face. 
These  muscles,  known  as  the  "mimetic"  or  mimicking  muscles 
of  higher  apes  and  man,  produce  the  wonderful  play  of  expres- 
sion of  which  the  human  face  is  capable,  and  through  control 
of  the  lips  aid  very  largely  in  speech.  They  are  controlled 
by  the  seventh  or  facial  nerve,  which  in  lower  animals  sup- 
plies the  upper  neck  and  lower  jaw.  In  both  racial  and  indi- 
vidual development  the  association  of  muscle  and  nerve  is 
very  constant.  Each  motor  nerve  is,  as  it  were,  assigned  the 
duty  of  controlling  a  certain  muscle,  and  regardless  of  the 
wanderings  of  its  muscle,  it  remains  faithful  to  its  charge, 
so  that  the  best  criterion  for  the  comparison  of  muscles  in 
two  animals  and  for  determining  the  segments  to  which  they 
belong,  is  the  nerves  which  supply  them.  So  it  comes  to  pass 
that  when  the  muscles  of  the  neck  wander  out  over  the  face, 
or  when  those  of  the  shoulder  region  spread  themselves  over 
the  back,  their  nerves  must  needs  go  along  with  them,  and  we 
are  in  this  way  enabled  to  tell  the  original  source  of  most 
of  the  complicated  muscles  of  the  higher  vertebrates.  And 
so  when  we  speak  or  smile  or  frown  we  are  using  muscles, 
which,  in  some  ancestor  of  the  long  forgotten  past,  controlled 
the  throat  and  jaws  and  probably  served  it  in  chewing  and 
swallowing  its  food. 

Thus  in  a  few  words  we  have  outlined  the  field  of  the 
morphologist.  Perhaps  some  of  my  readers  may  deem  the 
sketch  one  worthy  of  cubist  art,  or  modern  poetry.  If  per- 
chance however  we  have  gained  even  a  glimpse  of  the  mani- 
fold problems  here  involved  and  of  some  of  the  larger  facts 
thus  far  discovered,  the  attempt  will  not  have  been  in  vain. 


CHAPTER  IV 

The  story  of  the  rocks.     Contributions  of  palce ontology   to 
evolution.     Rise  and  fall  of  the  faunas  of  the  past. 

Not  alone  by  a  comparison  of  the  structure  of  living  forms 
and  their  development,  can  we  decipher  the  writings  of 
evolution  upon  the  page  of  time.  Perhaps  even  more  con- 
clusive is  the  story  of  the  life  which  is  no  more,  of  the  faunas 
and  the  floras  of  the  past.  For  in  the  record  of  the  rocks 
there  pass  in  review  before  us  the  generations  of  the  ages 
telling  us  the  story  of  how  life  has  come  to  be.  Therein  we 
can  read  in  a  moment  the  tale  of  a  million  years. 

Among  other  facts  it  was  the  existence  of  the  extinct  faunas 
of  South  America  which  first  turned  Darwin's  thought  into 
the  channel  of  evolution.  Yet  in  spite  of  its  contribution  to 
our  knowledge  of  evolution,  there  are  many  pages  missing 
from  the  record,  many  of  which  doubtless  may  some  day  be 
found,  more  probably  lost  forever.  These  "missing  links" 
of  the  palaeontologist  have  ever  been  a  ready  refuge  for  the 
dwindling  forces  of  the  opposition,  attempting  with  broom- 
stick arguments  to  hold  back  the  rising  tide  of  facts.  Many 
species  of  animals  and  plants,  especially  the  more  minute  and 
the  more  primitive  forms  are  lacking  in  hard  parts  and  are 
not  readily  preserved.  Some  may  have  been  destroyed  in  the 
upheavals  of  the  earth.  Still  others  are  doubtless  awaiting 
the  pick  of  the  geologist,  which  has  as  yet  but  scratched  the 
earth 's  surface  here  and  there.  Thus  does  the  paleontologist 
explain  the  gaps  in  his  record  where  the  story  is  not  complete. 

The  student  of  world  history  written  in  the  text  book  of 
the  rocks  need  not  trouble  himself  with  dates,  for  the  sequence 
and  causes  of  events  rather  than  their  times  are  what  nature 
strives  to  teach  us.  But  the  mind  of  curious  man  never  is 
content  unless  speculating  regarding  the  unknown,  and  so 
geologist,  biologist  and  physicist  have  all  endeavored  from 
different  data  to  form  estimates  of  the  age  of  the  earth  and 
its  geological  periods.  Without  detailing  their  methods  it  is 
sufficient  to  say  that  no  very  close  agreement  exists  among 
them,  the  geologists  claiming  from  100,000,000  to  800,000,000 
years'  since  the  oldest  rocks  were  formed,  the  biologist  asking 
for  hundreds  of  millions  of  years  for  the  development  of  life, 

116 


!rhe  Story  of  the  Rocks 


111 


while  the  physicist  is  yet  more  extravagant,  asking  in  the  light 
of  recent  experiments  on  radium  1,600,000,000  years  for  the 
age  of  the  earth  since  it  attained  its  present  diameter. 

So  in  rehearsing  brietly  the  story  of  the  roeks  perhaps  we 
cannot  do  better  than  employ  the  words  of  the  old  story  books 
and  say  that  "once  upon 
a  time"  when  the  waters 
covered  most  of  Nortli 
America  and  the  earliest 
Lauren  tian  rocks  of 
northeastern  Canada 
were  beginning  to  be 
lifted  up  above  the  sur- 
face of  the  sea,  life  prolj- 
ably  came  upon  the  earth 
ill  the  form  of  unieelluhir 
plants  and  animals.  But 
regarding  the  birth  (f 
life  the  rocks  are  mute. 
We  have  no  record  of  its 
advent  or  its  cradle. 

Its  earliest  remains 
known  are  those  of  the 
Huronian  period,  where 
liuried  beneath  rock  strata 

several  miles  in  thickness  are  marine  algie,  radiolarians  and 
the  tubes  and  burrows  of  annelid  worms.  Following  these 
there   appeared    in    the    Cambrian    period    all    the    principal 

branches  of  inverte- 
brate animals,  with 
the  trilobites,  the  cu- 
rious crustacean  fos- 
sils resembling  the 
modern  king  crabs, 
and  so  named  from 
the  two  longitudinal 
grooves  which  divide 
the  body  into  three 
parallel  lobes,  occu- 
jiying  the  dominant 
phice.  Hence  this 
period  is  known  as 
the  age  of  trihibites. 
Tlic  "Ordoviciau"  pe- 
riod, whicli  succeeded  the  Cambrian,  witnessed  tlie  rise  of 
laud  plants  and  corals,  the  marvelous  nautilids,  witli  their 
chambered  shells,  and  the  armored  "fishes"  or  ostracoderms. 


A  Trilobite 

Original  photograph  from  a  specimen 
in  the  geological  collection  of  the  Uni- 
versity of  North  Dakota. 

Courfrsj/  of  Dr.  A.   O.  LeoiKird. 


A  King  Crab 

A  living  ' '  fossil, ' '  related  to  the  trilobite 
on  the  one  hand,  and,  according  to  Professor 
Patten  of  Dartmouth,  to  the  vertebrate,  on 
the  other.     Photo  by  Elvvin  R.  Sanborn. 
Cuurtcs!/  of  the  New  York  Zoijloyical  Society. 


118 


Biology  in  America 


Tlic  latter  are  cnrions  fish-liko  croatnros  whose  remains  liave 
been  i'ouiid  in  several  parts  of  this  t'ountry  and  abroad.  They 
had  no  jaws,  and  were  abundantly  protected  with  coats  of 
mail,  their  heavy  armoring  of  plates  and  spines  giving  them 
both  their  scientific  and  common  names.  The  ostracoderms 
have  long  been  a  knotty  problem  for  the  palaeontologists.  By 
some  they  are  related  to  the  king  crabs,  by  others  to  the  as- 
cidians,  while  yet  others  regard  them  as  kin  to  the  cyclostomes. 
But  whatever  their  relationships  may  be  they  were  inidonbt- 
edly  highly  specialized  forms  and  have  no  direct  bearing  on 
the  problem  of  vertebrate  descent.    They  were  at  one  time  the 


Ostracoderms 
From   Pirsson  and  Schuchert  's   ' '  Geology, ' '  after  Koken. 


dominant  forms  of  life  in  the  ancient  seas,  for  though  small 
of  size  their  stout  coats  of  mail  evidently  served  as  efficient 
means  of  preservation.  Their  abundance  is  shown  by  the 
numbers  of  their  shells,  which  in  some  places,  notably  in  Caith- 
ness, Scotland,  occur  piled  together  in  great  masses,  where 
their  decaying  bodies  served  to  bind  together  the  shell  into 
compact  masses,  which  today  form  the  hard  tough  flagstones 
of  this  region. 

The  cause  of  this  great  destruction  is  difficult  to  surmise. 
Similar  instances  of  the  present  are  however  by  no  means 
unknown.  The  Mississippi  lowlands  are  annually  converted 
into  numerous  lakes  by  the  spring  overflow  from  the  river. 
Into  these  lakes  come  numerous  species  of  fish  to  breed,  which 


The  Story  of  the  Rocks  119 

when  the  river  recedes  would  be  destroyed  in  vast  numbers 
annually,  were  it  not  for  the  work  of  the  U.  S.  Bureau  of 
Fisheries  and  other  agencies,  which  rescue  thera  from  the 
receding  lakes  and  return  them  to  the  river,  or  use  them  for 
stocking  other  waters.  An  instance  of  the  destruction  of 
fishes  in  this  manner  is  cited  by  Lucas  in  his  "Animals  of  the 
Past,"  from  the  observations  of  Mr.  F.  S.  Webster  in  Texas, 
"Where  thousands  of  gar  pikes,  trapped  in  a  lake  formed  by 
an  overflow  of  the  Rio  Grande,  had  been,  by  the  drying  up 
of  this  lake,  penned  into  a  pool  about  seventy-five  feet  long 
by  twenty-five  feet  wide.  The  fish  were  literally  packed  to- 
gether like  sardines,  layer  upon  layer,  and  a  shot  fired  into 
the  pool  would  set  the  entire  mass  in  motion,  the  larger  gars 
as  they  dashed  about  casting  the  smaller  fry  into  the  air,  a 
score  at  a  time.  IMr.  Webster  estimates  that  there  must  have 
been  not  less  than  700  or  800  fish  in  the  pool,  from  a  foot  and 
a  half  up  to  seven  feet  in  length,  every  one  of  which  perished 
a  little  later.  In  addition  to  the  fish  in  the  pond,  hundreds 
of  those  that  had  died  i)reviously  lay  about  in  every  direction, 
and  one  can  readily  imagine  what  a  fish-bed  this  would  have 
made  had  the  occurrence  taken  place  in  the  past. ' ' 

Devils  Lake  is  a  remnant  of  the  glacial  lake  Minne- 
waukon,  which  at  one  time  covered  some  hundreds  of  square 
miles  in  North  Dakota.  Due  to  various  factors  this  lake  is 
gradually  drying  up.  Formerly  pickerel  abounded  in  it  in 
countless  numbers.  Old  settlers  tell  of  catching  the  fish 
through  the  ice  in  winter  with  pitchforks  and  shipping  them 
out  by  carloads.  But  between  1885  and  1890,  coincident  with 
a  marked  decrease  in  lake  level,  the  fish  suddenly  disappeared. 

In  1879  there  were  discovered  along  the  edge  of  the  Gulf 
Stream  off  the  coast  of  Massachusetts  members  of  a  group 
of  fishes  having  their  home  in  the  Gulf  of  Mexico,  known  as 
the  tilefish.  In  the  spring  of  1882  they  were  found  dead  and 
dying  by  tlie  million  over  an  area  estimated  at  from  5,000 
to  7,500  square  miles.  This  catastrophe  is  believed  to  have 
been  due  to  a  continuation  of  northerly  and  easterly  winds 
which  drove  the  cold  arctic  current  from  the  north  out  of 
its  usual  course,  overwhelming  the  fish  with  disaster.  For 
many  years  no  more  appeared  in  this  region,  but  about  1900 
they  reappeared  and  are  now  being  taken  in  considerable 
numbers. 

In  the  preceding  chapter  we  have  taken  a  glimpse  at  the 
lungfishes,  which  point  the  way  from  water  to  land  inhabit- 
ing vertebrates.  One  would  naturally  expect  such  creatures 
to  have  a  comparatively  high  standing  in  aquatic  society,  but 
strangely  enough  their  position  is  a  lowly  one  indeed.  This 
is    evidenced    not    alone    by    their    structure    but    by    their 


120  Biology  in  America 

appearance  very  early  upon  the  stage  of  life,  for  the  more 
primitive  the  creature  the  earlier  its  appearance  in  the  strata 
of  the  earth.  Thus  we  find  ancient  luiigfishes  in  the  Silurian, 
and  in  the  Devonian,  the  period  succeeding,  they  attained 
their  greatest  prominence;  wliile  the  sharks,  which  in  many 
respects  are  most  primitive  of  the  true  fishes  of  the  present, 
appeared  at  about  the  same  time  as  the  lungfishes,  but  did 
not  attain  dominance  in  the  seas  until  much  later. 

Tlie  ancient  lungfishes,  like  tlie  o.  tracoderms,  were  heavily 
armored;  some  possessed  powerfid  crushing  or  tearing  jaws, 
and  some  may  have  attained  a  size  of  twenty-five  feet  and  a 
gape  of  four  feet.^ 

The  fossil  sharks  include  many  forms  of  peculiar  interest. 
One  of  these  from  the  Devonian  period  Gladoselache  gives 
strong  evidence  in  its  paired  fins  for  the  lateral  fin  fold  theory, 
as  noted  in  the  preceding  chapter.  The  vertebrae  lacked 
centra,  resembling  in  this  respect  the  cyclostomes  and  dip- 
noans.  Perliaps  nowhere  else  have  fossil  forms  reproduced 
so  faithfully  their  structure  as  in  this  shark,  for  Dean  has 
shown  that  sections  of  its  muscles,  magnified  one  thousand 
times,  showed  very  clearly  the  finer  structure  of  the  muscle 
substance  (cross  striations  and  sarcolemma).  The  modern 
shark  is  covered  with  teeth-like  scales  known  as  shagreen 
denticles,  from  the  shagreen  leather  made  from  the  skin  of 
the  shark.  From  these  scales  have  arisen  on  the  one  hand 
teeth  which  are  covered  with  enamel,  and  on  the  other  scales 
and  plates  in  which  this  is  lacking.  Large  scales  or  bony 
plates  are  common  in  the  skin  of  many  fishes.  "We  have 
already  seen  them  in  the  ostracoderms  and  the  armored  fishes, 
but  they  are  absent  in  modern  sharks.  In  fossil  forms  how- 
ever they  were  frequent  and  closely  resembled  those  of  the 
fossil  lungfishes,  which  were  probably  cousin  to  the  sharks. 

The  evolutionist  is  accustomed  to  thinking  of  life  as  ever 
changing.  Yet  there  are  some  forms  which  have  come  down 
to  us  unchanged  through  untold  ages.  The  shark  Cestracion 
is  such  an  one.  It  roamed  the  seas  in  early  Mesozoic  days, 
the  dawn  of  the  "age  of  reptiles,"  possibly  100,000,000  or 

more  years  ago.  •       i       vi 

The  Australian  lungfish  Neoceratodus  has  persisted  Avith 
but  small  change  for  an  even  greater  length  of  time,  while  the 
Foraminifera,  Orlmlina  and  (Jlobigerina,  whose  shells  comr)osc 
much  of  the  ooze  on  the  sea  bottom,  are  found  as  far  back  as 
the  Ordovician,  perhaps  200,000,000  to  300,000,000  years  ago, 
and  possibly  existed  long  before.  Living  on  some  small 
islands  off  the  coast  of  New  Zealand  is  the  last  representative 
^  I  am  assuming  here  the  somewhat  problematical  relationship  of 
the  Arthrodiia  to  the  Dipnoi. 


The  Story  of  the  Bocks 


121 


of  a  decadent  race  of  lizards,  the  Khyncliocephalia,  whose 
members  were  among  the  earliest  of  the  reptiles  to  appear 
upon  the  earth,  and  whose  descendant  differs  but  little  from 
the  ancestral  types. 


^-  ,■     '■/,.     •-'."■.'."■'A'.k'.     .'.'-'VJi/,'/-  t.'     ■''    ■• '• 


A.     The  Shark  Cestracion 
From   Pirsson  and  Schuchert,  after   Gannaii. 

B.    The  Crossopterygian  Polypterus 
From  Dean,  ' '  Fishes,  Living   and  Fossil. ' ' 

C.     The  New  Zealand  Lizard  IIatteria 

From  Gadow,  "Amphibia  and  Eeptiles,  The  Cambridge  Natural  His- 
tory. ' ' 

Band   C  hy  permission    of  the  Macmillan   Company. 
Copy  furnished  by  Conrad  Lantern  Slide  Company,  Chivago. 

Other  relatives  of  the  early  sharks  were  the  Crossoptery- 
gians,  whose  descendants  are  found  today  in  the  Nile,  Niger 
and  other  African  rivers.  In  the  arrangement  of  the  dermal 
head  plates  they  are  suggestive  of  the  Stegocephala  or  extinct 
amphibians  which  flourished  in  the  Carboniferous  or  coal- 


122 


Biology  in  America 


forming  period,  and  which,  from  their  abundance  and  that  of 
the  <z:iant  club  mosses,  is  known  as  the  "age  of  amphibians 
and  lycopods. " 

The  modern  club  moss  is  an  inconspicuous  humble  plant, 
usually  creeping  upon  the  ground  in  the  forest,  and  covered 
witt  small  pointed  leaves.  It  is  most  familiar  to  us  in  the 
decorations  of  the  Christmas  time.  But  the  club  mosses  which 
we  burn  today  as  coal,  were  princely  trees  in  the  carboniferous 


Footprint  of  a  Primitive  Amphibian 
Courtesy  0/  Professor  It.  8.  Lull. 

forests,  one  hundred  feet  in  height  and  five  to  six  feet  in 
diameter.  Associated  with  them  along  the  borders  of  lake 
and  pond  were  giant  forerunners  of  our  "horse  tail  ferns," 
slender  plants,  sixty  to  one  hundred  feet  in  height,  though 
but  one  or  two  feet  in  diameter.  Their  descendants  of  the 
present  are  for  the  most  part  only  a  few  feet  in  height, 
though  a  few  of  the  South  American  forms  may  reach  thirty 
or  forty  feet. 

During  the  Carboniferous  period,  when  the  earth 's  surface 
was  covered  by  vast  swamps,  wherein  the  decaying  vegeta- 


I 


The  Story  of  the  Rocks 


123 


tion  was  forming  the  future  beds  of  coal,  conditions  were 
ripe  for  the  advent  of  new  types  of  life  upon  the  earth,  and 
here  occurred  the  birth  of  a  new  creation.  What  were  the 
creatures  that  linked  the  fishes  to  the  amphibians  Ave  do  not 
know,  but  we  have  already  noted  indications  of  a  change  in 
*  the  ancient  lung  fish  and  crossopterygian. 

The  earliest  traces  of  amphibians  known  are  some  "foot- 
prints on  the  sands  of  time"  left  for  our  information  in  the 
sandstone  of  the  late  Devonian  period  by  Thinopus,  and  pre- 
served for  our  further  instruction  in  the  museum  of  Yale 
University,  to  which  reference  has  already  been  made  in  the 
preceding  chapter. 

The  creatures  which  marked  the  coming  of  the  new  race 
were  many  in  number  and  varied  in  kind.  Some  were  great 
in  length  if  not  in  stature,  measuring  up  to  seven  or  eight 
feet,  while  others  were  minute,  not  exceeding  a  few  inches 
in  size.     Some  were  limbed  and  others  limbless,  some  had 


A  Stegocephalan 

After     Williston,     "Water     Keptiles     of     the     Past     and     Present' 
(adapted  from  Neumayr). 

By  permission  oj  the  University  0}  Chicago  Press. 

simple  teeth,  while  in  others  the  tooth  was  infolded  from  the 
sides  producing  so  complex  a  pattern  as  to  have  given  to  one 
group  the  name  of  labyrinthodont.  This  character  is  also 
found  in  one  of  the  crossopteiygian  fishes,  the  Devonian 
Holoptychius,  a  further  indication  of  a  possible  relationship 
between  them  and  the  early  amphibians.  They  all  however 
possessed  in  common  the  heavy  complicated  coats  of  mail  upon 
the  head  which  has  given  the  group  its  name  of  Stegocephala. 
In  these  early  armored  forms  as  well  as  in  many  recent  ones 
(i.  e.,  sturgeon  and  other  ganoid  fishes)  the  animal  carried 
much  of  his  skull,  like  a  helmet,  on  the  surface  of  his  head. 
This  was  developed  in  the  skin,  while  underneath  was  a  casing 
for  the  brain  developed  in  cartilage.  In  higher  forms  the 
dermal  bones  have  sunk  below  the  surface  becoming  intimately 
united  in  development  with  the  cartilaginous  brain  case,  the 
whole  forming  a  compact  structure  in  which  in  the  adult  it 


124 


Biology  in  America 


is  impossible  to  distinguish  by  structure  alone  the  two  types 
of  bone.  While  the  adults  were  terrestrial  in  habit  they 
nndonbtedly  possessed  aquatic  larva?  in  many  cases,  as  is 
showu  by  the  presence  of  gills  in  the  fossil  remains  of  the 
latter,  and  their  kinship  to  aquatic  forms  is  clearly  shown  by 
a  groove  in  the  dermal  bones  of  the  head,  indicating  the  pres- 
ence of  a  series  of  sense  organs  peculiar  to  fishes  and  known 
as  the  lateral  line  organs. 

The  Carboniferous  period  likcwis,'  witnessed  a  great  develop- 
ment of  nuiny  other  types  of  animal  life,  spiders,  scorpions, 


p^-'-- 


J 


-«.*i 


An  Imaginary  Landscape  of  the  Coal-Forming  Period 
Showing  stegocephalans   and   a  giant  insect  in   the  foreground,  with 
coal-forming  plants  in  the  background.     After  Williston,  "Water  Kep- 
tiles  of  the  Past  and  Present''   (adapted  from  Neumayr), 
By  permission  of  the  University  of  Chicago  Press. 

centipedes,  insects  and  snails,  while  the  plants  indulged  in 
a  veritable  riot  of  luxuriant  growth. 

We  may  perhaps  picture  to  ourselves  the  conditions  of  the 
evolution  of  land  from  water  vertebrates  in  some  such  way 
as  this :  With  the  gradual  recedence  of  the  sea  and  elevation 
of  the  land  extensive  swamps  were  formed  in  which  developed 
a  luxuriant  vegetation  consisting  of  giant  club  mosses,  "horse 
tail"  and  tree  ferns  and  primitive  representatives  of  our 
modern  pines  and  spruces.  In  the  dense  forests  bordering  the 
stagnant  pools,  no  touch  of  bright  color  was  there  to  enliven 
the  monotony  of  the  scene,   for  neither  bird  nor  butterfly 


The  Story  of  the  Rods  125 

had  yet  appeared  upon  the  earth.  All  Nature  was  clad  in 
somber  garb  of  gray  and  green.  The  air  was  moist  and  mild, 
with  seasons  same  the  year  around.  Those  were  indeed  the 
"dog  days"  of  the  world.  The  beating  wings  of  many  giant 
insects  filled  the  air,  some  of  which,  resembling  our  modern 
dragon  tlies,  having  a  spread  of  over  two  feet.  In  the  swamps 
the  decaying  vegetation  was  laying  down  the  future  stores  of 
fuel. 

Succeeding  the  warm  moist  climate  of  the  early  Carbonif- 
erous came  the  ice  age  of  the  Permian  period  with  its 
change  to  a  colder  climate  throughout  the  earth.  The  vast 
swamps  gradually  disappeared  and  in  their  place  the  Appa- 
lachian Mountains,  today  mere  relics  of  their  former  selves, 
reared  their  vast  bulk  perhaps  some  15,000  or  20,000  feet  above 
the  sea.  With  the  adoption  of  a  life  on  land  the  amphibian 
stem  branched  out,  giving  rise  in  one  direction  to  the  reptiles, 
in  another  to  the  modern  amphibians,  while  yet  another  line 
led  to  the  mammals.  The  earliest  reptiles  appeared  in  the 
Pennsylvanian  or  upper  Carboniferous  period,  but  not  until 
the  Mesozoic,  did  tliey  attain  a  position  of  dominance. 

In  1802  a  Connecticut  farmer  named  Moody  ploughed  up 
some  pieces  of  rock  bearing  some  small  imprints,  which  became 
popularly  known  as  the  tracks  of  Noah's  raven.  Later  on 
these  tracks  came  to  the  attention  of  Doctor  James  Deane  and 
Professor  Hitchcock  of  Amherst  College,  who  published  exten- 
sive descriptions  of  them.  The  tracks  were  made  mostly  by 
three-toed  beasts  and  were  at  first  thought  to  be  those  of 
birds.  But  occasionally,  similar  tracks  of  four-  or  five-toed 
animals  were  found,  and  they  were  later  shown  to  be  those 
of  dinosaurs,  extinct  reptiles,  which  at  one  time  thronged  the 
earth.  These  tracks  appear  to  have  been  made  in  a  long 
narrow  estuary  of  the  sea  where  we  may  picture  to  ourselves 
these  creatures  roaming  over  the  mud  flats  left  bare  by  the 
receding  water,  and  leaving  their  impression  on  the  mud  to 
be  hardened  by  the  heat  of  the  sun  and  preserved  throughout 
the  ages  as  a  record  of  the  life  which  was.  The  tracks  of 
some  150  species  of  various  animals  (not  alone  dinosaurs) 
have  been  recorded  by  Professor  Hitchcock  from  this  old 
estuary,  one  slab  alone  in  Amherst  College  INIuseum  showing 
forty-eight  tracks  of  one  species  of  dinosaur,  and  six  of 
another  species.  Strange  to  say  but  few  remains  of  the 
makers  of  these  tracks  have  been  found.  It  is  possible  that 
most  of  them  have  been  washed  out  to  sea  and  destroyed,  only 
those  few  left  upon  the  shores  being  preserved. 

But  the  happiest  hunting  ground  of  the  dinosaurs  was  not 
the  shores  of  the  Atlantic  but  the  borders  of  the  lakes  and 
rivers   which   occupied   the   present   Rocky   Mountain-Great 


126 


Biology  in  America 


Plains  area  of  the  West.  In  the  early  Mesozoic  rocks  of  this 
region  are  found  some  of  the  most  extensive  dinosaur  remains 
throujxhout  the  woi'ld.  althoupfh  these  are  of  virtually  world- 
wide distri])uti()n.  And  here  too  has  been  the  happy  hunting 
ground  of  the  palaeontologist,  whose  labors  have  revealed  to 
us  the  life  of  the  long  ago. 

In  size  the  dinosaurs  ranged  from  little  fellows  about  a 
foot  or  two  long  to  enormous  beasts,  veritable  Goliaths  among 
animals.  The  largest  of  all  was  Brontosaurus,  the  thunder 
lizard,  who  reached  a  length  of  sixty  feet,  and  stood  fourteen 
feet  high,  with  a  thigh  ])one  the  height  of  a  man.  ^lany  of 
them  were  armeil  wath  great  knife-like  plates  and  spines  u])on 


DixosAUR  Tracks 
(ointisii  of  the  Amcriiiin   Miixcum   of  Xdlural  Hintonj. 

the  back  and  tail.  Among  these  were  the  stegosaurs  nr 
armored  lizards,  the  largest  of  whose  plates  were  two  feet  in 
height  and  length,  w^hile  near  the  end  of  the  powerful  tail, 
eight  or  ten  feet  long,  projected  two  pairs  of  vicious  spines 
nearly  three  feet  long.  The  three-horned  dinosaur,  Tricer- 
atops,  who  S(jme  millions  cf  years  ago  inhabited  what  are  now 
the  plains  of  the  Dakotas,  Wyoming,  Montana  and  Colorado, 
bore  a  horn  over  either  eye  and  one  on  his  snout,  like  the 
horn  of  a  rhinoceros,  and  a  great  fringed  shield  upon  his 
neck;  while  many  another  was  equipped  with  armor  more 
bizarre  perhaps  than  practical  in  the  battle  of  life.  Many 
however  were  naked,  so  that  as  a  protective  adaptation  these 
various  plates  and  spines  seem  to  have  had  but  doubtful  value. 


The  Stary  of  the  Rocks  127 

Some  of  the  dinosaurs  browsed  on  the  abundant  vegetation 
of  lake  and  river  shore,  while  others  were  eaters  of  flesh  and 
may  have  preyed  upon  their  weaker  brethren  or  fed  upon 
their  decaying  carcasses. 

Unfortunately  for  the  dinosaur  and  vice  versa  for  their 
prey  and  their  enemies,  if  they  had  any,  their  brains  did  not 
keep  pace  with  their  brawn.  Thespesius,  who  was  twenty-five 
feet  long  and  a  dozen  high,  had  a  brain  weighing  less  than  a 
pound,  while  Triceratops,  who  probably  tipped  the  scales  at 
something  over  two  tons,  did  not  possess  over  two  pounds  of 
gray  matter.    Some  indeed  had  more  nerve  in  their  hind  quar- 


^^^pjhr 

ife"            -^B^H^QIl«»«kr  '    --iM 

»,.              /s^jK^^JISfc^ 

■ft.                        ^^^p^^^^^^^^^l 

L 

^^^^^^^^^^^^^r^^^^^l^^^^^^^^l 

Ik-     ''^ 

^^^^^^^^^^BjJr^^BK^H 

^HHB 

^^ 

^^ 

^^^C?|^^ 

m^^^Jj^mBSlM 

Si^S^*-"^  ♦ "  -  '■<' ' 

Brontosaurus,  the  ' '  Thunder-Lizard  ' ' 

From  a  restoration  by  Chas.  R.  Knight. 

Courtesy  of  the  American  Museum  of  Natural  History. 

ters  than  in  their  head ;  in  Stegosaurus,  the  sacral  enlargement 
of  the  spinal  cord,  which  controlled  the  powerful  hind  legs, 
being  twenty  times  as  large  as  the  brain.  Corresponding 
with  their  paucity  in  brain  substance  the  intelligence  of 
these  creatures  must  have  been  low  indeed,  and  this,  together 
with  the  vast  bulk  of  many  of  them,  may  have  contributed 
to  their  extinction. 

But  the  dinosaurs  were  not  the  only  members  of  the  reptile 
tribe  which  dominated  the  world  in  Mesozoic  days.  There 
were  reptilian  aeroplanes  and  submarines  as  well.  In  ^  the 
great  Cretaceous  sea  which  divided  North  America  into 
eastern  and  western  continents,  covering  the  fertile  plains  and 


r=*^: 

' 

^AM^ 

i 

:^iil 

aIP^^'-^-^^^H 

:  .v^^riMs 

* 

*  '^MT^J 

'#' 

'-■'■   '   ■■■w 

■^■"               rJtl 

^s^iB 

A 

0 

'.ki*"! 

>»fl^. 

^ 

1 

1 

Ti    iTriimTOwrrnrn^ri 

T*:  «?•.«"-.  .■--in-a' 

w 

Stegosaurus 

From  a  restoration  by  Chas.  E.  Kniglit. 

Courtesy  uj  the  American  Museum  of  Natural  History. 


Triceratops 

A  former  inhabitant  of  our  western  planes.     From  Lucas,  "Animals 
of  the  Past. ' ' 

Courtesy  o/  the  U.  S.  National  Museum. 


128 


The  Story  of  the  Bocks  129 

arid  plateaus  which  lie  between  the  Mississippi  River  and  the 
Rocky  Mountains,  were  swarms  of  giant  lizard-like  reptiles 
known  as  mososaurs,  whose  remains  have  l)een  unearthed  by 
thousands  in  the  chalk  bluffs  of  western  Kansas. 

While  the  mososaur  was  playing  the  role  of  Neptune  in 
the  Cretaceous  sea,  some  of  liis  relatives  took  to  flying  and 
as  pterodactyls  or  flying  lizards  competed  Avith  the  first  of 
the  birds  for  the  mastery  of  the  air.  The  old  classification 
of  beasts  that  fly  and  beasts  that  swim  and  beasts  that  walk 
w^as  about  as  logical  as  that  of  the  small  boy  who  divided 
people  into  men,  women  and  college  professors,  for  many 
different    animals    have    aspired   to    fly    and   most    of   them 


Khamphorhynchus,  a  Winged  Reptile 
From  Ncumeyer  after  Zlttel. 

have  met  with  eminent  success.  The  success  of  the  reptile 
at  aviation  was  but  short-lived  however  speaking  in  terms 
of  biological  time,  for  the  pterodactyls  soon  joined  their 
cousins  the  dinosaurs,  the  mososaurs  and  most  of  the  other 
antique  saurians,  and  sank  to  a  watery,  which  later  became 
a  rocky,  grave,  to  be  resurrected  after  untold  ages  by  the 
prying  eye  and  patient  pick  of  the  paleontologist.  The  ptero- 
dactyls had  wings  of  a  thin  skin  or  membrane  stretched 
between  fore  and  hind  limbs  somewhat  like  the  wings  of  a 
bat.  In  the  pterodactyls  however  only  one  of  the  fingers  was 
lengthened  as  a  support  for  the  membrane. 

While  the  pterodactyls  could  not  compete  with  the  dino- 
saurs or  mososaurs  in  respect  to  size,  nevertheless  one  at  least 


130  Biology  in  America 

attained  fairly  respectable  dimensions,  Pteranodon  having  a 
winf?  spread  of  twenty  to  twenty-tive  feet.  This  creature 
with  its  long  arms  outstretched,  a  slender  body  and  narrow 
neck,  at  the  top  of  which  was  poised  a  long  narrow  head,  about 
half  of  which  was  beak,  might  well  have  served  as  a  model 
for  some  P^gyptian  or  Assyrian  god  or  goddess.  Rhampho- 
rhynchus,  on  the  other  hand,  with  his  long  tail,  semi-human 
form  and  claw-like  fingers,  would  have  made  a  very  good 
model  for  a  winged  Satan. 

AVhile  the  pterodactyls  are  not  directly  related  to  birds, 
they  nevertheless  show  certain  distinctly  avian  features,  one 
of  the  most  notable  of  which  is  the  hollow  bones.  In  birds 
air  sacs  extend  from  the  lungs  throughout  the  body  even  into 
the  bones,  while  the  lungs  themselves  are  small,  but  richly 
supplied  with  blood  vessels.  These  air  sacs  serve  as  reservoirs 
for  air,  somewhat  after  the  manner  of  a  rubber  bulb  on  a 
pipette,  serving  to  force  strong  currents  in  and  out  of  the 
body  through  the  lungs,  and  thereby  gain  efficient  aeration  for 
the  blood ;  which  in  birds  is  kept  at  a  high  temperature  b}-  the 
active  oxidation  which  takes  place  in  the  body  in  correspond- 
ence with  their  great  activity.  Not  only  do  these  spaces  in  the 
bones  serve  as  air  reservoirs,  but  they  also  serve  to  lighten 
the  bones,  increasing  their  size,  relative  strength,  and  surface 
for  attachment  for  muscles,  without  unduly  increasing  their 
weight ;  just  as  the  greatest  strength  in  a  pillar  for  a  given 
amount  of  material  is  obtained  by  making  the  pillar  hollow. 

AVhile  we  know  very  little  about  the  lungs  in  the  ptero- 
dactyls it  is  interesting  to  find  precisely  the  same  adaptation 
for  lightness  and  strength  of  bone  as  we  find  in  the  birds. 
This  suggests  Lamarck's  idea  that  use  (flight)  produces 
change  (lightness  of  bone)  in  flying  reptile  as  in  flying  bird. 
But  let  us  not  be  too  hasty  in  swallowing  alluring  hypotheses. 
We  find  to  a  certain  extent  the  same  air  spaces  in  the  bones 
of  the  crocodile,  which  has  never  had  any  aspirations  for 
flying,  Avhile  the  lizard,  which  is  also  in  the  main  satisfied 
with  a  mundane  existence,  has  small  air  spaces  or  reservoirs 
attached  to  its  lungs.  Thus  we  are  driven  to  the  conclusion 
that  the  pterodactyl  and  the  bird  have  made  use  of  their 
opportunities  and  have  learned  to  fly  because  they  "were 
built  that  way,''  while  the  opportunities  for  flight  of  the  lizard 
and  the  crocodile  are  too  small  for  them  to  use. 

But  there  are  yet  other  j)oints  of  resemblance  between  bird 
and  pterodactyl.  In  ])irds  of  flight  the  sternum  or  breast 
bone  has  a  prominent  ridge  or  keel  like  a  boat,  which  has 
given  them  the  title  of  Carinata?  or  keeled.  This  keel  fur- 
nishes an  additional  surface  for  the  attachment  of  the  power- 
ful wing  muscles.     So  too  the  pterodactyl  had  a  keeled  ster- 


The  Story  of  the  Rocks 


131 


num.  The  pterodactyl's  skull  is  prolonged  into  a  prominent 
beak  like  that  of  a  bird,  while  in  some  instances  its  teeth 
are  as  scarce  as  those  of  the  proverbial  hen.  Yet  others  pos- 
sessed numerous  strong,  sharp  teeth  lodged  in  sockets  in  the 
jaw.  The  cavity  of  the  skull  bears  a  great  similarity  to  that 
of  birds,  while  the  sutures  or  lines  of  union  of  the  skull 
bones,  as  in  the  bird,  have  largely  disappeared.  The  zo- 
ologist believes  this  to  be  a  case  of  "parallel  evolution." 
The  pterodactyl  had  dreams  of  becoming  a  bird,  but  never 
quite  achieved  his  ambition. 

But  if  the  attempt  at 
aviation  by  the  true  rep- 
tile was  short-lived,  he 
yet  produced  the  great- 
est aviators  among  ani- 
mals— the  birds. 

In  the  famous  Solen- 
hofen  quarries  in  Ger- 
many there  was  discov- 
ered on  August  15,  1861, 
the  print  of  a  single 
feather,  and  a  few  weeks 
later  the  impresdon  of 
the  bird  itself  was  dis- 
covered. Archaeopteryx, 
the  primitive  or  ancient 
bird,  as  his  name  signi- 
fies, was  indeed  primi- 
was  distinctly 
for  he  wore 
a     distinction 


Restoration  of  Arcii^opteryx 
From  Lucas,  ' '  Animals  of  the  Past. ' ' 
Conriid  Lantern  Slide 


<'i)l>jl  fuDiislieil   hi/ 
CoiniHtity,  Cltii-ayn. 


tive,  but 

a     bird, 

feathers, 

possessed  by  none  of  his 

reptilian  ancestors  that 

we    now    know.     And     yet    the    improbability    of    a    bird 

hatching  full-fledged   out   of  a   reptile's  egg,   as   St.   Ililaire 

suggested,    is    so    unlikely,    that    we    must    assume    many 

intermediate    stages    in    avian    development;    stages,    which 

Mother  Earth  has  as  yet  declined  to  reveal.     While  Archas 

opteryx    is    a    full-fledged    bird    so    far   as    its   feathers    are 

concerned,  it  shows  its  reptilian  parentage  in  several  ways. 

The   modern    l)ird    possesses   only   a   few   small   vertebra   in 

lieu   of   a   fully   formed   tail,    from   which   the   tail   feathers 

radiate  fan-like;  Archaopteryx  however  liad  a  long  reptilian 

tail,  with  numerous  vertebrae,  and  the  feathers  arranged  in 

a  row  on  either  side.     It  still  had  a  full  set  of  teeth  like  the 

other  early  birds,  Hesperornis  and  Ichthyornis,  which  were 

discovered  by  Professor  Marsh  in  1870  in  the  chalk  beds  of 


132 


Biology  in  America 


western  Kansas,  which  were  once  at  the  bottom  of  the  old  Cre- 
taceous Sea.  Traces  of  teeth  still  occur  in  the  embryos  of  some 
birds  of  the  j)resent,  a  heritage  from  some  ancestor  of  the 
distant  past.  While  Icthyornis  still  had  teeth,  it  had  pro- 
gressed much  further  along  the  path  of  avian  development 
than  Archffiopteryx  in  the  structure  of  the  hand.  Nature  in 
her  experiments  is  prodigal  in  the  production  of  variations, 
most  of  which  she  will  never  use  in  the  development  of  new 
species ;  but  once  she  is  on  the  track  of  a  useful  variation  she 
becomes  a  strict  conservationist  and  wastes  no  energy  in  the 


Hesperornis 


extinct  diving  bird  with  teeth,  an  inhabitant  of  the  great  Creta- 
sea  wliif  h  once  covered  our  Great  Plains.     From  Lucas,  ' '  Animals 


Au 
ceous 
of  the  Past. ' ' 


Courtesy  of  the  U.  -b'.  yatiuiuil  Museum. 


maintenance  of  useless  parts.  So  in  the  hand  of  the  modern 
bird  and  in  Icthyornis  as  well,  we  find  one  of  the  fingers 
being  greatly  strengthened  for  the  support  of  the  wing 
feathers,  and  the  others  correspondingly  reduced.  The  typical 
reptile  has  five  fingers,  which  in  the  modern  bird  are  reduced 
to  one  plus  two  rudiments,  while  Archa?opteryx  had  dropped 
only  two  of  his  digits  and  still  remained  in  possession  of  the 
claws  on  his  wings  wliich  the  modern  bird  has  dispensed  with 
as  entirely  out  of  date.  There  is  however  one  conservative 
member  of  the  class  who  still  retains  a  reminder  of  his  rep- 
tilian past  in  the  form  of  a  claw  at  the  angle  of  the  wing, 


The  Story  of  the  Rocks 


ii^ 


Apteryx,  or  the  kiwi  of  New  Zealand,  a  country  which  in 
its  fauna  is  a  sort  of  old  curiosity  shop,  retaining  such  relics 
of  the  past  as  the  Port  Jackson  sliark,  the  tuatara,  the  kiwi 
and  until  recently  the  moas.  Yet  a  further  legacy  from  his 
reptilian  ancestry  did  Archaiopteryx  possess.  This  is  a  set 
of  abdominal  ribs,  or  rib-like  bones  in  the  ventral  wall  of  the 
abdomen,  which  he  shared  in  common  with  the  New  Zealand 
lizard  and  the  crocodile. 

As  to  how  birds  took  to  flying  we  of  course  have  no  certain 
knowledge.  But  we  have  some  very  ingenious  and  interesting 
theories.  In  the  first  place  what  was  the  probable  origin  of 
the  feathers?  A  feather  consists  of  a  central  shaft  or  quill 
from  which  extend  two  rows  of  branches  or  barbs,  and  these 


Part  of  a  Feather 
Showing  shaft,  barbs,  barlniles  and  liooks.     Original. 

in  turn  give  rise  to  a  series  of  little  barbs  or  barbules  which 
interlock  with  one  another  by  means  of  rows  of  small  hooks; 
the  whole  forming  a  firm  resistant  membrane  serving  as  a 
propeller  in  the  case  of  the  wing  feather,  a  rudder  in  that 
of  the  tail  feathers,  and  a  protective  and  insulating  covering 
for  the  general  body  surface.  At  the  base  of  the  quill  is  a 
small  papilla  or  projection  of  the  dermis,  or  lower  layer  of 
the  skin,  which  carries  nerves  and  blood  vessels  and  serves  to 
nourish  the  growing  feather.  The  feather  itself  arises  as  a 
tube  of  modified  horny  cells  derived  from  the  epidermis,  or 
outer  skin  layer,  whicli  splits  into  several  parts  in  develop- 
ment, which  spread  out  to  form  the  barbs  and  barbules.    This 


134  Biology  in  America 

applies  to  the  ordinary  or  "contour"  feather.  The  ''down" 
and  "liair"  feathers  differ  in  development,  although  all  have 
essentially  the  same  structure.  Hairs  are  also  developed 
fundamentally  in  the  same  way  as  the  feathers,  with  a  dermal 
papilla,  or  core,  at  the  base  and  a  horny  shaft,  which  however 
is  solid  and  not  hollow  as  in  the  feather. 

Both  of  these  structures,  being  derived  from  the  horny 
layer  of  the  skin,  are  believed  to  be  modifications  of  the  horny 
reptilian  scale,  which  in  its  turn  probably  owes  its  origin  to 
the  epidcniial  layer  or  enamel  of  the  placoid  scale  of  the  shark, 
from  which  also  has  evolved  the  enamel  of  the  mammalian 
tooth. 

But  to  return  to  the  original  question  of  the  origin  of  the 
birds.  The  theory  of  the  Plungarian  palaeontologist,  Nopsca, 
supposes  the  bird  to  have  arisen  from  a  long-legged,  long- 
tailed,  short-armed  running  reptile,  which  as  it  ran  flopped 
its  arms  to  aid  its  motion,  on  somewhat  the  same  principle 
that  a  man  uses  his  arms  in  a  race.  If  some  of  the  scales  along 
the  posterior  angle  of  the  arm  and  along  either  side  of  the 
tail  were  to  enlarge,  they  might  readily  aid  the  forerunner 
of  the  bird  in  its  motion  and  by  further  enlargement  and 
modification  give  rise  to  feathers,  and  the  arm  become  a  wing, 
and  the  reptile  a  bird. 

Another  theory,  advocated  by  Osborn,  and  more  recently 
by  Beebe,  assumes  an  arboreal  reptile  as  the  ancestral  bird. 
This  creature  is  supposed  to  have  been  gifted  with  four  wings 
instead  of  two  and  a  long  tail,  which  it  used  much  as  a  flying 
squirrel  uses  its  tail  in  sailing  from  tree  to  tree.  AVitli  loss 
of  the  hind  pair  of  wings  and  strengthening  and  improvement 
of  the  front  pair,  the  sailing  reptile  became  a  flying  bird. 
In  support  of  this  theory  Beebe  adduces  a  veiy  interesting 
fact.  lie  points  out  that  in  the  newly  hatched  bird  there  is 
a  row  of  quills  running  along  the  outer  side  of  the  leg,  in 
such  a  position  that,  if  developed,  they  would  produce  a 
miniature  wing.  And  further,  just  as  in  the  case  of  the 
"secondaries"  (the  smaller  of  the  flight  feathers  in  a  bird's 
wing)  there  develops  above  these  quills  and  alternating  with 
them  a  second  row  of  quills,  which  if  developed  would  produce 
"covert"  feathers.  Similar  tufts  of  feathers  occurred  in 
Archffiopteryx,  which  is  strong  evidence  for  Beebe 's  theory, 
for  as  we  have  already  seen,  higher  animals  tend  to  repeat 
in  an  abbreviated  way  the  structure  of  their  ancestors. 

Yot  others  adopt  a  compromise  theory  and  assume  that 
while  ArcluL'opteryx  lived  in  trees,  using  his  wings  as  well  as 
his  feet  for  grasping  the  branches,  yet  his  flight  was  not 
merely  a  sailing  one,  but  that  the  wings  were  actively  used 
for  this  purpose. 


The  Story  of  the  Bocks  135 

But  whatever  may  have  been  the  development  of  feathers 
and  origin  of  tiight  in  birds  we  find  in  Archieopteryx  one  of 
the  best  "links"  between  two  great  groups  anywhere  to  be 
found  in  the  animal  kingdom. 

While  Archa3opteryx  was  smaller  than  a  crow  many  of  his 
extinct  relatives  maintained  the  reputation  of  their  reptilian 
connections  for  size.  Among  these  are  the  moas  of  New 
Zealand,  which  must  have  become  extinct  within  the  memory 
of  man,  for  less  than  a  century  ago  the  Maoris  firmly  believed 
in  their  existence.  Their  largest  representative  was  the  giant 
moa,  Dinornis  maximus,  which  was  at  least  ten  feet  high. 
Another  giant  of  the  bird  world  was  ^pyornis  of  Madagascar, 
legends  of  which  may  have  served  as  the  basis  for  the  roc 
in  the  tales  of  Sinbad  the  Sailor ;  but  this  was  equalled  by 
Phoreracbis,  the  giant  of  the  Patagonian  pampas,  who  flour- 
ished in  Miocene  days,  long  before  the  advent  of  man,  and 
who  was  seven  or  eight  feet  in  height  and  had  a  skull 
larger  than  that  of  a  horse.  Another  although  smaller  bird 
was  the  vulture,  whose  remains  have  recently  been  unearthed 
or  rather  untarred  from  the  tar  pits  of  Rancho  La  Brea  near 
Los  Angeles,  Cal.,  whose  spread  of  wing  was  probably  greater 
than  that  of  the  great  condor,  which  today  circles  about  the 
Andean  peaks  of  South  America. 

And  so  for  the  present  we  may  leave  the  extinct  reptiles 
and  their  feathered  kin,  who  in  days  of  yore  ruled  earth  and 
sea  and  sky.  "For  the  wind  passeth  over  it  and  it  is  gone 
and  the  place  thereof  shall  know  it  no  more."  So  passed 
these  creatures  of  antiquity,  to  give  place  to  races  better 
fitted  to  cope  with  the  new  environments  of  the  passing  ages 
and  the  changing  earth.  Many  if  not  all  of  them  will  in  their 
turn  go  down  in  life's  struggle  before  the  advancing  armies 
of  future  generations,  these  in  turn  giving  place  to  others, 
until  life  itself  shall  be  no  more. 

The  reptiles  and  the  birds  form  one  of  the  topmost  branches 
of  the  vertebrate  tree,  while  the  mammals  form  the  other. 
The  latter,  while  less  spectacular  in  their  evolution  than  the 
former,  are  of  even  greater  interest  since  man  himself  is  one 
of  them,  and  since  they  are  the  latest,  and  in  many  ways 
dominant  group  among  the  vertebrates  of  today. 

As  in  the  case  of  all  great  groups  of  animals  and  plants 
the  actual  ancestor  of  the  mammals  is  unknown.  Nor  is  it 
certain  whether  they  are  the  offspring  of  amphibian,  reptile 
or  some  intermediate  stock.  Their  first  appearance  was  near 
the  beginning  of  the  Mesozoic  era,  when  the  reptilian  dynasty 
was  arising  to  rule  the  earth.  The  first  of  the  mammals  were 
small  creatures  and  were  probably  the  prey  of  the  carnivorous 
reptiles,  although  they  in  turn  may  have  been  one  cause  of 


136  Biology  in  America 

the  extinction  of  many  of  the  latter,  by  destroying  their  eggs 
with  sharp  gnawing  teeth  which  well  served  them  for  this 
j)urpose. 

Although  the  origin  of  mainiuals  is  uncertain  we  find  a 
possible  source  in  a  group  of  reptiles  known  as  cynodonts 
from  the  dog-like  character  of  their  teeth,  which  occur  in 
triassic  rocks  in  South  Africa.  The  skull  in  many  respects 
resembles  that  of  a  mammal,  while  in  othei^  it  shows  reptilian 
characters. 

But  the  cynodonts  are  found  in  the  Trias,  at  the  very  be- 
ginning of  the  Mesozoic  era,  at  a  time  when  the  great  rep- 
tilian tree  was  but  a  slender  sapling,  while  the  "age  of  mam- 
mals" does  not  commence  until  the  close  of  the  Mesozoic 
era  many  millions  of  years  later.  What  happened  then  to 
retard  mammalian  development  during  the  a;ons  of  time  in 
which  ' '  great  oceans  waxed  and  waned  and  tiny  hills  to  moun- 
tains grew"?  It  is  possible  that  during  all  this  time  our  an- 
cestors were  living,  like  the  Israelites  of  old,  in  bondage  to  the 
Pharaohs,  who  in  this  instance  were  represented  by  the  car- 
nivorous reptiles;  but  when  the  "first  born"  of  the  reptiles 
were  cut  down  and  the  reptilian  stock  smitten  by  the  inex- 
orable hand  of  time,  then  the  mammals  arose,  to  take  their 
"place  in  the  sun"  and  become  the  "lords  of  creation."  Or 
perchance  the  available  food  supply  was  not  abundant  at  the 
time  of  their  birth  and  thus  their  development  was  checked 
until  a  more  favorable  season. 

"Perhaps  the  most  remarkable  thing  which  the  history 
of  the  Mesozoic  brings  forth  is  the  immense  period  of  evo- 
lutionary stagnation  on  the  part  of  the  mammals.  They  are 
first  actually  recorded  in  the  Upper  Triassic  rocks  of  three 
rather  remote  localities.  North  Carolina,  Germany,  and  South 
Africa,  and  are  already  differentiated  in  dietary  habits. 
During  the  Mesozoic,  they  develop  in  numbers  and  to  a  cer- 
tain extent  in  tooth  specialization.  They  do  not,  however, 
increase  markedly  in  size,  but  are  humble  folk,  so  far  as  our 
records  have  revealed  them,  until  the  extinction  of  the  dino- 
saurs has  been  accomplished.  One  cannot  but  associate  the 
idea  of  mammalian  suppression  with  that  of  dinosaurian 
dominance  in  the  relation  of  cause  and  effect,  unless  it  shall 
some  day  be  revealed  that  the  mammals  were  undergoing  a 
marked  evolution  beyond  the  temperature-limited  habitat 
of  the  reptiles.  That  the  former  showed  no  marked  evolu- 
tionary advance  in  the  place  where  the  dinosaurs  actually 
occurred  is  an  attested  fact,  and  the  significance  of  the  dino- 
saurian check  is  no  more  graphically  shown  than  by  two 
specimens  in  tlie  Yale  Museum.  .  .  .  The  figure  here  repro- 
duced is  from  a  simultaneous  photograph  of  these  two  sped- 


The  Story  of  the  Roclcs 


137 


mens,  which  are  therefore  on  exactly  the  same  scale. 
The  single  dinosanrian  tooth  p-ceatly  exceeds  not  only 
the  tooth  of  the  nianniial,  but  the  (•<  ntaininj;  jaw  or 
even  the  entire  creature  as  the  imaj>ination  conjure.-;  it 
up.  "2 

As  to  the  cause  of  mammalian  development  we  can  again 
only  conjecture.  Lull  has  suggested  that  increasing  dryness 
of  climate  and  corresponding  desert  conditions,  necessitar- 
ing  speed  on  the  part  of  animals  in  search  of  food  and  water, 
or  in  flight  from  their  enemies,  coupled  with  the  extensive 
glaciation  in  the  Southern  hemisphere  in  late  Palaeozoic  times, 


Tooth  of  a  Dinosaur  Compared  with  the  Jaw  of  a  Coxtempuraky 

Mammal 

From  Lull 's  ' '  Organic  Evolution. ' ' 
Courtesji  of  Professor  Lull  mid   tlit'   Miicmilhiii    ComiJiniii. 


which  glaciation  would  mean  increasing  cold  and  the  nred 
of  a  furry  covering,  were  the  inciting  causes.  But  apart 
from  the  fact  that  this  explanation  implies,  if  it  does  not 
state,  an  acceptance  of  Lamarck's  doctrine,  which  at  the 
present  time  is  in  the  discard  with  most  zoologists,  is  the 
further  fact  that  the  succeeding  or  Mesozoic  era  was  one 
which  witnessed  the  remarkable  development  of  reptiles, 
which  are  distinctly  types  not  adapted  to  aridity  and  cold- 
ness of  climate.  Perhaps  the  best  we  can  do  after  all,  when, 
as  so  frequently  happens  in  pliilosophy  and  science,  we  find 

^Lull,  "Evolution  of  the  Earth,"  pp.  133-134.     By  permission  of  the 
Yale  University  Press. 


138 


Biology  in  America 


ourselves  "up  a  stump,"  is  to  accept  the  philosophy  of  Topsy 
and  admit  that  they  "jest  grew." 

Tlie  ]\Iesozoic  and  early  Eocene  mammals  were  all  primi- 
tive types  and  most  of  them  disappeared  from  the  face  of  the 
earth  without  leaving  any  descendants. 

"It  is  the  mammals  which  were  the  strangest  element  of 
Paleoccne  life,  and  (an)  imaginary  observer  would  find  no 
creature  tliat  he  had  ever  seen  before.  The  difference  from 
modern  mammalian  life  was  not  merely  one  of  species,  genera 
or  even  families,  but  of  orders,  for  only  one,  or  at  most  two, 


The  Opossum 

The  only  marsupial  at  j)reseiit  found  in  the  United  States. 

Photo    hij   Elu-iih   /'.    Sa)iJ)orn. 

By  permission  of  the  Neic  York  Zoological  Society. 

of  the  orders  now  living  were  then  to  be  found  in  North 
America,  and  both  of  these  (marsupials  and  insectivores)  were 
primitive  and  archaic  groups,  which  seem  like  belated  sur- 
vivals in  the  modern  world."  ^ 

It  is  possible  however  that  the  marsupial  types  of  these 
early  mammals  have  come  down  to  us  as  the  marsupials  of 
the  present.  The  marsupials  derive  their  name  from  the 
marsupium  or  pouch  in  which  they  carry  the  young  for  some 
time  after  birth.  These  latter  are  born  in  a  very  undevel- 
oped condition  and  at  birth  are  transferred  by  the  mother 

'Scott,  "History  of  Land  Mammals  in  the  Western  Hemisphere,"  p. 
284.     By  permission  of  the  Macmillan  Company. 


The  Story  of  the  Rocks 


139 


to  her  pouch  where  their  mouths  become  temporarily  attached 
to  the  mother's  teats  and  where  they  grow  in  safety  until 
ready  for  their  second  debut  in  the  world.  AVell-known  ex-- 
amples  are  our  own  opossum,  and  the  Australian  kangaroo. 
The  distribution  of  modern  marsupials  is  very  peculiar  and 
with  otlier  facts  has  given  rise  to  interesting  speculations  re- 
garding the  earlier  form  of  Mother  Earth.  Their  repre- 
sentatives are  found  today  exclusively  in  Australia  and  ad- 
jacent regions,  South  America  and  tropical  North  America, 
with  the  exception  of  the  opossum  of  the  United  States.     In 


The  8riNY  Ant-Eater 
A  luoiiotreme,  one  of  the  most  prii)iitive  of.  mammals. 
Photo   by  Elivin  R.  Sanhorn 
By  permisawti  of  the  Xeiv  York  Zoological  Society. 

Mesozoic  and  Eocene  time  however  the  marsupial  stock  was 
distributed  over  North  America  and  Europe  and  possibly 
Asia  as  well. 

The  distribution  of  the  ostrich  in  Africa  and  its  relatives, 
the  rhea  in  South  America,  and  cassowary  and  emu  in  Aus- 
tralia and  the  East  Indies  and  the  recently  extinct  moa  of 
New  Zealand,  is  similar  to  that  of  the  marsupials.  These 
facts  and  other  similar  ones  have  led  many  biologists  and 
palaeontologists  to  the  belief  in  a  migration  of  life  from  the 
northern  hemisphere  into  the  southern  at  some  very  early 
period  in  the  earth's  history.  They  have  also  suggested  the 
existence  of  former  land  connections  between  South  Amer- 


140  Biology  in  America 

iea,  Africa,  Tndi.i  jiikI  Australia  known  as  Antarctica  and 
Gondwana  Land  wliii-li  is  sniijxisod  to  account  for  the  simi- 
larity of  many  of  the  forms  of  life  in  the  two  reg:ions,  not 
oidy  of  birds  and  mammals  but  of  reptiles,  amphibia,  fishes, 
invertebrates  and  plants  as  well. 

Wliih'  the  early  luaniinals  disappeared  for  the  most  part 
without  issue  there  were  amony  them  some  which  were  elected 
to  serve  as  pro«jenitors  of  the  mighty  tribe  which  has  since 
peopled  the  ciirlh.  Whence  came  the  present  monotremes 
and  marsupials  is  matter  of  much  doubt,  tlieir  relationship 
to  the  pi-imitive  members  of  these  groups  being  uncertain, 
but  the  origin  of  modern  carnivores  is  pretty  certainly  to  be 
found   in   tlie  ancient  creodonts. 

After  the  close  of  the  Cretaceous  period  with  the  rise  of 
the  western  part  of  the  North  American  continent  and  con- 
sequent draining  of  the  great  inland  sea,  which  formerly 
stretched  from  the  Arctic  Ocean  to  the  Gulf  of  Mexico,  there 
appeared  extensive  swamps  or  fresh  water  lakes  in  what  is 
now  North  Dakota,  Montana  and  the  Rocky  Mountain  and 
Great  Basin  regions  and  British  Columbia.  These  various 
lakes  did  not  all  appear  at  once,  but  succeeded  one  another 
with  succeeding  changes  in  elevation  and  form  of  the  land. 
It  was  now  that  the  lignite  beds  of  North  Dakota  and  Mon- 
tana were  laid  down,  covering  an  area  approximately  60,000 
square  miles  in  extent. 

"The  clijnate,  as  shown  by  the  plants,  was  much  milder 
and  more  uniform  than  that  of  the  Recent  epoch,  though 
some  indication  of  climatic  zones  may  already  be  noted.  The 
vegetation  was  essentially  modern  in  character;  nearly  all 
our  modern  types  of  forest-trees,  such  as  willows,  poplars, 
sycamores,  oaks,  elms,  maples,  walnuts  and  many  others,  were 
abundantly  represented  in  the  vast  forests  which  would  seem 
to  have  covered  nearly  the  entire  continent  from  ocean  to 
ocean  and  extended  north  into  Alaska  and  Greenland,  where 
no  such  vegetation  is  possible  under  present  conditions.  Nu- 
merous conifers  were  mingled  with  the  deciduous  trees,  but 
we  do  not  find  exclusively  coniferous  forests.  Palms,  though 
not  extending  into  Greenland,  flourished  magnificently  far  to 
the  north  of  their  present  range.  On  the  other  hand,  the 
Paleocene  fiora  of  England  points  to  a  merely  temperate  cli- 
mate, while  that  of  the  succeeding  Eocene  was  subtropical."* 

Upon  the  land  and  in  the  lakes  were  laid  down  deposits 
of  wind-driven  dust  or  loess  and  volcanic  ash  or  tufa,  while 
the  streams  deposited  in  their  deltas  sand  and  gravel  carried 
down  from  the  higher  lands  in  which  they  took  their  rise. 
The  majestic  Rocky  Mountains  of  today  were  then  in  their 

*  Scott,  locus  citatus,  pp.  102-103. 


'jt 

• 

4 

[|gjp*-SN.\    SR^^Rr^B^^^H^F^jEpA^  "■SWftW''  ^^B  nB 

^^pc 

'    ^^w         ^W'^llm     i 

"jh^Wi-r 

Top — Restoration  of  Uixtatherium 

Center — Restoration  of  Coryphodon 

Boifom- — Restoration  of  the  Creodont  Dromocyon 

From    (Irnwings   by   Horsfall   in   Scott's   "  Mjiiunials   of   the   Western 
Hemisphere. ' ' 

Bi/  permission  of   the  MacmilUin   Company. 
Copy  furniished  by  Conrad  Lantern  Slide  Company,  Chicago. 

141 


142  Biology  in  America 

infancy,  and  great  was  the  travail  of  the  earth  in  bringing 
them  forth,  for  several  active  volcanoes  marked  their  course. 
From  these,  great  clouds  of  ashes  were  hurled  forth  to  set- 
tle upon  earth  and  water.  Such  was  the  home  of  the  creo- 
donts,  the  forerunners  of  modern  Carnivora.  Of  these  the 
j\Iiacid;i?  are  believed  to  represent  the  progressive  branch  des- 
tined to  flourish  and  bring  forth  fruit,  while  the  other 
branches  have  withered  and  died.  They  were  creatures  much 
like  the  modern  carnivores  in  general  appearance,  but  with 
small  brain-case  and  a  very  high  ridge  on  the  upper  side  of 
the  skull  for  attachment  of  the  powerful  jaw  muscles,  and 
the  teeth  were  not  so  well  formed  for  eating  flesh  as  in  mod- 
ern carnivores.  Remains  of  the  LliacidiE  have  been  found 
from  "Wyoming  to  New  Mexico.  As  in  many  another  case  of 
evolution  in  animals,  the  old  adage  "great  oaks  from  little 
acorns  grow"  applied  to  the  iNIiacidae,  for  the  forerunners 
of  the  "king  of  beasts"  and  the  man-eating  tiger  were  little 
fellows  content  to  prey  on  smaller  fry  of  field  and  forest. 
Many  of  their  relatives  however  were  larger  fellows,  equalling 
in  size  a  small  bear.  Associated  with  the  creodonts  were 
other  creatures,  many  of  them  of  huge  size  and  ungainly 
form.  Here  shambled  the  coryphodonts,  ugly  brutes,  equal- 
ling a  small  rhinoceros  in  size  and  somewhat  resembling  a 
hippopotamus  in  form,  with  heavy  tusks,  elephantine  feet 
and  short,  heavy  legs,  and  Uintatherium,  a  creature  so  bizarre 
in  form  that  it  seems  as  if  Nature  had  designed  it  to  grace  a 
pala^ontological  dime  museum.  The  skull  of  this  beast,  not 
being  able  to  find  room  for  growth  along  ordinary  lines,  ran 
riot  in  the  matter  of  horns.  He  had  horns  on  his  snout  and 
horns  on  his  forehead  and  horns  at  the  back  of  his  head  and 
as  if  these  were  not  enough  to  gratify  his  propensity  for 
horny  embellishment,  his  upper  canine  teeth  were  prolonged 
into  gi'cat  tusks,  or  horns  turned  upside  down.  The  female 
however  Avas  much  more  conservative  in  the  matter  of  horns, 
while  she  lacked  the  tusks  entirely.  The  general  form  of 
the  beast  was  quite  similar  to  that  of  its  relatives,  the  cory- 
phodonts. Beside  these  ungainly  beasts  there  were  othei'S 
resembling  the  present  sloths  of  South  America  and  repre- 
sentatives of  the  modern  shrews  and  moles. 

As  in  the  case  of  man  the  aborigine  has  given  place  to 
the  invader  from  distant  lands,  so  too  the  primitive  mammals 
of  North  America,  which  were  natives  of  the  country,  have 
been  displaced  by  more  recent  types  which  have  immigrated 
from  other  regions.  "Whence  they  came  cannot  certainly  be 
determined,  but  probably  Asia  was  their  birthplace,  whence 
like  the  human  race  they  have  wandered  throughout  the 
world.     It  has  repeatedly  happened  in  geologic  history  that 


The  Story  of  the  Rocks 


143 


North  America  has  been  connected  with  Asia  by  a  mass  of 
land  or  "bridg:e"  across  Behrin<if  Sea.  It  apjjcars  likely 
that  there  was  a  similar  "bridge"  joining  America  and  Eu- 
rope at  this  time  (Lower  Eocene),  for  many  mammals  were 
common  to  both  continents. 

The  canse  of  their  migration  is  likewise  nncertain,  but  nat- 
ural increase  and  competition  for  food  may  have  been  one 
of  the  compelling  causes  tlien  as  they  are  now  in  determin- 
ing animal  movements.  We  need  oidy  recall  the  move- 
ments of  the  herds  of  bison,  which  formerly  roamed  across 


v^-^.^'. 


..  # 


,^||PPi|i^ 


^5^3r^ 


Ciit'm^'': 


'^^^~'- 


fiw-K,V 


EoHipPus,  THE  ' '  Dawn  Horse  ' ' 

From  a  restoration  by  Chas.  K.  Knight. 

Courtesy  of  the  Amerwan  Museum  of  Natural  History. 

our  western  prairies  in  search  of  food,  the  plague  of  locusts 
which  overwhelmed  the  early  settlers  in  Kansas,  or  the  spread 
of  the  English  sparrow  from  east  to  west  to  find  an  explana- 
tion for  animal  movements  in  the  past.  But  possibly  an- 
other, and  even  more  potent  factor  was  the  gradually  in- 
creasing refrigeration  of  the  polar  region,  which  occurred 
subsequent  to  the  Eocene,  and  which  culminated  in  the  gla- 
eiation  of  the  "great  ice  age"  of  the  Pleistocene  epoch.  In 
the  latter  there  is  abundant  evidence  of  the  movement  of 
northern  mammals  before  the  advancing  ice,  for  we  "find  re- 
mains of  walruses  in  New  Jersey,  of  reindeer  in  southern 
France  and  of  the  musk  ox  in  Kentucky. 


144 


Biology  in  America 


Among  these  inniiigrants  of  Ihc  past  were  members  of  the 
rodent  or  rat  order,  tiny  forerunners  of  tlie  artiodaetyls  or 
mammals  Avith  paired  toes,  inelnding  eattlc,  sheep,  eamels, 
goats,  pigs,  etc.,  ancient  tapii-s,  and  Kohippus,  the  tirst  of 
the  horses,  a  graceful  little  creature  about  the  size  of  a  do- 
mestic cat,  with  four  front,  and  three  hind  toes  and  indi- 
cations of  a  fifth  toe  in  the  front,  and  possibly  two  extra  toes 
in  the  hind  foot.  In  the  Wasatch  beds  which  cover  large 
areas  in  New  Mexico,  Colorado,  Utah,  Wyoming  and  Mon- 
tana their  remains  are  found  in  great  numbers,  so  that  they 
must  have  been  common  inhabitants  of  this  region  in  early 
Eocene  da^^s. 


The  Tarsier 
Whose    relatives    in    rlays    gone    by    inhabited    the    forests    of    North 
America,  but  today   is   found  in   the   East   Indies   and  the  Philippines. 
From  Lull,  after  Brehm. 

But  perhaps  the  most  interesting  of  the  early  invaders  of 
North  America  were  small  monkey-like  habitues  of  the  tree- 
tops  in  the  Wasatch  forests.  Their  invasion  however  was 
but  temporary,  as  they  died  out  later  in  the  Eocene,  never 
to  reappear  in  North  America.  Inhabiting  the  forests  of 
the  Malay  Aichipelago  is  a  little  squirrel-like  monkey,  the 
tarsier.  "The  particular  interest  which  Tarsius  possesses  for 
the  student  of  American  mammals  is  its  resemblance  to  the 
Wasatch  genus  Ana])toniorphus,  the  type  of  a  family  which 
was  abundant  and  varied  in  the  lower  and  middle  Eocene. 
This  genus  was  remarkably  advanced  in  view  of  its  great 
antiquity.  .  .  .  The  face  was  very  much  shortened ;  the  orbits 
were  very  large  and  encircled  in  bone,  but  without  the  pes* 


The  Story  of  the  Rocks  145 

terior  wall.  This  produces  a  decided  likeness  to  the  Tar- 
sier  and  is  no  doubt  indicative  of  nocturnal  habits.  The  cra- 
nium was  remarkably  large,  and  no  other  Wasatch  animal 
had  a  brain-case  so  capacious  in  proportion  to  its  size.  .  .  . 
It  is  hardly  likely  that  these  American  lemurs  were  the  actual 
ancestors  of  the  anthropoids,  but  they  closely  represent  what 
those  ancestors  mnst  have  been. ' '  ^ 

With  the  passing  of  the  Eocene  epoch  the  early  mammals 
vanished  from  the  face  of  the  earth.  The  cause  of  their  ex- 
tinction is  as  uncertain  as  is  that  of  the  disappearance  of 
the  great  reptiles.  Undoubtedly  the  broad  underlying  fac- 
tor was  lack  of  adaptability  to  new  conditions,  both  physical 
and  biological.  With  changes  in  climate  and  in  the  form  of 
the  earth's  surface  (rise  of  mountains,  formation  of  seas  and 
lakes,  islands  and  archipelagoes  forming  out  of  continents, 
etc.)  new  environments  develop  and  animals  which  cannot 
meet  these  new  conditions  are  bound  to  perish.  Physical 
changes  also  produce  new  conditions  of  food  and  these  in 
turn  lead  to  new  competitions  among  animals  themselves. 
Osborn  believes  that  three  of  the  main  factors  in  the  extinc- 
tion of  the  ancient  mammals  were  their  small  brains,  their 
deficient  teeth  and  poor  feet,  all  of  which  are  serious  handi- 
caps today  in  human  evolution.  INIarsh  has  shown  that  sur- 
viving races  of  animals  have  in  general  larger  brains  than 
dying  ones,  and  while  it  is  not  a  hard  and  fast  rule  that  the 
larger  the  brain  the  greater  is  the  intelligence,  still  brain 
power  and  brain  size  do  in  general  go  hand  in  hand,  and 
these  in  turn  are  good  indices  of  success,  or  survival  in  the 
struggle  for  existence. 

From  the  northern  invaders  have  come  then  in  great  part 
the  mammals  of  today.  In  a  brief  review  such  as  the  pres- 
ent, space  does  not  permit  a  consideration  of  any  but  a  few 
of  many  interesting  forms  whose  remains  have  been  made 
known  to  us  by  the  labors  of  the  paleontologist.  But  we 
may  catch  a  fleeting  glimpse  in  passing  of  some  of  the  crea- 
tures of  the  past  which  once  roamed  upon  our  hills  and  dwelt 
within  our  valleys. 

One  of  the  most  picturesque  of  these  was  Smilodon  or  the 
saber-toothed  tiger,  which  stalked  his  prey  over  the  western 
continent  from  Pennsylvania  to  Argentina,  during  the 
Pleistocene  epoch,  when  the  polar  ice  cap  successively  invaded 
and  retreated  over  northern  North  America.  This  power- 
ful and  ferocious  beast  was  the  size  of  the  present  tiger,  with 
shorter,  stouter  legs  than  those  of  modern  cats,  a  heavy  body, 
powerfully  muscled,  and  a  short  tail  as  in  the  modem  bob- 
cat.    But  the  most  striking  feature  were  the  tusks  in  the 

•Scott,  locus  citatus,  p.  581. 


146 


Biology  in  America 


upper  jaw  which  are  eight  inches  long  or  more.  These  tusks 
have  sonicwliat  the  shape  of  a  scimitar,  being  flattened  on  the 
sides  and  narrow  transversely,  with  a  saw-tooth  edge  behind. 
The  opposing  teeth  of  the  lower  jaw  were  undeveloped.  How 
the  animal  eonld  have  handhnl  these  enormous  tusks  is  a 
problem,  but  it  has  been  suggested  tliat  they  were  used  some- 
what as  a  venomous  snake  uses  its  fangs,  to  strike  and  kill 
the  prey  rather  than  for  cutting  and  biting  it,  Tliis  theory 
is  supported  by  the  relatively  weak  lower  jaw,  as  compared 
with  that  of  a  modern  cat,  and  the  large  mastoid  process  at 
the  base  of  the  skull,  in  which  were  inserted  the  great  mus- 


B 

i 

w^jt  *^^^SSKt 

ki^^!^^^^^^^^^^^^^^! 

i^E  * 

m 

^'^^^^^^^1 

1   i^^^H 

m 

■fl 

The  Saber-Toothed  Tiger 

From  a  restoration  by  Chas.  R.  Knight. 

Courtesy  of  the  American  Muncum  of  Natural  History. 

cles  used  for  lowering  the  head  and  striking  the  prey.  The 
gape  must  have  been  enormous  to  allow  free  play  for  the  use 
of  these  great  fangs,  and  indeed  it  is  not  impossible  that  the 
animal  owes  its  extinction  to  overgrowth  of  these  teeth,  which 
finally  became  a  hindrance  rather  than  a  help  to  their  pos- 
sessor. 

And  what  were  tlie  victims  of  this  cruel  tyrant  of  the 
past?  Its  occurrence  with  the  thick-skinned  cumbrous  beasts 
like  the  elephant  and  the  giant  sloth,  and  the  fact  that  it 
must  have  been  less  agile  than  its  modern  cousins,  to  judge 
from  its  thick-set  legs  and  body,  have  been  advanced  by  Lull 
as  reasons  for  supposing  that  these  animals  formed  its  prin- 
cipal prey ;  while  the  swifter  footed,  more  agile  cats  of  to- 


The  Story  of  the  Rocks  147 

day,  like  the  lion  and  tiger,  are  adapted  to  preying  upon 
swift-footed  beasts  sueli  as  deer  or  horses. 

In  the  oil  flekis  of  southern  California  there  was  recently 
discovered  one  of  the  most  remarkable  ' '  finds ' '  of  bones  ever 
made  in  America,  and  the  Kancho  La  Brea  beds  are  now 
famous  the  world  over.  About  fifteen  feet  below  the  surface 
of  the  ground  is  a  layer  of  oil-bearing  rock,  from  which  oil 
and  tar  issue  and  evaporating  and  oxidizing  form  beds  of 
asphalt.  These  tar  pools  are  intermingled  with  pools  of 
water  at  many  points,  and  many  of  them  are  partly  covered 
with  water.  In  these  tar  pools  animals  are  occasionally 
trapped,  several  species  of  wild  animals  having  recently  come 
to  an  untimely  end  in  this  manner,  while  domestic  animals 
are  frequently  caught  and  liberated  only  with  great  diffi- 
culty. Professor  Merriam  of  the  University  of  California 
who  has  studied  these  pools  more  extensively  than  anyone 
else,  cites  the  following  amusing  incident  of  the  efficacy  of 
the  tar  as  a  trap  for  animals.  ''A  number  of  workmen  were 
engaged  in  covering  a  piece  of  road  with  asphalt,  and  had 
left  their  work  only  partially  completed  in  the  latter  part 
of  a  warm  afternoon.  A  drunken  man  passing  a  short  time 
afterward  fell  by  the  roadside  and  remained  there  to  take 
a  nap.  By  chance  he  extended  himself  on  some  of  the  partly 
softened  asphalt.  Falling  asleep  quickly  he  evidently  lay 
for  a  long  time  without  moving.  During  this  time  his  body 
sank  part  way  into  the  sticky  mass.  After  the  sun  went  down 
and  the  atmosphere  had  cooled,  the  tar  hardened  somewhat, 
and  by  morning  it  was  practically  solid.  When  the  man 
awoke,  he  found  it  impossible  to  extricate  himself.  His  cries 
attracted  a  number  of  persons,  who  attempted  to  free  him. 
Unfortunately  the  whole  side  of  his  body  and  his  head  were 
firmly  set  in  the  asphalt,  and  it  was  very  difficult  to  give 
him  any  assistance.  With  the  aid  of  an  axe  and  Various 
other  fools,  they  finally  succeeded  in  cutting  and  prying  him 
out,  but  not  without  injuring  him  somewhat.  He  was  taken 
to  a  hospital  nearby,  where  numerous  attempts  were  made 
to  separate  the  tar  from  his  body.  Only  after  shaving  his 
head  and  scrubbing  him  with  benzine  was  it  possible  to  give 
him  an  aspect  of  respectability, ' '  "^ 

The  presence  of  bones  in  tliese  tar  pits  has  been  known  for 
a  half-century,  but  until  recently  they  were  generally  as- 
sumed to  be  the  remains  of  modern  animals  and  but  little 
attention  was  paid  to  them.  About  twenty  years  ago  how- 
ever they  came  to  the  notice  of  Professor  Merriam,  and  since 
then  have  been  excavated,  and  carefully  studied  and  de- 
scribed.    The  pits  are  filled  with  a  heterogeneous  collection 

'"Harper's  WeeJcly,"  Dec.   18,  1909. 


148 


Biology  in  America 


ERTY 

.  State 


of  bones,  ^eat  and  small,  saber-toothed  tigers  and  giant 
wolves,  imperial  elephants,  camels,  bison,  horses  and  ground 
sloths  mingling  their  remains  with  those  of  mice,  rabbits  and 
squirrels.  Many  of  these  bones  are  those  of  modern  animals, 
but  a  large  number  represent  extinct  forms.  Of  bird  re- 
mains the  most  striking  are  those  of  the  giant  condor,  but 
even  more  interesting  are  those  of  a  peacock,  an  immigrant 
from  Asia,  and  unknown  elsewhere  in  America. 

The  frontispiece  to  Scott's  beautiful  work  on  the  mammals 
1  IBRAR^  ^^^^  western  hemisphere  is  a  drawing  by  Ilorsfall  repre- 
jiseiUing  one  of  these  tar  pools  of  southern  California  in  Pleis- 
Cotlflfcene  time,  which   is  of  fascinating  interest,   especially   to 
one  who  has  seen  these  wonderful  collections  of  prehistoric, 


Excavation  op  a  Tar  Pit  at  Eancho  La  Brea  near  Los  Angeles, 

California.     Original. 

mingled  with  modern  life.  Mixed  in  the  tar  at  the  edge  of 
the  pool  lies  the  carcass  of  a  giant  elephant,  over  which  a 
giant  wolf  and  a  saber-toothed  tiger  are  quarrelling  for  pos- 
session, while  another  wolf  caught  in  the  tar  nearby  snarls 
defiance  at  the  others.  In  the  background,  perched  on  a 
dead  tree,  or  soaring  overhead,  are  expectant  condors,  wait- 
ing to  feast  upon  vanquished  and  victor,  when  they  like 
their  prey  shall  have  fallen  victims  to  the  relentless  tar, 
while  on  the  shore  are  the  bleaching  bones  of  some  fonner 
visitant  to  the  fateful  pool.  And  thus  may  we  picture  to 
ourselves  the  tragic  fate  of  creatures  whose  remains  have 
come  down  to  us  today  to  tell  the  story  of  the  life  that  was. 
Here  too  are  found  the  bones  of  camels  which  once  inhab- 
ited North  America,  and  migrated  thence  to  the  old  world 
probably  via  the  Behring  Isthmus,  which  at  various  times 


The  Story  of  the  Rocks 


149 


formed  the  route  of  migration  of  many  fonns  between  the 
old  world  and  the  new.  Why  the  camels  should  have  left 
their  birthplace  in  North  America  and  wandered  forth  to  the 
ends  of  the  earth  is  a  mystery,  as  are  so  many  other  prob- 
lems in  the  history  of  animals  as  well  as  in  that  of  man.  So 
too  the  horse,  whose  earliest  home  is  uncertain,  underwent 
his  great  evolutionary  development  in  North  America,  whence 
he  migrated  from  time  to  time  into  South  America,  Europe, 
Asia,  and  Africa,  and  finally  disappeared  from  his  ancestral 
home,  only  to  be  re-established  there  by  the  agency  of  man. 


Early  Days  in  the  Tar  Pools  of  Southern  California 
A  saber  toothed  tiger  and  giant  wolf  coniestiiig  llie  carcass  of  an 
elephant  while  condors  are  waiting  nearby,  until  victor  and  vanquished 
alike  shall  have  fallen  victims  to  tiie  tar.  From  an  illustration  by 
Horsfall  in  Scott's  "History  of  Land  Mammals  in  the  Western  Hemi- 
sphere. ' ' 

Bii  permifinion   of   the  Mdcmithin  Company. 

Here  we  encounter  another  unsolved  problem  in  palasontol- 
ogy — the  extinction  of  the  horse  in  the  Americas.  Glacial 
conditions  alone  would  seem  inadequate,  nor  does  there  seem 
to  have  been  a  sufficient  development  of  larger  carnivores  to 
explain  it.  So  some  sort  of  a  pestilence  has  been  called  in 
to  aid  in  the  explanation,  but  this  is  merely  a  recourse  to  the 
unknown,  a  last  stand  of  the  defeated  philosopher,  when  no 
available  facts  will  serve  his  purpose. 

Thus  in  the  "sands  of  time"  as  well  as  in  flesh  and  bone 


1'50  Biology  in  America 

and  sinew  of  living  creatures  may  we  trace  the  ways  of  evo- 
lution, whose  workings  "declare  the  glory  of  God."  Many 
indeed  are  the  blank  pages  in  the  rccor^l,  which  must  be  left 
for  the  future  to  fill  in ;  but  in  spite  of  all  the  gaps  the  voices 
of  rock  and  flower,  of  the  "bird  of  the  air"  and  the  "beast 
of  the  field"  tell  the  same  story — a  tale  of  attempt  and 
achievement,  of  progress  and  of  promise  for  the  days  which 
are  to  be. 


i 


i 


CHAPTER  V 

Geographical  distrihutian  of  plants  and  anhnals.  Relation 
between  organism  and  enviromnent.  Methods  of,  and 
barriers  to  the  spread  of  plants  and  animals.  Plant  and 
animal  societies.     Life  zones  of  North  America. 

Ill  surveying  the  organic  world  today  one  is  struck  by 
the  fact  that  the  lower  organisms  as  well  as  man  are  distrib- 
uted in  societies,  each  of  which  has  its  characteristic  aspect. 
From  the  wind-swept  tundras  of  the  north  to  the  sunlit  ever- 
glades of  the  south,  we  may  pass  in  review  one  succession 
after  another  of  plant  and  animal  societies,  each  more  or 
less  distinctive  of  the  region  in  which  it  occurs;  and  if  we 
encompass  the  earth  from  east  to  west  we  encounter  an  even 
greater  diversity  of  living  things,  even  though  the  physical 
characters  of  every  realm  are  more  or  less  alike.  And  fur- 
ther, if  we  survey  the  past  history  of  life  upon  the  earth,  we 
find  an  ever-shifting  panorama,  as  fascinating  in  its  chang- 
ing scenes  as  is  the  restless  sea  of  human  life,  whose  ebb  and 
tlow  make  history.  And  what  the  cause  of  all  this  change? 
"Where  may  we  find  a  key  to  the  checker-board  puzzle  of 
the  living  world?  How  have  arisen  the  organic  societies  of 
past  and  present,  and  why  their  ceaseless  succession  like  the 
play  of  light  and  shade?  AVliile  the  immediate  causes  of  the 
movement  and  association  of  plants  and  animals  upon  the 
earth  is  as  yet  in  many  instances  obscure,  we  may  seek  for 
the  ultimate  cause  in  the  great  principle  of  competition  among 
living  things  and  in  their  adjustment  to  their  environment. 
Not  alone  does  the  fitness  of  the  organism  to  its  environment 
determine  its  survival,  but  the  fitness  of  the  environment  to 
the  organism  and  the  ability  of  the  latter  to  find  its  proper 
place  in  nature.  Many  a  square  peg  has  gone  down  in  the 
battle  of  life  because  it  failed  to  find  a  square  hole,  among 
lower  organisms  as  well  as  among  men. 

The  problem  of  geographical  distribution  then  is  that  of 
finding  the  place  of  origin  of  any  given  type  of  life,  the  rea- 
sons for,  and  the  routes  and  methods  of  its  spread  from  its 
center  of  origin,  as  well  as  the  manner  of  its  adaptation  to 
the  surroundings,  both  biological  and  physical,  in  which  it 
lives  today. 

151 


152 


Biology  in  America 


As  the  explorer  setting  forth  upon  an  unknown  journey 
concerns  himself  first  of  all  with  his  equipment  and  means 
of  travel,  so  must  tlie  student  of  l)i()-gcography  consider  pri- 
nuirily  the  factors  wliieli  th^terminc  the  dispersal  of  plants 
and  animals  throuf^hout  the  world.  Animals  of  strong 
Hight,  like  most  birds  and  bats,  are  relatively  unhindered  in 
their  movements  and  coiisequently  these  groups  are  of  world- 
wide distribution.  The  greatest  travelei-  in  tlie  world  is  the 
arctic  tern  which  spends  its  summers  amid  the  arctic  snows, 
where  its  newly  hatched  young  have  been  found  surrounded 
by  a  wall  of  freshly  fallen  snow  scraped  out  of  the  nest  by 
the  parent  bird,  and  journeys  south  11,0(JU  miles  to  spend 
its  winter  on  the  shores  of  the  antarctic  continent.     Many 


The  Aectic  Teen 
The  greatest  traveller  in  \\\v  world.      !■  rom  Cuoke,  "Bird  Migration," 
in  Bulletin  Bureau  of  JViological  Survey. 

other  birds  make  semi-annual  journeys  of  close  to  10,000  miles 
and  the  great  majority  of  them  travel  long  distances  on  their 
migrations.  Bats  also  migrate  long  distances,  this  fact  of- 
fering a  possible  explanation  of  their  presence  on  some  oceanic 
islands,  otherwise  destitute  of  native  mammals. 

Marine  animals,  especially  fishes,  are  often  widespread  in 
their  distrilnition  because  of  their  powers  of  migration  and 
the  relative  absence  of  barriers  within  the  sea,  but  fresh 
water  fishes  are  generally  limited  more  or  less  closely  to  the 
area  in  wiiieli  Ihey  occur.  No  general  rule  however  can  be 
laid  down. 

Among  terrestrial  animals  the  greatest  travellers  are  the 
mammals  and  these  often  perform  long  journeys,  a  habit 
characteristic  of  the  bison  "that  ever-journeying  animal, 
which  moves  in  countless  droves  from  i)oint  to  point  of  the 


/  Geographical  Distnhution  153 

vast  wilderness;  traversing  plains,  pouring  through  the  in- 
tricate defiles  of  mountains,  swimming  rivers,  ever  on  the 
move.  .  .  .  These  great  migratory  herds  of  buffalo  have  their 
hereditary  paths  and  highways,  worn  deep  through  the  coun- 
try, and  making  for  the  surest  passes  of  tlie  mountains,  and 
the  most  practicable  fords  of  the  rivers.  When  once  a  great 
column  is  in  full  career,  it  goes  straight  forward,  regardless 
of  all  obstacles;  those  in  front  being  impelled  by  the  moving 
mass  behind.  At  such  times  they  will  break  through  a  camp, 
trampling  down  everything  in  their  course. 

"It  was  the  lot  of  the  voyagers,  one  night,  to  encamp  at 
one  of  these  buffalo  landing  places,  and  exactly  on  the  trail. 
They  had  not  been  long  asleep  when  they  were  awakened  by 
a  great  bellowing,  and  tramping,  and  the  rush,  and  splash, 
and  snorting  of  animals  in  the  river.  They  had  just  time 
to  ascertain  that  a  buffalo  army  was  entering  the  river  on 
the  opposite  side  and  making  toward  the  landing  place.  With 
all  haste  they  moved  their  boat  and  shifted  their  camp,  by 
which  time  the  head  of  the  column  had  reached  the  shore, 
and  came  pressing  up  the  bank. 

"It  was  a  singular  spectacle,  by  the  uncertain  moonlight, 
to  behold  this  countless  throng  making  their  way  across  the 
river,  blowing  and  bellowing,  and  splasliing.  Sometimes  they 
pass  in  such  dense  and  continuous  column  as  to  form  a  tem- 
porary dam  across  the  river,  the  waters  of  which  rise  and 
rush  over  their  backs,  or  between  their  squadrons.  The  roar- 
ing and  rushing  sound  of  one  of  these  vast  herds  crossing 
a  river,  may  sometimes  in  a  still  night  be  heard  for  miles. ' '  ^ 

The  common  house  rat  is  sometimes  a  wide  traveler.  "]\li- 
grations  of  rats  have  often  been  recorded.  Pallas  narrates 
that  in  the  autumn  of  1727  the  brown  rat  arrived  at  Astra- 
khan in  southern  Russia  from  the  east  in  such  numbers  and 
in  so  short  a  time  that  nothing  could  be  done  to  oppose  them. 
They  crossed  the  Volga  in  large  troops.  The  cause  of  the  mi- 
gration was  attributed  to  an  earthquake ;  but  since  similar 
movements  of  this  species  often  occur  unattended  by  earth 
disturbance,  it  is  probable  that  only  the  food  problem  was 
involved  in  the  migration  which  tirst  brought  the  brown  rat 
to  Europe. 

**In  nearly  all  countries  a  seasonal  movement  of  rats  from 
houses  and  barns  to  the  open  fields  occurs  in  spring,  and 
the  return  movement  takes  place  as  cold  weather  approaches. 
The  movement  is  noticeable  even  in  large  cities. 

"But  more  general  movements  of  rats  often  occur.  In 
1903  a  multitude  of  migrating  rats  spread  over  several  coun- 

*  Irving,  ' '  The  Adventures  of  Captain  Bonneville, "  U.  S.  A.,  p.  354. 
By  permission  of  G.  P.  Putnam's  Sons. 


154  Biology  in  America 

ties  of  western  Illinois,  They  were  noticed  especially  in 
jMercer  and  Kock  Island  counties.  For  several  years  prior 
to  this  invasion  no  abnormal  numbers  were  seen,  and  their 
coming  was  remarkably  sudden.  An  eyewitness  to  the  phe- 
nomenon informed  the  writer  that  as  he  was  returning  to  his 
home  by  moonlight  he  heard  a  general  rustling  in  the  field 
near  by,  and  soon  a  vast  army  of  rats  crossed  the  road  in 
front  of  him,  all  going  in  one  direction.  The  mass  stretched 
away  as  far  as  could  be  seen  in  the  dim  light.  These  animals 
remained  on  the  farms  and  in  the  villages  of  the  surrounding 
country,  and  during  the  winter  and  summer  of  1904  were  a 
veritable  plague."  - 

Even  the  humble  field  mouse  may  perform  long  pilgrimages. 
"The  lemings,  also,  a  small  kind  of  rat,  are  described  as  na- 
tives of  the  mountains  of  Kolen,  in  Lapland;  and  once  or 
twice  in  a  quarter  of  a  century  they  ajjpear  in  vast  numbers, 
advancing  along  the  ground  and  'devouring  every  green 
thing.'  Innumerable  bands  march  from  the  Kolen,  through 
Northland  and  Finmark,  to  the  AVestern  Ocean,  which  they 
immediately  enter;  and  after  swimming  about  for  some  time, 
perish.  Other  bands  take  their  route  through  Swedish  Lap- 
land to  the  Bothnian  Gulf,  where  they  are  drowned  in  the 
same  manner.  They  are  followed  in  their  journeys  by  bears, 
wolves,  and  foxes,  which  prey  upon  them  incessantly.  They 
generally  move  in  lines,  which  are  about  three  feet  from  each 
other,  and  exactly  parallel,  going  directly  forward  through 
rivers  and  lakes ;  and  when  they  meet  with  stacks  of  hay  or 
corn,  gnawing  their  way  through  them  instead  of  passing 
round.  These  excursions  usually  precede  a  rigorous  winter, 
of  which  the  lemings  seem  in  some  way  forewarned. ' '  ^ 

Reptiles  and  Amphibia,  because  of  their  inadeijuate  means 
of  locomotion  and  their  sluggish  habits,  are  poor  travellers 
and  their  dispersal  must  be  due  in  the  main  to  natural  in- 
crease or  to  i)urely  passive  causes  such  as  transfer  of  eggs 
by  currents  of  water  or  to  the  agency  of  man. 

Apart  from  the  insects  the  invertebrates  are  for  the  most 
part  inactive  migrants,  and  here  too  dispersal  is  mainly  pas- 
sive, though  some  animals,  such  as  the  squid  or  octopus,  are 
active  swimmers,  and  probably  travel  considerable  distances 
"under  their  own  steam,"  so  to  speak. 

The  means  of  passive  dispersal  of  animals  are  numerous 
and  varied.  In  the  transport  of  marine  animals  currents 
play  the  greatest  part.  In  this  way  animals  are  carried 
great  distances  at  sea,  distances  Avhich  are  limited  only  by 
the  animal's  power  of  survival  and  by  the  extent  of  the  cur- 

='Laiitz,  "The  Brown  Eat  in  the  United  States,"  pp.  16-17. 
"Lyell,  "Principles  of  Geology,"  11th  cd.,  Vol.  II,  p.  361. 


Geographical  Distribution  155 

rent  itself.  Even  land  animals  may  be  carried  over  wide 
stretches  of  water  by  winds  and  currents.  The  late  Alfred 
Russell  Wallace  records  the  transjjort  of  a  boa  constrictor 
from  Africa  to  St.  Vincent,  two  hundred  miles  away,  on  a 
floating  cedar  tree.  Polar  bears  have  occasionally  been 
stranded  upon  the  shores  of  Iceland  by  icebergs.  Lyell  quotes 
an  early  observer  to  the  effect  that  "wolves,  in  the  arctic  re- 
gions, often  venture  upon  the  ice  near  the  shore,  for  the  pur- 
pose of  preying  upon  young  seals,  which  they  surprise  when 
asleep.  When  these  ice-floes  get  detached,  the  wolves  are 
often  carried  out  to  sea ;  and  though  some  may  be  drifted  to 
islands  or  continents,  the  greater  part  of  them  perish,  and 
have  been  heard  in  this  situation  howling  dreadfully,  as  they 
die  by  famine.  According  to  the  same  authority  travellers 
in  the  Amazon  country  have  on  several  occasions  observed 
monkeys,  squirrels,  crocodiles  and  other  animals  journeying 
down  that  river  on  rafts  of  floating  trees  and  tangled  vege- 
tation. Four  pumas  from  such  rafts  are  reported  to  have 
visited  ]\Iontevideo  in  one  night."* 

Fresh  water  invertebrates  may  be  carried  by  currents  of 
water  or  attached  to  the  feet  of  birds,  or  by  the  wind  in  the 
case  of  the  eggs  or  cysts  from  the  bottom  of  diy  pools. 

JNIan's  role  in  the  spread  of  the  animal  inhabitants  of  the 
earth  is  a  very  important  one.  The  early  Spanish  explorers 
brought  horses  to  South  America  in  1537,  "and  the  colony 
being  then  for  a  time  deserted,  the  horse  ran  wild ;  in  1580, 
only  forty-three  years  afterwards,  we  hear  of  them  at  the 
Strait  of  Magellan!"^  The  spread  of  the  English  sparrow 
and  the  brown  rat,  both  introduced  species  from  Europe,  is 
too  well  known  to  need  repetition  here,  while  the  devastation 
wrought  among  the  trees  of  New  England  by  the  brown-tail 
and  the  gypsy  moths,  is  a  warning  example  of  the  danger  of 
disturbing  the  scales  which  Nature  ordinarily  holds  so  nicely 
balanced. 

The  spread  of  animals  and  their  occupation  of  the  earth 
resolves  itself  into  a  gi-eat  obstacle  race,  and  "the  race  is  not 
always  to  the  swift."  The  barriers  to  the  spread  of  animals 
are  manifold — temperature,  moisture,  sunlight,  chemical  char- 
acter of  water,  mountains,  rivers,  lakes  or  seas,  deserts,  for- 
ests and  treeless  plains  are  all  barriers  to  various  kinds  of 
animals.  Temperature  is  probably  the  greatest  obstacle  to 
the  dispersal  of  marine  animals.  AVere  it  not  for  the  trop- 
ics intervening  between  the  temperate  and  colder  seas  of 
north  and  south  their  distribution  would  probably  be  world 

*  Lyell,   locus   citatiis,   p.   366. 

^Darwin,  "Voyage  of  a  Naturalist,"  p.  233.  D.  Appleton  and 
Company. 


156  Biology  in  America 

wide,  but  temperature  is  usually,  though  not  always,  a  very 
effective  barrier  to  their  spread.  This  was  strikingly  illus- 
trated by  the  disappearance  of  the  tiiefish  off  the  xVtlantic 
coast  some  years  ago,  which  has  been  described  in  a  previ- 
ous chapter.  Currents  may  serve  not  alone  as  a  means  of 
transport  for  inactive  forms,  but  through  temperature  dif- 
ferences as  a  bari'ier  to  their  spread,  as  well.  Northern  ani- 
mals drifting  southward  in  the  Atlantic  under  the  influence 
of  the  Labrador  current,  sweeping  past  the  shores  of  Labra- 
dor and  Newfoundland,  may  be  caught  by  the  Gulf  Stream 
moving  toward  the  northwestern  coasts  of  Europe,  and  their 
southern  journey  terminated. 

During  the  cruise  of  the  U.  S.  Bureau  of  Fisheries  steamer 
in  1884,  Captain  Tanner  reports  that  on  July  20,  when  off 
the  mouth  of  Chesapeake  Bay  "we  passed  numerous  dead 
octopods  floating  on  the  surface.  This  unusual  sight  at- 
tracted immediate  notice  and  no  little  surprise  among  those 
who  knew  their  habits,  as  it  was  not  suspected  at  first  that 
they  were  dead.  .  .  .  These  dead  cephalopods  were  seen  fre- 
quently on  the  100-fathom  line  and  outside  of  it,  from  the 
position  given  above  to  the  meridian  of  jMontauk  Point,  a 
distance  of  180  miles.  They  were  less  numerous  however  as 
we  went  to  the  northward  and  eastward.  Several  dead  squid 
were  seen  also,  and  two  specimens  were  picked  up  with  a 
scoop-net."*^ 

"From  the  Barents  Sea  we  know  many  instances  of  a  sim- 
ilar destruction  of  animals  on  a  large  scale.  The  case  of  the 
boreo-arctic  fish,  the  capelan  ...  is  specially  striking,  niil- 
lions  of  this  fish  having  occasionally  been  found  drifting 
dead  at  the  surface.  In  the  Barents  Sea  very  sudden  changes 
of  temperature  occur,  and  it  is  natural  to  conclude  that  the 
death  of  the  fish  is  caused  thereby.  The  greatest  destruction 
of  this  kind  probably  occurs  among  the  young  stages,  eggs 
and  larvae  of  fishes.  As  we  shall  see  later,  these  young 
stages  may  be  removed  by  currents  very  far  from  the  places 
where  they  are  capable  of  developing,  and  in  all  probability 
they  are  liable  to  encounter  catastrophes  which  sweep  them 
off  in  enormous  numbers."'^ 

So  too  the  chemical  environment  prevents  the  invasion  of 
inland  waters  by  marine  forms  and  vice  versa,  although  this 
is  not  true  of  those  fish  like  the  shad  and  salmon,  which 
ascend  the  rivers  at  spawning  time.  In  such  cases  however 
the  age  and  sexual  maturity  of  the  fish  determine  their  move- 
ments, so  that  at  most  times  of  the  year  with  these  fish  as  well 

•Tanner    "Eoport  of  U.  S.  Fish  Commissioner  for  1884,"  p.  32. 
'Murray,  "The  Depths  of  the  Ocean,"  pp.  707-8.     By  permission  of 
the  Macmillan  Company. 


Geographical  Distribution  157 

as  others  the  salt  eontent  of  tlie  water  does  limit  their  distri- 
bution. The  extent  to  Avhieh  fresh  water  fisli  can  with- 
stand salt  water  and  vice  versa  is  still  a  moot  question,  but 
the  salt  content  certainly  does  i^\n.j  a  determining  role  in  the 
distribution  of  all  fish. 

The  inhabitants  of  inland  w^aters  also  find  the  chemical 
environment  one  of  the  determining  factors  in  their  distri- 
bution. Here  one  may  find  all  degrees  of  salinity  from  fresh 
or  slightly  saline  waters,  to  those  such  as  the  Dead  Sea  in 
Palestine  or  the  Great  Salt  Lake  of  Utah,  containing  much 
greater  amounts  of  salt  than  does  the  ocean.  Correspond- 
ing to  the  differences  in  the  saltiness  of  these  inland  waters 
there  are  marked  diiferences  in  the  kinds  of  life  inhabiting 
them. 

The  barriers  to  the  spread  of  land  animals  are  more  nu- 
merous than  are  those  which  affect  aquatic  forms.  As  with 
the  latter  so  too  with  these  does  temperature  play  an  impor- 
tant part.  Every  one  is  familiar  with  the  great  differences 
between  the  animal  life  of  the  tropics  and  the  poles,  and 
equally  marked  are  those  which  strike  the  observer  as  he  as- 
cends some  lofty  mountain,  and  the  more  so  the  farther  south 
the  mountain  lies.  Mountain  ranges  have  a  notable  influ- 
ence in  separating  one  fauna  from  another.  The  animal  life 
of  the  Great  Plains  of  the  east  is  distinctly  different  from  that 
of  the  Great  Basin  to  the  west  of  the  Rocky  Mountains. 
Wide  stretches  of  desert  present  an  impassable  obstacle  to 
most  forms  of  life,  while  bodies  of  water  may  with  equal  em- 
phasis say  to  the  animal  wanderer  "Thus  far  shalt  thou  go, 
and  no  farther." 

Plant  journeys  are  wholly  passive  ones,  and  affected  mainly 
by  the  carriage  of  fruit  or  seed  by  wind,  water  and  animals. 
The  tumble-weed  driven  across  the  prairie  by  the  wind  and 
heaping  itself  up  in  great  piles  along  the  fences,  the  down  of 
the  dandelion  as  it  floats  idly  through  the  air  on  a  summer 
afternoon  to  settle  softly  in  some  protected  corner  of  your 
front  lawn,  and  the  long-awned  heads  of  the  fox-tail  grass 
tumbling  merrily  over  field  and  roadside  all  bear  emphatic 
testimony  to  the  part  played  by  wind  in  the  spread  of  plants, 
especially  those  which  are  an  unmitigated  nuisance ;  while 
any  one  who  has  watched  a  dog  disentangling  himself  from  a 
coat  full  of  burs  will  realize  the  important  role  played  by 
animals  in  plant  distribution.  One  of  the  most  important 
factors  in  plant  distribution  is  man  himself.  To  prove  this 
one  need  only  follow  a  railway  track  or  a  highway  and  note 
the  never-ending  succession  of  Avecds,  which  are  distributed 
thereon.  ]\Iany  of  the  most  common  and  pestiferous  mem- 
bers of  plant  as  well  as  of  animal  and  human  society  are  im- 


158  Biology  in  Anio-ica 

migrants  from  Europe — witness  the  Eussian  sow  thistles,  the 
wild  radisli  and  the  barnyard  grass. 

To  discuss  in  any  detail  the  past  movements  and  distribu- 
tion of  plants  and  animals  in  North  America  would  in  itself 
fill  a  more  than  ample  volume.  In  the  preceding  elmpter 
some  of  the  great  movements  of  animal  life  in  North  Amer- 
ica have  been  briefly  mentioned,  and  under  the  present  head- 
ing it  must  suffice  to  consider  briefly  some  of  the  facts  and 
problems  of  present  day  distribution  and  of  the  relations  of 
plant  and  animal  societies  to  one  another  and  to  their  sur- 
roundings. 

The  study  of  plant  ecology,  that  is,  the  study  of  the  plant 
at  home,  as  an  individual  and  as  a  member  of  society,  owes 
its  inception  in  America  to  the  work  of  Pound  and  Clements, 
who  in  their  " Phytogeography  of  Nebraska"  in  1897  de- 
scribed the  plant  societies  of  that  state  and  developed  new 
and  more  accurate  methods  for  their  study.  This  was  fol- 
lowed in  1905  by  Clements'  "Research  INIethods  in  Ecology," 
in  which  the  whole  field  of  plant  ecology  and  the  methods  for 
its  investigation  were  presented.  Following  the  appearance 
of  these  works  came  a  host  of  papers  dealing  with  various 
phases  of  plant  ecology,  the  most  comprehensive  of  which  is 
that  of  Clements  on  "Plant  Succession." 

When  an  area  of  land  is  denuded  of  its  plant  covering,  as 
happens  far  too  often  in  our  fire-swept  forests,  or  as  a  result 
of  fioods  or  landslides ;  or  when  a  new  area  appears  as  in  the 
case  of  the  drying  up  of  a  lake  or  the  shifting  of  a  river, 
there  is  an  inrush  of  plant  settlers  to  occupy  the  virgin  soil. 
The  character  of  the  new  settlers  depends  upon  many  fac- 
tors— the  character  of  the  new  soil,  the  relative  proximity  of 
adjacent  species  of  plants,  the  ease  with  which  the  seeds  or 
runners'  of  these  plants  can  reach  the  new  territory  and  their 
readiness  to  establish  themselves  there  after  their  arrival. 
The  arrival  of  the  new  settlers  will  depend  upon  all  the  many 
factors  which  determine  plant  dispersal — strength  and  direc- 
tion of  wind  currents,  presence  of  streams  and  rainfall,  drain- 
age which  may  carry  seeds  on  to  the  new  area,  and  the  abim- 
dance  and  movements  of  seed-bearing  animals. 

In  the  broken  chasms  of  mountain  fastnesses,  where  the 
shattered  peaks  that  were,  now  lie  in  a  mass  of  tumbled  ruin, 
or  upon  the  sheer  slopes  of  granite  cleft  by  some  contortion 
of  the  earth,  the  humble  lichen  finds  its  home.  In  some  small 
chink  or  crevice  of  tlie  rock  where  a  few  drops  of  water  lin- 
ger from  the  winter's  snow,  its  filaments  take  hold,  and  when 
the  breath  of  summer  dries  its  niche  it  lies  dormant  waiting 
for  the  rain  or  melting  snow.  Through  the  acids  secreted 
by  these  lichens,  and  by  the  hardy,  drouth-resistant  mosses 


i 


Geographical  Distribution 


159 


which  soon  join  them,  and  by  the  more  powerful  action  of 
the  frost,  and  the  ever-wearing  action  of  the  dust  blast  driven 
by  the  wind,  the  rock  is  gradually  crumbled  into  dust,  which 
together  with  the  decay  of  moss  and  lichen  forms  a  little 
soil,  in  which  other  mosses  may  take  root ;  and  by  and  by  the 
seeds  of  a  few  hardy  grasses  find  a  place,  and  by  their  roots 
the  wind  and  rain-borne  dust  is  caught  and  soon  a  little  turf 


A  Lichen   Society 

Lichens  are  among  the  earliest  invaders  of  a  rocky  surface,  preparing 
the  way  for  higher  plants  to  follow. 

Courtesy  of  the  Con/rad  Lantern  Slide  Company,   Chicago. 

is  formed.  Now  some  hardy  perennials  wander  in,  and  their 
stouter  roots  serve  as  wedges  to  pry  apart  the  smaller  chips 
of  rock  and  aid  in  making  new  soil.  And  in  course  of  time 
a  heather  society  is  formed,  made  up  of  grasses  and  the  low- 
growing  matted  bodies  of  perennial  herbs,  mingled  with  a 
few  annuals,  which  live  but  a  single  year.  And  now  some 
hardy  shrub,  perchance  a  mountain  willow,  or  it  may  be  a 
seedling  pine  comes  in,  and  ever  and  anon  new  trees  take 
root  and  grow,  decay  of  root  and  leaf  and  fallen  stem  adds 
to  the  humus  soil,  and  in  the  shadow  of  the  growing  trees 
sun-loving  plants  die  out  and  shade-lovers  take  their  place; 
and  now  a  forest  stands  where  once  was  barren  rock. 


160 


Biology  in  America 


So  too  the  deathbed  of  a  lake  is  the  birthplace  of  a  new 
cormminity  of  plants.  In  the  sliallow  margins  of  the  lake 
rises  a  niiniatnre  forest  of  cat-tail,  rnsh  and  sedge.  With  the 
gradual  shrinkage  of  the  lake  through  evaporation  or  drain- 
age, and  the  slow  accumulation  of  wind-borne  dust  and  debris 
on  its  bottom,  runners  of  rush  and  sedge  press  further  from 
the  shore.  Their  decaying  stems  and  leaves,  together  with 
wdnd-borne  sediments  form  ever-increasing  mud  in  the  shal- 
low water,  which  with  the  recession  of  the  lake  forms  a  fer- 
tile field  for  the  advancing  grasses  along  its  shores.  And 
thus  a  meadow  is  formed  into  which  soon  come  the  moisture- 


A  Glacial  Pond  in  the  Eocky  Mountains 
Showing   the   encroaching   forest.      Original. 

loving  herbs,  and  then  from  near  or  far  wind-driven  catkins 
come  and  willows  grow  from  these,  the  vanguard  of  the  for- 
est ;  which  soon  are  joined  by  other  trees,  of  various  sorts, 
dependent  on  proximity  and  ease  of  carriage  of  their  seeds; 
and  thus  a  young  forest  takes  its  stand  upon  the  old  lake 
bottom  and  meadow  herb  and  grass  give  place  to  trees  and 
plants  which  love  the  dark — the  victors  in  the  "struggle  for 
existence."  Where  however  forests  are  far  away  or  soil  and 
climate  are  not  adapted  to  growth  of  trees,  the  grasses  per- 
sist and  a  meadow  marks  the  graveyard  of  the  lake. 

The  inter-relationships  of  the  various  members  of  plant 
communities,  both  to  one  another  and  to  their  environment, 


Geographical  Distribution 


161 


are  well  nigh  as  varied  as  are  those  of  human  society.  Tem- 
perature, moisture,  wind  and  light  are  the  four  principal 
parts  of  the  plant's  environment,  but  these  in  turn  are  de- 
pendent on  other  factors,  such  as  altitude,  topography  and 
soil.  The  structure  of  the  plant  itself  determines  its  re- 
sponse to  these  factors  and  its  survival  or  extinction,  while 
the  relation  of  plant  to  plant  in  determining  such  factors 
as  light,  food  supply,  growing  space,  etc.,  and  the  inter- 
relationship between  plants  and  animals,  affecting  transport 
of  seeds,  and  forage  for  herbivorous  animals,  all  have  a  life 
and  death  meaning  in  the  existence  of  the  plant. 

Not  only  is  the  distribution  of  plants  determined  in  large 
measure  by  that  of  animals,  but  even  more  is  the  occurrence 
of  the  latter  dependent  upon  that  of  the  former.     Especially 


/so    I2a    30      iO    JO 


/?«?     ISO    160 


Diagram  of  the  Six  Great  Zoogeographical  Eealms  of  the  Earth 

After  Sclater  and   Wallace. 

is  this  tiiie  of  herbivorous  types,  which  necessarily  are  de- 
pendent upon  the  presence  of  their  forage  plants.  The  move- 
ments of  grazing  animals,  such  as  horses  and  cattle,  are  in 
particular  dependent  upon  the  abundance  of  grasses,  and  in 
the  early  days  of  the  West,  Indians  and  white  men  alike 
guided  their  movements  in  the  search  for  buffalo  largely  by 
the  condition  of  the  prairies  over  which  the  bison  roamed. 
Not  only  are  the  herbivorous  types  dependent  on  the  vege- 
tation in  their  movements,  but  also  the  carnivorous  animals 
which  prey  upon  the  former.  In  the  northern  forests  the 
movements  of  the  deer  in  winter  largely  determine  those  of 
their  enemy,  the  wolf.  During  the  mouse  plague  in  the  Hum- 
boldt Valley  in  Nevada  in  1907-8  the  abundance  of  the  mice 
attracted  thither  large  numbers  of  hawks  to  feed  upon  them. 
Based  on  the  distribution  of  their  animal  inhabitants  the 


162 


Biology  in  America 


zoogeographer  divides  the  earth  into  five  great  rcahns,  which 
are  more  or  less  overlapping  but  which  show  in  a  broad  way 
the  arrangement  of  animal  life  upon  our  globe.  These  realms 
are  the  Iloloarctic,  including  North  America  to  Mexico,  Eu- 
rope, northern  Africa,  and  most  of  Asia;  the  Neotropical, 
comprising    South    and    Central   America    and    Mexico;    the 


Arctic- Alpine      |        ] 

Hucisonian 

Canadian 

Transition 

Upper  Sonoran 

Lower  Sonoran 

Tropical      Hi',' I 


After   U.    S.    Biolocical    ISukvey 


Ethiopian,  Africa,  south  of  the  Sahara;  the  Oriental,  India  and 
most  of  the  Malay  Archipelago ;  and  the  Australian,  Australia, 
New  Zealand,  the  southeastern  portion  of  the  Malay  Archi- 
pelago and  the  South  Sea  Islands. 

In  the  study  of  the  geographical  distribution  of  animals 
(especially  birds  and  mammals)  in  the  United  States  and 
in  the  correlation  of  their  distribution  with  that  of  plants, 
the  principal  agency  has  been  the  United  States  Biological 


Geographical  Distribution 


163 


Survey,  although  the  studies  of  other  workers,  especially 
those  of  Allen  on  mammals  and  Jordan  on  fish,  have  contrib- 
uted largely  to  our  knowledge  of  this  subject. 

The  Biological  Survey  divides  North  America  into  zones  of 
plant  and  animal  life  based  primarily  on  temperature,  which 
zones  may  be  subdivided  to  a  large  extent  on  the  basis  of  mois- 
ture. These  zones  follow  in  a  very  broad  way  the  parallels 
of  latitude  in  the  lower  country  and  the  levels  of  altitude  in 
the  mountains.  Let  us  take  for  an  example  San  Fran- 
cisco Mountain  in  northern  Arizona,  whose  life  zones  have 
been  studied  by  Doctor  Merriam,  the  former  chief  of  the  Sur- 
vey.    The  zonal  distribution  of  life  shows  somewhat  more 


Arctic  Alfine 


Cdna'^ion 


Trjfisition 


upper  i>onora/t       Lo^ar  ionoran 


Profile  of  San  Francisco  and  0  'Leary  Peaks   in   Arizona 

To  illustrate  their  life  zones.  The  left  side  of  the  diagram  is  S.  W., 
the  right  is  N.  E.  The  horizontal  lines  indicate  contour  intervals  of 
IjUUU  feet.  Modified  after  Merriam 's  "Biological  Survey  of  the  Sail 
Francisco  Mountain  Region  .  .  .  Arizona,"  North  American  Fauna, 
No.   3. 

clearly  in  the  case  of  an  isolated  group  of  mountains  such  as 
those  of  which  San  Francisco  Mountain  forms  the  principal 
peak,  than  it  does  in  an  extended  range  such  as  the  Rockies  or 
the  Sierra  Nevada,  where  the  zones  are  more  or  less  broken  up 
by  the  irregular  contour  of  the  mountains,  with  their  jum- 
bled masses  of  peaks  and  valleys.  These  mountains  further 
include  more  zones  from  base  to  summit  than  do  those  of  like 
altitude  further  north,  where  the  temperature  range  from 
base  to  summit  is  less. 

San  Francisco  Mountain  is  located  in  north  central  Ari- 
zona on  the  elevated  plateau  tlirough  which  the  Colorado 
River  has  cut  its  titanic  chasm.  The  town  of  Flagstaff,  site  of 
the  Lowell  Observatory,  from  which  the  late  Professor  Lowell 


164 


Biology  in  America 


brought  us  so  many  wonderful  messages  from  Mars,  is  located 
near  its  southern  base.  The  mountain,  12,794  feet  in  height, 
marks  the  grave  of  an  extinct  volcano,  and  several  lesser  vol- 
canic peaks  rise  from  the  plateau  near  the  main  peak. 

If  we  reverse  the  usual  order  of  things  and  fancy  ourselves 
deposited  by  aeroplane  on  the  summit  of  the  peak  we  shall 
find  ourselves  in  a  treeless,  wind  swept  area  of  "bare  vol- 


An  Alpine  Dwarf 

At   13,000  feet  on  Pike's  Peak,   Colorado.      From    "Plant   Indicators." 

Courtesy  of  Doctor  F.  E.   Clements  and  the  Carnegie  Institution. 

canie  rock,"  which  even  in  this  southern  latitude  (35°N.)  is 
snow-clad  for  three-fourths  of  the  year.  Here  many  of  the 
herbs  tend  to  form  spreading  rosettes,  their  leaves  keeping 
close  to  the  earth,  and  sending  up  a  short  flower  stalk  from 
the  center.  In  the  intense  sunlight  of  the  clear  mountain 
air,  growth  is  rapid  and  flowers  and  fruits  mature  early. 
To  paraphrase  an  old  saw  the  plants  make  fruit  while  the 
sun  shines.     Most  of  th=em  are  species  occurring  on  high  moun- 


Geographical  Distribution 


165 


tain  summits  and  arctic  lands  in  North  America,  while  some 
extend  around  the  world.  On  the  mountain  summits  they 
form  isolated  groups,  cut  off  from  their  congeners  of  the 
north  by  the  wide  intervening  plains  and  valleys.  How  have 
they  come  there?  In  glacial  days,  when  the  ice  sea  swept 
southward  to  New  Jersey,  Illinois  and  Nebraska,  and  gla- 
ciers covered  the  higher  slopes  of  our  western  mountains, 
plants  and  animals  were  forced  to  move  before  it ;  for  the 
Ice  King  is  an  inexorable  landloi-d,  and  when  he  undertook 
to  dispossess  the  tenants  of  the  lands  there  was  no  gainsay- 


PiKA,   OR   EocKY   Mountain    Hare 

An  inhabitant  of  rock  slides  both  above  and  below  timber  line.    Photo 
by  E.  R.  Warren.     From  Metcalf,  "Organic  Evolution," 
By  permission   of   the  Maimillan  ComiJany. 

ing  his  wishes  in  the  matter.  But  with  the  retreat  of  the 
ice  the  former  tenants  returned  to  their  old  abodes.  Some 
of  them  however  instead  of  moving  north  once  more  after 
the  retreating  ice,  found  a  more  convenient  path  up  the 
mountain  sides  and  thus  came  to  settle  in  a  new  home,  on 
the  bleak  mountain  tops  where  they  found  the  climate  to 
their  liking. 

So  too  the  animal  life  of  alpine  summits  contains  many 
species,  common  alike  to  inonntain  top  and  ban-en  ground  of 
tlie  far  North,  tiiongh  the  number  repoi'ted  for  the  San  Fran- 
cisco Mountain  is  too  few  to  allow  any  generalizations  con- 


ITARMIGAN   IN  (SUMMER  PLUMAGE 
Photo  hy  E.  R.  Warren. 


Ptaemigan  in  Autumn  Plumage 
Photo  ly  E.  R.  Warren. 

166 


Ptarmigan  in  Winter  Plumage 
Photo  hy  E.  R.   Warren. 


Clarke's  Crow 
A  characteristic  bird  of  the  high  mountains. 
Photo  by  E.  R.  Warren. 

167 


168 


Biology  in  America 


cerning  them.  On  alpine  summits  of  the  Rocky  Mountains 
and  Sierra  Nevada  however  one  meets  with  several  more  or 
less  characteristie  species.  Here  the  marmot's  whistle  and 
the  sharp  call  of  the  pika  or  mountain  hare,  mingled  with 
the  harsh  note  of  the  leucosticte,  and  the  pipit's  plaintive  call 
are  carried  across  the  barren  slopes  by  the  rush  of  the  wind. 
Here  too  is  the  home  of  the  ptarmigan,  whose  changing  fash- 
ion with  the  changing  season — white  in  winter,  mottled  black, 


- 

w^ 

l^tf'''^^ 

'f^SHKS 

.^ 

■-^■lijf-ssr  .v.^4 

^ 

&rfi^'^ 

.'■^^ 

■-',•■■'■ 

H^Bj^^^BPi-  —  .^"^ 

oMm 

..-^^'^  -1^ 

^     ^-^ 

.t-'".  *i 

^^•ffeS-   '•>*-i*»3>'f" 

^ 

't^t.^immmi-^ 

■-■••'    '."^V^yr-o-.V 

^-•^;;.i^^;(^:.^ 

..>iys?.>-  ■  .-1-.- . ;>/»  ^  \%  -i 

^ 

©Ifgpi 

g^^ 

:*^^ 

^p'      ' 

H^^ 

0-- 

'^^b^9^^^?^i^^^^^^^Bjflnl^|R 

.>--^  """'^'^■t;^:'' 

^^p^*^^^ 

% 

^2^^::'^ 

^^^^ 

Timber  Line  in  the  Rocky  Mountains 
Alpine  firs  at  11,000  feet  altitude  on  Long's  Peak,  Colorado.     From 
"Plant  Indicators." 

Courtemj  of  Doctor  F.  E.   Clements  and  tite  Carnegie  Institution. 

buff  or  white  in  summer — matches  them  so  closely  with  their 
background,  that  one  stumbles  upon  them  before  he  is  aware 
of  it.  The  birds  seem  to  realize  their  protection,  for  they 
are  very  tame  and  may  sometimes  be  killed  with  a  stick  or 
stone.  This  lameness  is  however  more  likely  due  to  infre- 
quent molestation.  The  ptarmigan  is  also  a  characteristic 
member  of  the  arctic  community  nesting  on  the  tundras  of 
the  far  north,  together  with  the  little  lapland  longspur  and 
the  snow  bunting,  wliofie  change  of  coat  in  spring  and  au- 
tumn  resembles  that   of   the  ptarmigan.     Even   the   gauzy- 


Polar  Bears 
Courtesy  of  the  National  Zoological  Park. 


The  Cariboo 

Photo  hy  Elwin  R.  Sanborn. 

Courtesy  of  the  Neio  York  Zooloyiral  KocUty. 


1G9 


-Mmr^^-^ 


>ft5*>-.-  .- 


Musk  Oxen 
Inhabitants  of  the  barren  lands.    Photo  by  Elwin  E.  Sanborn. 
Courtesy  of  the  New  York  Zoological  Society. 


The  Wolverine 
A  prowling  marauder  of  the  north  woods. 
Courtesy  of  the  New  York  Zoological  Society. 


170 


Canadian  Zone  Forest  in  Colorado 

The  spruce   tree  in  the  middle  foreground   is  a  striking  example  of 
symmetry.     Original. 


171 


172  Biology  in  America 

winjred  butterfly  may  be  found  flitting  over  the  barren  lands 
of  the  Arctic  and  the  highest  mountain  peaks.  Many  other 
types  of  insects  may  also  be  found  here. 

Over  the  ice  and  snow  fields  of  the  Arctic  the  polar  bear 
holds  sway,  the  mortal  enemy  of  the  seal,  while  the  arctic 
fox  plays  the  part  of  a  hanger-on  at  court,  feasting  upon 
the  remains  of  seal  which  <lrop  from  the  royal  table.  Over 
the  tundras  of  the  barren  lands,  covered  with  an  abun- 
dant vegetation  in  the  brief  summer,  roam  the  musk  ox  and 
the  barren  ground  carilxni,  while  the  arctic  hare,  the  mar- 
mot and  the  lemming  or  northern  mouse,  find  a  table  plen- 
tifully spread  with  roots  and  grasses. 


The  Woodchuck 

Photo  by  Eltcin  R.   Sanhorn. 
Courtcmj   of   the  Neic   York  Zoological  Society. 

Descending  from  the  barren  summit  of  the  mountain  to 
timber  line  one  encounters  the  outposts  of  the  forest  at  an 
altitude  of  11,500  feet  in  the  form  of  stunted  spruce  and  pine, 
"whose  gnarled  and  weather-beaten  forms  bear  testimony  to 
the  severity  of  their  struggle  with  the  elements." 

Below  timber  line  one  comes  to  a  rather  indefinite  zone 
characterized  by  spruces  and  fox-tail  pines.  IMany  of  the 
plants  characteristic  of  this  zone  on  San  Fi'ancisco  Mountain 
are  represented  by  the  same  or  closely  related  species  in  the 
"upper  spruce  belt  of  the  higher  Alleghenies,  the  Rocky 
Mountains,  the  Cascades,  and  the  Sierra  Nevada,  and  ...  the 
great  northern  spruce  forest  of  Canada."     Here  live  several 


The  Weasel  in  Its  Winter  Dress 

Photo  by  Elwin  R.  Swiborn. 

Courtesy  of  the  New  York  Zoological  Society. 


The  Snowshoe  Rabbit 

So  named  from  its  large  feet. 

Photo  by  Elwin  R.  Sanborn. 

Courtesy  of  the  New  York  Zoological  Society. 

173 


174 


Biology  in  America 


animals  which  extend  further  down  into  the  following  zone, 
the  Hudsonian  possessing  so  little  that  is  characteristic  that 
it  may  perhaps  best  be  included  in  the  following  or  Cana- 
dian, and  the  two  grouped  together  as  the  Boreal  zone.  The 
Canadian  zone,  which  on  San  Francisco  Mountain  lies  between 
9,500  and  8,200  feet,  is  characterized  by  the  Douglas  spruce, 
the  limber  pine,  balsam  fir  and  aspens.  In  the  Boreal  zone  on 
San  Francisco  Mountain  occur  a  number  of  animals  charac- 
teristic of  this  zone  in  Canada  and  the  mountains  in   the 


Am'^'   > 


Canadian  and  Transition  Zone  Landscape 
Fir  forest  of  Canadian  zone  at  left,  open  pine  timber  of  transition 
zone  at  right,  showing  effect  of  slope  exposure. 

Courtesy  of  the  V.  S.  Bureau  of  Biological  Survey. 

United  States.  Some  of  the  better  known  which  inhabit  it 
throughout  the  United  States  and  Canada  are  the  elk,  moose 
and  woodland  caribou;  the  weasel,  fisher,  martin,  mink,  red 
fox,  wolverine,  gray  wolf;  the  marmot  or  woodchuck,  por- 
cupine, pika  and  snowshoe  rabbit;  most  of  the  mountain 
sheep  and  the  Rocky  Mountain  goat,  which  is  not  a  goat  at 
all,  but  a  relative  of  the  European  chamois  or  antelope. 
"The  mammals  of  this  sub-region  (boreal)  are  largely  of  old 
world  origin,  many  of  them  coming  in  with  the  great  immigra- 
tions of  the  Pliocene  and  Pleistocene  epochs,  but  there  are 
also  native  American  elements  and  even  one  genus  of  South 


Geographical  Distribution  175 

American  origin,  the  short-tailed  or  Canada  porcupine."^ 
Of  birds  there  are  a  large  number  of  characteristic  species,  a 
mere  enumeration  of  which  would  hardly  carry  conviction 
to  the  general  reader. 

Leaving  behind  us  the  forests  of  Douglas  sprace  and  bal- 
sam fir,  we  enter  an  open  "forest  of  statelj^  pines  .  .  .  which 
average  at  least  ...  100  feet  in  height.  There  is  no  under- 
growth to  obstruct  the  view,  and  after  the  rainy  season  the 
grass  is  knee-deep  in  places.  ..."  This  forest  covers  the 
mountain  side  between  7,000  and  8,200  feet,  some  of  its  trees 
extending  even  to  8,800  feet  among  the  spruce  and  fir.     It 


■^  K'      '■ 

.    mm^n 

m^ 

The  Beaveb 

From  a  group  in  the  American  Museum  of  Natural  History. 

Courtesy  of  the  Museum. 

marks  a  debatable  area,  where  boreal  forms  come  down  co- 
mingling  with  southern  types,  and  hence  has  been  aptly 
termed  the  transition  zone.  It  has  but  few  distinctive  spe- 
cies either  on  San  Francisco  jMountain  or  elsewhere,  being 
characterized  rather  by  a  mixture  of  types.  In  general  it 
occupies  the  northern  half  of  the  United  States,  bending  far 
southward  along  the  mountain  ranges,  and  running  north 
along  the  river  valleys,  which  serve  as  paths  of  northern  in- 
vasion for  southern  forms.     Southern  animals  which   cross 

'Scott,  "History  of  Land  Mammals  of  the  Western  Hemisphere,"  p. 
151.     By  permission  of  the  Macmillan  Company. 


176 


Biology  in  America 


the  transition  zone  inclndo  tlio  mountain  "lion"  or  puma, 
whit'h  extends  liis  j)ro\vIin<j:  patli  fi-oin  I'atagonia  to  (-anada, 
the  Canada  lynx,  a  skunk,  the  raeeoon,  hadger  and  one  of  the 
deer.  Viee  versa  Canadian  mammals  extending  across  the 
transition  zone  southward  into  the  Sonoran  include  the  chip- 
munks, l)eaver.  meadow  mouse  (Microtus)   and  the  muskrat. 


Grove  of  Aspens  Overflowed  by  a  Beaver  Pond 
WiUi   the  (l.Miii  and  stumps  cut  by  beaver   in  the  foreyrouud.     Original. 

Below  the  yellow  pine  forest  on  San  Francisco  IMountain 
we  reach  the  icgion  of  pinon  pines  and  red  cedars  which  ex- 
tends between  6,000  and  7,000  feet,  while  below  this  we  leave 
the  mountain  and  enter  the  desert.  Both  of  these  latter 
areas  belong  to  the  southern  or  Sonoran  life  area  in  North 
America,  so  named  from  the  province  of  Sonora  in  ^Mexico, 
which  is  at  or  near  the  center  from  which  its  characteristic 


Geographical  Distribution 


177 


species  have  inig:rated  into  the  United  States.  There  are 
several  birds  (jays  and  titmice)  which  are  characteristic  of 
the  piiion  belt  on  San  Francisco  Mountain  and  a  few  mammals 
(mice  and  ground  squirrels),  while  several  lizards  come  in 
from  the  "Painted  Desert"  to  the  east.  Two  species  of  liz- 
ards however  appear  to  be  characteristic  of  this  zone,  and 
one  (a  horned  toad)  wanders  up  into  the  transition  zone 
above. 


Cypress  Swamp,  Arkansas 
Courtesy  of  the  U.  S.  Bureau  of  Biological  Hurvey. 


But  temperature  is  not  the  sole  factor  regulating  the  dis- 
tribution of  animals  and  plants.  Moisture,  light,  the  char- 
acter of  the  soil  and  the  surface  of  the  countiy — these  and 
other  factors,  all  work  together  and  influence  one  another  to 
determine  this  distribution.  Perhaps  the  most  important  of 
these  is  moisture.  The  traveller  passing  across  the  United 
States  from  east  to  west,  finds  himself  at  the  outset  of  his 
journey  on  the  moist  plain  of  the  Atlantic  Coast,  a  region 
w^hich  has  but  recently  (in  geologic  time)  been  raised  above 
the  level  of  the  sea.  Along  the  New  England  Coast,  the  cold 
Labrador  current  in  its  southward  sweep,  produces  the  fogs 
which  so  often  shroud  these  shores,  while  the  Florida  penin- 
sula receives  the  moisture  laden  winds  from  both  the  Atlantic 


178 


Biology  in  America 


Ocean  and  the  Gulf  of  Mexico,  and  is  drenched  with  the  abun- 
dant rainfall  of  the  tropics.  Characteristic  of  the  coastal 
plain  and  the  eastern  slope  of  tlie  Appalachian  Range  to  the 
west  are  several  species  of  pines,  the  low  sandy  areas  of  the 
plain  being  largely  characterized  by  these  trees,  which  have 
given  their  name  to  the  New  Jersey  "Pine  Barrens." 

Upon  the  slopes  of  the  mountains  and  in  the  valleys  of 
their  intersecting  rivers,  are  the  remains  of  some  splendid 
hardwood  forests  of  maple,  oak,  elm,  linden,  hickory,  beech 


Cotton  Eat  and  Nest 
Courtesy  of  the  U.  >S'.  Bureau  of  Biological  Survey. 


and  chestnut,  while  in  the  swamps  of  the  South  are  the  cy- 
press, magnolia  and  palmetto. 

In  its  large  features  the  animal  life  of  this  region  does 
not  differ  from  that  of  the  Canadian,  transition  and  upper 
Sonoran  zones  of  a  western  mountain,  which  has  already 
been  described;  although  differing  therefrom  in  many  minor 
details.  But  along  the  southeastern  coast  occur  a  few  spe- 
cies which  distinguish  this  region  from  other  parts  of  the 
country.  In  the  rice  fields  of  the  South  occurs  the  rice  rat, 
while  the  cotton  rat  is  another  animal  characteristic  of  the 
South  Atlantic  and  Gulf  States.    The  Florida  Everglades  are 


Alligators  Enjoying  a  Quiet  Siesta 

Photo  by  Ehvin  R.  l^anhorn. 

Courtesy  of  the  New   York  ZoUloylcal  Society. 


The  Water  Moccasin 
An  inhabitant  of  the  lowhuuls  of  tlie  South  Atlantic  and  Gulf  States. 
Courtesy  of  the  A'civ   York  Zoological  Society. 


179 


180  Biology  in  America 

included  in  tlie  tropical  zone,  which  except  here  and  at  the 
mouth  of  the  Rio  Grande  does  not  enter  the  United  States. 
In  the  streams  of  southern  Florida  lives  the  alligator,  while 
the  dark  forests  are  the  home  of  the  parrakeet,  an  intruder 
from  the  numerous  family  of  parrots  in  South  and  Central 
America.  A  hundred  years  ago  this  bird  ranged  as  far  north 
as  the  Great  Lakes,  but  it  is  at  present  restricted  to  a  few 
areas  in  our  Southern  States,  if  indeed  it  is  not  wholly  extinct 
at  present. 

Crossing  the  Appalachians  our  traveler  descends  into  the 


The  Burrowing  O'vvl 

Photo  by  Eiwin  R.  Sunburii: 

Courtesy  uf  the  A'e/r   York  ZoiiJoniiul  Hoviity. 

great  valley  of  the  IMississippi  River,  with  its  branches  stretch- 
ing far  to  east  and  west  and  draining  nearly  half  the  total  area 
of  the  United  States.  Here  he  at  first  encounters  a  climate 
not  greatly  different  from  that  of  the  eastern  seaboard,  al- 
though subject  to  somewhat  greater  extremes  of  temperature. 
The  fauna  and  the  flora  too  are  similar  to  those  of  the  At- 
lantic Coast.  As  he  passes  westward  however  out  of  the  basin 
of  the  Mississippi,  rising  over  the  slope  of  the  Great  Plains 
to  the  foothills  of  the  Rockies,  the  climate  changes,  the  rain- 
fall materially  decreasing  and  the  temperature  extremes  in- 
creasing. 

Accompanying   these    changes    of    climate    occur    marked 
changes  in  the  life  of  the  land.     The  eastern  forests  disap- 


Prairie  Dog 


Prairie  Dog  at  Burrow 

The  **dog   towns"   of  the  West   are  familiar  objects. 

Courtesy  of  the  U.  S.  Bureau  of  Biological  Survey. 


181 


182  Biology  in  America 

pear  save  for  a  fringe  of  timber  along  the  stream  bottoms, 
giving  place  to  the  vast  prairies  of  the  west.  New  types  of 
animals  also  appear  upon  the  scene.  Squatting  on  his 
haunches  outside  the  entrance  to  his  subterranean  home  the 
prairie  dog  squeaks  defiance  at  the  passing  traveler,  and  the 
burrowing  owl  utters  its  shrill  cry  in  protest  at  the  pres- 
ence of  the  intruder.  Several  species  of  ground  squirrels  or 
gophers  are  characteristic  members  of  the  animal  commun- 
ity, some  of  which  extend  eastward  across  the  Mississippi. 
The  black  and  white  of  the  lark  bunting  is  a  conspicuous  fea- 
ture of  the  landscape,  while  the  magpie  in  his  coat  of  green 
and  white  lends  color  as  well  as  noise  to  the  cottonwood 
groves  along  the  rivers.  The  Great  Plains  form  an  inter- 
esting "tension  line,"  as  the  biologist  calls  it,  "where  east 
is  west  and  west  is  east  and  ever  the  twain  shall  meet. ' '  ^  The 
eastern  and  western  movement  of  the  western  and  eastern 
flora  and  fauna  respectively  is  one  of  the  most  interesting 
features  of  this  area.  The  dicksissel,  one  of  the  sparrow 
family,  a  characteristic  bird  of  the  Mississippi  Valley,  has 
only  in  recent  years  ventured  from  his  ancestral  home  across 
the  vast  prairies  to  the  west.  Conversely  the  magpie  appears 
to  be  moving  slowly  eastward.  The  red-eyed  vireo,  whose 
home  is  in  the  eastern  United  States,  appears  within  recent 
years  to  have  followed  the  Missouri  Valley  westward,  crossed 
the  Rocky  Mountains  and  established  itself  in  the  northwest- 
ern United  States  and  British  Columbia. 

An  interesting  suggestion  as  to  how  the  migration  routes 
of  various  birds  may  have  become  established,  many  of  which 
are  very  devious  and  hard  to  explain,  is  to  be  found  in  the 
route  of  this  bird.  Wintering  in  South  America,  it  moves 
northward  in  spring  following  the  course  of  the  Mississippi 
River  to  near  its  headwaters,  whence  it  turns  northwestward 
across  mountains  to  its  breeding  grounds  in  the  North.  A 
much  shorter  route  lies  west  of  the  Rockies ;  but  inherited  in- 
stinct (or  is  it  parental  example?)  carries  the  bird  in  the 
path  of  its  forefathers  far  from  the  course  which  is  most 
easy  and  direct. 

Another  interesting  case  of  recent  extension  of  a  bird's 
breeding  range  is  furnished  by  the  bobolink,  which  is  an  in- 
habitant of  marsh  and  meadow  land.  With  the  settling  of 
the  arid  territory  of  the  West,  accompanied  by  its  irrigation, 
the  bobolink  is  accompanying  the  western  march  of  empire, 
and  settling  itself  in  Nevada,  Oregon  and  other  western  states. 

Between  the  Rockies  and  the  Sierras  lies  the  Great  Basin, 
scorched  with  the  torrid  heat  of  summer  and  frozen  with  the 
icy  blasts  of  winter,  a  land  parched  with   endless  drouth. 

"With  apologies  to  Mr.  Kipling. 


The  Horned  Toad 
Which  is  not  a  "toad"  at  all,  but  a  lizard,  resembling  in  its  scaly 
attire  a  miniature  monster  of  the  past. 

Photo  hy  Eltoin  R.  Sanborn. 
Courtesy  of  the  Netv   York  Zoological  Society. 


The  Kangaroo  Rat 
Characteristic  of  the  arid  Southwest. 
Courtesy  of  the  U.  S.  Bureau  of  Biological  Survey. 

183 


184  Biology  in  America 

The  life  of  this  region  is  widely  different  from  that  of  the 
East,  but  the  mere  enumeration  of  the  names  of  its  inhabi- 
tants would  be  of  little  interest.  Many  of  its  species  are  in- 
habitants of  the  ground  and  buslies  and  are  more  or  less 
bleached  in  color  corresponding  to  the  backgi'ound  upon  which 
they  live.  IIow  this  adaptation  has  been  effected  no  one  can 
surely  say.  But  more  of  this  in  a  later  chapter.  One  of  the 
most  characteristic  of  its  inhabitants  is  the  "horned  toad," 
which  is  not  a  toad  at  all,  but  a  lizard.  This  little  creature 
with  its  horned  head  is  a  miniature  Triceratops,  the  giant 
dinosaur  which  once  shambled  across  our  plains. 

The  towering  Sierras  rising  like  a  mighty  wall  shut  off 
the  Great  Basin  from  the  interior  valleys  of  California,  and 
these  in  turn  are  separated  from  the  Pacific  Coast  by  the 
Coast  Kange  of  mountains,  which  while  pygmies  compared 


The  Gila  Monster 
Characleristic  of  the  arid  Southwest.     Froui  Ditmars,  "Reptiles  of  All 
Lands,"   in   "National   Geographic   Magazine,"    Vol.    22. 

with  their  mighty  neighbors  to  the  east,  nevertheless  form  a 
very  efficient  climatic  barrier  to  the  moisture  laden  winds 
sweeping  landward  from  the  sea.  The  climatic  diff'erences 
thus  caused  are  reflected  in  the  life  of  the  interior  valleys  and 
the  coastal  slope.  In  no  similar  area  in  North  America  are 
there  such  gi-eat  extremes  of  climate  or  more  marked  dif- 
ferences in  the  corresponding  life.  Especially  is  this  true 
of  Death  Valley  in  the  interior  of  southern  California,  whose 
lowest  point  is  276  feet  below  the  surface  of  the  sea.  Here 
the  temperature  in  summer  frequently  reaches  125°F.  in  the 
shade,  and  the  relentless  sun  scarce  ever  hides  its  shameless 
face  behind  a  cloud.  Here  lives  a  little  community  of  desert 
dwellers,  for  the  most  part  characteristic  of  their  arid  home. 
The  fauna  and  flora  of  California  are  peculiar  to  them- 
selves, following  however  the  general  principles  of  distri- 
bution of  life  elsewhere.  Here  occur  the  Goliaths  among 
plants — the  California  big  trees.     At  one  time  in  the  past 


Geographical  Distribution 


185 


these  trees  were  widely  distributed  over  North  America,  but 
today  they  are  restricted  to  our  western  coast/°  and  it  may 
be  are  doomed  to  extinction, 

Amono-  the  most  characteristic,  and  witlial  attractive  mem- 
bers of  California  society  are  the  hummiii<^  birds,  a  group 
occurring  only  in  America.     The  several  species  found  along 


A  California  Big  Tree  Grove 
Courtcny  of  the  U.  t>.  Bureau  of  Bioloykul  Surrey. 

the  Pacific  Coast  and  the  few  occurring  elsewlierc  are  in- 
vaders from  the  tropics  where  most  of  the  more  than  four 
hundred  species  find  a  home.  Another  interesting  inhabitant 
of  southern  California  and  Arizona  is  the  great  condor, 
which  spreads  its  wings  from  eight  and  a  half  to  eleven  feet. 
Dwelling  in  the  damp   forests  of   Oregon   and   Cialifornia 

"Sequoia  gigantea  is  limited  to  a  few  small  areas  in  California,  while 
S.  sempervirens  or  the  "redwood"  extends  north  along  the  coast  into 
Oregon. 


ISfi 


Biology  in  America 


is  the  last  representative  of  a  once  thriving  family,  which  at 
one  time  had  a  much  wider  distribution  than  at  present.  The 
sewellel  is  an  animal  somewhat  resembling  a  large  rat,  which 
digs  his  home  among  the  roots  of  the  forest  trees  and  stores 
therein  the  harvest  which  he  gathers  from  its  herbs. 

Several  million  years  ago,  more  or  less,  there  lived  in  North 
America  a  numerous  race  of  animals  related  to  the  opossum 
and  kangaroo,  the  marsupials,  to  which  reference  has  been 
made  in  the  preceding  chapter.  Then  they  disappeared  from 
what  is  now  the  United  States,  for  what  reason  we  do  not 


Mountain  Beaver,  or  Sewellel 
Courtesy  of  the  U.  8.  Bureau  of  Biological  Survey. 

know— a  mysterious  disappearance  of  the  past,  which  the 
palffiontological  sleuth  may  never  solve.  The  most  likely  ex- 
planation is  that  they  were  driven  south  by  the  wolves  and 
tigers  and  others  of  their  ilk,  the  robber  barons  of  the  ani- 
mal world.  More  recently  one  of  their  number,  the  opossum, 
has  once  more  ventured  northward  as  far  as  the  northern 
United  States  (Michigan  and  New  York). 

Have  all  these  facts  laboriously  gathered  by  many  men 
in  many  years  any  practical  value?  Even  had  they  none 
they  would  still  be  well  worth  while  because  of  the  light  which 
they,  in  conjunction  with  the  "hard  facts"  of  palaBoutology, 


Geographical  Distribution  187 

throw  upon  llie  great  questions  of  evolution,  adaptation  and 
the  vicissitudes  and  changes  of  plants  and  animals  in  the 
past.  But  apart  from  this  purely  ''theoretical"  interest  they 
have  an  important  hearing  upon  human  life  today,  for  they 
give  us  a  clue  to  the  suitability  of  any  region  for  crops  of  a 
given  type.  Thus  if  a  settler  in  a  given  region  wishes  to 
know  what  kind  of  crops  will  grow  best  in  his  region,  it  is 
essential  for  him  to  know,  not  only  the  character  of  the  soil 
in  his  area  and  the  amount  of  rainfall,  temperature  range, 
etc.,  but  the  type  of  plants  which  will  grow  well  in  that  par- 
ticular climate,  or  in  other  words  the  life  zone  in  which  his 
area  lies.  To  make  this  information  available  to  our  farmers 
the  Biological  Survey  has  prepared  a  life  zone  map  of  the 
United  States  and  Canada,  together  with  a  list  of  the  various 
cereals,  fruits  and  vegetables  best  adapted  to  each  zone. 

Thus  does  the  biologist  seek  to  make  his  knowledge  "prac- 
tical" in  the  rendering  of  service  to  the  world. 


CHAPTER  VI 

Experim^ital  hiologt/.  Prcfannation  in  a  new  dress,  organ- 
izaiimi  of  the  egg,  regeneration  and  gmfting,  plastic 
mrgery,  tissue  culture,  the  prahleni  of  death,  and  im- 
mortality of  the  cell. 

The  last  thirty  years  have  seen  remarkable  developments 
in  the  field  of  experimental  biology.  True  it  is  that  the 
method  of  experiment  was  a  very  early  one,  especially  among 
human  and  plant  physiologists.  Nevertheless  experimental' 
biolog\^  has  lagged  behind  experimental  physics  and  chem- 
istry and  has  but  recently  found  its  proper  place  among  the 
other  branches  of  biological  science.  In  the  development  of 
this  field  Germany  and  America  have  played  the  leading 
part,  while  with  the  recent  upheaval  in  Europe,  and  conse- 
quent check  to  scientific  progress  there,  the  coming  era  of 
reconstruction  finds  this  country  better  fitted  than  any  other 
to  lead  in  the  development  of  the  new  science. 

"While  the  earlier  biologists  were  in  the  main  satisfied  with 
the  observation  of  phenomena,  and  speculation  as  to  their 
causes,  the  experimental  biologist  demands  that  these  pl^e- 
nomena  shall  be  analyzed  under  certain  imposed  conditions, 
in  order  that  their  causes  may  be  scientifically  ascertained. 
Thus  the  method  of  transmission  of  yellow  fever  could  only 
be  conjectured  until  the  Yellow  Fever  Commission  in  1900, 
by  exposing  subjects  to  all  possible  conditions  of  infection, 
proved  that  the  bite  of  the  mosquito  (Stegomyia)  was  the 
only  natural  means  of  transfer. 

Experimental  biology  has  followed  a  few  main  lines  of 
thought,  with  many  side  lines  which  are  branched  and  in- 
terwoven with  one  another  in  an  intricate  maze.  A  gen- 
eral review  may  best  be  given  by  tracing  the  main  lines,  the 
branches  being  folloAved  only  so  far  as  they  are  essential  to 
an  understanding  of  the  former.  The  principal  questions 
then  with  which  we  shall  deal  are  the  following: 

Are  the  factors  which  determine  the  development  of  an 
organism  internal  or  external  ?  AYhy  does  an  organism  grow 
old  and  die?  What  are  the  factors  of  organic  evolution? 
Is  the  organism  a  machine,  governed  by  the  laws  of  physics 
and  chemistry,  or  is  there  a  "vital  principle,"  an  "en- 
telechy"  or  a  "soul,"  transcending  in  its  activity  the  bounds 
of  the  purely  material  universe? 

A  century  and  a  half  ago  Caspar  Friedrich  Wolff  overthrew 

1 


The  Organization  of  the  Egg 


189 


the  generally  accepted  doctrine  of  piefoniialion,  according 
to  which  the  adult  animal  was  present  in  miniature  within 
the  egg  or  the  sperm  cell,  both  of  which  had  their  advocates, 
so  that  embryologists  were  divided  into  the  rival  schools  of 
"ovists"  and  "spermatists. "  One  enthusiastic  and  imagina- 
tive observer  even  pictured  a  miniature  human  body  within 
the  spermatozoon. 


sp 


BERoii 

Showing  tlie  four  rows  of  swiinuiing  ]>lntes,  sj 
Chun. 


Vrom  Lankosfcr,  after 


While  such  fancies  have  long  since  been  laid  to  rest,  pre- 
formation, in  a  new  dress,  is  playing  a  very  important  role 
on  the  biological  stage  today.  The  importance  of  this  theory 
is  due  largely  to  the  work  of  two  American  biologists — 
Morgan  at  Columbia  and  Conklin  at  Princeton. 

In  modern  form  preformation  assumes  the  presence  in  the 
sex  cells  of  certain  formative  stutfs  or  entities  (more  exact 
terminology  is  impossible  in  the  present  state  of  our  knowl- 
edge) which  determine  the  development  of  parts  or  features 
of  the  adult  organism.  These  things,  whatever  they  are,  may 
reside  either  in  the  nucleus  or  the  cytoplasm.     In  the  former 


190 


Biology  in  America 


case  tliey  are  present  in  both  sperm  and  egg  cell ;  in  the  latter 
case  only  in  the  egg,  the  amount  of  cytoplasm  in  the  typical 
sperm  being  too  small  to  contain  the  ''organ-forming  sub- 
stances." 

If  such  formative  stuffs  are  unequally  distributed  to  dif- 
ferent daughter  cells  in  the  division  of  the  egg,  then  we  should 
expect  each  of  these  cells  to  give  rise  to  a  definite  part  of  the 
embryo  and  to  that  part  only.     If,  on  the  other  hand,  these 


••y-:»lv.---.-.     .     ■    ;,'-A:'5; 


I  P' 


(Left)  The  Egg  of  thk  Tunicate  Cynthia 
Showing  the  ' '  organ  forming  substances ' '  and  their  distribution  in 
different  stages,  a,  anterior;  p,  posterior  pole  of  egg;  c,  clear  proto- 
plasm; cr,  yellow  crescent;  e,  cortex  containing  yellow  pigment;  g.v., 
germinal  vesicle;  k,  chorion;  p.  b.,  polar  bodies;  t,  test  cells;  y,  yolk; 
y.  h.,  yellow  hemisphere;  6,  sperm  nucleus.   Prom  Kellicott,  after  Wilson. 

(Eight)     Development  of  the  Mollusc  Dentalium 

A,  distribution  of  materials  in  undivided  egg;  B,  commencement  of 
division  showing  the  "polar  lobe"  p,  which  in  C  and  D  (division  stages) 
is  found  at  D  and  X  respectively.  In  E  the  cell  X  is  absent,  the  polar 
lobe  having  been  removed  at  an  earlier  stage.  F  and  H,  normal  larvae 
of  twenty-four  and  seventy-two  hours,  respectively,  G  and  I,  larvae  of 
the  same  ages  lacking  the  "polar  lobe"  material.  From  Kellicott  after 
Wilson. 

stuffs  are  equally  distributed  to  the  daughter  cells,  then  these 
cells  should  be  mutually  interchangeable,  and  any  one  of 
them,  if  isolated  from  its  fellows,  should  give  rise  to  com- 
plete, though  dwarfed  embryos.  Is  the  egg  a  mosaic,  or  is 
it  uniform  in  its  structure? 

The  ctenophore  Beroe  has  normally  eight  rows  of  ciliary 
bands.     After  one  division  of  the  egg,  if  the  two  resulting 


The  Organization  of  the  Egg  191 

cells  are  separated,  each  one  will  develop  into  a  half  larva, 
with  only  four  rows  of  bands.  Similarly  each  cell  of  the 
four  and  even  the  eight  cell  stage  may  be  made  to  develop 
into  a  partial  larva  with  two  or  even  only  one  row  of  bands. 
And  further  if  a  part  be  removed  from  the  egg  before  divi- 
sion, a  defective  larva  is  the  result. 

The  egg  of  the  aseidian  Cynthia  has  been  shown  by  Conklin 
to  contain  at  least  five  different  "organ-forming  substances," 
distinguishable  by  color  and  texture,  which  are  symmetrically 
placed  with  reference  to  the  median  plane  of  the  embryo, 
but  differentially  located  antero-posteriorly.  If  one  of  the 
first  two  cleavage  cells  (for  example  the  right)  is  killed,  the 
other  develops  into  the  opposite  (left)  half  of  the  body,  which 
contains  all  the  normal  part>;,  but  of  one-half  the  norn'ial 
size.  But  if  in  the  four  cell  stage,  when  the  second  cleavage 
has  differentiated  the  anterior  from  the  posterior  ends  of  the 
body,  one  or  both  of  the  anterior  or  posterior  cells  is  killed, 
the  resulting  larva  lacks  those  parts  which  are  present  only 
in  the  cells  which  have  been  destroyed. 

A  similar  result  has  been  obtained  by  Wilson  in  the  egg 
of  the  mollusc  Dentalium,  in  which  three  different  substance.^ 
can  be  identified.  Thus  the  yolk  is  here  at  first  located  at 
one  pole  of  the  egg,  and  later  in  a  single  one  of  the  cleavage 
cells.  If  this  "yolk  lobe"  be  removed  from  the  egg,  when 
it  starts  to  divide,  the  resulting  larva  lacks  certain  parts 
(foot,  mantle,  shell,  etc.)  normally  formed  from  the  yolk 
cell. 

Centrifuging  the  egg  of  Cynthia  with  consequent  dis- 
arrangement of  the  organ-forming  substances  may  so 
disturb  the  development  that  the  resulting  larva  may  be 
turned  inside  out,  with  entoderm  on  the  outside  and  ectoderm 
within. 

At  the  posterior  end  of  one  of  the  chrysomelid  beetles 
(Calligrapha)  occurs  a  disk  of  granules,  which  seemingly 
function  as  germ  cell  determinants,  for  if  the  end  of  the 
egg  containing  this  disk  be  pricked,  and  its  component  gran- 
ules allowed  to  escape,  or  if  the  disk  be  destroyed  with  a  hot 
needle,  and  the  egg  is  then  allowed  to  develop,  the  resulting 
embryo  lacks  germ  cells. 

There  are  many  experiments  however  which  point  to  dif- 
ferent conclusions.  Thus  in  eggs  of  fresh  water  snails  and 
certain  annelids,  substances  of  different  color  and  specific 
gravity  occur,  but  these  may  be  displaced  from  their  normal 
positions  by  centrifuging,  without  in  any  way  affecting  the 
development.  This  has  led  Lillie  and  others  to  the  conclusion 
that  the  so-called  organ-forming  substances  are  not  in 
reality  such,  but  merely  an  accompaniment  of  a  more  pro- 
found organization  resident  in  the  protoplasmic  framework 


192  Biology  in  America 

of  the  egrfr,  which  cannot  be  mechanically  rearranged  by 
centrifuginj?  or  otherwise. 

The  foregroing  experiments  seem  to  show  conclusively  that 
the  developing  animal  is  in  some  sense  at  least  prefonned 
in  the  egg.  No  less  conclusive  however  is  the  evidence  of 
a  directly  opposite  character.  In  Amphioxus  and  many 
Ilydromedusa'  isolated  cleavage  cells  give  rise  to  complete 
though  dwarf  larvfp,  while  on  the  contrary  it  has  been  pos- 
sible in  some  eases  (Ascaris,  Sphterechinus)  to  produce  nor- 
mal, though  giant  larvae,  by  the  fusion  of  two  eggs  or  embryos. 
Many  intermediate  forms  exist  between  those  eggs  in  which 
one  of  the  cleavage  cells  produces  a  partial,  and  those  in  which 
it  forms  an  entire  larva.  In  some  cases,  as  for  instance  in 
certain  echinoderms,  an  isolated  cleavage  cell  may  undergo 
at  first  a  partial  development,  but  later  a  process  of  regula- 
tion may  ensue,  resulting  in  the  formation  of  a  complete 
larva.  Different  results  may  be  obtained  in  the  same  animal, 
depending  on  the  method  of  experimentation.  Thus  if  one 
of  the  first  two  cleavage  cells  of  a  frog's  egg  be  destroyed 
with  a  hot  needle  and  the  egg  left  in  its  normal  position  a 
half  embryo  results,  but  if  the  position  be  inverted  a  whole 
embryo  develops  in  the  majority  of  cases. 

In  this  maze  of  conflicting  evidence  a  final  word  can  scarcely 
be  spoken.  Undoubtedly  different  eggs  differ  in  the  extent 
of  their  organization.  If  a  part  of  the  egg  of  the  nemertine 
Cerebratulus  be  removed  prior  to  fertilization,  no  disturbance 
of  development  ensues.  If  the  two  cells  of  the  first  cleavage 
are  separated,  they  undergo  for  a  time  a  partial  cleavage,  but 
very  soon  the  normal  development  is  resumed.  But  if  one 
of  the  four  cells,  resulting  from  the  second  cleavage,  be  iso- 
lated, partial  development  proceeds  for  a  longer  time  than 
in  the  preceding  case,  the  normal  process  not  being  resumed 
until  much  later.  We  find  here  a  possible  explanation  of  the 
divergent  behavior  of  different  eggs.  In  some  the  embryo 
may  be  preformed  in  the  egg,  in  others  only  in  later  stages 
of  cleavage. 

The  phenomena  of  regeneration  speak  strongly  for  the 
uniformity  of  both  egg  and  adult.  If  the  parts  of  the  or- 
ganism are  predetermined  in  the  former,  then  when  one  of 
these  parts  is  lost  its  replacement  should  be  impossible;  but 
if  the  egg  be  isotropic  (one  part  the  same  as  another),  and  if 
this  uniformity  persist  in  the  adult,  then  a  lost  part  should 
be  replaceable. 

The  ability  of  regeneration  in  many  animals  has  long  been 
known,  being  mentioned  by  Aristotle  and  Pliny.  In  the  mid- 
dle of  the  eighteenth  century,  the  famous  work  of  Trembley  on 
Hydra  attracted  widespread  attention  and  several  workers 
entered  this  field. 


Tho  Organization  of  Ihc  Egg  193 

Rpgeneratioii  occurs  to  a  greater  or  less  extent  in  all  the 
great  groups  of  animals  and  plants.  If  Hydra  be  cut  into 
several  pieces  each  will  develop  into  a  new  animal.  Earth- 
worms and  flatworms  can  regenerate  either  head  or  tail  if 
these  be  removed.  The  starfish  can  have  a  new  arm  made  to 
order;  the  lobster  a  claw;  the  snail  may  acquire  a  new  head, 
and  the  sea  cucumber  a  new  stomach.  In  higher  plants  a 
piece  of  leaf  or  root  may  give  rise  to  an  entire  new  plant. 

Among  animals  the  regenerative  power  decreases  with  in- 
creasing specialization.  The  relative  size  of  a  piece  of  Hydra 
necessary  to  produce  a  new  animal  is  much  less  than  that 
of  a  crab  or  a  frog.  In  vertebrates  the  amphibians  have 
been  most  used  for  regeneration  experiments.  There  are 
many  salamanders  which  can  regenerate  legs  or  tail,  but 
there  appear  to  be  differences  in  the  regenerative  ability  of 
different  forms.  Age  has  an  influence,  as  well  as  degrees 
of  specialization,  for  while  the  tadpole  will  readily  regenerate 
a  lost  limb  the  frog  is  unable  to  do  so. 

In  man  the  power  of  regeneration  is  relatively  slight, 
although  skin,  muscles^  bone  and  other  tissues  show  this  power 
to  some  extent  in  the  healing  of  wounds,  while  the  lens  of 
the  eye  may  occasionally  regenerate.  There  are  some  remark- 
able cases  on  record  of  regeneration  of  internal  organs  in 
mammals,  although  these  are  sometimes  merely  cases  of  hyper- 
trophy of  part  of  an  organ,  in  compensation  for  the  loss  of 
another  part  of  that  same  organ,  rather  than  instances  of  true 
regeneration.  Thus  the  removal  of  one-half  or  even  three- 
fourths  of  the  liver  of  a  dog  or  rabbit  may  result  in  the 
enlargement  of  the  remainder,  without  any  replacement  of 
the  lost  part.  It  is  well  known  that  in  man  injury  to  a 
lung  or  kidney  may  be  compensated  by  increased  growth  and 
activity  of  its  opposite.  There  are  recorded  instances  how- 
ever of  true  regeneration  of  internal  organs  in  mammals. 
In  the  rabbit  removal  of  as  much  as  five-sixths  of  a  salivary 
gland  may  be  followed  by  complete  regeneration,  and  the 
kidney  of  a  rat  or  a  rabbit  may  develop  new  tissue  to  a 
certain  extent,  after  part  has  been  removed. 

The  regeneration  of  the  lens  in  vertebrates  ha«  been  a  bone 
of  contention  among  zoologists  for  many  years.  In  the 
development  of  the  normal  eye  there  first  arises  an  evagina- 
tion  of  the  primary  forebrain  forming  a  primary  optic  cup 
or  vesicle,  wliich  is  shoi-tly  followed  by  an  invagination  of  the 
adjacent  ectoderm  to  foi'm  a  secondary  cuj)  or  vesicle,  from 
which  is  formed  the  lens.  The  question  at  issue  is:  Is  the 
lens  dependent  upon  the  presence  of  the  primary  vesicle  for 
its  development,  or  may  it  arise  independently  of  the  latter? 
Many  ingenious  expei'iments  have  been  performed,  prin- 
cipally  on   amphibian   larvaj,   in   the   attempt   to   solve  this 


194  Biology  in  America 

problem,  with  unfortunately  widely  divergent  results.  The 
ectoderm  has  been  eut  around  the  developing  primary  vesicle, 
and  the  tlap  folded  back  so  as  to  expose  the  latter;  vidiich  has 
then  been  excised,  the  tiap  replaced  and  the  wound  allowed 
to  heal.  In  other  experiments  the  primary  vesicle  has  been 
supposedly  destroyed  by  pricking  it  with  a  hot  needle;  and 
in  still  others  the  vesicle  has  been  transplanted  to  a  strange 
area  of  the  same,  or  a  different  species,  such  as  the  abdominal 
wall.  In  the  latter  experiments  lenses  have  been  formed  from 
parts  of  the  ectoderm  which  never  give  rise  to  them  in  nature, 
and  similar  results  have  been  obtained  by  destroying  a  lens 
already  formed,  thereby  causing  its  regeneration  from  the 
iris. 

In  the  former  experiments  the  results  have  been  incon- 
sistent, a  lens  sometimes  regenerating  and  sometimes  failing 
to  do  so,  after  the  removal  of  the  primary  vesicle.  Werber 
has  suggested  that  this  apparent  inconsistency  is  due  to  the 
incomplete  destruction  of  the  vesicle  in  some  cases  in  which 
it  had  supposedly  been  entirely  removed,  and  the  consequent 
formation  of  a  "  lens  stimulus ' '  by  small  pieces  of  the  vesicle 
which  remained.  Of  interest  in  this  connection  are  the  experi- 
ments of  Stoekard,  Werber  and  others  in  the  production  of 
Cyclopean  and  other  monsters,  which  will  be  considered  later. 
In  some  of  these  experiments  a  single  median  eye  has  been 
produced  in  place  of  two  lateral  ones,  with  the  resultant 
formation  of  a  single  lens  associated  Avith  the  single  eye,  and 
the  absence  of  any  lateral  lenses.  In  other  cases  lenses  have 
developed  at  almost  any  place  on  the  monster,  apparently 
unassociated  with  any  optic  material.  Werber  has  suggested' 
however  that  these  so-called  "independent  lenses"  owe  their 
origin  to  the  stimulus  of  microscopic  bits  of  optic  vesicles 
scattered  over  the  body  of  the  monster,  through  a  process  of 
blastolysis  or  tissue  destruction  induced  by  chemical  or 
osmotic  action,  and  in  some  cases  he  is  able  to  demonstrate 
what  he  considers  bits  of  such  material  in  close  proximity 
to  these  lenses. 

Whatever  the  truth  of  the  matter  may  be,  the  evidence  is 
I  think  conclusive  that  lenses,  and  presumably  other  organs 
also,  are  not  iji  any  sense  preformed,  but  result  from  the 
interaction  between  the  parts  of  the  organism  itself  and  their 
environment. 

Nearly  related  to  experiments  on  regeneration  are  those  on 
grafting.  The  custom  of  grafting  in  plants  has  been  prac- 
tised by  horticulturists  for  a  long  time.  Trembley  with  his 
celebrated  woik  on  Hydra  was  a  pioneer  in  this  field  among 
animals.  JMoi'e  recently  this  work  has  been  continued  by 
King,  Rand,  Peebles  and  others  in  this  country.  The  an- 
terior end  of  one  Hydra  may  be  grafted  onto  the  posterior 


The  Organization  of  the  Egg 


195 


end  of  another ;  two  Hydras  may  be  united  by  either  anterior 
or  posterior  ends,  or  one  Hydra  may  be  o-rafted  onto  the 
side  of  another.  The  results  differ  depending  upon  the  condi- 
tions of  the  experiment,  and  the  speeies  of  Hydra  employed; 
but  the  general  result  is  that  a  process  of  regulation  ensues 
whereby  a  new  animal  is  formed,  similar  in  size  and  pro- 
portion to  the  normal  individual.  One  of  the  most  interest- 
ing results  l)earing  on  the  question  of  predetermination  of 
parts  is  that  obtained  by  grafting  two  Hydras  by  their 
anterior  ends  and  then  cutting  off'  the  posterior  end  of  one 
near  the  graft  line.     In  this  case  a  new  head  forms  on  the 


Four-Legged  Tadpoles 

Produced   by   transplanting   the   limbs   from   one   tadpole   to   anotlicr. 
After  Harrison,   "Journal  of  Experimental  Zoology,''   Vol.   4. 


(originally)   posterior  end  of  the  graft,  where  a  head,  in  the 
ordinary  course  of  events  would  never  develop. 

Some  of  the  most  interesting  grafting  work  of  recent  years 
has  been  done  by  Harrison,  in  connection  with  studies  on  the 
developing  nerve  fiber.  Two  positions  have  been  held  on  this 
question — one,  that  the  axone  of  the  nerve  cell,  the  conducting 
part  of  the  nerve  fiber,  arose  in  situ  from  surrounding  cells ; 
the  other,  that  the  axone  was  an  outgrowth  from  the  nerve 
cell  itself.  The  latter  view  appears  to  have  been  definitely 
established  by  Harrison.  Our  interest  here  however  centers 
primarily  upon  certain  secondary  results  of  Harrison's  work 
rather  than  upon  the  question  of  nerve  fiber  development. 
In  these  experiments  Harrison  has  shown  that  limb  buds  can 
be  transplanted  from  one  tadpole  to  another,  the  tail  of  one 


196 


Biology  in  America 


species  of  tadpole  can  be  grafted  on  that  of  another  species, 
two  entire  animals  may  be  united,  and  even  the  head  of  one 
species  (Rana  virescens)  can  be  united  to  the  body  of  another 
(R.  palustris),  and  a  young  frog  reared  from  the  combina- 
tion. Similar  results  have  been  obtained  by  Crampton  in 
the  union  of  tlie  puinn  of  moths,  (■()ml)inations  of  ceeropia 
moths  with  promethea  and  polyphenuis  mollis  having  been 
successfully  made. 

Most  remarfeable  of  grafting  results  witli  higher  animals 


A  Combination  Frog 
With  the  head  of  one  species  grafted  onto  the  body  of  another.     The 
tadpole    to    the    left,    the    adult    to    the    right.      From    Harrison,    in    the 
"Anatomical  Record,''  Vol.  2. 

have  been  those  of  Carrel  on  mammals.  lie  has  removed 
sections  of  arteries  of  one  animal  and  replaced  them  with 
pieces  of  vessels  taken  from  another.  He  has  even  made 
this  graft  successfully  with  vessels  which  had  been  kept  in 
an  ice  chest  for  several  weeks  after  death.  Thus  a  piece 
of  a  human  artery  taken  from  an  amputated  leg  and  pre- 
served for  twenty-five  days  in  cold  storage  was  used  to  replace 
a  piece  of  the  aorta  of  a  small  dog.  The  graft  took  and  the 
dog  recovered  and  lived  for  over  four  years,  during  which 
time  she  bore  several  litters  of  pupi)ies,  finally  dying  during 


The  Organization  of  the  Egg  197 

labor.  A  post-mortem  examination  sliowed  the  p^rafted  vessel 
to  be  slightly  dilated  and  lacking  muscular  tissue,  but  other- 
wise normal.  Carrel's  success  in  grafting  vessels  enabled  him 
to  transplant  entire  organs.  He  performed  this  operation  on 
cats'  kidneys,  with  a  certain  amount  of  temporary  success, 
the  transplanted  organ  functioning  for  a  number  of  weeks. 
Ultimately  however  the  animals  died.  But  even  the  tem- 
porary success  of  so  daring  an  operation  gives  ground  for 
hope  that  complete  success  may  ultimately  be  possible. 

Grafting  on  the  human  body  or  plastic  surgery  is  supposed 
to  have  been  practised  by  the  Egyptians  as  early  as  1,500 
B.  C.  In  recent  years  great  advances  have  been  made  in  this 
branch  of  surgery,  and  not  only  have  skin,  bones,  muscles, 
fascia  and  tendons  been  transplanted,  but  parts  of  internal 
organs  have  been  used  to  repair  defects  in  other  parts.  Thus 
the  urethra  has  been  replaced  by  the  appendix  and  a  vagina 
has  been  made  from  a  piece  of  intestine.  A  piece  of  cornea 
from  a  human  eye  kept  in  cold  storage  for  eight  days  has 
been  successfully  used  to  partially  restore  the  sight  of  a  man 
blinded  by  alkali. 

The  story  of  the  recent  achievements  of  surgery  in  repair- 
ing the  features  of  soldiers,  who  had  been  so  badly  wounded 
as  to  be  merely  caricatures  of  their  former  selves,  reads  almost 
like  a  tale  from  the  "Arabian  Nights."  Jaws,  noses,  ears, 
cheeks,  almost  entire  faces  have  been  remade,  so  that  the  vic- 
tims have  in  the  end  presented  a  fairly  good  facsimile  of  their 
former  selves.  While  details  cannot  be  given  here,  a  brief 
outline  of  the  method  may  be  of  interest.  A  former  picture 
of  the  patient  if  available  is  taken  as  the  model  of  what  the 
surgeon  aims  to  make.  Then  a  piece  of  bone  of  the  proper 
size  and  shape  to  refit  the  lost  part  (a  jaw  or  nose)  will  be 
cut  out  of  a  rib  or  shin  bone  and  inserted  beneath  the  skin 
of  an  adjoining  part  (the  neck  or  forehead).  After  the  skin 
has  attached  itself  to  the  inserted  bone,  the  latter  is  cut  out 
on  three  sides,  leaving  a  stalk  on  one  side  to  maintain  the 
circulation,  the  skin  is  now  cut  open  around  the  scar  and 
the  new  member  inserted  in  the  open  cavity.  The  adjoining 
skin  is  attached  to  the  insert,  and  after  the  graft  has  "taken," 
its  stalk  is  cut  away,  and  when  finally  healed  the  skin  is 
massaged,  and  the  scar  removed  in  this  way  as  far  as  possible. 
Thus  a  fairly  natural  part  may  be  made  to  replace  a  jawless 
mouth  or  a  repulsive  hole  where  a  nose  once  grew. 

Carrel  and  others  have  shown  that  not  only  blood  vessels 
and  cornea,  but  also  skin,  fascia,  tendon,  bone  and  cartilage 
may  be  preserved  in  a  condition  of  latent  life  for  weeks  or 
months  in  cold  storage,  and  still  be  used  successfully  for 
transplantation.     Thus  pieces  of  skin   taken  from  the  body 


198 


Biology  m  America 


of  an  iufaiit,  which  died  during  labor,  and  preserved  in 
vaseline  at  a  temperature  of  -|-3°C.  were  successfully  used 
for  grafts  after  forty-two  days;  and  pieces  of  fat,  bone  and 
cartilage  taken  from  amputations  have  been  similarly  pre- 
served in  cold  storage  for  varying  lengths  of  time,  and  later 
used  in  grafting  operations.  Seemingly  the  day  is  not  far 
distant  when  cold  storage  will  supply  us  with  our  tissues  as 
well  as  our  foods. 

The  liberties  which  may  be  taken  with  living  tissues  and 
their  ability  to  grow  in  strange  surroundings  is  I  believe 
strong  evidence  for  the  plasticity  of  the  cell,  showing  as  they 
do  the  profound  influence  of  environment  on  its  development. 
Such  a  view  of  course  must  not  be  pushed  too  far.     It  would 


Three  Stages  in  the  Eeconstruction  of  a  Wounded  Soldier's  Face 

From   Esser   in   ' '  Annals   of   Surgery, ' '   Yol.   65. 

By  pennisskm  of  J.  li.  Liiiitincott  Company. 

be  absurd  to  expect  that  every  cell  could  be  modified  by  its 
surroundings  so  as  to  form  every  other  kind.  With  high 
specialization  the  cell  loses  j^ari  passu  its  adaptability.  But 
in  the  lower  organisms  there  is  abundant  evidence  of  the 
ability  of  cells  to  be  molded  into  new  structures,  even  after 
they  have  reached  the  usual  limits  of  their  development. 

Further  evidence  in  favor  of  this  view  is  afforded  by  the 
apparently  unlimited  power  of  reproduction  possessed  by 
certain  cells.  If  the  development  of  the  organism  were  pre- 
determined in  the  egg,  then  the  growth  of  its  parts  should" 
be  limited,  and  there  should  come  a  time  in  its  development, 
as  ordinarily  there  does  come  in  the  life  of  the  individual, 
when  growth  should  cease  and  the  power  of  repair  should  not 
exceed  the  need  created  by  waste.     But  in  some  cases,  notably 


The  Organization  of  the  Egg 


199 


in  cancer,  certain  cells  possess  the  power  of  seemingly  un- 
limited growth,  increasing-  at  the  expense  of  other  tissues, 
running  wild  within  the  body,  and  finally  destroying  it  as  a 
result  of  their  riotous  living.  This  power  of  seemingly  un- 
limited growth  of  the  cell  may  in  many  cases  be  initiated 
artificially. 

Unquestionably  the  most  important  of  Harrison's  results 


A  Piece  of  Growing  Tissue 

The  (lark  center  is  the  original  tissue,  the  brandling  boilies  radiating 
out  from  it  are  the  growing  cells.  It  has  been  possible  to  cultivate  in 
glass  cells  many  different  kinds  of  tissue,  including  those  from  man 
himself.  This  method  has  been  used  for  studying  the  growth  and 
reaction  of  cancer  cells,  and  may  throw  light  on  the  cause  of  this  dreail 
malady.  After  Lambert  and  Hanes,  "Journal  of  Experimental  Medi- 
cine."  Vol.   13. 


on  nerve  growth  was  his  development  of  the  method  of  grow- 
ing tissues  outside  of  the  animal  body.  He  transplanted  bits 
of  the  central  nervous  system  of  the  tadpole  to  drops  of 
coagulable  lymph  from  the  frog,  and  by  placing  these  in  a 
glass  cell  under  the  microscope,  he  was  able  to  follow  the 
growth  of  the  nerve  fibers.  More  recently  a  large  number 
of  workers,  mostly  Americans,  have  developed  Harrison's 
method  and  applied  it  to  both  embryonic  and  adult  tissues 
of  birds  and  mammals.     The  method  has  been  applied  to  the 


200  Biology  in  America 

study  of  tlio  growth  not  only  of  normal  but  of  pathological 
tissues,  such  as  tumors  and  cancers. 

When  a  bii  of  tissue  is  removed  from  a  living,  or  recently 
killed  animal,  and  placed  in  a  suitable  medium  (blood  plasma 
is  the  one  mostly  emjjloyed)  at  a  pr()i)er  temperatun^  it 
sooner  or  later,  depending  on  the  age  of  the  animal  from 
which  it  is  taken,  begins  to  grow,  sending  out  sheets  of  cells 
in  all  directions  into  the  surrounding  medium.  After  a  time 
however  growth  ceases,  but  may  recommence  if  the  tissue  be 
removed,  washed  and  transferred  to  a  fresh  medium.  In 
this  way  tissues  have  been  kept  alive  for  more  than  nine  years 
and  carried  through  nearly  two  thousand  transfers.  Carrel 
has  grown  chick  tissues  in  this  way,  which  had  been  kept  in 
cold  storage  for  six  days,  and  even  human  tissues  taken  from 
a  cadaver  several  hours  after  death  may  grow. 

But  what  is  death  if  our  tissues,  as  well  as  our  actions,  will 
live  after  we  are  gone?  Does  the  grim  specter  lie  in  wait 
for  us  in  the  coils  of  our  intestines,  as  jMetsehnikolf  would 
have  us  believe  ?  Or  is  it  the  hardening  of  our  arteries  which 
ushers  us  into  the  great  unknown?  Is  death  inherent  in  life, 
or  were  the  first  living  things  immortal,  and  death  an  adapta- 
tion secondarily  acquired  for  the  benefit  of  the  race,  although 
working  to  the  detriment  of  the  individual,  as  AVeismann  has 
suggested  ? 

For  an  answer  to  these  questions  let  us  turn  to  the  uni- 
cellular organisms  and  see  what  they  have  to  teach  us.  If 
a  single  Paranuecium  be  put  in  a  fresh  infusion  of  hay  in 
water  it  soon  divides  to  form  two  daughter  cells,  which  divide 
again  in  their  tuin,  and  so  on ;  until  the  infusion  is  teeming 
with  millions,  all  offspring  of  one  cell,  which  is  still  living 
in  its  descendants.  For  this  reason  Weismann  maintained 
that  the  Protozoa  were  immortal.  But  after  a  time  repro- 
duction ceases  and  the  Paramo'cia  begin  to  die  off.  The  cul- 
ture has  passed  its  climax  and  begun  to  retrograde.  Finally 
the  Pai'am(ecia  disappear  entirely,  unless  fresh  material  be 
meantime  added  to  the  culture.  But  if  this  be  done  the 
cells  ac(iuire  a  new  lease  of  life  and  connnence  to  multiply 
again  as  merrily  as  ever. 

By  using  a  varied  culture  of  hay,  leaves,  moss,  etc.  in 
rotation  and  transferring  his  animals  daily  to  fresh  culture. 
Woodruff  has  carried  a  race  of  ParauKccia  through  some  seven 
thousand  generations  extending  over  a  period  of  twelve  years, 
without  any  evidence  of  degeneration.  While  an  exact  analy- 
sis of  the  different  stimuli  controlling  the  Paramo^cia  in  a 
hay  infusion  has  not  been  made,  it  has  been  shown  ])retty 
conclusively  that  waste  products  materially  check  their 
growth,  while  purity  of  the  culture  in  this  respect  stimulates 


The  Organization  of  the  Egg  201 

growth  and  keeps  tlie  animals  healthy.  The  food  supply- 
must  also  exercise  a  controlling  influence,  the  growth  of 
bacteria,  which  serve  as  food,  being  also  cheeked  by  waste 
products  (toxins)  in  the  culture.  It  can  be  shown  however 
that  even  in  the  presence  of  abundant  food  supply,  stale 
culture  will  inhibit  tlie  growth  of  ParanKecia. 

We  can  compai-e  the  metazoan  with  a  culture  of  Paramrecia, 
all  descendants  of  one  cell.  The  former,  as  well  as  the  latter, 
starts  as  a  single  cell  (the  fertilized  egg).  After  a  period  of 
active  division  or  growth  the  climax  is  reached,  when  the 
processes  of  repair  can  only  keep  pace  with  those  of  waste, 
and  from  then  on  the  organism  passes  through  the  decline 
of  old  age  followed  by  death.  But  if  a  few  cells  be  removed 
from  the  parent  body  and  transferred  to  a  fresh  medium 
(blood  plasma)  they  forthwith  start  to  grow  abundantly,  and 
this  growth  can  apparently  be  maintained  indefinitely,  if  the 
transfers  be  repeated  from  time  to  time. 

The  influence  of  the  age  of  the  animal  from  which  the 
plasma  is  taken  is  very  marked.  In  that  from  young  animals 
growth  is  much  more  active  than  in  that  taken  from  adults, 
but  if  an  extract  of  the  tissues  of  a  young  animal  be  added 
to  the  latter  the  growth  is  materially  increased. 

May  not  then  old  age  and  death  be  caused  by  waste  prod- 
ucts excreted  by  the  cells  of  the  metazoan  body?  May  it 
not  be  a  process  of  auto-intoxication,  not  localized  as  Metseh- 
nikoff  suggests,  in  the  intestines,  but  generalized  throughout 
the  entire  body?  Whatever  answer  to  this  question  the  future 
may  make,  the  faculty  of  unlimited  growth  possessed  by  most, 
if  not  all  the  tissues  of  higher  animals,  suggests  not  only  the 
indeterminate  nature  of  development,  but  also  the  inherent 
immortality  of  the  cell. 


CHAPTER  VII 

Experimental  hiology  continued.  The  role  of  the  chromosomes 
in  inheritance.  Inhcritanee  of  sex  and  sex-linked  char- 
acters. 

In  the  preceding  chapter  we  have  considered  the  question 
of  the  influence  of  the  cytoplasm  upon  development,  par- 
ticularly in  respect  to  the  "orfi,an-formin«i'  sub.tances"  winch 
it  contains ;  and  the  ability  of  one  part  of  an  organism  to 
regenerate,  not  only  itself,  but  some  other  part  normally 
foreign  to  it.  We  shall  now  consider  the  role  of  the  nucleus 
in  development,  especially  that  of  the  chromosomes. 

Whether  or  not  development  be  locally  predetermined  in 
the  egg,  there  is  of  course  no  question  that  the  latter  is  pre- 
determined in  its  general  development.  J\Ien  do  not  gather 
"grapes  of  thorns  or  figs  of  thistles,"  nor  can  the  specific, 
e.  g.,  characteristic  of  the  species,  development  be  altered  by 
any  change  in  the  environment.  AVhat  is  it  then  which  deter- 
mines the  specific  characters  of  the  organism? 

While  the  theory  of  cellular  units  responsible  for  the 
hereditary  transmission  of  specifie  and  individual  characters, 
originated  with  Darwin  as  the  well  known  "pangenesis" 
theory,  in  an  attempt  to  explain  the  origin  of  new  characters 
by  environmental  influence,  and  was  amplified  and  more 
definitely  formulated  by  Weismann,  it  has  never  received 
stronger  support  than  througli  tlie  ejioch-making  work  of  Mor- 
gan and  his  students  at  Columbia  University  within  the  last 
decade.^ 

In  order  to  appreciate  the  significance  of  this  work,  it  is 
necessary  to  turn  back  the  pages  of  time  for  a  half  century 
and  pause  a  moment  to  look  into  the  garden  of  the  monastery 
at  Briinn  in  the  Tyrol,  where  the  monk  Gregor  Mendel  was 
busy  with  his  peas. 

Mendel  was  monk  and  later  abbot  at  Briinn,  and  for  a  time 

^I  do  not  wish  in  this  statement  to  accuse  modern  biologists  of 
accepting  Darwin's  theory  of  "pangenesis"  in  its  entirety.  Darwin- 
ian and  modern  viewpoints  have  in  common  however  the  assumption 
oi  some  sort  of  cell  units,  be  they  physical  or  be  they  chemical,  which 
are  responsible  for  reappearance  in  the  offspring  of  characters  pres- 
ent in  the  parent. 

202 


The  Role  of  the  Chromosomes  203 

taught  tlie  physical  and  natural  sciences  in  the  monastery 
school.  While  monk  and  teacher  he  was  essentially  a  great 
investigator,  and  in  spite  of  his  other  duties,  he  found  time 
to  perform  a  large  number  of  breeding  experiments  with 
sweet  peas,  the  results  of  which  he  published  in  1865  in  the 
'  *  Proceedings  of  the  Natural  History  Society  of  Briinn. ' '  This 
paper,  which  he  sent  to  his  friend  Niigeli  the  botanist,  made 
no  impression  on  the  latter  and  attracted  no  attention,  until 
thirty-five  years  later,  when  Mendel's  principle  was  inde- 
pendently discovered  by  three  botanists — DeVries,  Correns 
and  Tschermak.  Since  then,  Mendel's  discovery  has  been 
recognized  as  one  of  the  greatest  in  biology,  and  his  paper 
has  become  a  great  scientific  classic. 

The  results  of  his  work  have  been  so  extensively  quoted, 
and  are  known  so  widely  and  so  well  that  their  rehearsal  is 
needless  here.  There  are  certain  features  of  his  results  how- 
ever which,  while  well  known  to  biologists,  are  perhaps  not 
fully  appreciated  by  the  general  reader,  and  which  it  may 
therefore  be  worth  while  to  emphasize.  Thus  it  is  commonly 
known,  for  example,  that  a  cross  between  a  tall  pea  and  a 
dwarf  produces  only  tall  offspring,  which,  when  bred  to- 
gether, produce,  on  the  average,  three  tall  and  one  dwarf 
descendants.  But  the  meaning  of  this  well-known  Mendelian 
ratio  is  possibly  not  widely  understood.  A  ready  explanation 
is  found  however  in  the  behavior  of  the  chromosomes  of  the 
germ  cells,  prior  to,  and  during  fertilization. 

The  nucleus  of  an  undividing  or  resting  cell  contains  a  sub- 
stance known  as  chromatin,  which,  when  the  cell  is  sectioned 
and  stained  for  microscopic  study,  appears  as  a  mass  of  deeply 
stained  blotches  and  specks  scattered  indiscriminately  over 
a  very  delicate  network  of  threads  or  "linin"  fibrils.  When 
the  cell  becomes  active  and  starts  to  divide  this  chromatin 
material  is  gathered  together  into  an  irregular  twisted  thread 
known  as  the  "skein"  or  "spireme,"  which  is  at  first  long 
and  thin,  but  soon  shortens  and  thickens  and  then  breaks  up 
into  a  number  of  segments  in  the  form  of  rods,  loops  or 
balls,  the  number  of  which  is  characteristic  for  any  given 
species  of  plant  or  animal.  ])ut  which  varies  in  different 
species  from  two  to  upwards  of  two  hundred.  In  division 
these  chromosomes  are  equally  divided  so  that  each  new  cell 
receives  the  same  number  as  the  parent  cell  contains. 

But  when  the  animal  or  plant  is  ready  to  reproduce  there 
is  a  striking  difference  in  the  behavior  of  the  chromosomes— 
a  difference  to  which  is  probably  related  all  the  varied  and 
wonderful  phenomena  displayed  by  Mendelian  inheritance. 

Nearly  forty  years  ago  Van  Beneden  ascertained  that  the 
germ  cells  of  Ascaris,  an  intestinal  parasite  of  the  horse,  each 
contained,  at  the  time  of  fertilization,  one-half  the  number 


204 


Biology  in  Amrrica 


of  chromosomes  characteristic  of  the  species;  which  number 
was  thci-cfore  restored  at  the  time  of  fertilization  by  the 
union  of  tlie  egg  and  sperm  inielei.  Now,  if  this  reduction 
in  number  can  be  shown  to  involve  the  separation  of  definite 


mwmmh 


Photographs  of  Chromosomes 

Showing  various  stages  in  the  division  of  a  sea  urchin 's  egg.  The 
minute  dark  masses  at  the  center  of  the  egg  are  the  chromosomes.  The 
light  areas,  surrounded  by  dark  radiations  to  either  side  of  the  chromo- 
somes are  the  "asters,"  so-called  from  their  star-like  appearance. 
Biologists  are  still  in  the  dark  as  to  the  cause  of  this  wonderful  process 
of  cell  division.  In  certain  respects  it  closely  resem))les  an  electro- 
magnetic phenomenon,  the  poles  of  the  magnet  being  located  at  the 
centers  of  the  asters.  These  chromosomes  are  more  delicate  than  the 
finest  filament  of  a  sjjider  's  web.  Fig.  B  is  magnified  3,000  times,  the 
others  1,500.  After  Wilson,  "Atlas  of  Fertilization  and  Karyokinesis 
of  the  Ovum. ' ' 

Bi/  pcrminKion  of  the  Macmlllan  Company. 

chromosomes  from  one  another  so  that  different  sex  cells 
receive  different  chroinosonie  combinations,  then  an  ideal 
arrangement  exists  in  the  cell,  for  realization  of  the  Men- 
del ian  results.  Referring  to  the  case  of  the  tall  and  dwarf 
peas,  let  us  suppose  that  both  partners  in  the  cross  are  "pure," 


The  Role  of  the  Chromosomes 


205 


T 

t 

T 

It 

Tt 

t 

It 

tt 

e.  g.,  that  all  the  germ  cells  of  the  tall  pea  carry  the  deter- 
miner for  talliiess  (T)  and  all  those  of  the  dwarf  pea  the 
determiner  for  dwarf ness  (t).  If  now  we  cross  the  tall  (T) 
with  the  dwarf  (t)  we  shall  have  in  the  cells  of  the  hybrid 
both  T  and  t,  and  the  resnlt  will  be  a  tall  pea  (since  tallness* 
dominates  dwarfness)  carrying  latent  the  determiner  for 
dwarfness. 

Before  the  germ  cells  of  the  hybrid  are  ready  for  fertiliza- 
tion they  must  undergo  a  process  of  ripening  or  maturation 
in  the  course  of  which  the  chromosomes  of  each  are  reduced 
to  one-half  the  number  in  the  l)ody  cells  of  the  species.  This 
reduction  is  effected  by  the  union  of  the  chromosomes  in 
pairs  and  their  subse(iuent  division  as  apparently  single, 
though  in  reality  double  elements.  One  of  these  divisions, 
kiiown  as  the  "reducing  division"  is  as- 
sum,ed  to  separate  the  paired  elements 
from  each  other.  If  now  we  assume  that 
the  determiner  for  tallness  be  carried  by 
one  chromosome  and  that  for  dwarfness 
by  another,  and  that  these  two  chromo- 
somes pair  with  one  another  in  the  matu- 
ration of  the  germ  cells  of  the  hybrid, 
separating  from  each  other  in  the  reduc- 
ing division,  then  the  germ  cells  of  the 
latter  will  be  of  two  kinds,  e.  g.,  those 
containing  the  T  chromosome  and  those 
containing  t.  Now  when  the  hybrids  are 
crossed  with  one  another  there  will  be 
three  possible  combinations  resulting  from 
the  union  of  their  germ  cells,  in  the  fol- 
lowing ratio  (ITT,  2Tt,  Itt),  which  re- 
sults from  the  chance  combination  of  T  and  T  with  t  and  t. 
These  chance  results  may  be  demonstrated  by  a  simple  ex- 
periment. If  four  billiard  balls,  two  black  and  two  white, 
be  shaken  together  in  a  box  and  drawn  out  in  pairs,  one- fourth 
of  the  drawings  will  be  two  blacks,  one-fourth  tAVO  whites 
and  one-half  a  black  and  a  white.  If  then  the  behavior  of 
the  chromosomes  at  the  time  of  maturation  and  fertilization 
is  as  assumed,  and  if  secondly  the  chromosomes  carry  "deter- 
miners" (whatever  they  may  be)  for  the  characters  of  the 
organism ;  then  the  Mendelian  results  must  follow  as  a 
mathematical  necessity  of  the  chance  separation  and  recom- 
bination of  till'  chromosomes  in  the  maturation  and  fertiliza- 
tion of  the  germ  cells. 

We  have  used  a  iuntil)er  of  "ifs"  in  the  above  discussion. 
Are  our  conclusions  based  purely  on  assumptions?  Let  us 
see.     In  the  ease  cited  we  have  assumed  in  the  first  place 


Diagram  to  illus- 
trate inheritance  of 
size  in'  the  sweet  pea. 
A  cross  of  a  tall 
with  a  dwarf  pea 
produces  3  tall  and 
1  dwarf  pea  in  the 
second  generation. 


200 


Biology  in  America 


that  chromosomes  carrying:  the  alternative  determiners  for 
tallness  and  dwarfness  pair  with  each  other  and  later  separate 
in  the  maturation  divisions,  goin<?  into  different  gerin  cells. 
Now  it  is  manifestly  impossible  to  loeate  directly  the  deter- 
miners for  any  character  in  any  particular  chromosome,  or 
in  the  chromosomes  at  all,  for  that  matter.  The  direct 
analysis  of  the  chromosome  is  as  yet  impossible.  Nor  can  we 
prove  directly  that  the  paired  chromosomes  separate  from 
each  other  in  the  maturation  divisions,  instead  of  retaining 
their  paired  character  and  dividing  equally. 

We  have  however  certain  indirect  evidence  which  strongly 
supports  our  assumptions.  In  many  species  of  animals  and 
plants,  notably  among  insects,  the  chromosomes  differ  mark- 


dHlllllh 


®  fllllllllb 


aiiiiiiift 


fliiiiiiit) 


® 


Diagram  Showing  Eight  i'ossible  Distributions  of  Three  Pairs  of 
Chromosomes  in  the  Maturation  of  the  Germ   Cells 

After  Morgan,  Sturtevant,  Muller  and  Bridges,  ' '  The  Mechanism  of 
Mendelian  Heredity. ' ' 

By  permission  of  Henry  Holt  and  t'umininy. 

edly  in  size  or  shape.  In  the  equatorial  plates  of  most 
mitoses  these  chromosomes  are  very  definitely  arranged  in 
pairs  with  similar  members.  But  after  the  reduction  division, 
when  the  chromosome  number  is  reduced  by  half,  the  result- 
ing cells  each  receive  similar  groups  of  chromosomes,  so  that 
each  chromosome  of  one  cell,  has  its  exact  counterpart  in  its 
sister  cell,  with  certain  exceptions  in  the  case  of  the  sex 
chromosomes  to  be  noted  later. 

Seemingly  then  we  are  warranted  in  our  conclusion  that 
in  the  reduction  division  the  members  of  each  pair  are 
separated  from  one  another  and  distributed  to  sister  cells. 
And  further,  since  the  male  and  female  sex  cells  each  con- 
tain similar  groups  of  chromosomes,  it  is  reasonable  to  assume 
that  similar  or  "homologous"  chromosomes  from  male  and 
female  pair  with  each  other  in  fertilization,  remaining  paired 
until  the  next  generation  of  germ  cells  matures,  when  they 
separate  to  be  recombined  once  more  in  the  succeeding  fer- 
tilization. 


The  Role  of  the  Chromoaumcs  207 

In  this  way,  and  in  this  way  only,  may  be  roas()iia1)ly 
explained  the  results  of  ]\Iendelian  inheritance,  in  which  tiic 
characters  of  the  parents  are  shuffled,  and  dealt  to  the  off- 
spring- like  the  cards  in  a  pack.  Mother  Nature  is  an  invet- 
erate gambler,  and  every  living  thing  a  pack  of  cards. 

But  is  such  a  scheme  of  chromosome  distril)ution  adecjuate 
to  account  for  the  infinitude  of  characters  sliown  by  so  com- 
plex an  organism  as  man,  no  two  individuals  of  whom  are 
ever  exactly  alike,  with  the  possible  exception  of  the  very 
rare  cases  of  identical  twins?  Chromosome  counts  in  man 
are  hard  to  make  as  may  be  readily  understood  from  the 
difficulty  of  securing  fresh  and  undiseased  material  for  micro- 
seoi)ic  study.  If,  as  seems  probable  hcwever  the  numl)er  is 
48,  which  in  maturation  unite  to  form  24  pairs,  then  the 
number  of  possible  arrangements  of  these  chromosomes,  deter- 
mining their  distribution  to  the  different  germ  cells,  is  2-*  or 
16,776,116,  and  the  number  of  possible  combinations  re- 
sulting from  the  union  of  the  germ  cells  in  fertilization  is 
(16,776,116)-  or  about  2S0,0(}0,00(),0()0,()()0.  This  calculation 
is  based  on  the  assumption  that  each  chromosome  carries  but 
a  single  determiner.  It  is  highly  probable  however  as  we 
shall  see  later,  that  each  chromosome  carries  a  large  number 
of  determiners,  and  that  these  are  mutually  interchangeable 
between  the  members  of  each  pair  of  chromosomes.  Allowing 
ten  determiners  to  every  chromosome,  which  is  probably  a  mod- 
erate estimate,  and  the  last  stated  figures  become  about  3,- 
000,000,000,000,000,000, 000, 000, 000,000,000, 000,000,()00,0()(),- 
000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,- 
000,000,000,000,1000,000,000,000,000.000,000,000,000,000,000- 
000,000,000.'-  If  any  reader  cares  to  form  a  mental  pictui'c 
of  this  number  he  is  welcome  to  try ! 

It  is  by  no  means  certain  however  that  the  determiner  is  a 
fixed  and  unchangeable  unit.  In  fact,  the  very  reverse  U 
undoubtedly  the  case.  Chemical  analysis  of  the  exceedingly 
complex  components  of  the  cell  is  very  difficult,  and  the  results 
vary  widely.  All  observers  are  agreed  however  as  to  the  great 
complexity  of  protoplasm.  According  to  Miescher,  nuclein, 
wdiich  forms  the  major  part  at  least  of  the  chromosome,  has 
the  formula  C^g  H4n  N^,  Pg  Oo.  Now  there  are  certain  sub- 
stances, especially  among  the  compounds  of  carbon,  that 
wonderfully  kaleidoscopic  element,  which  analysis  shows  to 
have  the  same  structure,  but  which  nevertheless  exhibit  dif- 
ferent properties.  These  ditferences  are  explained  on  the 
assumption  that  while  the  molecules  of  these  substances  con- 

^  Computed  by  Professor  E.  F.  Chandler,  of  the  I^nivcrsity  of  Xortli 
Dakota.  Even  should  the  above  figure  be  greatly  redueed  by  linkage  it 
would  still  be  so  large  as  to  be  absolutely  incomprehensible, 


208 


liioluijij  in  America 


tain  tlio  same  iiuinhci-  and  kinds  of  atoms,  tlie  latter  are 
ditH'crently  arranjied  in  the  molecnles.  Such  molecules  dif- 
fering in  the  arrangement  of  their  component  atoms,  are 
known  by  the  somewhat  formidable  term  of  stereoisomers. 
Miescher  has  shown  that  serum  albumen  for  example  has  a 
possibility  of  1,()0U,U()(),()(J()  stereoisomers.  Now  if  nuclein  has 
one-tenth  as  many  and  if  eacli  determiner  in  the  human 
chromosome  consists  of  but  a  single  molecule  of  nuclein,  the 
number  of  possible  arrangements  within  the  nucleus  of  the 
fertilized  egg  becomes  so  great  as  to  be  wholly  beyond  the 
range  of  human  ken. 


0 

2 

3 

4 

•?<• 
%'*• 

D 

i$ 

lO 

-> 

0 

^. 

It 

It 

13 

/# 

7S- 

Photographs  of  Chrojiosomes 
From  an  insect  magnified  1,500  times.  The  pair  of  sex  chromosomes 
is  shown  at  x  in  Fig.  3.  In  Figs.  14  and  15,  which  show  the  chromo- 
somes divided  into  two  groups,  each  of  which  passes  into  a  new  cell, 
the  larger  one  of  the  pair,  which  ' '  determines ' '  the  female  sex,  is  seen 
passing  to  the  loAver  group.  After  Wilson,  ' '  Journal  of  Experimental 
Zoology, ' '  Vol.  6. 


Still  stronger  evidence  of  the  behavior  of  the  chromosomes 
as  outlined  above  is  afforded  by  that  of  the  sex  chromosomes, 
which  have  been  found  in  a  large  and  ever  increasing  number 
of  animals.  Like  the  devils  in  the  herd  of  swine  on  the 
shores  of  Galilee,  the  number  of  hypotheses  regarding  the 
cause  of  sex,  which  have  in  times  past  infested  the  human 
mind,  is  legion.  As  early  as  the  eighteentli  century-  Drelin- 
court  enumerated  262  untenable  theories  of  sex  determination, 
and  as  Blumenbach  aptly  said,  "Drelincourt's  theory  formed 
the  263rd."  Since  then,  possibly  as  many  more  sex  theories 
have  blossomed  and  Avithered  without  bearing  fruit.  Recent 
investigation  indicates  that  sex  determination  is  in  Nature's 


The  Role  of  the  Chromosomes 


209 


hands,  and  that  tlio  most  wliich  niaii  can  experimentally 
accomplisli  is  to  intlnence  tlie  survival  ratio  between  males 
and  females. 

In  many  animals,  including  insects,  myriapods,  arachnids, 
nematodes,  echinoderms,  fowls,  amj)liil)ians,  rats,  guinea  pigs 
and  man,  difiPerences  occur  in  the  number  or  size  of  the  chro- 
mosomes of  the  male  and  the  female.  In  some  cases  one  sex, 
usually  the  female,  has  from  one  to  several  more  chromosomes 
than  the  male ;  in  others  there  is  a  size  difference  between 
two  chromosomes  of  a  corresponding  pair,  which  consists  in 
the  female  of  two  large  chromosomes,   in  the  male,  on  the 


Gynandromorph  Fruit  Flies 
Courtesy  of  Professor  T.  H.  Morgan. 


contrary,  of  a  large  and  a  small  element.  The  ** accessory" 
or  sex  chromosome  may  occur  either  free  or  attached  to 
another  chromosome,  while  the  relative  differences  in  size 
between  the  unequal  members  of  a  pair  of  sex  chromosomes 
varies  all  the  way  from  equality  in  the  two  members  to 
absence  of  the  smaller  one. 

The  process  of  sex  determination  in  these  forms  is  briefly 
as  follows :  In  the  reduction  division  in  the  maturation  of  the 
sex  cells  in  the  male,  the  members  of  the  unequal  pair  of  sex 
chromosomes  separate  from  each  other,  the  larger  passing  into 
one  cell  and  the  smaller  into  another  cell;  or  one  or  more 
elements  may  pass  into  one  cell,  while  its  sister  cell  receives 
none  or  a  smaller  number.     The  details  vary,  but  the  general 


210  Biology  in  Amryica 

result  is  tlio  samo,  namely,  an  uneven  distribution  of  chromo- 
somes to  (litiferent  sex  eells,  judical in<>'  clearly  a  separation 
of  entire  clirumosomes  from  one  another  in  maturation,  and 
the  production  of  different  kinds  of  sex  cells  as  a  result 
thereof.  Now  when  a  sperm  carrying  a  larger  nmnber  of 
chromosomes,  or  a  lai'ger  member  of  an  nnequal  pair,  unites 
with  an  egg,  the  resulting  oftspring  is  a  female;  while  those 
sperms  which  carry  fewer  or  smaller  chromosomes,  upon 
fertilizing  an  egg,  give  rise  to  males. 

In  most  cases  studied  thus  far  the  differential  divisions 
occur  in  the  male,  the  spei'm  being  of  two  classes,  male  and 
female  producing;  but  in  a  few  animals,  notably  birds,  m(  tl.s 
and  butterflies,  the  eggs  are  of  two  classes  and  sex  determina- 
tion occurs  in  the  female. 

While  the  greatest  mass  of  evidence  available  thus  far 
indicates  that  sex  is  predetermined  in  the  fertilized  egg,  there 
is  some  recent  work  which  does  not  apparently  agree  with 
this  theory.  A  consideration  of  this  evidence  however  may 
best  be  deferred  to  a  later  chapter. 

There  are  also  two  sexual  conditions  of  more  or  less  common 
occurrence  in  plants  and  animals,  which  are  dif^cult  to  explain 
on  the  basis  of  sex  chromosomes.  One  of  these,  hermaphro- 
ditism, is  of  very  general  occurrence  in  plants  and  certain 
groups  of  animals;  and  the  other,  gynandromorphism,  occurs 
occasionally  in  animals.  In  the  former  case  both  sex  glands 
are  normally  present  in  the  same  animal ;  in  the  latter  vary- 
ing conditions  of  the  glands  occur,  sometimes  male,  sometimes 
female,  sometimes  both  are  present,  while  externally  the  body 
may  be  of  different  sexes  on  opposite  sides,  or  opposite  ends, 
or  one-fourth  may  differ  from  the  remaining  three-fourths;^ 
in  fact,  almost  any  mosaic  of  external  sex  characters  may 
occur. 

Hermaphroditism  is  characteristic  of  most  worms,  and  some 
molluscs,  and  occurs  occasionally  elsewhere.  In  vertebrates 
it  is  rare,  l)eing  characteristic  only  of  the  hagtish  (Myxine). 
In  mammals  true  hermaphroditism  is  not  known,  so-called 
hermaphrodites  having  only  the  external  sex  organs  hermaph- 
roditic. Various  hypotheses  have  been  advanced  to  bring 
these  conditions  into  line  with  the  chromosome  hypothesis,  but 
thus  far  without  any  marked  degree  of  success. 

By  far  the  most  valuable  contribution  of  recent  years  to 
the  chromosome  theory  of  inheritance  is  the  work  of  ^Morgan 
and  his  students  at  Columbia  on  the  fruit  fly,  Drosophila. 
By  a  combination  of  breeding  and  cytological  studies  they 
have  carried  this  theory  almost  to  the  point  of  fact.  Droso- 
phila is  a  little  fly,  about  half  the  size  of  the  ordinary  house 
fly,  which  breeds  abundantly  in  decaying  fruit  and  vegetables, 


The  Role  of  the  Chromosomes 


211 


and  may  be  reared  ad  libitum  on  ripe  bananas  to  whicb  a 
little  yeast  has  been  added.  The  fly  has  many  variable  char- 
acters which  are  well  marked  and  readily  Mendelized.  Tiie 
chromosomes  also  are  well  defined,  so  that  it  furnishes  an 
exceptionally  good  subject  for  studies  of  this  character. 

The  fruit  fiy  has  typically  four  pairs  of  chromosomes,  and 
thus  far  more  than  400  distinct  characters  have  been  found. 
Now  if  these  characters  has  each  its  determiner  in  one  of 
the  chromosomes,   it  is  obvious  that  each   chromosome  must 


A 


►>* 


•;• 


#^^ 
'•^1  — 


lilMiTill 


m 


■''I'll 

'illllll 

••••• 


B 


Diagrams  Illustrating   the   Distribution   cf   the   Sex   Chkojisomes 

AT  Maturation 
A,  in  the  female;  B,  in  the  male;   C,  the  resulting  possible  combina- 
tions  in   fertilization.     A   and    B   from    Morgan,   "Heredity   and   Sex," 
by   permision   of   the   Columbia   University   Press;    C   from   Loeb,   after 
Wilson. 


carry  a  large  number  of  characters.  That  being  so,  all  those 
characters  which  are  lodged  in  one  chromosome  should  be 
inherited  as  a  unit.  And  that  is  precisely  what  happens  in 
many  cases,  giving  rise  to  the  phenomenon  known  as  "link- 
age." One  of  the  best  known  examples  of  this  is  shown  by 
certain  sex-linked  (sometimes  incorrectly  called  "sex-limited" 
characters.) 


Fruit  Flies 

The  two  uj)per  figures  show  the  male  (right)  and  female  (left)  of  the 
fryit  fly.  The  six  lower  figures  show  some  of  its  200  ami  uiore  muta- 
tions, some  of  the  most  striking  of  which  are  shown  by  the  wings. 
Note  the  wingless  individual  in  the  lower  riglitliand  corner,  and  the 
one  with  asymmetrical  wings  just  above.  By  their  extensive  studies  of 
this  humble  insect,  Professor  Morgan  and  his  students  have  added  vastly 
to  our  knowledge  of  tlie  laws  of  inheritance,  which  luild  true  not  only  for 
lower  animals,  but  for  num  himself.  After  Morgan,  "Heredity  and 
Sex, ' ' 

By  permlf:xion  of  the  Cohimhia  Univcrk-iii/  Press. 

212 


The  Hole  of  the  Chromosomes  2l3 

Usually  the  fruit  fly  has  red  eyes,  but  occasional  individuals 
occur  with  white  eyes.  If  a  red-eyed  male  be  mated  with  a 
white-eyed  female  the  offspring  will  be  of  two  classes  of 
approximately  equal  numbers,  namely,  red-eyed  females  and 
white-eyetl  males.  If  now  the  first  generation  be  inbred,  four 
classes  will  appear  in  the  second  generation,  of  approximately 
equal  numbers  each,  namely,  white-eyed  and  red-eyed  nuiles 
and  females.  If  the  reciprocal  cross  be  made,  i.  e.,  white- 
eyed  males  by  red-eyed  females,  the  results  will  differ  depend- 
ing upon  the  purity  or  impurity  of  the  mother  in  respect  to 
eye  color  (i.  e.,  whether  or  not  she  carries  the  white-eye  color 
latent).  In  the  former  case  (the  mother  pure  red)  the  first 
generation  will  all  have  red  eyes,  while  the  second  generation, 


xY         XX 
xY^Xx  XY  Xx 


Xx  XX  XY  xY        XX  Xx  XY  xY 


Diagrams  Eepresenting  the  EOle  of  the  Chromosomes  in  Deter- 
mining Sex  and  Eye  Color  in  the  Fruit  Fly 

The  female  of  this  fly  carries  a  pair  of  chromosomes,  represented  by 
XX  or  XX  in  the  diagrams,  and  the  male  a  pair  differing  in  respect 
to  one  member,  thus  represented  as  XY  or  xY.  The  factor  for  red 
eye  color  is  represented  as  carried  by  X.  Thus  a  red-eyed  female  has 
the  formula  XX  or  Xx  and  a  white-eyed  female  xx,  while  red-eyed  and 
white-eyed  males  are  respectively  XY  and  xY.  In  the  right-hand 
diagram  is  shown  a  mating  between  a  white-eyed  male  and  a  red-eyed 
female,  all  of  the  offspring  of  which  are  red-eyed.  If  these  are  mated 
with  each  otlier,  four  kinds  of  offspring  result,  which  are  sliown  in 
the  third  row,  all  the  females  having  red  eyes,  while  half  the  males 
have  white  eyes.  The  reciprocal  cross  and  its  results  are  shown  in  the 
left-hand  diagram. 


resulting  from  inbreeding  the  former,  will  have  red  and 
white  eyes  in  the  ratio  of  three  to  one.  In  the  latter  ease  (the 
mother  red-eyed  with  white  latent)  the  results  will  be  the 
same  as  those  obtained  by  inbreeding  the  first  generation  of 
the  red-eyed  male  by  the  white-eyed  female  cross. 

Sex  in  the  fruit  fly  appears  to  be  determined  by  a  pair 
of  chromosomes,  which  differ  slightly  in  form  and  size  from 
the  others.  This  pair  is  called  the  XX  pair  in  the  female 
and  the  XY  pair  in  the  male. 


214  Biology  in  America 

The  results  of  the  crosses  above  described  can  be  most 
readily  explained  by  assnining  that  one  of  the  X  chromosomes 
cariics  the  determiner  for  r(\l  eye  color  and  another  X  the 
determiner  for  white.  They  are  shown  graphically  in  the 
accompanying  diagrams,  in  which  the  chromosomes  carrying 
the  determiner  for  red  eyes  ai-e  shown  as  capitals,  and  those 
carrying  the  white  eye  determiner  as  small  letters. 

Many  other  cases  of  sex-linked  inheritance  occur  in  animals, 
notably  in  moths,  fish,  birds  and  mammals,  including  man. 
In  the  latter,  color  blindness  and  hfemopliilia  (imperfect  clot- 
ting of  the  blood  causing  continuous  How  from  wounds)  are 
examples,  although  the  manner  of  inheritance  here  is  slightly 
different  than  that  of  eye  color  in  the  fruit  fly. 

While  the  phenomena  of  linkage  are  clearly  shown  in  the 
fruit  fly,  not  only  in  the  eye  color  but  also  in  color  of  wings 
and  body,  size  of  wings,  etc.,  the  linkage  in  many  cases  is 
imperfect,  some  of  the  combinations  of  characters  in  the  off- 
spring being  different  from  those  shown  by  the  parents. 

Some  fruit  flies  have  vestigial  wings  and  black  bodies, 
while  the  ordinary  type  has  long  gray  wings  and  a  light  yellow 
body,  banded  with  black  on  the  abdomen.  Black  body  and 
vestigial  wings  tend  to  stay  together  in  inheritance,  indicating 
that  their  determiners  are  both  lodged  in  the  same  chromo- 
some. But  there  are  some  exceptions  to  this  rule.  If  a 
black  fly  with  vestigial  wings  be  crossed  with  one  having  long 
gray  wings,  the  offspring  will  all  have  long  gray  wings,  this 
type  dominating  the  former.  If  now  we  "back  cross"  these 
offspring  with  the  black  vestigial  parent,  we  obtain  a  curious 
result.  If  on  the  one  hand  we  back  cross  a  hybrid  male  with 
a  black  vestigial  female,  we  obtain  only  black  vestigial  and 
gray  long  flies.  The  characters  have  "stuck  together,"  com- 
ing out  of  the  cross  in  the  same  combination  in  which  they 
entered  it.  The  linkage  is  perfect  and  the  evidence  is  strong 
that  the  determiners  for  the  characters  tested  are  lodged  in 
the  same  chromosome  (black  vestigial  in  one,  gray  long  in 
another),  which  retains  its  identity  throughout  the  matura- 
tion and  fertilization  processes.  But  if,  on  the  other  hand, 
we  back  cross  a  female  hybrid  and  a  black  vestigial  male  we 
obtain  a  very  different  result;  namely,  41.5%  of  black  ves- 
tigial and  gray  long  offspring  respectively,  and  8.5%  of  black 
long  and  gray  vestigial.  In  other  words,  some  of  the  charac- 
ters have  become  mixed  in  the  shuffle  and  the  cards  are  not 
dealt  "according  to  Hoyle." 

Is  such  a  result  a  fatal  blow  to  the  chromosome  hypothesis  ? 
On  the  contrary  it  furnishes  indirectly  one  of  the  strongest 
evidences  in  its  favor. 

We  have  seen  above  that  the  chromosomes  pair  with  one 


I 


The  Rule  of  the  Chromosomes  215 

another  in  maturation  and  then  separate  in  the  reduction 
division,  so  that  dififerent  germ  cells  receive  different  contri- 
butions. We  have  not  however  considered  how  the  chromo- 
somes pair,  whether  end  to  end,  or  side  by  side.  INIuch  dis- 
pute has  arisen  over  this  question,  which  is  probably  due  to 
the  occurrence  of  different  methods  in  different  species.  In 
some  cases  at  least  there  is  definite  evidence  of  a  side  by  side 
conjugation  or  "  parasynapsis, "  and  in  some  of  these  it  has 
been  shown  that  the  chromosomes  do  not  lie  parallel  but  wind 
about  one  another,  forming  a  more  or  less  twisted  braid. 
When  this  occurs  it  is  probable,  although  not  definitely  proven, 
that  in  separating  the  chromosomes  do  not  unwind  but  rather 
pull  apart  irrespective  of  the  twist,  so  that  a  part  of  one 
chromosome  may  now  be  switched  over  into  another  chromo- 
some and  vice  versa.  This  phenomenon  of  "crossing  over" 
as  it  is  called,  would  readily  explain  the  8.5%  of  gray  vestigial 
and  black  long  files  obtained  in  the  last  experiment ;  for  if 
the  chromosomes  carrying  the  black  vestigial  and  gray  long 
determiners  were  occasionally  to  wind  about  each  other  and 
then  separate  without  untwisting  the  determiners  would  be 
apt  to  get  mixed  up  and  find  themselves  in  the  wrong  pews, 
so  to  speak.  Why  this  should  occur  only  in  the  female  and 
not  in  the  male  is  a  problem.  Possibly  more  extensive  experi- 
ments would  show  it  to  occur  in  the  male  also.  However,  the 
lack  of  cross-overs  in  the  male  of  another  species  of  Droso- 
phila    (viriles)   suggest  that  it  is  a  constant  feature  of  this 


genus. 


Now  if  this  explanation  of  crossing  over  be  correct,  we 
should  expect  those  characters  to  cross  over  most  frequently, 
the  loci  of  whose  determiners  in  the  chromosomes  are  most 
widely  separated,  for  in  the  twisting,  points  at  either  end  of 
a  pair  of  chromosomes  would  be  more  apt  to  interchange 
places  from  one  chromosome  to  the  other,  than  closely  adjoin- 
ing points.  And  as  a  matter  of  fact,  great  differences  do 
exist  in  the  amount  of  crossing  over  between  diff'erent  charac- 
ters. On  the  basis  of  these  differences  Morgan  and  his 
students  have  made  a  plan  of  the  chromosomes,  locating  with 
a  high  degree  of  probability  in  tiny  threads  of  protoplasm, 
possibly  the  diameter  of  the  finest  filameit  of  a  spider's  web, 
the  determiners  of  more  than  two  hundred  characters  already 
studied  in  the  fruit  fly. 

The  fact  that  all  these  characters  fall  into  four  groups  in 
respect  to  their  linkages,  thus  corresponding  to  the  four  pairs 
of  chromosomes  in  the  fruit  fly;  and  further,  that  the  cal- 
culated separation  between  the  extremes  in  each  series,  based 
upon  the  frequency  of  the  cross-overs,  corresponds  to  the 
relative   lengths   of   the   chromosomes,    is   very   strong   addi- 


^o' 


216 


Biology  in  America 


tional  evidence  for  the  cliromosome  hypothesis  as  outlined 
a])()ve. 

In  the  course  of  their  experiments  tlie  students  of  the  fruit 
fly  were  suddenly  confronted  with  an  unexpected,  and  at 
first  sight  unexplaiiuihle  case,  which  seemingly  set  the  chromo- 
some hypothesis  on  its  head.     As  already  explained,  if  a  pure 


0  0  VI  I  LOW.  SPOT 

II  7  I.MHAL  I 

I  ..WHITF.iOMN.  CMERKy 

I.U  AnSOKllAL 

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14  7  CLUB 


■  100  SHlfTED 


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■»v»  iniiM  IV, 


f  0!>EPIA 


-loo  DACHS 


:S.U  PINK    PEACH 


•■MBOSr.VJOTT. 


'1  ''.WOftULA. 


Chromosome  ATap  Hhowing  Distkiiuition  of  Linked  Characters  in 

The  Fruit  Fly 
After   Morgan,   "Heretlity   and   Sex." 
By  permission  of  the  Columbia  University  Press. 

white-eyed  female  be  mated  to  a  red-eyed  male,  red-eyed 
daughters  and  white-eyed  sons  in  approximately  equal  num- 
bers are  the  result.  But  in  one  set  of  experiments  this  cross 
produced,  in  addition  to  the  expected  classes  of .  offspring, 
about  2.5%  of  white-eyed  females  and  an  equal  number  of 
red-eyed  males.  Such  a  result  is  readily  explainable  how- 
ever "on  the  assumption  that  the  two  X  chromosomes  of  the 


The  Role  of  the  Chromosomes 


217 


female  stick  together  in  the  reduction  division,  so  that 
one  class  of  eggs  receives  two  X  and  the  other  none.  A 
detailed  analysis  of  all  the  possible  combinations  resulting 
from  snch  a  case  is  rather  too  complicated  for  consideration 
here.  Suffice  it  to  say  that  the  unexpected  class  of  white- 
eyed  females  could  be  obtained  by  tlie  fertilization  of  an  XX 
egg  by  a  Y  sperm,  and  that  of  red-eyed  males  by  the  union 
of  an  egg  lacking  an  X  with  an  X  sperm  (the  X  being  the 
important  chromosome  in  sex  determination,  the  Y  ai)i)arently 


l\. 


I\ 


^.^ 
/»^ 


Diagrammatic  Kepresentation  of  the  Chromosomes  of  the 

Fruit  Fly 

The  female  (left)  and  male  (right).  The  chroinosomos  are  shown  in 
pairs,  the  sex  jjairs  being  indicated  by  XX  (female)  and  XY"  (male) 
respectively.  In  the  lower  figuie  is  shown  tlie  peculiar  case  of  a  female 
carrying  2  X  and  1  Y,  owing  to  the  failure  of  the  2  X  to  separate  from 
each  otlier  in  the  ripening  divisions  of  the  egg.  This  condition  explains 
certain  unusual  results  found  by  Morgan  and  his  students  in  bree<iing 
these  flies  for  eye  color.     After   Morgan   cf   al. 

non-functional  in  this  connection,  2  X  giving  a  female  and 
1  X  a  male).  It  is  also  possible  theoretically  to  obtain  a 
female  with  foitr  sex  chromosomes,  2  Xs  and  2  Ys.  Not  only 
can  the  unusual  breeding  results  be  explained  theoretically 
in  this  manner,  but  cytological  research  shows  that  such  cases 
actually  occur,  some  exceptional  females  having  been  found 
which  contained  one  or  two  Y  chioiuosomes  in  additiou  to 
the  usual  XX. 


218  Biology  in  Amei'ica 

While  there  are  some  objections  to  the  chromosome  theory, 
and  while  it  as  yet  has  only  the  status  of  a  theory,  it  never- 
theless serves  better  than  any  other  to  explain  the  observed 
results  of  IMendelian  inheritance.  To  what  extent  the  cyto- 
plasm shares  with  the  chromatin  the  role  of  determination, 
and  whether  all  the  characters  of  livin<>:  things,  or  only  the 
more  superficial  are  determined  by  the  latter,  cannot  at  pres- 
ent be  said. 

In  this  tinj''  workshop  of  the  cell  wonderful  things  are 
taking  place.  Here  is  recorded  the  liistory  of  the  past,  and 
here  is  meted  out  the  fate  of  generations  yet  unborn. 


CHAPTER  VIII 

Experimental  biology  continued.  Influence  of  environment 
in  determining  the  development  of  organisms.  Effects  of 
temperature,  light,  moisture,  chemicals  and  food  upon  the 
form  of  ammals  and  plants.     The  control  of  sex. 

And  what  of  the  development  of  this  marvelous  cell  ?  What 
hand  glides  the  growth  of  the  future  organism  in  all  its 
wonderful  detail  from  this  apparently  simple,  but  unspeakably 
complex  drop  of  protoplasm?  Is  it  predestined,  or  is  it 
plastic,  to  be  molded  by  the  experimenter  at  his  will  1  These 
two  possibilities  are  in  no  wise  incompatible  with  each  other. 
While  the  pattern  of  the  cloth  may  be  fixed,  the  form  of  the 
garment  to  be  shaped  therefrom  is  as  variable  as  the  caprice 
of  fashion.  Nor  can  the  former  be  permanently  fixed,  unless 
evolution  is  a  myth. 

As  we  have  already  seen  in  IMendelian  inheritance  the  char- 
acter determiners  are  apparently  distributed  according  to  the 
laws  of  chance.  But  there  is  evidence  showing  that  this  dis- 
tribution can,  to  some  extent  at  least,  be  controlled. 

If  the  female  fruit  i\y  be  exposed  to  temperatures  ranging 
from  50°  to  86°  C.  at  a  certain  period  during  the  maturation 
of  her  germ  cells,  it  is  found  that  the  amount  of  crossing 
over  between  two  factors  may  be  increased  by  more  than 
100%,  That  external  factors  may  profoun(ily  influence 
Mendelian  results  has  been  clearly  shown  by  Tower.  The 
genus  Leptinotarsa,  of  which  the  common  potato  beetle  is  a 
member,  shows  several  color  variations,  which  have  been 
designated  as  species.  When  the  female  L.  signaticollis  is 
crossed  with  the  male  L.  diversa  at  an  average  temperature 
of  75°-79°  F.  and  a  relative  humidity  of  75%,  the  hybrid 
offspring  fall  into  two  distinct  groups  of  practically  equal 
numbers,  one  of  them  indistinguishable  from  the  mother  and 
the  other  intermediate  between  the  two  parents.  The  former 
group  breeds  true  for  several  generations ;  but  the  latter  when 
inbred  give  the  typical  Mendelian  ratio  of  1  signaticollis, 
2  intermediate  and  1  diversa,  the  first  and  last  of  which  breed 
true,  but  the  second  continues  to  split  up  in  further  breeding, 
into  the  two  parent  and  the  intermediate  types.  If  however 
the  crossing  be  done  at  an  average  temperature  of  50°  to  75° 

219 


220  liioloyii  ill  America 

F.  aiul  ivl;itivc  linmidity  of  50-80%  only  tlic  intonnediate 
form  is  obtainod.  Not  only  ai'o  llioso  rosidts  jriven  by  dif- 
ferent pairs  of  elosely  related  individuals,  brothers  and  sistei-s, 
l)ut  1h("  same  pair  wlien  mated  under  different  conditions  give 
ditfereut  I'esults. 

While  ^lendelian  eliaraeters  are  evidently  represented  by 
definite  determiners  in  the  germ  cells,  there  is  abundant  evi- 
dence that  the  development  of  these  characters  can  be  con- 
trolled by  enviroument.  There  is  a  sex-linked  dominant 
chaiacter  iti  Drosophila  known  as  abnormal  abdomen,  in  which 
the  usual  black  bands  upon  tiie  abdomen  are  irregular  and 
broken  and  may  even  be  absent.  That  this  character  depends 
on  the  type  of  food  (whether  wet  or  dry)  for  its  development 
may  be  shown  by  tiie  following  experiment.  If  an  abnormal 
male  be  crossed  with  a  normal  female  and  the  larvae  fed  on 
wet  food,  the  daughters  will  be  abnormal  and  the  sons  normal ; 
but  if  the  food  be  drv^,  both  daughters  and  sons  will  "be 
noi-mal.  From  these  latter  daughters  however  abnormal  off- 
spring may  be  obtained  if  the  conditions  are  favorable,  show- 
ing that  the  determiner  for  abnormality  is  present,  regardless 
of  external  conditions,  but  the  development  of  the  character 
itself  is  dependent  upon  tliis  latter  factor. 

The  influence  of  environment  in  determining  the  form  of 
the  individual  animal  or  plant  is  so  well  known  as  to  be 
connnonplace.  Food,  temperature,  pressure,  moisture,  chem- 
icals, radiation  may,  one  or  more,  so  profoundly  change  the 
development  of  an  organism  that  two  differently  cultured 
individuals  may  not  be  recognizable  as  members  of  the  same 
species. 

The  effect  of  environment  on  individual  development  is 
perhaps  nowhere  more  strikingly  shown  than  in  many  species 
of  mountain  plants,  which  range  froni  the  low  moist  valleysi 
to  the  high  arid  slopes  above  timber  line.  Seeds  of  the  same 
species  will  produce  in  the  former  situation  tall  stemmed 
plants,  with  large  thin  leaves,  small  roots  and  pale  flowers, 
which  require  from  two  to  three  months  to  mature  seed ;  while 
in  the  latfer  environment  they  develop  plants  with  short  stems, 
small,  thick  leaves,  and  bright  colored  flowers,  which  set  seed 
within  a  few  weeks  after  the  blossoms  open ;  all  of  which, 
possibly  excepting  the  flower  color,  are  adaptations  to  their 
different  environments. 

A  test  of  the  influence  of  the  environment  upon  plants  has 
been  made  by  the  Department  of  Hotanical  Eesearch  of  the 
Carnegie  Institution,  by  the  introduction  of  various  species 
of  ])lants  into  areas  having  very  different  climates,  in  the  hot 
dry  <lesert  at  Tucson,  Arizona,  in  the  cool  climate  of  the 
neighboring  mountains,  and  in  the  cool  moist  climate  of  the 


The  Infll'kxlk  uf  I-^n vikonmkxt  on  Plants 
A,  Campanula  from  8,300  feet  altitude  at  the  left  and  one  from  14,100 
et   at   right.     B,   from    left   to    rijrht,   gentians   growing   in    shade   and 
sunlight  at  8,300  feet  altitude,  and  alpine  form  from   13,000  feet.     0,  at 
the  left,  alpine  form,  at  tlio  center,  sunlight,  and   at  the  right,   shade 
forms  of  Androsace.-    From  "Plant  Indicators." 


feet 
sunligl 


Courtesy   of  Doctor   F 


E.    Clcmrntu   and    the   Carnegie   Institution. 
221 


222  Biology  in  America 

California  Coast  near  Monterey.  A  very  pretty  exanii)le  of 
the  response  of  plants  to  such  climatic  changes  is  given  by 
the  common  iioke-weed  (Phytolacca)  of  the  eastern  United 
States.  In  California  the  body  of  the  plant  grows  well,  but 
the  flowers  are  usually  reduced  and  seed  is  not  formed,  while 
at  Tucson,  on  the  contrary,  the  plant  body  grows  low  and 
prostrate,  and  flowers  and  fruit  are  abundant.  There  are 
many  other  changes  also,  both  of  leaf  and  flower.  In  this 
instance  at  least  the  variations  appear  to  be  temporary  and 
not  inherited. 

The  common  water-cress  of  our  eastern  ponds  and  streams, 
when  cultivated  out  of  water,  develops  enlarged  roots,  and 
marked  changes  in  the  form  of  the  leaves,  the  submerged 
leaves  having  very  narrow,  almost  thread-like  leaflets,  while, 
when  grown  in  the  air,  the  leaflets  are  broader. 

The  results  of  experimental  modification  of  the  form  of 
animals  are  too  numerous  for  full  discussion  here.  ]\Iany 
of  them  are  cited  by  Darwin  in  his  different  books,  and  the" 
majority  of  them  have  been  obtained  by  European  workers. 
The  seasonal  variations  (summer  and  winter)  of  certain 
butterflies  can  be  produced  at  will  by  temperature  control 
during  the  pupa  stage.  Similarly  local  varieties  (northern 
and  southern)  of  butterflies  can  be  produced  by  temperature 
control  during  the  developing  period.  Differences  of  color 
between  the  sexes  can  similarly  be  controlled.  The  seasonal 
changes  of  arctic  birds  and  mammals  are  well  known,  and 
are  supposed  to  have  selective  value,  either  for  offense  or 
defense.  That  these  changes  are  at  least  secondarily  depend- 
ent upon  temperature  was  shown  by  the  experience  of  the 
arctic  explorer  Ross  with  the  lennning,  or  arctic  mouse; 
which  when  kept  in  the  ship's  cabin  in  wdnter  retained  its 
gray  coat,  but  when  put  on  deck  promptly  changed  to  white. 
The  celebrated  experiment  with  the  Porto  Santo  rabbits 
recorded  by  Darwin  is  supposed  to  illustrate  the  influence 
of  climate  in  changing  animals.  These  rabbits  are  believed 
to  have  originated  from  the  progeny  of  a  single  female  pro- 
duced on  shipboard  about  1418  or  19.  According  to  Darwin 
these  rabbits,  when  examined  b.y  him  in  1861,  showed  marked 
differences  from  domestic  rabbits,  being  much  smaller  and 
differing  in  the  form  of  the  skull  and  in  color.  Four  years 
later  however  under  the  influence  of  the  English  climate,  they 
had  resumed  the  color  of  the  domestic  form.  Kecently  how- 
ever Mr.  Gerrit  S.  Miller  of  the  U.  S.  National  ]\Iuseum  has 
claimed  that  the  celebrated  Porto  Santo  rabbits  are  nothing 
more  nor  less  than  the  rabbits  native  to  southern  Europe. 
Even  if  this  is  so  however  it  does  not  invalidate  Darwin's 


The  Hole  of  the  Chromosomes  223 

observation  on  the  change  induced  by  transferring  the  rab- 
bits from  Porto  Santo  to  England. 

Great  differences  also  have  been  produced  in  butterflies 
and  moths  by  changes  in  the  food  of  the  caterpillar,  while 
light,  electric  and  chemical  stimuli,  etc.,  show  marked  effects. 

The  results  of  some  American  workers  will  now  be  con- 
sidered in  more  detail. 

The  salamander  Amblystoma  has  gills  and  fins  and  lives 
in  the  water  during  its  larval  or  axolotl  stage.  At  metamor- 
phosis it  loses  fins  and  gills,  leaves  the  water  and  thereafter 
lives  upon  the  land.  In  some  cases  however  metamorphosis 
does  not  occur,  and  sexual  maturity  appears  in  the  larval 
form.  Although  the  relationship  between  the  axolotl  and 
some  terrestrial  form  was  suspected  by  Cuvier,  it  was  not 
discovered  until  1865  in  the  Jardin  des  Plantes  at  Paris, 
when  the  young  of  some  axolotls  gradually  lost  their  gills, 
their  fins  disappeared  and  they  came  forth  upon  land  to  live 
thenceforward  as  Amblystomas.  All  the  factors  controlling 
the  metamorphosis  cannot  at  present  be  stated  with  certainty, 
but  apparently  a  regular  but  small  supply  of  food  as  opposed 
to  abundant  but  irregular  feeding  tends  to  prevent  meta- 
morphosis. It  has  been  generally  supposed  that  drying  up 
of  the  water,  with  consequent  lack  of  oxygen,  forced  the  sala- 
manders to  an  air-breathing  habit  and  induced  metamorphosis. 
But  Powers  has  shown  that  the  axolotl  will  metamorphose  in 
abundant  and  well-aerated  water,  if  its  food  supply  be  cut 
off,  and  conversely  forcing  the  salamanders  out  of  the  water 
will  not  induce  metamorphosis  unless  accompanied  by  a 
change  from  an  abundant  to  a  meagre  diet.  His  explanation 
of  the  control  of  metamorphosis  by  nutrition  is  that,  when 
suddenly  deprived  of  food,  the  salamanders  are  forced  to 
live  on  their  own  tissues,  and  that  those  of  gills  and  fins 
being  the  first  consumed,  causes  the  reduction  of  these  organs, 
and  induces  metamorphosis.  His  interpretation  is  supported 
by  the  fact  that  during  metamorphosis  the  animals  are  gener- 
ally in  a  state  of  semi-starvation. 

As  is  well  known,  Amblystoma  is  an  exceedingly  variable 
animal,  and  Powers  has  related  these  variations  in  large 
measure  to  nutrition.  Kegular,  but  moderate  amounts  of 
food,  produces  slender  and  agile  animals,  while  heavy  feeding, 
on  the  contrary,  produces  fat  and  lazy  beasts,  which  spend 
most  of  their  time  on  the  bottom  of  ponds  or  aquaria.  Most 
marked  of  all  the  varieties  are  certain  animals  of  large  size, 
very  broad  heads  and  frequently  emaciated  appearance, 
which  result  from  cannibalism.  Axolotls  ordinarily  feed 
upon  microscopic  life  in  the  water  such  as  larvaB  of  insects, 


224  Biology  in  America 

etc.,  l)iit  ooeasioiially  tliey  take  to  preying?  upon  each  other, 
oftentimes  witli  results  fatal  alike  to  cannibal  aiul  to  prey. 
Towers  records  his  observations  of  some  cannibals  as  follows: 

"It  was  curious  that  in  every  instance  where  two  or  more 
of  tlie  cannibals  Avere  placed  at  close  quarters,  even  though 
other  larva}  were  present,  the  result  was  the  destruction  of 
one  or  both  of  the  cannibals,  while  the  others  frequently 
remained  unharmed.  This  result  is  not  due  to  the  natural 
enmity  of  competitors  or  to  a  wise  foresight  with  regard  to 
a  limited  food  supply,  but  purely  to  the  strongly  modified 
reactions  of  the  cannibals  themselves.  "While  an  ordinary 
larva  instinctively  avoids  close  contact  with  another,  and 
beats  the  most  precipitate  retreat  at  the  merest  touch  of 
cannibalistic  jaws,  the  possessors  of  these  weapons  them- 
selves are  apparently  wholly  divested  of  this  innate  fear. 
Unless  decidedly  hungry  they  lie  sluggishly  at  the  bottom, 
either  ignoring  the  chance  contacts  of  other  specimens,  or 
savagely  nabbing  the  intruder.  The  violence  and  instan- 
taneousness  of  their  occasional  movements  contrast  strongly 
with  their  sluggish  inactivity  between  whiles.  Even  com- 
plete satiety  does  not  usually  check  their  savage  attacks,  pro- 
vided that  the  proper  stimulus  is  offered ;  the  prey  is  then 
seized  and  held  some  time  or  half  swallowed,  to  be  then  as 
quickly  rejected  by  a  sudden  jerk  much  like  the  one  by  which 
it  was  seized.  Thus  it  is  that  cannibals  in  close  proximity 
almost  invariably  prove  each  other's  undoing,  the  swallower 
frequently  succumbing  as  Avell  as  the  swallowed.  Even  when 
taken  in  the  reservoir,  not  a  few  of  the  broad-heads  were 
sadly  bitten  or  abraded,  some  having  been,  it  would  seem, 
nearly  swallowed  before  meeting  with  the  resistance,  no  doubt, 
of  some  friend  who  had  just  gone  before."^ 

Not  only  may  ordinary  individuals  be  induced  to  assume 
the  cannibalistic  habit,  with  resultant  change  of  shape,  but 
cannibals  may  occasionally  be  reformed  and  made  to  resume 
the  ordinary  shape.  Obviously  the  larval  form  is  very  plastic 
and  readily  amenable  to  the  influence  of  habit.  The  greatly 
exaggerated  head  with  its  wide  gape  is  clearly  the  result  of 
swallowing  large  prey,  while  the  emaciation  of  other  parts 
of  the  body,  especially  gills  and  legs,  Powers  ascribes  to  the 
"energy — absorbed  in  the  heroic  efforts  of  ingestion"  and 
the  nourishment  required  for  the  excessive  development  of 
head,  digestive  tract  and  body  length. 

The  change  of  plumage  in  birds  in  the  spring  and  fall 
months  is  a  commonplace,  but  none  the  less  wonderful  phe- 
nomenon, a  satisfactory  explanation  for  which  has  not  yet 

^"Studies  from  the  Zoological  Laboratory,"  University  of  Nebraska, 
Vol.  IV,  pp.  57-58. 


The  Role  of  the  Chromosomes 


225 


been  given.  One  of  tlic  most  striking  of  these  color  changes 
occurs  in  the  male  scarlet  tanager,  which  during  the  breeding 
season  wears  a  uniform  of  brilliant  scarlet  with  black  wings; 
after  which  he  assumes  a  dull  olive  drab  like  the  female, 
which  he  wears  during  the  winter,  resuming  his  brilliant  garb 
in  spring.  Another  bird  with  a  pronounced  difference  be- 
tween summer  and  winter  plumage  is  the  male  bobolink. 
We  hail  with  joy  his  return  to  our  northern  fields  in  spring, 
with  his  bright  livery  of  black,  buff  and  cream,  and  his  ring- 
ing, cheery  song.     In  the  fall,  when  in  his  dull  drab  coat 


Effect  of  Diet  on  Body  Form  in-  Amblystoma 

Fig.  1,  young  cannibal  after  full  meal.  Fig.  2,  typical  larva.  Figs. 
3-5,  young  cannibals.  Fig.  6,  normal  larva,  typical  of  the  ordinary 
specimens  among  ■which  the  cannibals  were  found.  From  Powers, 
"Morphological  Variation  and  its  Causes  in  Amblystoma  tigrinum. " 
Studies  from  the  Zoological  Laboratory  of  the  University  of  Nebraska, 
Vol.  IV,  No.  71. 


he  gathers  in  flocks  of  thousands  upon  our  marshes,  we  shoot 
him  as  the  plump  little  "reed  bird";  while  over  the  rice  fields 
of  the  Carolinas,  upon  his  return  from  his  summer  sojourn 
in  the  North,  he  meets  an  even  worse  reception  from  the  rice 
grower  as  his  inveterate  enemy,  the  "rice  bird." 

Immediately  following  the  breeding  season,  i.  e.,  at  the 
time  of  the  fall  molt,  birds  are  usually  in  poor  condition 
both  in  respect  to  feathers  and  flesh.  Some  male  tanagers 
and  bobolinks  in  the  New  York  Zoological  Gardens  were  pre- 
vented from  breeding  for  one  season,  during  which  time  they 
remained  in  full  song  and  excellent  physical  condition  and 
retained  their  full  breeding  plumage.    About  a  month  previous 


226 


Biology  in  America 


to  the  time  of  the  fall  molt  the  birds  were  put  in  a  darkened 
room  and  their  food  supply  slightly  increased.  On  this  regi- 
men the  birds  grew  fat  and  lazy  and  ceased  to  sing.  Most  of 
them  passed  the  winter  thus  in  full  summer  plumage,  but 
one  of  the  tanagers  molted  into  the  winter  plumage  as  a 
result  of  a  siidden  change  of  temperature.  In  the  spring 
the  birds  were  brought  under  normal  conditions  again  and 
promptly  molted  into  the  spring  plumage,  the  winter  molt 
having  been  entirely  suppressed,  a  beautiful  example  of 
environmental  control  of  an  hereditary  trait. 


The  Scarlet  Tanager,  Male  and  Female  (Right) 

A  striking  example  of  sexual  difference  in  birds.  The  winter  dress 
of  the  male  is  similar  to  that  of  the  female.  From  Cooke,  "Bird 
Migration,"  in  Bulletin  Bureau  Biological  Survey. 

The  Bobolink  (Left) 

A  bird  of  many  aliases,  admired  in  the  North,  detested  in  the  South. 
From  a  drawing  liy  Louis  Agassiz  Fuertes  in  Cooke,  "Bird  Migration," 
Bulletin  Bureau  Biological  Survey. 

The  effects  of  light  on  the  color  of  animals  are  clearly 
marked  in  some  instances,  and  in  others  seemingly  negligible. 
The  typical  fauna  of  caves  comprises  animals,  which  have 
little  or  no  pigment,  and  either  partly  or  wholly  degenerate 
eyes.  The  amphipod  Eucrangonyx  gracilis  occurs  both  in 
the  open  and  in  caves.  In  the  latter  situation  its  eyes  alone 
are  pigmented,  while  in  the  former,  other  parts  of  the  body 


The  Bole  of  the  Chromosomes  227 

are  pigmented  also.  If  the  young  of  specimens  living  in  the 
open  are  kept  in  the  dark  during  development,  the  pigment  is 
more  or  less  absent.  Different  species  of  salamanders  show 
differing  results  when  reared  in  artificial  caves ;  in  some  there 
is  very  slight  reduction  of  pigment  and  in  others  this  reduc- 
tion is  temporarily  almost  complete.  These  latter  however 
may  develop  the  normal  amount  of  pigment  at  metamorphosis. 
Vice  versa,  cave  animals  lacking  pigment  may  or  may  not 
develop  pigment,  when  reared  in  the  light.  Possibly  the  less 
responsive  types  are  those  which  have  lived  longest  in  their 
respective  habitats.  However  the  fact  that  there  is  consider- 
able individual  variation  in  this  respect  suggests  that  some 
other  factor  is  involved. 

An  interesting  adaptation  of  certain  cave  animals  is  their 
greater  sensitiveness  to  tactile  than  to  light  stimuli  as  com- 
pared with  their  free-living  relatives. 

Animals  respond  readily  to  chemical  treatment.  Some  of 
the  most  noted  experiments  along  this  line  are  those  of 
Stoekard  in  the  production  of  Cyclopean  fish.  By  treating 
developing  minnows  with  magnesium  salts,  alcohol,  chloro- 
form, etc.,  he  has  replaced  the  paired  eyes  with  an  unpaired 
median  one  resembling  that  of  the  fabled  Cyclops,  and  similar 
results  have  been  obtained  by  McClendon  and  Werber.  Not 
only  may  Cyclopean  monsters  be  formed  by  chemical  treat- 
ment, but  deformities  of  many  kinds.  Eye  deformities  may 
range  all  the  way  from  various  stages  in  the  approach  and 
fusion  of  the  eyes,  through  Cyclopean  eyes,  to  no  eyes  at  all. 
The  eyes  may  be  rudimentary  in  size  and  displaced  dorsally ; 
or  there  may  be  inequality  of  the  two  eyes,  leading  to  the 
absence  of  one  of  them.  An  eye  may  even  be  developed 
entirely  outside  the  body  of  the  embryo,  on  the  surface  of 
the  yolk  sack.  Abnormalities  of  the  eyes  are  usually  accom- 
panied by  those  of  nose  and  mouth,  which  are  frequently 
drawn  out  into  a  snout-like  projection.  In  cases  in  which  one 
eye  is  lacking  its  place  may  occasionally  be  taken  by  the 
mouth.  The  nasal  pits  may  fuse  into  one,  and  the  same 
may  be  true  of  the  ears.  Or  these  latter  may  be  enormously 
swollen,  or  on  the  contrary  exceedingly  small,  when  one  or 
more  of  the  semi-circular  canals  may  be  defective  or  lacking. 
Partial  embryos  may  occur,  or  the  parts  of  the  embryo  may 
develop  separately,  as  in  the  case  of  a  yolk  sack  eye,  already 
mentioned.  In  fact  every  imaginable  deformity  may  be  pro- 
duced by  chemical  treatment,  from  very  slight  defects-  to  those 
so  great  that  the  resulting  creature  is  merely  a  formless 
mass  of  living  matter. 

Abnormal  development  may  sometimes  run  a  more  orderly 
course  and  produce  symmetrical,  relatively  perfect  creatures 


228 


Biology  in  America 


which  Professor  Wilder  calls  ' '  cosmobia. ' '  Thus  in  man  there 
exists  a  whole  series  of  duplicities  from  a  slight  cleft  of  the 
spinal  cord  to  those  in  which  the  cord  is  doubled  for  its  entire 
length  and  is  more  or  less  rudimentary.  The  doubling 
process  may  go  furtber,  resulting  in  a  double-headed  monster, 
or  one  with  two  heads  and  four  arms.  Or  if  the  process 
proceed  in  the  reverse  direction  a  single  body  and  head  may 
possess  tAvo  pairs  of  legs ;  while  if  the  doubling  process  occur 
at  both  ends  simultaneously  "Siamese  twins"  result;  until 
finally  if  the  body  be  completely  separated  "identical  twins" 


Cyclopean  Pish 

Produced   by   treatment   with   magnesium   salts.      From    Stockard,    in 
"Journal  Experimental  Zoology,"   Vol.   6.     Mouth;   yolk  sack. 


occur,  which  are  always  of  the  same  sex,  and  resemble  each 
other  as  closely  as  the  proverbial  "two  peas  in  a  pod." 

The  experiments  on  fish  embryos  strongly  support  the 
theory  of  Mall,  that  monstrosities  in  man  are  due  to  diseased 
conditions  in  the  mother's  uterus,  with  resultant  metabolic 
disturbances  and  the  formation  of  toxins  in  the  embryo  and 
fetus. 

We  have  seen  in  the  last  chapter  that  our  present  evidence 
very  strongly  indicates  that  sex  is  predetermined  in  the  egg, 
so  that  most  of  the  supposed  instances  of  its  artificial  control 
are  at  the  present  time  of  historical  interest  only.  One  of  the 
most  popular  tbeorios  of  sex  determination  ascribes  to  food  a 
sex  determining  influence.     Experiments  of  this  nature  have 


A    IIl'MAX    Twix    AlnXSTER 


Types  of  Human  Facks 
From  the  sinjjle  "Cyclopean  oye"  type    (I-V)    tlir()U<,'li    normal    (VI- 
IX)     to    (hiplicate     (X-XIV),    showing    intergi-adatioiis.       From    Wilder, 
"The    Morphology   of    CosnioLia/'    "American   Journal    of    Anatomy," 
Vol.   8. 

229 


230 


Biology  in  America 


been  performed  on  insects,  frogs,  birds  and  mammals.  Better 
nutrition  is  supposed  to  produce  more  females  and  vice  versa. 
In  this  way  the  attempt  has  been  made  to  explain  the  increase 
in  males  in  France  during  the  Napoleonic  wars.  One  observer 
has  cited  data  showing  that  among  the  nobility  of  Sweden 
the  proportion  of  males  to  females  is  98-100,  while  among  the 
clergy  the  ratio  is  108.6-100.  Another  has  shown  on  the 
contraiy  that  in  London  the  more  well-to-do  have  a  larger 
percentage  of  sons  than  daughters.  Temperature,  age  of 
parents  and  ripeness  of  eggs  are  other  popular  factors  in 
sex  determination.  But  one  of  the  most  naive  of  recent 
theories  supposes  that  there  is  a  regular  alternation  of  male 


A  Human  "Monster  " 
Courtesy  of  Dr.  Oeo.  L.  Streeter. 

and  female  producing  ova  in  man,  the  former  coming  from 
the  right,  and  the  latter  from  the  left  ovary,  and  that  sex 
might  be  determined  by  the  position  of  the  prospective  mother, 
whether  lying  on  her  right  or  left  side. 

Extensive  experiments  have  been  conducted  on  the  influ- 
ence of  external  factors  in  determining  the  sex  cycle  in  par- 
thenogenetic  animals.  The  most  familiar  example  of  this  type' 
is  the  bee,  in  which  the  unfertilized  egg  gives  rise  to  a  male 
(drone)  and  the  fertilized  to  a  female  (queen)  or  an  unde- 
veloped female  (worker).  Here  sex  depends  upon  the  act  of 
fertilization,  and  is  probably  determined  by  the  chromosomes, 
which  differ  in  number  in  the  two  sexes.  The  influence  of 
food   in   controlling   development   is   here   most  beautifully 


The  Role  of  the  Chromosomes 


231 


shown,  for  the  fertilized  egg  becomes  either  a  queen  or  a 
worker,  according  to  the  kind  of  food  which  it  receives. 

In  other  parthenogenetic  forms  the  sex  relations  are  not 
so  clear.  Among  the  fresh  water  Crustacea  the  daphnids  pre- 
sent a  well-known  example  of  parthenogenesis.  When  the 
daphnids  appear  in  spring  or  summer  only  females  are  found. 
They  lay  thin-shelled  eggs  which  develop  without  fertilization 
into  other  females  which  in  turn  lay  parthenogenetic  eggs, 
and  so  the  story  goes  for  several  generations ;  when  suddenly, 
males  make  their  appearance,  together  with  the  "winter"  or 
"resting"  eggs,  which  are  fertilized,  and  surrounded  by  a 
thick  shell,  in  which  they  pass  the  winter  inactive  in  the  ooze 
at  the  bottom  of  the  water.  AVith  the  advent  of  warm 
weather  the  following  year  these  eggs  hatch,  giving  rise  to 


Molted  Skin  and  Liberated  Egg  Case  op  a  Daphnid 

Photo    by    Lloyd,    from    Needham    and    Lloyd's    "Life    of 
Waters,"  Comstoek  Publishing  Company. 


Inland 


parthenogenetic  females,  which  repeat  the  story.  The  time 
of  appearance  of  males  varies  in  different  species.  In  some 
it  appears  to  be  correlated  with  the  lowered  temperature  of 
autumn,  and  in  others  with  the  drying  up  of  the  pools  in 
which  the  animals  live.  A  similar  life  history  is  presented 
by  the  rotifers,  or  "wheel  animalcules,"  so  called  from  the 
circlet  of  vibrating  cilia  at  the  anterior  end. 

The  group  of  nematodes  or  thread  worms  present  some 
curious  modifications  of  the  sex  cycle.  Some  of  these  are 
parasitic,  others  are  free-living  and  yet  others  present  a 
so-called  "alternation  of  generations"  in  which  one  genera- 
tion lives  parasitically  and  the  other  free.  Moreover  some  are 
hermaphroditic,  others  bi-sexual.  Among  the  bi-sexual,  free- 
living  forms,  parthenogenesis  is  of  common  occurrence,  having 
gone  so  far  that  in  one  species,  males  occur  only  in  the  ratio 
of  13  to  100,000  females,  while  in  others  they  have  not  as 


232  Biology  in  America 

yet  been  discovered.  Furthermore  in  some  cases  the  males 
have  lost  the  sexual  instinct  and  the  females  have  partly 
developed  hermaphroditism,  producing  sperms,  which  enter 
the  eggs  but  take  no  further  part  in  their  development,  the 
latter  developing  by  parthenogenesis. 

The  principal  American  workers  on  control  of  the  sexual 
cycle  in  parthenogenetic  forms  have  been  ShuU  and  Whitney. 
It  has  been  claimed  by  some  European  zoologists  that  tem- 
perature or  food  are  controlling  factors  in  the  production  of 
males  in  daphnids  and  rotifers.  The  influence  of  the  former 
factor  is  seemingly  borne  out  by  the  occurrence  in  nature 
of  differences  in  the  cycle  in  different  races  of  the  same 
species.  Thus  Chydorus  spha^ricus,  a  European  daphnid, 
reproduces  both  parthenogenetically  and  sexually  in  the  low- 
lands of  central  Europe,  while  in  the  mountains,  reproduction 
is  said  to  be  exclusively  parthenogenetic.  The  influence  of 
these  factors  is  denied  by  the  former  workers.  They  have 
demonstrated  however  a  marked  influence  of  the  purity  of 
the  culture  medium  on  production  of  males,  the  proportion 
of  males  to  females  in  Hydatina  senta  being  greater  the 
more  the  culture  medium  was  diluted  with  spring  water. 
Possibly  the  controlling  factor  here  was  the  relative  acidity 
of  the  medium,  for  Banta  has  shown  the  influence  of  this 
factor  in  controlling  the  production  of  males  in  daphnids. 
It  has  been  argued  that  these  experiments  have  nothing  to 
do  with  sex  control,  that  all  they  prove  is  the  possibility  of 
shifting  one  way  or  another  the  time  of  appearance  of  males, 
in  an  alternating  sex  cycle,  in  support  of  which  argument 
is  presented  the  fact  that  the  same  mother  will  produce  males 
or  females  from  the  same  eggs,  depending  on  whether  or  not 
these  are  fertilized,  similarly  to  the  case  of  the  bee  mentioned 
above.  But  is  not  this  begging  the  question,  for  what  is  it 
that  determines  the  appearance  of  the  males  in  the  first  place? 
The  evidence  indicates  that  it  is  an  external  factor,  and  in 
so  far  as  this  is  true  we  certainly  are  controlling  sex. 

There  is  some  recent  work  by  Riddle  which  indicates  that 
sex  in  birds  is  a  question  of  metabolism,  males  arising  from 
germ  cells  of  higher  metabolism,  larger  water  content  and 
less  fat  and  phosphatides.  Riddle  claims  the  sex  may  be 
controlled  by  controlling  these  factors  in  spite  of  the  sex 
chromosomes,  which  are  "but  a  sign  or  index,  not  an  efificient 
cause  of  sex."  His  results,  while  seemingly  conclusive,  need 
to  be  extended,  and  correlated  with  those  of  the  cytologists 
before  any  certain  conclusions  can  be  drawn  however. 

The  conditions  found  in  some  of  the  Crustacea  and  gephy- 
reans  indicate  that  sex  is  not  a  predetermined,  unchange- 
able condition.     Some  of  the  parasitic  isopods  are  first  males 


The  Role  of  the  Chromosomes  233 

and  later  become  females.  In  the  sand  hopper  (Orchestia) 
occur  alternate  periods  of  maleness  and  (partial)  femaleness, 
while  in  Bonellia,  one  of  the  gephyrean  worms,  the  larva 
develops  into  a  male  or  female,  depending  upon  whether  it 
lives  attached  or  free.  "While  sex  appears,  in  many  cases  at 
least,  to  be  predetermined  in  the  egg,  it  would  not  be  safe 
at  present  to  say  that  this  predetermination  was  in  all  cases 
irrevocable. 

A  curious  condition  has  been  discovered  by  Banta  in  some 
of  the  daphnids  (Daphnia  and  Simocephalus)  in  the  form  of 
"  sex-intergrades. "  In  these  animals  the  sexes  are  readily 
distinguishable  externally  by  several  secondary  sexual  char- 
acters, such  as  size  and  form  of  body  and  appendages,  hair- 
iness of  ventral  surface,  etc,  Banta  has  found  a  complete 
series  of  intergrades,  ranging  from  normal  males  on  the  one 
hand,  through  males  with  one  or  more  of  the  secondary  char- 
acters of  the  female,  to  hermaphrodites  and  females  with 
certain  secondary  male  characters,  and  finally  to  normal 
females  on  the  other.  A  similar  condition  has  been  found 
by  Goldschmidt  in  the  gypsy  moth,  and  by  Stout  in  the 
common  plantain  weed.  How  far  these  results  agree  with 
the  chromosome  hypothesis  of  sex  determination  is  very  much 
"up  in  the  air"  at  present. 

Reference  has  already  been  made  to  Hydra,  a  name  classic 
in  biology  as  in  mythology.  Hydra  may  reproduce  either 
by  simple  division  of  its  body  into  two  parts,  by  forming 
buds  which  develop  into  new  Hydras  and  are  then  pinched 
off  the  parent  stock,  or  by  developing  sex  organs  followed  by 
fertilization.  "Whitney  has  shown  that  the  appearance  of 
sex  organs  can  be  controlled  by  external  factors,  such  as  tem- 
perature and  food.  Thus,  if  Hydra  be  kept  for  a  time  at  a 
low  temperature,  and  the  temperature  be  then  raised  and  the 
animal  starved,  testes  and  ovaries  develop.  Sexual  repro- 
duction in  lower  plants  (i.  e.,  Vaucheria,  etc.)  has  also  been 
controlled  by  external  factors.  These  latter  experiments  how- 
ever deal  with  the  control  of  sexual,  as  distinct  from  asex- 
ual reproduction,  and  not  with  the  determination  of  sex 
itself. 

In  the  foregoing  pages  we  have  sketched  very  briefly  a  few 
of  the  facts  bearing  upon  the  relative  roles  played  by  hered- 
ity and  environment  in  the  development  of  the  organism. 
Needless  to  say  the  two  factors  are  in  no  sense  antagonistic 
or  mutually  exclusive,  but  both  work  together  in  fashioning 
the  final  product.  The  inheritance  of  the  organism  may  be 
compared  to  the  molten  metal;  the  environment,  the  mold 
in  which  the  metal  is  cast. 


CHAPTER  IX 

Experimental  'biology  continued.  The  factors  of  evolution: 
natural  selection,  mutation,  orthogenesis,  isolation,  inherit- 
ance of  acquired  cliaracters.  Experimental  modification  of 
the  germ  cells. 

The  search  for  the  beginnings  of  things  was  one  of  the  ear- 
liest tasks  of  the  human  mind.  Man,  like  a  little  child,  with 
a  '  *  why  ? ' '  ever  present  on  its  tongue,  has  never  ceased  to  ask 
the  questions,  "Whence  came  I,  and  whither  am  I  bound?" 
With  the  latter  question  science,  with  her  present  limitations 
of  time  and  space,  has  naught  to  do,  but  the  latter  ever  has 
been,  and  perchance  ever  will  be  the  focal  spot  of  human 
thought.  Strange  and  curious  are  the  many  fancies  with 
which  primitive  philosophy  has  invested  the  problem,  and  in 
spite  of  all  the  wonderful  achievements  of  modern  science  she 
is  still  but  playing  with  the  pebbles  on  the  seashore.  We 
smile  complacently  as  we  read  of  the  fat  turtle  of  the  Iroquois 
philosopher,  which,  waddling  along  one  hot  summer  day, 
found  his  shell  too  great  a  burden,  and  throwing  it  off  became 
a  man;  or  of  the  crude  philosophy  of  the  early  Greeks  who 
imagined  a  fish  coming  upon  land,  bursting  its  horny  capsule 
and  stepping  forth  a  man ;  or  yet  of  the  old  French  philoso- 
pher who  related  a  tale  of  a  wonderful  tree,  whose  leaves, 
falling  on  the  one  hand  upon  water,  gave  rise  to  fish,  and  on 
the  other  upon  land,  took  wings  and  flew  away  as  birds, 
naively  remarking  that  while  this  magical  tree  was  not,  to 
be  sure,  to  be  seen  in  France,  yet  it  was  said  to  be  common 
in  Scotland,  a  land,  which  to  the  reader  of  those  days,  was  a 
terra  incognita.  And  we  shake  our  heads  learnedly  as  we 
talk  today  of  "fortuitous  variation,"  "internal  perfecting 
principles,"  "entelechics"  or  "orthogenetic  evolution."  But 
when,  in  the  language  of  the  street,  we  "get  down  to  brass 
tacks"  are  we  really  any  wiser  than  our  forbears?  And  yet 
the  denser  our  ignorance  the  more  alluring  becomes  the  field 
of  research,  while  the  frontiers  of  knowledge  ever  recede  as  we 
approach,  impelled  by  the  primeval  instinct  to  explore. 

While  the  theory  of  evolution  has  become  axiomatic  among 
thinking  men  of  every  school,  the  ways  and  means  of  evolu- 
tion are  as  great  a  bone  of  contention  as  ever.    It  is  but  nat- 

234 


The  Factors  of  Evolution  235 

ural  therefore  that  the  factors  of  evolution  and  heredity,  for 
the  two  processes  are  of  necessity  indissolubly  united,  should 
be  the  center  of  modern  biology. 

The  success  of  Darwin  in  establishing  the  theory  of  evolu- 
tion was  due  primarily  to  his  explanation,  by  the  theory  of 
natural  selection,  of  a  reasonable  process  by  which  evolution 
could  be  effected,  and  his  support  of  this  theory  with  a  vast 
array  of  facts,  and  of  logical  arguments  deduced  therefrom. 
And  yet  the  theory  of  natural  selection  or  survival  of  the 
fittest  antedates  Darwin  by  more  than  two  thousand  years. 

The  Greek  poet-musician-naturalist,  Empedocles,  who  lived 
in  the  fifth  century  before  Christ,  fancied  living  creatures  as 
arising  from  the  four  elements — earth,  air,  fire  and  water,  un- 
der the  action  of  the  forces  of  love  and  hate.  The  animals 
first  formed,  "appeared,  not  as  complete  individuals,  but  as 
parts  of  individuals, — heads  without  necks,  arms  without 
shoulders,  eyes  without  their  sockets.  As  a  result  of  the  tri- 
umph of  love  over  hate,  these  parts  began  to  seek  each  other 
and  unite,  but  purely  fortuitously.  Thus  out  of  this  con- 
fused play  of  bodies,  all  kinds  of  accidental  and  extraordinary 
beings  arose, — animals  with  the  heads  of  men,  and  men  with 
the  heads  of  animals,  even  with  double  chests  and  heads  like 
those  of  the  guests  in  the  Feast  of  Aristophanes.  But  these 
unnatural  products  soon  became  extinct,  because  they  were 
not  capable  of  propagation."  ^ 

These  crude  ideas  of  Empedocles  are  interesting  historically 
because  they  show  how  early  the  survival  idea  arose  in  man's 
mind.  By  many  other  writers  also,  previous  to  Darwin,  this 
idea  was  expressed,  notably  Hume,  Buffon,  Kant  and  St. 
Hilaire,  and  when  Darwin's  thesis  itself  was  presented  to  the 
world  it  appeared  as  two  papers  published  simultaneously  in 
the  Journal  of  the  Linnean  Society  by  himself  and  Alfred 
Russell  Wallace. 

In  spite  of  the  splendid  exposition  given  by  Darwin  of  the 
theory  of  natural  selection,  and  its  very  general  acceptance 
by  scientific  men  of  a  few  decades  ago,  the  pendulum  of  sci- 
entific thought  is  swinging  today  in  the  opposite  direction, 
and  the  consensus  of  opinion  is  distinctly  adverse  to  the  ac- 
ceptance of  the  theory  in  all  its  important  points. 

Before  considering  the  experimental  work  which  has  largely 
induced  this  reversal  of  opinion,  let  us  see  what  the  essen- 
tial features  of  the  theory  are.  Three  factors  are  involved, 
namely,  variation,  inheritance,  and  selection  or  survival.  Let 
us  illustrate  their  co-operation  to  produce  evolution  by  a  con- 
crete example  from  Darwin's  ''Origin  of  Species."    "The 

^Osborn,  "From  the  Greeks  to  Darwin,"  p.  38.  B7  permission  of  the 
Macmillan  Company. 


236  Biology  in  America 

pirafTe,  by  its  lofty  stature,  inucli  elongated  neek,  fore  legs, 
head  and  tongue,  has  its  whole  frame  beautifully'  adapted  for 
bi'owsing  on  the  higher  braneiics  of  trees.  It  can  thus  ob- 
tain food  beyond  the  reach  of  the  other  ,  .  .  hoofed  animals 
iidiabiting  the  same  country,  and  this  must  be  a  great  advan- 
tage to  it  during  dearths.  ...  So  under  nature  with  the  nas- 
cent giratfe,  the  individuals  which  were  the  highest  browsers 
and  were  able  during  dearths  to  reach  even  an  inch  or  two 
above  the  others  (variation)  will  often  have  been  preserved 
(selection).  ,  .  .  They  will  have  intercrossed  and  left  off- 
spring, either  inheriting  the  same  bodily  peculiarities,  or  with 
a  tendency  to  vary  again  in  the  same  manner  (inheritance)  ; 
whilst  the  individuals,  less  favored  in  the  same  respects,  will 
have  been  the  most  liable  to  perish."^ 

One  of  the  strongest  evidences  cited  by  Darwin  in  support 
of  his  theory  was  that  of  artificial  selection.  If  man,  he  said, 
in  a  few  hundreds  or  at  most  thousands  of  j^ears,  could  pro- 
duce, by  selection,  all  the  manifold  varieties  of  domestic  plants 
and  animals  which  we  know  today,  why  could  not  Nature, 
working  through  the  countless  ages  of  biologic  time,  perform 
the  creative  wonders  of  the  past  and  present  kingdoms  of  ani- 
mals and  plants  inhabiting  the  world?  It  is  difficult  however 
to  subject  the  work  of  the  practical  breeder  to  scientific 
analj'sis,  based  as  it  is  upon  purely  economic  grounds.  Fur- 
thermore, we  have  today  a  mass  of  information  regarding  in- 
heritance which  was  not  available  to  Darwin.  Within  re- 
cent years  therefore  the  problem  has  been  attacked  scien- 
tifically by  a  number  of  workers,  the  pioneer  being  the  Dan- 
ish liotanist,  Johannsen. 

If  one  choose  any  group  of  organisms,  be  they  men  or  be 
they  microbes,  and  carefully  aiTange  them  according  to  size, 
he  will  find  that  they  form  a  series,  with  an  average  and 
two  extremes — a  greater  and  a  lesser.  If  now,  on  the  one 
hand,  the  largest  individuals,  and  on  the  other  the  smallest, 
be  chosen  for  breeding,  and  from  their  offspring  in  turn  the 
largest  and  the  smallest  be  again  selected,  can  finally  two  new 
races,  a  larger  and  a  smaller,  be  developed?  This  question 
forms  the  crux  of  the  selection  theory. 

To  test  it  Professor  Johannsen  of  Copenhagen  chose  at  ran- 
dom 12,000  beans  and  measured  the  length  and  breadth  of 
eacli  to  obtain  an  average.  From  these  he  chose  nineteen,  rang- 
ing from  the  largest  to  the  smallest.  Breeding  these  for  seven 
years,  and  selecting  the  largest  and  smallest  seeds  for  each 
planting,  he  found  that,  while  the  largest  beans  produced 
seed  larger  than  the  average  of  the  12,000,  and  the  smallest 
produced  seed  smaller  than  the  average,  bubsequent  selection 
» Pp.  276-7,  6th  ed. 


The  Factors  of  Evolution 


237 


availed  nothing  to  increase  or  decrease  tlic  size  of  each  "pure 
line"  as  Professor  -lohannsen  called  the  progeny  of  his  nine- 
teen seeds,  "('an  a  man  add  one  cubit  unto  his  stature,"  or 
a  bean  one  millimeter  unto  its  length?  Professor  Johannsen 
thinks  not. 


Population 


Diagram  Showing  the  Effi  ct  of  Selection  Upon  a  Mixed  Lot  of 

Beans  or  ' '  Po(Pulation  ' ' 

If  several  thousand  beans,  selected  at  random,  are  sorted  ac- 
cording to  size  and  placed  in  test  tubes,  the  lower  figure  will  result ; 
those  beans  of  an  average  size  will  be  greatest  in  number,  while 
the  larger  and  smaller  sizes  will  be  fewest.  If  beans  from  different 
test  tubes  be  selected  for  planting  the  "pure  lines"  1,  2,  3,  etc.  will 
result.  Further  breeding  of  these  "pure  lines"  will  not  serve  to  change 
the  average  size  of  the  population^  selection  serving  merely  to  sort  out 
the  varieties  jumbled  together  in  a  inLxed  "population."  From  Walter, 
after  Johannsen. 

Similar  results  have  been  obtained  by  several  American 
workers,  notably  Professor  Pearl,  who,  while  at  the  Maine 
Agricultural  Experiment  Station,  attempted  by  selection  to 
increase  the  laying  capacity  of  hens — and  failed ;  and  Pro- 
fessor Jennings  of  Johns  Hopkins,  who  has  likewise  shown 
that  selection  is  powerless  to  change  the  size  of  the  one-celled 
animal  Paramcecium. 


238 


Biology  in  America 


But  tlie  voice  of  the  selectionist  is  not  yet  stilled.  Perhaps 
tlie  chief  American  exponent  of  tlie  tlieory  has  been  Professor 
Castle  of  Hai^'ard,  whose  work  on  hooded  rats  is  well  known 
to  all  biologists.  The  hooded  rat  is  a  color  variety  of  the 
common  brown  rat,  with  black  head  and  shoulders  and  a  black 
stripe  on  the  middle  of  back  and  tail.  By  persistent  selec- 
tion of  individuals  with  more  black  and  more  white  respec- 
tively, Castle  has  obtained  individuals  ranging  all  the  way 
from  those  with  a  small  median  stripe  of  white  upon  the  belly 
to  others  with  only  a  small  patch  of  black  upon  the  snout. ^ 

For  over  twenty  years  a  selection  experiment  has  been 
conducted  at  the  experiment  station  at  the  University  of  Il- 
linois, which  also  appears  to  give  strong  support  to  the  the- 


" Hooded"  Eats 

Showing  the  results  of  experiments  by  Professor  Castle  of  Harvard  in 
selecting  these  animals  for  extent  of  black  and  white  in  the  pattern. 
After  Castle  &  Phillips,  "Piebald  Eats  and  Selection,"  Carnegie  In- 
stitution, Publication  No.  195. 


ory.  In  1896,  Professors  Hopkins  and  Smith  began  selecting 
seed  from  ears  of  corn  which  had  on  the  one  hand  a  high,  and 
on  the  other  a  low  protein  content.  This  continual  selection 
has  resulted  not  only  in  producing  grades  of  high  and  low 
content,  but  each  succeeding  year  shows  on  the  average  a  wider 
divergence  in  the  two  grades.  Thus,  starting  in  1896  with 
an  average  per  cent  (in  weight  of  grain)  of  10.92  they  pro- 
duced the  first  year  a  high  grade  of  11.10%  and  a  low  of 
10.55%  with  a  difference  of  only  0.55%.  By  gradually  in- 
creasing steps  these  figures  after  twenty  years'  selection 
reached  14.53%  for  the  high,  7.26%  for  the  low  and  7.27% 
for  the  difference.  Similar  results  were  obtained  by  them  in 
selecting  for  oil  content. 

The  anti-selectionists  however  have  explained  these  results 
as  due  merely  to  the  sorting  out  of  variations  already  pres- 
ent in  a  very  mixed  stock.    A  better  understanding  of  the 

•Eecently  Professor  Castle  has  modified  his  original  contentiou. 


The  Factors  of  Evolution 


23!) 


whole  question  of  selection  can  be  had  after  a  discnssioii  of 
the  next  factor  of  evolution,  namely  mutation. 

The  mutation  theory  is  not  a  new  one  to  biolofjists.  A 
century  ago  St.  Ililaire  suggested  the  origin  of  birds  fi'om 
reptiles,  the  first  formed  bird  hatching  full-fledged  from  a 
reptile's  egg.  The  existence  of  mutants  or  "sports"  were  well 
known  to  Darwin,  and  are  cited  by  him  as  a  source,  although 
a  minor  one,  of  evolution.     The  cases  wbicli  lie  gives  are  how- 


MUTATION    IN    QDnOTHEKA 

The  original  stock  laninrkiana  to  the  left,  gigas  a  mutant  to  the  right. 
From    Castle,    ' '  Genetics    and    Eugenics, ' ' 

By  permission  of  Harvard  University  Press. 


ever  of  a  striking  and  unusual  sort.  The  A  neon  ram  is  one 
of  these.  In  1791  a  Massachusetts  farmer  discovered  in  his 
flock  a  ram  with  short  crooked  legs  and  a  long  body.  The 
thrifty  farmer  bred  from  this  ram  in  order  to  obtain  a  flock 
of  sheep  which  could  not  jump  fences,  and  would  thereby 
save  himself  much  worry,  and  his  sheep  dog  much  exercise. 
This  was  the  origin  of  the  famous  breed  of  Ancon  sheep,  which 
is  now  however  extinct.  The  merino  sheep,  a  breed  having 
long  silky  wool,  which  originated  in  1828,  is  another  exam- 


12K) 


/iinio;/)/   ill   Aiiirrica 


j)le  filed  by  Darwin.  Si  ill  other  iiislaiiees  are  tiiose  of  liorn- 
less  eatlle,  hairless  clogs,  l)oi)-tailecl  cats,  web-footed  chiekens 
and  extfa-finjrered  men.  These  however  are  exceptional 
cases;  the  <i:reat  mass  of  mntations,  tliose  mainly  productive 
of  evolution,  are  of  the  minor  sort,  appreciable  only  by  care- 
ful measurement  and  statistical  analysis. 

The  presentation  of  the  mutation  theory  in  its  present  form 
we  owe  nuiinly  to  tiie  Dutch  botanist,  DeVries.  A  brief 
resume  of  the  hitter's  work  will  bring  the  subject  fairly  be- 


iN  1     example    of     mu 
Poulry,  "    Carncyie    Instil  u1  ion,     PuliKcation 


A  RuMPLESs  Fowl 
ton.        J''roiii      l)a\  i'n|iort, 

No. 


Inherit  a  nt-e 


in 


fore  us.  Over  thirty  years  ago  DeVries  found  certain  well- 
marked  varieties  of  the  evening  primrose,  a  native  of  Amer- 
ica, which  had  been  introduced  into  Pairope  and  was  grow- 
ing as  a  weed  around  the  city  of  Amsterdam.  Specimens  of 
these  varieties  and  of  the  parent  species  were  transplanted 
in  his  garden  and  bred  for  many  years  including  eight  gen- 
erations, during  wdiich  time  he  discovered  and  recorded  over 
800  variations  from  the  parent  type,  whose  possessors  bred 
true  to  themselves.  By  selection  of  these  variations  he  was 
able  to  produce  a  large  number  of  distinct  types  of  prim- 
rose which  he  called  "elementary  species," 


The  Factors  of  Evolution  241 

Since  tlie  publication  of  DeVries'  work  on  the  mutation 
theory  the  attention  of  biologists  has  been  focnssed  more  and 
more  on  this  factor  of  species  building,  and  large  numbers 
of  cases  have  been  recorded  in  both  animals  and  plants. 
These  cover  the  whole  garant  of  variation  and  are  both  (juali- 
tative  and  quantitative  in  kind.  They  include  variations  in 
color,  markings  and  size ;  in  form ;  length  and  number  of 
hairs,  bristles,  etc. ;  ditferences  in  shape  of  parts  such  as  leaves 
of  plants,  wings  of  insects,  horns  of  cattle,  etc. ;  differences 
in  habit  of  plants,  whether  erect  or  procumbent,  straight  or 
branching,  etc. ;  differences  in  the  number  and  union  of  parts, 
such  as  syndactylism  and  polydactylism  in  man  and  other 
animals ;  differences  in  presence  or  absence  of  parts,  such  as 
absence  of  a  tail  in  cats  and  chickens ;  in  fact,  virtually  every 
character  known  of  either  animal  or  plant  is  liable  at  some 
time  or  other  to  show  mutation.  INIutations  vary  moreover 
in  size,  from  the  large  "sports"  already  mentioned,  down  to 
variations  so  small  that  it  is  mere  hair-splitting  to  attempt 
to  distinguish  between  them  and  Darwin's  "fortuitous"  vari- 
ations on  the  basis  of  size  alone. 

What  distinction  then  if  any  can  be  made  between  these 
two  classes?  Darwin  did  not  attempt  to  define  "fortuitous" 
variations,  but  speaks  of  the  term  as  serving  "to  acknowl- 
edge plainly  our  ignorance  of  the  cause  of  each  particular 
variation."  His  distinction  between  them  and  "sports"  or 
mutations  was  one  of  size  alone.  More  recently  however  we 
have  learned  to  recognize  in  the  small  "fortuitous"  varia- 
tions of  Darwin  two  distinct  kinds  of  variability,  one  of  which 
we  call  "continuous"  or  "fluctuating"  and  the  other  "dis- 
continuous" or  "mutating."  If  the  sizes  of  any  group  of 
organisms,  let  us  say  men,  be  plotted  on  a  chart,  as  Ave 
shall  find  a  point  which  is  called  the  mode,  at  which 
fall  a  greater  number  of  measurements  than  at  any  other, 
while  the  remainder  graduate  to  either  side  of  this  point 
until  the  limits  of  the  series  are  reached.  Such  a  chart  is 
called  a  frequency  polygon  (or  curve,  if  the  measurements  are 
sufficiently  numerous  and  close  together).  Such  a  chart  rep- 
resents graphically  "fluctuating"  variation,  the  variations 
falling  indiscriminately  on  either  side  of  the  mode.  If  indi- 
viduals from  either  end  of  the  series  be  mated,  their  off- 
spring will  be  widely  diff'erent  from  the  average  of  the  series, 
but  will  nevertheless  approach  that  average  more  nearly 
than  their  parents,  and  no  amount  of  selection  will  serve  to 
raise  or  lower  the  limits  of  the  series,  that  is,  to  increase  the 
original  variability.  In  the  cases  of  Johannsen's  beans  and 
Jenning's  Parama?cia  and  similar  cases  above  cited  however, 
selection  does  serve  to  sort  out  groups  of  individuals  whose 


242 


Biology  in  America 


cliaractors  (weip:lit,  length,  etc.)   center  around  a  new  mode 
wliieli  is  higher  or  lower  than  the  original.     If  the  character 


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\ 

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(Se  /S3  tez  1€6  /69  /7/  /7i  /77  130  /B3  /06  I8S  fSZ  /35B8 

Frequency-polygon  and  Curve 

Showing   variation   in  height    of   one   thousand   Harvard   students   of 
ages    18-25.     Number   of   individuals   shown   by   ordinates,    and   heights 
(in  centimeters)  by  abscissae.     After  Castle,  "Genetics  and  Eugenics." 
By  permission  of  Harvard  University  Press. 


of  each  of  these  groups  be  plotted,  a  series  of  curves  is  ob- 
tained, each  of  which  represents  "fluctuating"  variability  of 
the  smaller  group  and  has  its  owu  mode.     If  all  of  these 


The  Factors  of  Evolution  243 

smaller  curves  be  compounded  they  produce  the  large  curve 
representing  the  larger  group.  In  some  instances  the 
existence  of  several  modes  is  seen  in  the  original  chart  of  a 
group  of  organisms.  In  other  eases  however  mere  inspection 
fails  to  reveal  the  compound  nature  of  a  variability  curve,  and 
only  experimeiital  analysis  will  tell  the  story. 

These  minor  groups  which  when  selected  breed  true  to  their 
own  type,  are  the  "elementary  species"  of  DeVries,  or  dis- 
continuous variations,  while  the  "fluctuating  variations"  are 
those  which  fluctuate  about  a  mode  and  which  cannot  be  re- 
solved into  smaller  components  by  selection.  From  this  view- 
point "species"  and  "elementary  species'  may  be  compared 
in  a  rough  way  to  the  molecule  and  atom  of  the  chemist. 

The  objection  has  been  raised  to  DeVries'  theory  that  his 
mutations  are  the  results  of  hybridization,  producing  a  new 
combination  of  characters  already  present,  but  not  anything 
really  new  in  itself.  The  wide  range  of  mutation  however 
among  both  plants  and  animals,  wild  as  well  as  domesticated, 
from  the  large  "sports"  of  Darwin  down  to  those  so  small 
that  they  cannot  be  distinguished  at  sight  from  "fluctuat- 
ing" variations,  the  fact  that  in  some  species  there  are  peri- 
ods of  frequent  mutation,  alternating  with  those  in  which 
it  is  absent  or  rarer,  and  the  possibility  of  inducing  them 
artificially  all  speak  in  their  favor  as  something  new,  and 
not  due  to  a  mere  mixing  and  rearrangement  of  characters 
already  present.  Unless  indeed  we  accept  Bateson's  view 
that  most  if  not  all  variation  is  due  to  the  loss  of  something 
already  present,  which,  carried  to  its  logical  conclusion, 
brings  us  face  to  face  with  the  reductio  ad  ahsurdum  that 
all  the  possibilities  of  man  were  wrapped  up  in  the  original 
iV*nioeba,  or  whatever  it  was  that  initiated  the  long  line  of  life 
upon  the  earth. 

But  having  analyzed  the  species  into  its  component  parts, 
having  found  the  blocks  from  which  the  organism  is  built, 
are  we  any  the  wiser?  Whence  came  these  ultimate  units, 
if  indeed  they  are  such,  and  how  does  Nature  fashion  them 
to  her  use?  Are  we  any  nearer  an  understanding  of  varia- 
tion today  than  was  Darwin? 

The  attack  on  the  problem  of  variation  has  been  made 
along  two  distinct  lines,  that  of  Aristotle  and  Nageli,  with  the 
assumption  of  an  "internal  perfecting  principle,"  or  in- 
herent tendency  in  the  organism  itself  to  vary  along  certain 
definite  lines,  for  iinhnown  reasons,  and  that  of  Kimer  and 
his  school,  who  believe  that  variation  in  the  organism  is  a 
very  definite  physico-chemical  response  to   physico-chemical 


244  Biology  in  America 

changes  in  its  environment,  either  internal  *  or  external.  The 
former  metliod  is  metaphysical  and  unscientific;  the  latter, 
while  beset  by  many  difficulties,  is  the  only  one  of  promise. 

What  then  has  been  done  to  discover  the  influence  of  en- 
viroiunent  upon  variability?  In  a  previous  chapter  we  have 
briefly  surveyed  tlie  influence  of  environment  upon  individ- 
ual development,  and  have  seen  that  this  influence  is  often 
of  a  profound  character.  But  is  such  influence  lasting,  does 
it  through  heredity  control  future  as  well  as  present  gen- 
erations? And  this  brings  us  face  to  face  with  one  of  the 
greatest  stumbling  blocks  in  biology ;  namely,  the  inheritance 
of  acquired   characters. 

In  the  first  place  what  is  the  meaning  of  the  term?  V{e 
owe  the  theory  to  the  great  French  naturalist  Lamarck,  one 
of  those  lonely  and  pathetic  figures  who  look  down  upon  the 
pathway  of  human  progress  unheeded  by  the  passing  throngs. 
Lamarck  as.sumed  first,  what  is  universally  granted ;  namely, 
the  influence  of  use  and  disuse  of  organs  upon  individual  de- 
velopment, and  second,  what  is  generally  denied;  namely, 
the  perpetuation  of  such  influence  by  heredity.  Thus  let  us 
suppose  a  grouj)  of  early  race  horses  to  have  increased  their 
speed  by  training  until  they  were  materially  faster  than  their 
parents.  If  now  such  increase  in  speed  were  handed  down 
to  their  offspring,  and  these  in  turn  improved  by  further 
training,  aiul  so  on  from  generation  to  generation,  there 
would  evolve  in  time  the  speedy  animal  of  today.  Or  if,  on 
the  other  hand,  a  race  of  fishes  living  at  one  time  in  the  open, 
for  some  reason  or  other,  perhaps  to  escape  the  attack  of  ene- 
mies, took  to  dwelling  in  caves,  where  sight  was  of  little  ad- 
vantage; there  would  in  course  of  time,  through  lack  of  use 
of  sight,  develop  the  blind  cave  fishes  of  the  present.  The 
theory  is  the  prettiest  and  simplest  of  the  modua  operandi  of 
evolution  which  has  been  proposed,  and  could  it  be  proven, 
would  remove  many  difficulties  in  our  path.  Unfortunately 
however  proof  thus  far  is  lacking.  Skepticism  toward  the 
theory  has  been  mainly  founded  on  failure  of  mutilations  of 
various  sorts  (circumcision  among  the  Jews,  cramping  of 
feet  by  the  Chinese,  docking  of  horses'  tails),  and  finally  Weis- 
mann's  classical  experiments  in  amputating  the  tails  of  twen- 
ty-two geiu'rations  of  mice,  to  produce  any  inheritable  modi- 
fication whatever  in  the  parts  so  mutilated.  It  should  be 
noted  however  that  while  Lamarck's  theory  postulates  use 
and  disuse  as  the  prime  factors  in  causing  change,  some  of 
the  mutilations  above  cited  do  not  involve  the  factors  of  use 

■*  Ultiniatoly  "internal"  chantros  tlu'iiisc'l\es  are  prol)aT)ly  roforalile  to 
external  causes.  I  have  in  niiml  tlie  manifold  metabolic  changes,  which 
may  produce  variation.     Regarding  this  we  have  no  certain  knowledge. 


The  Factors  of  Evolution  245 

and  disuse  and  consequently  have  no  bearing  whatever  on 
the  question  at  issue.  Whoever  heard,  for  example,  of  a 
horse  with  a  docked  tail  ceasing  to  use  the  stump  just  as  vig- 
orously in  fiy  time,  as  though  possessed  of  the  complete  mem- 
ber? What  was  there  in  the  mutilations  of  Weismann's  mice 
to  prevent  the  use  of  the  muscles  at  the  hase  of  the  tail  ?  With 
the  bound  foot  of  the  Chinese  woman  this  objection  would  not 
apply,  because  the  muscles  of  the  foot  are  intrinsic  to  the  foot 
itself ;  but  in  this  case  we  have  to  consider  the  intluence  of  the 
father  as  well  as  the  mother  upon  the  children,  and  the  prac- 
tise of  foot  binding  in  China  has  been  limited  to  the  female 
sex. 

Are  there  then  no  environmental  influences  which  are  trans- 
mitted from  parent  to  child?  Is  environment  a  negligible 
factor  in  evolution?  On  the  contrary  it  is  undoubtedly  the 
most  potent  factor,  either  indirectly  in  the  preservation  of 
those  variations  (however  caused)  best  fitted  to  survive,  or 
directly  in  the  induction  of  variation  itself. 

The  seed  of  a  flowering  plant  is  the  plant  itself  in  minia- 
ture, containing  more  or  less  "endosperm"  or  nourishment 
for  the  growing  seedling,  until  it  is  able  to  take  root,  unfold 
its  leaves  and  obtain  its  own  sustenance  from  the  soil  and  air. 
If  the  chemical  environment  of  the  developing  plant  (the 
young  ovule)  be  modified,  what  effect  will  this  have  on  the 
adult  plant?  This  question  led  MacDougal,  director  of  the 
Desert  Botanical  Laboratory  of  the  Carnegie  Institution,  to 
inject  various  solutions  of  zinc,  calcium,  iodine,  etc.,  into 
the  ovaries  of  many  species  of  plants,  with  the  result  that  the 
ovaries  so  treated  produced  seeds  from  which  developed 
plants  showing  many  modifications  in  form  of  leaves  and 
flowers  and  markings  of  the  latter,  as  well  as  in  the  form  of 
the  plant  as  a  whole,  and  some,  at  least,  of  these  variations 
have  persisted  through  several  subsequent  generations. 

The  common  potato  bug  has  in  part  redeemed  its  shady 
reputation,  by  materially  aiding  us  in  our  search  for  the  ulti- 
mate factor  of  evolution,  namely,  the  origin  of  variation. 
This  beetle  was  originally  an  inhabitant  of  ]\Iexico.  Feeding 
upon  the  night-shade,  it  followed  its  food  plant  northward, 
and  the  early  settlers  found  it  establislied  on  the  eastern 
slope  of  the  Rocky  Mountains.  The  spread  of  its  food  plant 
is  attributed  by  Professor  Tower,  who  has  made  an  exhaustive 
study  of  the  beetle  and  its  habits,  to  the  movements  of  the 
early  Spanish  explorers,  and  to  the  migrations  of  animals, 
especially  the  buffalo,  whose  mighty  herds  in  early  days  were 
wont  to  wander  north  and  south  across  the  plains  with  the 
changing  seasons,  and  in  whose  furry  coats  the  burrs  of  the 
night-shade  might  readily  have  been  entangled.     The  eai-ly 


246  Biology  in  America 

settlors  bronglit  with  them  plenty  of  English  grit,  Scotch 
whiskey  ;iml  Irish  ])otatoes;  and  the  beetles,  finding  the  lat- 
ter more  to  their  liking  than  their  native  food,  soon  showed 
proper  appreciation  of  the  good  things  set  before  them,  and 
became  inveterate  potato  feeders.  After  this  change  in  the 
diet,  it  was  not  long  before  they  had  overrun  all  of  the 
eastern  United  States  and  lower  Canada. 

There  are  many  species  of  these  beetles,  distributed  in 
different  parts  of  the  range  of  the  genus,  and  most  of  them 
show  considerable  variation.  There  are  two  generations  each 
season,  the  duration  of  each  varying  both  with  the  species  and 
the  locality.  The  beetles  retire  for  the  winter  underground 
and  upon  emergence  in  spring,  seek  out  the  potato  plants, 
upon  which  the  eggs  are  laid.  From  these  hatch  the  grub- 
like larvae,  which  after  a  varying  period  cease  feeding,  and 
drop  to  the  ground  into  which  they  burrow  and  there  pupate, 
surrounding  themselves  with  a  thin  shell.  From  this  the 
adult  beetles  escape,  make  their  way  to  the  surface  and  pro- 
ceed to  a  repetition  of  this  performance,  the  second  brood 
of  beetles  hibernating  in  the  earth  at  the  end  of  summer.  If 
the  larvae  are  taken  soon  after  hatching  and  kept  in  experi- 
mental cages  at  higher  or  lower  temperatures  than  normal, 
or  in  more  or  less  humid  atmospheres,  or  in  various  combina- 
tions of  temperature  and  humidity,  until  development  is  com- 
plete, the  adult  beetle  developing  from  them  will  be  lighter 
or  darker  in  shade  and  will  show  many  differences  from  the 
usual  color  pattern,  these  differences  in  many  cases  closely 
corresponding  to  differences  in  beetles  from  different  locali- 
ties. Thus  it  was  possible  to  produce  in  the  laboratory  in 
Chicago  beetles  resembling  closely  those  occurring  in  nature 
in  Arizona,  The  same  stimulus  produced  different  results 
depending  upon  its  strength.  Thus  a  moderate  increase  of 
temperature  made  the  beetles  darker  in  color,  while  a  greater 
increase  made  them  lighter,  and  precisely  similar  results  were 
obtained  by  lowering  the  temperature,  and  by  raising  and 
lowering  the  relative  humidity. 

But  these  results  were  temporary,  lasting  for  one  genera- 
tion only,  and  were  not  inherited.  If  on  the  other  hand  the 
beetles,  shortly  before  egg-laying  occurred,  were  subjected  to 
similar  conditions,  variations  were  produced  which  persisted 
in  subsequent  generations.  In  the  former  case  only  the 
"soma"  or  body  cells  of  the  individual  were  affected;  in  the 
latter,  the  germ  cells  at  a  sensitive  stage  in  their  develop- 
ment— at  least  so  Professor  Tower  interprets  his  results. 
Samples  of  some  of  his  "creations"  are  shown  in  the  accom- 
panying figure. 

Not  alone  by  laboratory  experiment  is  it  possible  to  control 


The  Factors  of  Evolution 


247 


evolution  in  the  potato  beetle.  The  same  experiment  has  been 
performed  in  Nature 's  laboratory  by  transferring  beetles  from 
the  relatively  cool,  moist  climate  of  Chicago  to  the  hot  arid 
air  of  Tucson,  Arizona.  As  a  result  of  this  transfer  not  only 
are  morphological  (color)  changes  induced,  but  physiological 
ones  as  well.  '  The  beetles  gradually  acquire  the  power  to  re- 


MUTATIONS    IN   THE    PoTATO    BEETLE 

2  represents  a  type  derived  experimentally  from  1  by  the  use  of  high 
temperature.  5  was  derived  from  4  by  using  high  temperature  and 
relative  humidity  and  7  from  8  by  high  temperature  and  low  humidity. 
From  Tower,  "  li]volution  in  Chrysomelid  Beetles,"  Carnegie  Institution, 
Publication  No.  48. 

tain  more  water  in  their  tissues  during  hibernation,  and 
thereby  to  resist  the  effects  of  the  dry  climate.  They  show 
also  certain  changes  in  their  responses  to  stimuli.  These 
changes  moreover  are  not  reversible,  but  persist  when  the 
beetles  are  returned  to  their  original  home  at  Chicago.    They 


248  Biology  in  America 

behave  furtheniiore  as  definite,  fixed  characters  in  inherit- 
ance, Mendelizing  when  crossed  with  the  original  stock. 

It  is  well  known  that  the  X-rays  and  those  of  radium  and 
related  substances  exercise  a  profound  influence  on  living 
tissue.  In  general  the  influence  of  such  agents  has  been  de- 
structive, inducing  abuornml  developments  of  various  sorts. 
The  careless  use  of  X-rays  has  been  the  cause  in  some  in- 
stances of  cancer,  while  on  the  other  hand  their  use,  and  es- 
pecially that  of  radium  rays  lias  been  advocated  as  a  cure  for 
this  disease.  Unfortunately  the  results  in  this  direction  are 
as  yet  unsatisfactory. 

In  some  instances  it  has  been  possible  to  produce  changes 
in  the  developing  organism  without  any  apparent  injury  to 
it.  One  of  the  prettiest  experiments  of  this  sort  is  that  of 
Gager,  who  exposed  the  pollen  of  one  of  the  evening  prim- 
roses to  radium  rays,  and  obtained  a  few  individuals  with 
thick,  leathery  leaves  from  ovules  fertilized  by  this  pollen, 
which  character  reappeared  in  their  offspring.  That  such 
radiations  produce  profound  effects  upon  the  structure  of  the 
cell  is  shown  by  exposing  growing  root  tips  to  their  influence, 
the  mitotic  figures  in  the  dividing  cells  being  greatly  distorted 
thereby. 

The  probable  influence  of  environment  upon  animal  form 
and  color  is  very  clearly  shown  in  the  extensive  collections 
of  birds  and  mammals  made  by  American  ornithologists  and 
mammalogists,  especially  those  of  the  U.  S.  Biological  Sur- 
vey, in  which  an  almost  endless  series  of  gradations  may  be 
seen  between  the  various  "geographic  races"  of  one  "spe- 
cies"''' from  different  i)arts  of  North  America.  These  varia- 
tions are  so  great  in  some  cases  that  specimens  from,  extremes 
of  the  geographic  range  would  not  be  recognized  as  members 
of  the  same  species,  did  not  a  complete  series  of  intergrades 
exist. 

If  one  compares  a  mammal,  a  field  mouse  let  us  say,  from 
Florida  or  tropical  Mexico  with  its  nearest  relative  from 
Labrador  or  Alaska,  he  will  find  the  legs,  ears  and  tail  of 
the  former  a  trifle  longer,  and  the  fur  a  little  lighter  than 
the  same  parts  of  its  northern  cousin.  Is  it  mere  accident 
that  the  northern  mouse  is  more  warmly  clad,  and  has  ap- 
pendages which  are  shorter,  and  consequently  less  liable  to 
freeze,  than  the  southern  one?  Or  is  it  a  question  of  sur- 
vival, has  Nature  selected  those  individuals  best  adapted  to 
the  regions  where  they  live?  Or  yet  again,  is  this  a  case  of 
the  influence  of  environment,  and  if  so,  has  the  latter  di- 

'^  Accord inj;;  to  soiiio  writers  these  "  jreographic  r.Tces "  are  accorded 
the  status  of  ' '  species. ' '  Tlie  question  of  terminology  does  not  how- 
ever influence  the  facts  in  the  case. 


The  Factors  of  Evolution  249 

rectly  affected  the  germ  cells,  or  has  such  influence  been  trans- 
mitted to  them  indirectly,  by  affecting  first  the  body  cells  of 
the  parent,  which  effect  has  been  secondarily  transmitted  to 
its  germ  cells?  If  the  latter  is  true,  it  would  go  far  to  es- 
tablish Lamarck's  theory  of  the  inheritance  of  acquired  char- 
acters.. In  an  attempt  to  solve  this  problem,  Sumner  has 
reared  several  generations  of  white  mice  under  different  con- 
ditions of  temperature  and  relative  humidity.  The  mice  were 
kept  in  unheated  and  heated  rooms  respectively,  in  the  for- 
mer of  which  the  relative  humidity  was  much  higher  than  in 
the  latter,  although  in  neither  were  the  conditions  at  all  con- 
stant. As  a  result  the  mice  in  the  cold  room  developed  a 
greater  amount  of  hair  and  shorter  tails,  feet  and  ears.  These 
differences  however  diminished  as  the  mice  grew  older.  Un- 
fortunately his  equipment  did  not  enable  him  to  control  his 
factors  properly,  so  that  his  comparisons  were  made  between 
the  general  conditions  of  greater  and  less  heat  and  moisture 
respectively,  and  not  between  definite  degrees  of  these  factors. 
However  his  results  do  show  a  rather  definite  influence  of 
temperature  and  humidity,  not  alone  upon  the  parents,  but 
also  upon  their  offspring  of  the  first  generation.  These  re- 
sults, so  far  as  they  go,  show  then  that  environment  may  di- 
rectly affect  not  only  the  organism  itself,  but  also  its  off- 
spring. 

When  we  come  to  the  question  however  of  how  these  re- 
sults were  obtained,  we  are  very  much  at  sea.  In  the  case 
of  Tower's  experiments  described  above  there  can  be  little 
doubt  that  the  influence  of  the  external  factors  upon  the  germ 
cells  was  direct,  because  inheritable  variations  were  obtained 
only  when  the  experimental  factors  were  operative  at  a  cer- 
tain definite  time  in  the  development  of  the  germ  cells.  Here 
too  the  latter,  in  the  body  of  an  animal  whose  temperature  is 
not  constant,  but  varies  with  that  of  its  environment,  are 
readily  subject  to  environmental  influence,  at  least  so  far 
as  temperature  is  concerned.  In  the  case  of  humidity  it 
is  more  difficult  to  see  how  the  germ  cells  could  be  directly 
influenced.  In  mice  however  whose  body  temperature  and 
moisture  is  constant  under  normal  conditions,  regardless  of 
external  factors,  it  is  impossible  to  postulate  a  direct  ac- 
tion of  such  environmental  factoi-s  upon  the  germ  cells,  and 
the  only  possible  interpretation  to  be  placed  on  Sunnier 's 
results,  assuming  their  accuracy,  is  that  of  an  indirect  in- 
fluence of  external  factors  upon  the  germ  cells,  through 
changes  primarily  induced  in  the  body  cells  or  soma,  and  sec- 
ondarily transmitted  from  them  to  the  germ  cells;  i.e.,  the 
inheritance  of  acquired  characters. 

Unfortunately  Sumner's  results  have  not  been,  so  far  as 


250 


Biology  in  America 


I  know,  substantiated  by  any  other  investigator,  and  his  own, 
more  reeent  work  in  California  has  strikingly  failed  to  sup- 
port his  previous  experiments.  In  his  later  work  Sumner 
has  been  studying  the  relatioji  between  climate  and  color  of 
several  races  of  California  deer  mice  (Peromyscus).  The 
climate  of  California  presents  all  possible  gradations,  from  the 
arctic  conditions  of  the  Sierra  summits  to  the  torrid  heat  of 
the  southern  valleys,  and  from  the  humid  air  of  the  northern 
coast  to  the  parched  atmosphere  of  the  interior  deserts. 
Widelv  distributed  over  the  state  the  ubiquitous  deer  mouse 


The  Deer  Mouse,  Peromyscus 
Photo   l)ij  E.   R.   Warren. 

is  found  with  three  distinct  varieties  of  one  species,  one  of 
which  occupies  the  cold  humid  coast  region  from  San  Fran- 
cisco northward,  another  the  interior,  including  both  moun- 
tains and  valleys,  and  the  southern  coast,  while  a  third  lives 
in  the  hot,  arid  deserts  of  the  southeastern  part.  Possibly 
a  more  ideal  region  for  studies  of  environmental  influence  on 
variation  could  not  be  found.  Sumner  has  reared  several' 
generations  of  mice  taken  from  the  humid  northern  coast,  and 
the  desert  to  the  southern  coast  at  La  Jolla,  and  to  Berkeley 
on  San  Francisco  Bay,  but  thus  far  without  obtaining  any 
definite  results.  The  imported  mice  remain  true  to  their  an- 
cestry. 


The  Factors  of  Evolution  251 

Far  back  in  the  dim  shadows  of  the  past,  primitive  man  is 
represented  as  asking  his  Creator,  "Am  I  my  brother's 
keeper?"  And  that  qnestion  has  come  down  to  ns  through 
all  the  ages,  with  ever-growing  insistency.  What  measure  of 
responsibility  do  we  bear  for  the  well-being,  not  only  of  our 
brothers  of  the  present,  but  our  children  of  the  future  ?  Does 
a  man's  conduct  influence  for  weal  or  w^oe  the  lives  of  his 
children  ?  Alcoholism  is  a  well  recognized  inherited  trait. 
But  what  is  its  origin?  Can  a  man  through  indulgence  in 
the  "cup  that  cheers"  affect  the  inheritance  of  his  children? 
AVhile  abundant  data  are  available  from  human  inheritance 
to  show  its  inheritability,  evidence  regarding  its  origin  can- 
not be  readily  obtained  here.  And  so  the  experimenter  has 
turned  to  the  long-suffering  guinea  pig,  the  rat  and  the 
chicken  for  an  answer  to  his  question.  And  here  only  indi- 
rect evidence  at  best  can  be  obtained.  We  cannot  induce  an 
alcoholic  tendency  or  fondness  in  a  lower  animal,  or  at  least 
it  has  not  yet  been  done ;  but  we  can  determine  whether  sub- 
jecting the  parent  to  alcohol  will  in  any  way  influence  the 
offspring,  and  whether  such  effects,  if  any,  will  persist  in 
future  generations. 

Trial  of  several  methods  of  subjecting  animals  to  alcohol 
has  shown  that  the  best  method  is  to  allow  them  to  breathe 
the  fumes  for  stated  periods  daily,  the  length  of  the  period 
being  determined  by  the  ease  with  which  the  animal  is  in- 
toxicated by  the  fumes.  The  method  is  objectionable  because 
of  the  tendency  of  the  animals  to  become  blind  under  the  in- 
fluence of  the  fumes.  This  does  not  however  interfere  wdth 
their  breeding,  nor  does  it  reappear  in  the  offspring.  Using 
this  method  on  guinea  pigs  Stockard  has  found  that  of  one 
hundred  and  three  matings  between  parents,  either  one  or 
both  of  which  had  been  treated  with  alcohol,  forty-three  were 
either  sterile  or  resulted  in  abortions;  in  fourteen  matings 
the  young  were  stillborn,  while  in  the  forty-six  matings  pro- 
ducing a  total  of  eighty-nine  young,  thirty-seven  of  these 
died  soon  after  birth  and  only  fifty-two  survived,  many  of 
which  were  undersized  and  nervous. 

MacDowell  has  carried  out  a  long  series  of  experiments  to 
test  the  effects  of  treating  rats  with  alcohol  upon  the  ability 
of  their  young  to  learn  a  path  through  an  intricate  passage 
or  "maze,"  which  indicate  that  the  grandchildren  of  young 
so  treated  learn  less  readily  than  do  those  of  normal  rats. 
MacDowell  has  also  obtained  a  very  definite  effect  upon 
the  rats  so  treated,  their  weight  and  fecundity  being  ma- 
terially reduced.  Pearl,  in  a  similar  series  of  experiments  on 
fowl,  "found  that  while  the  proportion  of  fertile  eggs  laid 
by  alcoholized  parents  was  nuicli  lower  than  in  those  from 


252  Biology  in  America 

normal  paioiits,  these  whicli  wci'c  I'crtik'  wore  more  re- 
sistant (fewer  died  before  hatching)  and  the  chicks  hatched 
were  heavier  than  those  of  normal  chickens.  Pearl  has  ap- 
parently pnblished  no  resnlts  dealin*?  with  the  effects  of  alco- 
holism on  {^generations  later  than  the  first,  but  Stockard's  ex- 
periments seem  to  show  that  such  effects  are  transmitted  to 
the  grandchildren. 

In  the  light  of  these  contiadictoi'y  results  no  final  word  can 
be  said  regarding  the  intfuence  of  alcohol  .on  animals  and 
the  transmission  of  such  influence  to  subsequent  generations. 
In  neither  the  experiments  of  Stockard  nor  of  Pearl  did  the 
treated  animals  themselves  show  any  conspicuous  effect 
(apart  from  blindness  in  the  guinea  pigs,  which  was  the  di- 
rect result  of  the  action  of  the  alcohol  fumes  upon  the  eye) 
although  the  alcoholic  chickens  increased  somewhat  in  flesh 
and  became  rather  lazy,  a  result  easily  paralleled  in  some 
cases  in  man. 

Recognizing  then  the  occurrence  of  variations  produced 
by  physico-chemical  factors  either  internal  or  external  to  the 
organism  itself,  and  granting  that  such  variations  may  in 
some  cases  be  preserved,  but  probably  neither  increased  nor 
diminished  by  selection;  are  there  other  factors  which  may 
influence  evolution  ? 

In  1868  ]\Ioritz  Wagner  suggested  the  influence  of  geo- 
graphic isolation  as  a  factor  in  the  evolution  of  plants  and 
animals,  and  this  theory  has  more  recently  been  advocated 
by  David  Starr  Jordan  in  this  country. 

One  of  the  objections  to  the  theory  of  natural  selection  is 
the  swamping  effect  of  intercrossing  betw'een  nascent  spe- 
cies. How  this  "swamping"  is  effected  if  new  varieties  are 
discontinuous  or  mutating,  breed  true  and  do  not  blend  when 
intercrossed,  is  difficult  to  understand.  It  is  possible  how- 
ever that  the  dominant  types  being  more  numerous  have 
caused  the  reccssives  to  be  overlooked,  and  that  consequently 
the  "swamping  effect  of  crossing"  is  more  apparent  than 
real.  If  however  such  objection  is  valid,  the  danger  to  the 
new  species  could  be  removed  were  a  barrier  to  such  inter- 
crossing to  arise  between  nascent  types,  thereby  preventing 
them  from  interbreeding.  That  such  isolation  does  play  an 
important  role  in  evolution,  there  is  good  reason  to  believe. 

Isolation  may  be  of  several  kinds:  psychical,  physiolog- 
ical, structural,  habitudinal  and  geographical.  It  is  well 
known  that  many  species  of  nearly  related  animals  will  re- 
fuse to  interbreed.  In  other  cases  in  which  different  species 
of  animals  do  interbreed  the  offspring  are  ordinarily  infer- 
tile, perhaps  the  best  known  instance  being  the  mule,  which 
is  a  hybrid  of  the  jackass  and  the  mare.     Mulatto  women, 


The  Factors  of  Evolution  253 

while  fertile,  are  said  to  have  frequent  miscarriages,  and 
after  a  few  generations  to  be  generally  barren.  In  more  ex- 
treme eases,  while  fertilization  is  possible  and  development 
may  proceed  for  a  time,  the  offspring  of  the  cross  do  not  at- 
tain maturity.  This  is  especially  true  of  crosses  between 
widely  divergent  forms  such  as  the  salamander  and  the  frog, 
or  the  sea  urchin  and  the  starfish. 

In  some  instances  isolation  is  effected  by  a  difference  in 
the  time  of  mating  of  different  individuals.  There  are  many 
species  of  butterflies  which  have  different  color  phases,  to 
which  reference  has  already  been  made.  These  color  phases 
are  apparently  due  to  the  time  of  year  at  which  the  eggs 
are  hatched,  whether  in  spring,  summer  or  autumn.  It  is' 
probable  that  those  butterflies  which  hatch  at  the  different 
seasons  mate  together,  thus  producing  isolation  of  the  dif- 
ferent color  phases  of  the  same  species,  due  to  the  different 
hatching  seasons  of  the  eggs.  Inhabiting  the  Kermadec  Is- 
lands northeast  of  New  Zealand  are  two  varieties  of  a  spe- 
cies of  shore  bird,  which  flock  together  but  breed  at  different' 
times,  thus  producing  isolation  between  them. 

In  other  cases  structural  differences,  notably  of  the  external 
sexual  organs,  such  as  occur  in  various  species  of  insects  and 
other  arthropods,  effectually  serve  to  prevent  interbreeding; 
while  yet  again  structural  differences  in  the  germ  cells  them- 
selves interfere  with  cross  fertilization. 

Habitudinal  isolation  may  be  effected  by  the  preference  of 
different  groups  of  animals  for  different  modes  of  life  (dif- 
ferences in  food  or  habitat).  Inhabiting  the  southern  hemi- 
sphere are  several  species  of  albatrosses,  which  mingle  with 
one  another  throughout  most  of  their  range,  but  breed  in 
separate  localities.  Professor  Kellogg,  whose  name  is  famil- 
iar to  us  all  for  his  services  to  Belgium,  some  years  ago  made 
a  study  of  the  bird  lice,  a  group  of  wingless,  biting  insects 
living  on  birds  and  mammals,  similar  in  habit,  though  dif- 
fering in  structure  from  the  "ugly,  creepin'  blastit  wonner, 
detested,  shunned  by  saunt  an'  sinner,"  but  immortalized  by 
Burns.  In  this  study  he  found  that  while  the  similarity  of 
the  environment  in  which  these  lice  live  tends  to  keep  the 
different  species  unchanged,  nevertheless  the  isolation  pro- 
duced between  groups  of  individuals  living,  it  may  be  for 
years  on  the  body  of  the  same  bird,  tends  to  fix  the  minor 
variations  which  occur  in  all  living  things,  and  thus  pro- 
duce slight  but  noticeably  distinct  variations  within  the  spe- 
cies. 

The  student  of  geographical  distribution  of  plants  and" 
animals  recognizes  as  axiomatic  the  fact  that  the  more  widely 
separated  are  any  two  regions  of  the  earth's  surface,  the  more 


254  Biology  in  America 

divei'freiil  will  be  llu'ir  J'aiiiias  and  floras,  liy  ''separation" 
in  this  sense  is  meant  separation  in  time  and  environment 
ratlun-  tlian  space.  Thus  the  fauna  of  Australia  and  New 
Zeahuid  shows  a  vastly  jrreater  difference  from  that  of  th^ 
Asiatic  nuiinland,  although  separated  therefrom  by  less  than 
2,000  miles,  than  does  that  of  Japan  from  England,  which  are 
about  8,000  miles  distant  from  each  other.  By  some  biolo- 
gists these  differences  are  referred  to  the  effect  of  isolation, 
by  others  to  the  direct  influence  of  environment  (tempera- 
ture, moisture,  etc.),  natural  selection  in  either  case  exercising 
the  veto  power  or  final  control  over  the  other  factors.  Prob- 
ably all  three  factors  are  so  closely  inter-related  in  deter- 
mining the  final  result  in  most  cases  that  an  exact  analysis 
of  their  relative  roles  is  impossible.  The  inhabitants  of  cen- 
tral Africa,  separated  from  those  of  northern  Africa  by  less 
than  2,000  miles,  differ  more  widely  from  each  other,  than  do 
those  of  North  America  and  Siberia,  separated  by  several 
times  that  distance.  But  between  the  former  intervenes  the 
wastes  of  the  Sahara,  impassable  to  most  forms  of  life,  while 
the  latter  have  an  almost  continuous  land  area  between  them, 
broken  only  by  the  narrow  Behring  Strait,  which  freezes  in 
winter.  Prior  to  the  Miocene  epoch  a  few  million  years  ago, 
which  is  comparatively  recent,  geologically  speaking,  tlie  At- 
lantic and  Pacific  Oceans  were  connected,  where  now  ex- 
tends the  Isthmus  of  Panama.  The  elevation  of  the  isthmus 
has  thus  separated  an  originally  single  fauna  into  two,  with 
the  result  that  many  of  the  species  on  either  side  of  the  isth- 
mus are  represented  by  nearly  related  ones  on  the  opposite 
side,  both  doubtless  derived  from  one  ancestral  form. 

In  the  instances  already  cited  it  is  impossible  to  distin- 
guish between  the  possible  effects  of  environment,  selection 
and  isolation ;  in  fact,  it  is  very  probable  that  all  of  them 
have  worked  together  in  producing  the  final  result.  But  in 
the  case  of  the  land  snails  of  the  Hawaiian  Islands,  the  two 
former  factors  are  seemingly  ruled  out,  and  isolation  appears 
to  have  been  the  only  factor  involved.  The  Hawaiian  Islands 
are  a  group  of  volcanic  origin,  the  chief  of  which,  Oahn,  con- 
sists of  a  long  mountain  ridge,  rising  to  an  elevation  of  4,000 
feet  above  the  sea,  from  which  extend  inimerous  lateral  ridges, 
with  deep  intervening  valleys.  Inhabiting  these  valleys  are 
800  or  1,000  different  varieties  of  land  snails  (Achatinellidae), 
over  200  of  which  the  conchologists  recognize  as  ''good  spe- 
cies." These  snails  feed  upon  the  vegetation  in  the  valleys 
and  seldom  cross  the  high  rocky  ridges  of  the  intervening 
slopes.  Each  valley  therefore  has  its  own  community  of 
snails,  which  is  effectively  isolated  from  neighboring  com- 
munities, but  a  few  miles  distant.     As  a  result  of  such  iso- 


The  Factors  of  Evolution  255 

lation  there  have  developed  in  each  valley  varieties  peculiar 
to  it.  In  some  cases  a  species  is  restricted  to  a  single  valley, 
while  in  others  it  may  extend  over  two  or  three  adjacent 
ones.  The  most  nearly  related  forms  are  found  in  adjacent 
valleys,  and  the  most  divergent  in  those  widely  separated. 
Gulick,  who  has  made  a  special  study  of  these  snails,  says,  "I 
had  found  not  simply  a  large  section  of  the  world,  within 
which  peculiar  species  had  originated,  but  ascending  a  certain 
mountain  ridge  a  few  miles  from  Honolulu,  and  looking  down, 
I  could  say,  'That  valley  to  the  right,  a  couple  of  miles  in 
length  and  half  a  mile  in  width,  is  the  birthplace  of  the 
Achatinella  producta  and  Achatinella  adusta ;  and  within  the 
groves  of  this  valley  upon  which  we  look  on  our  left  were 
created  Achatinella  stewartii  and  Achatinella  johnsonii; 
while  behind  us  a  mile  to  the  northeast,  in  the  jungle  that 
clings  to  the  almost  precipitous  cliffs  on  the  other  side  of  the 
backbone  of  the  island,  is  the  secret  home  of  the  very  rare 
and  beautiful  Achatinella  versipellis. ' '  ^ 

Crampton,  who  has  made  an  extensive  study  of  the  distri- 
bution, variation  and  evolution  of  the  land  snails  of  the 
genus  Partula,  inhabiting  Tahiti,  one  of  the  Society  Islands 
of  the  South  Pacific,  forms  closely  related  to  the  Achatinel- 
lidse  of  Hawaii,  has  reached  conclusions  similar  to  those  of 
Gulick.  He  finds  that  "with  only  one  exception  each  group 
of  islands  has  its  own  characteristic  species  which  occur  no- 
where else,"  while  with  few  exceptions  each  island  in  the 
different  groups  "possesses  distinct  species  not  found  in  the 
others,"  and  the  species  "may  vary  from  valley  to  valley 
of  an  island;  one  form  sometimes  extends  over  a  wide  range, 
while  another  may  be  restricted  to  a  few  valleys  or  even  to 
one."^ 

In  many  of  the  habitats  of  the  different  species  of  snails  of 
Oahu  and  Tahiti,  the  environment  is  seemingly  identical.  In 
two  adjacent  valleys,  but  two  or  three  miles  apart,  different 
species  of  snails  may  be  found,  feeding  on  the  same  trees  at 
similar  altitudes  and  experiencing  the  same  degrees  of  tem- 
perature, humidity  and-  barometric  pressure.  In  some  cases 
contiguous  valleys  present  greater  differences  in  vegetation 
than  those  more  widely  separated,  and  yet  the  diversity  of 
the  snails  in  the  former  ease  is  less  than  in  the  latter.  Di- 
vergence of  environment  is  therefore  obviously  not  the  cause 
of  the  differences  involved.  Nor  is  there  any  apparent  in- 
fluence of  selection.     When  two  environments  differ  widely, 

'Gulick,  "Evolution,  Racial  and  Habit udinal,"  Carnegie  Institution, 
Publication  25,  pp.  1-2. 

'Crampton,  "Variation,  Distribution  and  Evolution  of  the  Genus 
Partula,"  Carnegie  Institution,  Publication  228,  p.  11. 


256  Biology  in  America 

selection  may  step  in  to  eliminate  a  species  which  is  not 
adapted  to  one  or  the  other  of  them.  But  as  we  have  just 
seen  there  is  no  correlation  between  differences  in  the  snails 
themselves  and  amount  of  difference  in  their  surroundings. 
Nor  do  the  possible  enemies  of  the  snails  differ  in  their  dis- 
tribution in  the  different  regions. 

Isolation  however  cannot  of  itself  have  caused  these  dif- 
ferences which  must  have  arisen  by  spontaneous  variation  of 
the  snails  themselves,  due  to  factors  as  yet  unknown ;  isola- 
tion playing  merely  a  preservative  role  in  maintaining  the 
variations  tluis  originated,  which  tend  to  increase  by  "ortho- 
genesis," for  reasons  equally  obscure. 

For  several  years  past  Dr.  Paul  Baartsch  of  the  Smith- 
sonian Institution  has  been  carrying  on  an  interesting  and 
significant  experiment,  when  taken  in  conjunction  with  the 
studies  of  Gulick  and  Crampton  on  the  snails  of  the  Pacific 
Islands.  Baartsch  has  employed  a  genus  (Cerion)  of  land 
snails  found  in  Florida,  the  Bahamas,  Porto  Rico  and  neigh- 
boring islands.  Several  colonies  of  these  have  been  trans- 
planted to  the  Florida  Keys,  and  while  the  plantings  have 
not  in  every  case  been  successful,  many  have  thrived  and 
after  some  years  in  their  new  home,  the  snails  in  some  in- 
stances have  shown  marked  differences  in  size  from  the  orig- 
inal type.  His  results  are  as  yet  too  incomplete  to  permit  of 
generalization  however. 

Out  of  all  the  haze  of  evolutionary  theory  do  any  facts  loom 
large  against  the  background  of  the  past?  We  may  I  think 
safely  say  that  evolution  itself  is  such  a  fact ;  that  organisms 
tend  to  vary  for  reasons  in  the  main  as  yet  obscure,  but  un- 
doubtedly due  in  the  last  analysis  to  the  influence  of  environ- 
ment, either  internal  or  external  to  the  organism  itself ;  while 
natural  selection  and  isolation  play  an  important,  but  sec- 
ondary role,  by  preserving  those  variations  which  are  fitted 
to  survive. 


CHAPTER  X 

Experimental  biology  contimiect.  Mendelism  and  the  mul- 
tiple factor  hypothesis.    Human  inheritable  and  eugenics. 

We  have  considered  in  a  previous  cliapter  the  physical  basis 
of  inheritance  and  have  seen  that  the  manifold  characters 
of  organisms  are  probably  determined  by  certain  entities  in 
the  cell,  which  are  shuffled  about  at  the  time  of  maturation 
like  the  cards  in  a  pack  or  dice  in  a  box,  and  recombined  in 
fertilization  so  as  to  produce  entirely  new  combinations  of 
characters  in  the  offspring.  In  the  present  chapter  we  shall 
consider  the  applications  of  these  facts  to  inheritance  in  or- 
ganisms in  general  and  man  in  particular,  with  especial  ref- 
erence to  eugenics  or  the  improvement  of  the  human  race. 

"While  variation  is  the  foundation  of  evolution,  inheritance 
may  be  likened  to  the  keystone  of  its  arch,  without  which* 
permanence  would  be  impossible.  The  truth  of  inheritance 
has  been  recognized  throughout  the  ages.  Aristotle  and  other 
early  writers  discuss  it.  ' '  Plutarch  mentions  a  Greek  woman 
who  gave  birth  to  a  negro  child,  and  was  brought  to  trial  for 
adultery,  but  it  transpired  that  she  was  descended  in  the 
fourth  degree  from  an  Ethiopian."  ^ 

Many  types  of  inheritance  have  been  recognized  in  the  past 
(reversion,  atavism,  telegony,  particulate,  blending,  etc.),  but 
modern  research  points  strongly  to  a  single  method,  modified 
indeed  by  many  factors,  but  nevertheless  unifonn  in  its  un- 
derlying principle.  So  far  at  least  as  higher  types  of  life 
are  concerned.  When  we  come  to  the  beginnings  of  life,  to 
the  unicellular  forms  and  the  simpler  metaphytes  and 
Metazoa,  our  knowledge  is  too  limited  to  admit  of  anything 
approaching  generalization.  In  the  unicellular  forms  the 
mechanism  of  inheritance  itself  is  evolving,  and  the  type  of 
inheritance  must  therefore  of  necessity  be  indeterminate. 

The  essential  feature  of  Mendelian  inheritance  is  not  the 
dominance  of  one  trait  over  another,  but  rather  the  persist- 
ence of  identical  traits  from  generation  to  generation   (un- 

^Eibot,  "Heredity,"  p.  167.  T>.  Appleton  and  Company.  While 
Plutarch's  information  was  i)robably  faulty,  viewed  in  the  light  of 
modern  research,  his  statement  nevertheless  sliows  the  belief  of  his  day 
in  the  controlling  influence  of  heredity  in  human  life. 

257 


258 


Biology  in  America 


luodilird  by  oilier  trails)  in  the  make-up  of  the  organism. 
The  basis  of  this  persistence  we  liave  already  seen  to  bo  the 
chromosome.  In  those  cases  in  which  one  character  domi- 
nates anotlier  (tallness  vs.  dwarfness  in  peas,  color  vs.  al- 
binism in  animals,  etc.),  we  have  the  phenomenon  known 
as  latency,  in  which  the  determiner  of  a  character  may  be 
passed  along  for  several  generations,  without  the  character 
itself  coming  to  expression.  In  such  cases  the  character  is 
definite  and  the  individual  is  distinct  in  respect  to  its  pos- 
session.    There  is  no  uncertainty  for  example,  as  to  whether 


InHEKITANCE    of    COLOIi    IN    THE    FoUR    O'CLOCK 

F],  Fo,  first  and  second  generations.     From  Morgan,  Stiirtcvtint,  Mul- 
ler  and  Bridges,  "Mechanism  of   Mendclian  Inheritance." 

By  permission  of  J.  B.  Lippincott  Company. 


a  guinea  pig  is  spotted  or  uniform  in  color,  or  a  man's  liair 
is  curly  or  straight.  There  are  cases  however  in  which  the 
organism  is  neither  "fish,  flesh,  nor  good  red  herring,"  or 
speaking  scientifically  dominance  is  imperfect  or  incomplete. 
The  four  o'clock  (INlirabilis  jalapa)  has  a  white-  and  a  red- 
flowered  race,  which  when  crossed  produce  plants  with  pink 
flowers.  When  these  pink-fiowered  plants  however  are  bred 
inter  se  they  produce  1  red  to  2  pink  to  1  white  offspring, 
the  firet  and  last  classes  of  which  breed  true,  while  the  mid- 
dle class  when  inbred  continues  to  "throw"  red,  white  and 
pink  plants  in  the  above  ratio.  A  crude  chemical  analogy 
to  these  phenomena  may  be  made  in  the  following  way :     At 


Mendelism 


259 


ordinary  temperatures  chromic  sulphate  forms  a  violet-col- 
ored solution  in  water,  but  at  lower  temperatures  the  salt 
crystallizes  out  leaving  the  water  colorless  as  before.  A  con- 
centrated solution,  deep  violet  in  color,  may  be  taken  to  rep- 
resent the  color  of  the  red-flowered  four  o'clock,  while  water 
may  represent  the  color  of  the  white-flowered  variety.  By 
mixing  the  concentrated  solution  and  water  in  equal  quanti- 
ties, a  solution  of  light  violet  color  is  obtained,  which  may 
represent  the  pink-flowered  hybi-ids  of  tlie  first  generation. 
If  this  dilute  soliilion  be  now  divided  into  four  equal  parts, 


Inheritance  in  Andalusian  Fowl 

P„  parents;   F^  and  Fj,  the  first  and  second  generation  offspring  of 
the  cross.     From  Morgan,  "The  Physical  Basis  of  Heredity." 

By  permission  of  J.  B.  Lippincott  Company. 


to  one  of  which  a  sufficient  volume  of  salt  be  added  to  restore 
the  original  color,  while  two  are  left  unchanged  and  the  fourth 
is  cooled,  thereby  separating  the  salt  from  the  water  and  leav- 
ing the  latter  colorless,  a  superficial  analogy  to  the  phenom- 
ena of  color  inheritance  in  the  four  o  'clock  is  obtained.  I  say 
''superficial"  or  "crude"  analogy,  because  the  physical  proc- 
ess outlined  above  is  far  too  simple  to  represent  the  compli- 
cated bio-chemical  processes  involved  in  that  of  inheritance. 

One  of  the  liest  known  cases  of  imperfect  dominance  is  that 
shown  by  Andalusian  fowls,  although  as  we  shall  see  this 
case  is  not  strictly  comparal)le  to  the  preceding.  The  "blue" 
Andalusian  is  a  chicken  in  which  black  is  mixed  with  white 


260 


Biology  in  America 


in  very  small  flecks.  If  two  blue  Andalusians  are  crossed 
they  produce  one  black,  two  blue,  and  one  white  splashed 
with  black ;  while  when  the  first  and  last  of  these  offspring 
are  interbred,  only  "blue"  fowls  result — a  Mendelian  pro- 
ceeding, which  is  strictly  "according  to  Hoyle."  Here  we 
have  two  factors,  black  and  white,  which  instead  of  blending 
in  the  cross  enter  into  it  unmodified,  but  distributed  in  such 
a  way  as  to  produce  a  result  different  from  that  of  either 
parent.  Furthermore,  the  ' '  recessives ' '  Tiere  carry  a  little 
of  the  "dominant"  factor  in  the  splashes  of  black  on  a  white 
background. 


Inheritance  of  Ear  Length  in  Eabbits 
Figs.  A  and  B,  parents;   C  and  D,  offspring  of  the  first  and  second 
generations,   respectively,  with   ear   lengths  intermediate   between   those 
of  the  parents.     From  Castle,  "Genetics  and  Eugenics." 
By  permission  of  Harvard  University  Press. 


A  closely  similar  case  is  that  of  red  and  white  cattle,  which, 
when  interbred,  produce  "roan"  offspring,  these  latter  in 
their  turn  "throwing"  red,  roan  and  white  in  the  proportion 
of  1:2:1. 

In  some  cases  of  supposedly  complete  dominance  careful 
measurements  show  that  the  dominant  factor  is  slightly  modi- 
fied by  the  recessive.  Thus  when  wild  fruit  flies  are  crossed 
with  those  having  small  wings,  the  long  wings  of  the  for- 
mer dominate  the  short  wings  of  the  latter ;  but  not  com- 
pletely, for  the  wings  of  the  hybrid  average  slightly  less 
than  those  of  the  wild  parent.  And  this  gives  rise  to  the  ques- 
tion whether  dominance  is  ever  perfect,  even  in  those  cases  in 


Mendetism 


261 


which  it  appears  to  be  so.     The  fundamental  fact  in  Men- 
delian  inheritance  then  is  segregation,  not  dominance. 

In  the  cases  just  cited  segregation  is  perfectly  evident  in  the 
second  generation,  but  there  are  cases  in  which  it  is  not. 
There  is  a  breed  of  domestic  rabbit  known  as  the  "lop- 
eared"  rabbit  in  which  the  ears  are  very  long  and  pendant. 
When  such  a  rabbit  is  paired  with  the  ordinary  kind,  the 
ears  of  the  hybrid  are  intermediate  in  length,  and  this  condi- 
tion persists  in  succeeding  generations.     Is  this  not  a  true 


3 


J3 


Inheritance  in  Guinea  Pigs 
Figs.  A  and  B,  the  parents;  C,  the  first  generation,  the  second  gener- 
tion  containing  animals  of  all  four  types,  A,  B,  C  and  D.     From  Castle, 
' '  Genetics  and  Eugenics. ' ' 

By  permission  of  Harvard  University  Press. 


"blend"  between  different  degrees  of  ear  length?  The  mu- 
latto is  another  example  of  an  apparent  blending  of  charac- 
ters in  inheritance.     Is  a  different  interpretation  possible? 

There  are  certain  varieties  of  corn  with  yellow  kernels, 
which  when  crossed  with  white  corn  give  yellow  offspring. 
These  latter,  when  mated  with  each  other,  give,  instead  of 
the  usual  Mendelian  ratio  of  3  :1,  fifteen  yellows  to  one  white. 
This  is  exactly  what  we  should  expect  if  there  were  two  char- 
acters involved  in  producing  the  color  of  the  yellow  variety, 
for  when  two  pairs  of  factors  are  involved  in  a  cross — i.e., 
tall,  red  peas  x  dwarf  whites;  long-winged,  gray  fruit  files  x 
black,  dwarf -winged ;  black,  rough  ("rosette")  haired  guinea 


B 

b 

B 

BB 

Bb 

b 

Bb 

bb 

BP 

Br 

bR 

br 

Bf? 

BR 

BR 

Bp 
BR 

bR 
BR 

br 
BR 

Br 

Bfr 
Br 

Br 
Br 

bR 
Br 

br 
Br 

bR 

BR 
bR 

Br 
bR 

bR 
bR 

br 
bR 

br 

BR 
br 

Br 
br 

bR 
br 

br 
br 

BRS 

BR3 

BrS 

Brs 

bRS 

bRs 

brS 

brs 

BRS 

BRS 

BRs 
BRS 

BrS 
BRS 

Brs 
BRS 

bRS 
BRS 

bRs 
BRS 

brS 
BRS 

brs 
BRS 

BR5 

BRS 
BRs 

BRs 
BR5 

BrS 
BRs 

Brs 
BRs 

bRS 
BRs 

bRs 
BRs 

brS 

BRs 

brs 
BR« 

BrS 

BRS 
BrS 

BRs 
BrS 

BrS 
BrS 

Brs 
3r5 

bR5 
BrS 

bRs 
BrS 

brS 
BrS 

brs 
BrS 

Brs 

BRS 
Brs 

BRs 
Brs 

BrS 
3rs 

Brs 
Brs 

bRS 
Brs 

bRs 

brS 
Brs 

brs 
Brs 

bRS 

BRS 
bRS 

BRs 
bRS 

BrS 
bRS 

Brs 
bRS 

bRS 
bRS 

bRs 
bRS 

brS 
bRS 

brs 
bRS 

bf?s 

BRS 
bRs 

BRs 
bRs 

BrS 
bRs 

Brs 
bRs 

bRS 
bRs 

bRs 
bRs 

brS 
bRs 

brs 
bRs 

brS 

BRS 
brS 

BRs 
brS 

&r5 
brS 

Brs 
brS 

bRS 
brS 

bRs 
brS 

brS 
brS 

brs 
brS 

br5 

BRS 
brs 

BRs 
brs 

BrS 
brs 

Brs 
brs 

bRS 
brs 

bRs 
brs 

brS 
brs 

brs 
brs 

Diagrams  Illusteating  Inheritance  in  Guinea  Pigs 
Of  one,  two  and  three  pairs  of  characters  respectively.  B=black, 
b  =  white,  R  =  rough  coat,  r  =  smooth  coat,  S  =  short  hair,  and  s  = 
long  hair.  The  second  generation  results  are,  respectively,  3  black,  1 
white;  9  black-rough,  3  black-smooth,  3  white-rough,  1  white-smooth; 
and  27  black-rough-sliort,  9  black-rough-long,  9  black-smooth-short,  9 
white-rough-short,  3  black-smooth-long,  3  white-smooth-short,  3  white- 
rough-long,  and  1  whitesmooth-long,  which  result  from  the  summation 
of  the  combinations  in  the  above  diagrams. 


262 


Mendelism  263 

pigs  X  albino,  smooth-haired;  dark,  curly  x  light,  straight 
hair  in  man,  etc.,  there  is  only  one  out  of  sixteen  offspring 
in  the  second  generation  in  which  both  of  the  recessive  factore 
come  to  expression.  Thus  in  the  case  of  black  rough  x  white 
smooth  hair  in  guinea  pigs,  only  one  in  sixteen  second  gen- 
eration offspring  will  be  white  with  smooth  hair.  This  re- 
sult follows  as  a  mathematical  necessity  of  the  chance  com- 
bination of  two  pairs  of  characters,  just  as  the  3  :1  ratio  re- 
sults from  the  combination  of  one  pair.  Similarly  if  three 
pairs  of  characters  are  involved  in  a  cross,  i.e.,  black,  rough, 
short  and  white,  smooth,  long  hair  in  guinea  pigs,  there  will 
be  only  one  out  of  sixty-four  offspring  in  the  second  genera- 
tion, which  will  show  all  three  recessive  characters.  And  if 
four  pairs  are  involved,  only  1  in  25G,  etc.  A  graphical  rep- 
resentation of  these  results  is  given  in  the  accompanying  dia- 
grams, which  make  sufficiently  clear  the  chance  combination 
of  characters  in  Mendelian  inheritance. 

That  two  factors  may  be  involved  in  the  production  of  an 
apparently  simple  character  is  conclusively  shown  in  the  case 
of  the  sweet  peas  described  by  the  English  naturalist,  Bate- 
son.  Bateson  found  that  when  two  white  peas  were  crossed 
they  produced  colored  offspring,  which  he  interpreted  as  due 
to  the  presence  of  two  factors,  one  in  each  of  the  white  par- 
ents, which,  uniting  in  the  cross,  produced  a  colored  pea. 
The  results  obtained  by  inbreeding  these  colored  offspring, 
details  of  which  need  not  figure  here,  showed  clearly  that  two 
pairs  of  Mendelian  factors  were  concerned.  In  the  case  of 
the  corn  cited  above  a  single  factor  for  yellow  produces  the 
same  apparent  result  in  the  first  generation,  as  do  two  fac- 
tors, but  in  a  variety  of  oats  described  by  the  Swedish  breeder 
Nilsson-Ehle,  a  different  result  is  obtained.  In  this  case  a 
variety  of  oats  characterized  by  dark  brown  glumes  or  husks, 
when  crossed  with  a  white-glumed  variety  produced  in  the 
second  generation  nine  plants  with  dark  brown,  six  with  light 
brown,  and  one  with  white  glumes.  This  result  may  be  ex- 
plained as  due  to  the  presence  of  two  factors  for  brown  in 
the  dark-glumed  plants,  one  only  in  those  wath  light  brown 
glumes  and  none  in  those  with  white  glumes.  It  is  obtained 
in  the  same  way  as  in  the  second  diagram,  two  factors  for 
brown  being  substituted  for  black,  rough. 

The  theory  that  two  or  more  factors  may  in  some  cases  com- 
bine to  produce  an  apparently  simple  result  is  known  as  the 
"multiple  factor"  hypothesis.  In  the  case  of  lop-ear  in  rab- 
bits and  color  in  man,  the  results  are  readily  explicable  by 
means  of  this  hypothesis  on  the  assumption  (1)  that  several 
factors  are  involved  in  the  production  of  the  character  in 
question,  (2)   that  in  order  to  produce  the  maximum  result 


2G4  Biology  in  America 

the  full  number  must  be  present,  and  (3)  as  a  corollary  to 
(2)  if  less  than  the  full  number  are  present  the  result  will 
be  more  or  less  intermediate  or  "blending"  between  the 
maximum  of  the  character  and  its  total  absence.  Thus,  let 
us  assume  with  Davenport  that  the  African  negro  contains 
four  factors  for  blackness,  while  the  white  man  has  none. 
Two  factors  produce  a  "mulatto,"  one  a  "quadroon,"  and 
three  a  "sambo,"  while  the  "octoroon"  and  the  "near- 
white"  resemble  the  pure  white,  so  far  at  least  as  skin  color 
is  concerned.  The  offspring  of  a  cross  between  a  full  black 
and  a  white  will  be  a  mulatto  containing  two  factors  for 
black.  If  the  latter  marry  a  white  the  offspring  will  be  of 
three  classes,  1  mulatto,  2  quadroons  and  1  "  near- white. "  A 
cross  between  two  mulattoes  will  result  in  1  black,  4  sambos, 
6  mulattoes,  4  quadroons  and  1  "near-white,"  a  result  readily 
derived  from  the  second  diagram  on  page  262  if  for  the  domi- 
nant factors  we  substitute  the  factors  for  negro  color  BB. 
Thus  the  chance  of  either  original  color  (black  or  white)  ap- 
pearing in  the  second  generation  is  only  1 :16,  Avhile  there  are 
14  chances  of  an  intermediate  or  "blending"  color  appearing. 
If  more  than  four  factors  are  involved,  the  chance  of  either  of 
the  original  characters  reappearing  in  the  second  generation  of 
a  cross  will  be  correspondingly  lessened.  Thus  if  six  factors 
(3  pairs)  are  involved  the  chance  will  be  1 :64,  with  8  fac- 
tors (4  pairs)  1:256,  with  10  factors  (5  pairs)  1:1024  and 
with  12  factors  (6  pairs)  only  1:4096.  Such  an  hypothesis 
readily  explains  on  a  Mendelian  basis  the  case  of  the  lop- 
eared  rabbit  if  we  assume  the  necessity  of  several  factors  in 
the  production  of  a  superficially  simple,  but  fundamentally 
complex  result. 

An  interesting  corollary  of  Davenport's  main  thesis, 
founded  on  a  study  of  more  than  a  hundred  negro-white  fam- 
ilies in  Jamaica,  Bermuda  and  Louisiana,  is  the  overthrow,  or 
at  least  serious  weakening  of  the  popular  belief  that  a  mar- 
riage of  two  "near-whites"  may  result  in  children  of  negro 
color.  His  results  indicate  that  the  offspring  of  a  cross  be- 
tween persons  of  negro  ancestry,  can  in  no  event  have 
more  than  the  sum  of  the  factors  for  black  of  the  two 
parents;  so  that  the  children  of  two  "near- white"  parents 
can  never  produce  other  than  w^iite  children,  while  a  near- 
white  and  a  quadroon  can  at  most  have  only  quadroon 
children. 

The  basis  of  Mendelian  inheritance  is,  as  we  have  seen,  the 
chance  combination  in  calculable  proportions  of  definite  char- 
acters, which  are  segregable  from  one  another,  and  do  not 
form  permanent  "blends."     How  well  do  the  calculated  or 


Mendelism  265 

"expected"  results  agree  with  those  actually  obtained  in 
breeding  experiments?  Obviously  the  larger  the  number  of 
individuals  the  greater  the  probability  of  agreement  between 
expectation  and  realization,  and  when  the  former  is  small, 
say  1 :64  or  256,  a  very  large  number  of  tests  may  be  neces- 
sary before  it  can  be  realized.  While  the  correspondence  be- 
tween expectation  and  realization  is  seldom  exact,  the  agree- 
ment is  nevertheless  generally  close  enough  to  furnish  a  sub- 
stantial basis  for  the  theory.  A  few  random  examples  may 
be  cited.  In  the  common  weed,  the  shepherd's  purse  (Bursa 
bursa-pastoris)  there  is  a  variety  with  round  and  another 
with  triangular  fruits.  The  latter  dominates  the  former  and 
is  determined  by  two  factors.  Therefore  the  expectation  for 
round  vs.  triangular  fruits  is  1  in  16.  In  a  total  of  2907  sec- 
ond generation  hybrids  Shull  found  2782  with  triangular  and 
125  with  round  fruits,  a  ratio  of  23.3  to  1,  as  compared  with 
an  expectation  of  2725  of  the  former  and  182  of  the  latter,  a 
ratio  of  16  to  1.  In  crosses  between  quadroons  and  whites 
Davenport  found  out  of  99  children  there  were  42  "near- 
whites,"  56  quadroons  and  1  mulatto,  whereas  the  expectation 
was  an  equal  number  of  "near-whites"  and  quadroons  and 
no  mulattoes.  In  another  series  of  matings  between  quadroons 
he  found  out  of  a  total  of  134  children,  24  "near-whites," 
87  quadroons  and  23  mulattoes,  the  expectation  being  3.5,  67 
and  33.5  respectively. 

Any  rabbit  breeder  knows  what  a  mixture  of  colors  and 
markings  he  may  expect  in  his  product.  Professor  Castle, 
who  has  recently  analyzed  the  color  varieties  of  rabbits,  clas- 
sifies them  as  follows:  gray,  black,  yellow  (with  white  belly 
and  tail),  sooty  (a  variety  of  yellow  with  the  belly  and  tail 
colored  like  the  rest  of  the  body),  and  white.  The  first  four 
of  these  may  in  turn  be  modified  by  intensity  of  pigment  (dark 
or  light),  by  its  uniformity,  or  lack  of  uniformity  (spotting), 
and  the  white  may  be  either  wholly  so  or  cream  colored  with 
black  nose,  ears,  feet  and  tail  (the  so-called  "Himalayan" 
of  the  fanciers).  This  makes  a  total  of  eighteen  varieties 
in  all,  which  when  interbred  can  theoretically  produce  243 
different  varieties,  different,  that  is,  from  the  viewpoint  of 
their  hereditary  structure,  not  in  their  external  appearance, 
for  things  "are  (very  often)  not  what  they  seem"  in  genetics. 
Many  of  these  varieties  have  been  obtained,  others  still  re- 
main to  be  "created."  There  are  thirty-two  possibilities  in 
gray  rabbits,  many  of  which  are  already  known.  As  a  com- 
parison of  the  results  realized  with  those  expected  when  one 
variety  of  these  grays  is  crossed  with  itself,  the  following 
table  from  Professor  Castle 's  paper  is  of  interest : 


266  Biology  in  America 

Color  Observed  Expected 

Gray    24  27 

Black  8  9 

Yellow     16  9 

Sooty  2  9 

Blue-gray   8  3 

]31ue 2  3 

Cream    3  3 

Pale  sooty 2  1 


Another  cross  between  two  grays  of  a  different  sort  gave 
the  following  results  as  compared  with  those  to  be  expected: 


Color  Observed  Expected 

Gray    20  27 

Black  8  9 

Yellow 12  9 

Sooty  1  3 

Blue-gray    7  9 

Blue    4  3 

Cream   (?)  3 

Pale  sooty    1  1 

White    8  21 

"The  categoiy  yellow  is  probably  too  large  because  of  a 
failure  on  our  part  to  discriminate  between  yellow  and  cream, 
a  difference  which  at  first  we  failed  to  record.  It  is  possible 
also  that  albino  young  were  not  enumerated  in  all  the  rec- 
ords which  we  have  combined,  and  so  albinos  are  apparently 
deficient  in  number.  "2 

What  is  the  new  science  of  genetics  doing  for  the  world  in 
a  practical  way?  It  is  scarcely  necessary  to  suggest  that  a 
knowledge  of  inheritance  is  fundamental  to  the  practice  of 
breeding  animals  and  plants.  But  the  new  genetics  is  scarce 
two  decades  old,  while  during  the  preceding  centuries  man 
has  produced  the  wonderful  diversity  in  domesticated  varie- 
ties which  we  know  today.  Has  all  this  earlier  improvement 
been  due  to  chance  alone?  Is  the  scientific  breeder  a  prod- 
uct of  the  last  twenty  years?  Hardly,  for  we  are  using 
today  the  same  principle  of  selection  which  has  been  the 
magic  wand  of  the  breeder  in  the  past.  But  to  this  prin- 
ciple has  been  added  more  accurate  knowledge  of  kinds  of 
variation  and  the  laws  of  their  inheritance,  so  that  today  the 
breeder  can  work  more  surely  and  swiftly  than  his  predeces- 
sor in  the  past. 

='(;:istlo  "  Inhoritaiicc  in  TJabliils,"  Ciriiegie  TiistitutioTi,  Publica- 
tion No.  114,  p.   5'J. 


Mendelism 


267 


A  few  examples  of  what  breeders  have  accomplished  may 
be  of  interest.  Professor  Castle  has  shown  that  there  is  in 
guinea  pigs  a  factor  which  restricts  black  and  brown  pigment 
to  the  eyes,  while  yellow  pigment  is  unaffected  by  it.  When 
a  brown  pig  is  crossed  with  a  black-eyed  yellow  one  con- 
taining this  factor,  some  of  the  offspring  receive  it  in  com- 
bination with  the  factor  for  brown  and  are  consequently 
brown-eyed  yellow — a  new  "creation"  unknown  before  Cas- 
tle's   experiments    were    made.     "While    brown-eyed    yellow 


A  Herd  of  Hornless  Cattle 
Hornlessness  may  be  bred  in  cattle  by  proper  attention  to  Mendelian 


laws. 


Courtesy   of   the   U.   8.   Bureau   of  Animal  Industry. 


guinea  pigs  may  not  mean  any  more  to  the  fancier  in  dol- 
lars and  cents  than  do  black-eyed  yellow  ones,  nevertheless 
the  experiment  demonstrates  the  possibility  of  scientific 
breeding  in  the  production  of  varieties  which  do  have  eco- 
nomic value. 

The  presence  of  horns  on  a  vicious  bull,  or  a  refractory 
cow,  has  always  constituted  a  serious  menace  to  tlie  owner's 
peace  of  mind,  and  often  such  animals  have  to  be  dehorned. 
But  the  breeder  has  a  better  means  for  dehorning  his  stock, 
for  lack  of  horns  in  cattle  is  dominant  to  the  horned  condi- 
tion, and  by  crossing  horned  cattle  with  hornless  ones  of  other 


268  Biology  in  America 

breeds  it  is  possible  to  produce  hornless  cattle  in  breeds  which 
are  usually  horned. 

The  "upland"  cotton  of  the  South  has  a  short  fiber  which 
is  worth  much  less  than  the  long  fiber  of  the  "sea  island" 
variety.  The  former  however  is  a  much  better  bearer  than 
the  latter,  and  has  a  pod  which  opens  widely,  rendering  the 
cotton  more  easy  to  pick,  while  the  latter  is  more  easily  ginned, 
tlie  fibres  not  adhering  so  tightly  to  the  seeds.  By  crossing 
"upland"  and  "sea  island"  plants,  the  U.  S.  Department  of 
Agriculture  has  produced  a  prolific  race  of  "sea  island" 
cotton,  with  wide-opening  bolls,  thereby  adding  hundreds  of 
thousands,  if  not  millions  of  dollars  annually  to  the  value 
of  the  cotton  crop  in  the  United  States. 

We  are  all  familiar  with  the  frequent  alarms  that  come 
from  Florida  to  the  effect  that  the  orange  crop  is  a  failure 
due  to  some  recent  freeze.  And  we  can  never  be  quite  sure 
whether  the  freeze  is  genuine,  or  faked  for  the  purpose  of 
making  us  pay  a  premium  for  Florida's  delicious  fruit.  Oft- 
times  however  the  danger  to  the  orange  grower  is  very  real, 
and  many  a  sleepless  night  he  spends  tending  the  bonfires  in 
his  groves  to  save  his  crop  from  ruin.  And  so  the  plant 
breeder  has  come  to  his  rescue  and  by  crossing  the  hardy, 
frost-resistant  orange  of  Japan  with  the  Florida  orange,  has 
produced  a  fruit  known  as  the  citrange  with  many  of  the 
good  qualities  of  the  orange  and  yet  capable  of  resisting  a 
temperature  as  low  as  8°F. 

These  instances  might  be  multiplied  many-fold,  but  they 
must  suffice  as  a  suggestion  merely  of  the  possibilities  open 
to  the  scientific  breeder  of  the  future. 

But  in  no  direction  has  Mendelism  better  served  than  in  the 
development  of  the  new  science  of  eugenics,  concerning  which 
we  hear  so  much  today,  both  of  fact  and  fancy.  The  germ 
of  the  eugenic  idea  is  contained  in  the  witticism  of  Oliver 
Wendell  Holmes,  who,  when  asked  for  advice  on  how  to  reach 
a  good  old  age,  replied  that  the  best  way  was  to  select  long- 
lived  grandparents. 

It  is  indeed  true  that,  as  Kimball  says  in  his  fascinating 
essays  on  the  "Romance  of  Evolution":  "The  scientific  way 
of  selecting  a  wife  and  falling  in  love,  going  first  to  a  phrenol- 
ogist and  getting  a  chart  of  her  skull  with  all  its  bumps,  com- 
bativeness,  destructiveness  and  the  like  marked  upon  it,  then 
to  the  physiologist  to  find  out  whether  her  temperament  is 
bilious  or  phlegmatic,  then  to  the  family  physician  to  make 
sure  she  is  free  from  scrofula  and  consumption  and  then  to 
the  woman  herself  to  exchange,  not  vows  but  charts  and  cer- 
tificates, is  not  certainly  on  the  face  of  it  quite  so  romantic 
as  where  Arthur  and  Amelia  fall  in  love  with  each  other  at 


Mendelism  269 

first  sight,  and  after  the  requisite  number  of  haunted  castles, 
diabolic  rivals  and  cruel  partings  rush  exactly  at  the  end  of 
the  second  volume  ecstatic  into  each  other's  arms.  But  this 
destructive  and  prosaic  side  of  science  is  only  its  beginning, 
only  the  clearing  away  of  the  old  rubbish  to  lay  the  founda- 
tion of  a  nobler  and  fairer  structure.  Its  first  object  is  in- 
deed truth,  truth  whatever  the  ugliness  and  humility  of  its 
outlines  may  be.  But  truth  and  beauty  in  their  final  result 
are  always  sure  to  blend  together  and  always  nourish  and 
require  in  those  who  follow  them  to  the  end  something  at 
least  of  their  own  grand  and  heroic  qualities.  Truth  here, 
the  same  as  elsewhere,  is  found  to  be  stranger  than  fiction, 
the  world  effect,  however  prosaic  its  surface  may  be,  to  have 
roots  which  go  down  to  infinite  depths  of  mystery.  And  sci- 
entific discovery  dealing  with  these  truths  and  facts  has  come 
already  to  a  revelation,  lit  up  the  world  too  with  a  light,  that 
for  romance  and  wonder  surpasses  all  that  was  ever  seen  or 
dreamed  of  in  the  grandest  days  of  old. ' '  ^ 

We  speak  of  eugenics  as  new  and  yet  as  a  matter  of  fact 
the  eugenic  idea  dates  back  to  the  time  of  Plato,  who  advo- 
cated in  his  republic  the  building  of  a  better  state  by  the 
elimination  of  the  unfit,  and  who  urged  the  appointment  of  a 
state  official  for  this  purpose.  Since  Plato's  day  many  vi- 
sionary schemes  have  been  suggested  for  the  improvement 
of  the  human  race,  but  the  modern  movement  is  due  to  the 
great  English  geneticist.  Sir  Francis  Galton,  who,  in  his 
"Hereditary  Genius"  published  in  1869,  pointed  out  the 
desirability  of  improving  the  human  race.  His  suggestions 
fell  upon  stony  ground,  but  with  the  confidence  bred  of  con- 
viction he  returned  undaunted  to  the  struggle,  and  the  out- 
come of  his  efi^orts  was  the  establishment  of  the  Eugenics 
Laboratory  of  the  University  of  London  in  1905,  which  under 
the  direction  of  Karl  Pearson  is  collecting  data  on  human 
inheritance,  and  publishing  them  in  its  "Treasury  of  Hu- 
man Inheritance. ' ' 

In  America  the  movement  for  race  betterment  has  been 
largely  in  the  hands  of  the  Eugenics  Section  of  the  Amer- 
ican Breeders'  Association  and  the  Eugenics  Laboratory,  a 
brief  account  of  the  work  of  which  latter  institution  has 
been  given  in  the  chapter  on  American  Biological  Insti- 
tutions. 

In  the  following  pages  we  shall  consider  briefly  a  few 
examples  of  human  inheritance,  both  mental  and  physical, 
and  the  burden  of  the  unfit  which  society  has  to  bear,  to- 
gether with  an  outline  of  what  the  practical  eugenist  pro- 

^ Kimball,  "The  Eomance  of  Evolution,"  pp.  3-4.  American  Uni- 
tarian Association. 


270  Biology  in  America 

poses  for  the  amelioration  of  social  ills  and  the  building  of 
a  better  Iminan  race.  The  cases  of  the  Jukes  and  the  Kal- 
likaks  on  the  one  hand,  and  the  family  of  Jonathan  Edwards 
on  the  other,  are  classics  and  have  been  cited  so  widely  as 
to  require  no  repetition  here.  An  equally  instructive  case  is 
that  cited  by  Goddard  from  his  studies  of  the  inmates  of  the 
New  Jersey  Training  School  for  the  Feeble-minded.  The  his- 
tory of  this  case  is  described  by  Goddard  in  the  following 
words:  "Here  we  have  a  feeble-minded  woman  who  has  had 
three  husbands  (including  one  'who  was  not  her  husband'), 
and  the  result  has  been  nothing  but  feeble-minded  children. 
The  stoiy  may  be  told  as  follows: 

"This  w'oman  was  a  handsome  girl,  apparently  having  in- 
herited some  refinement  from  her  mother,  although  her  father 
was  a  feeble-minded,  alcoholic  brute.  Somewhere  about  the 
age  of  seventeen  or  eighteen  she  went  out  to  do  housework 
in  a  family  in  one  of  the  towns  of  this  State  (New  Jersey). 
She  soon  became  the  mother  of  an  illegitimate  child.  It  was 
born  in  an  almshouse  to  which  she  fled  after  she  had  been 
discharged  from  the  home  where  she  had  been  at  work. 
After  this,  charitably  disposed  people  tried  to  do  what  they 
could  for  her,  giving  her  a  home  for  herself  and  her  child 
in  return  for  the  work  which  she  could  do.  However  she  soon 
appeared  in  the  same  condition.  An  effort  was  then  made 
to  discover  the  father  of  this  second  child,  and  when  he  was 
found  to  be  a  drunken,  feeble-minded  epileptic  living  in  the 
neighborhood,  in  order  to  save  the  legitimacy  of  the  child, 
her  friends  (sic)  saw  to  it  that  a  marriage  ceremony  took 
place.  Later  another  feeble-minded  child  was  born  to  them. 
Then  the  whole  family  secured  a  home  with  an  unmarried 
farmer  in  the  neighborhood.  They  lived  there  together  until 
another  child  was  forthcoming  which  the  husband  refused 
to  own.  When  finally  the  farmer  acknowledged  this  child 
to  be  his,  the  same  good  friends  (sic)  interfered,  went  into 
the  courts  and  procured  a  divorce  from  the  husband,  and 
had  the  woman  married  to  the  father  of  the  expected  fourth 
child.  This  proved  to  be  feeble-minded,  and  they  have  had 
four  other  feeble-minded  children,  making  eight  in  all,  born 
of  this  woman.  There  have  also  been  one  child  stillborn  and 
one  miscarriage. 

"...  This  woman  had  four  feeble-minded  brothers  and 
sisters.  These  are  all  married  and  have  children.  The  older 
of  the  two  sisters  had  a  child  by  her  own  father,  when  she 
was  thirteen  years  old.  The  child  died  at  about  six  years 
of  age.  This  woman  has  since  married.  The  two  brothers 
have  each  at  least  one  child  of  whose  mental  condition  noth- 
ing is  known.     The  other  sister  married  a  feeble-minded  man 


Mendel  ism  27 1 

and  had  three  children.     Two  of  these  are  feeble-minded  and 
the  other  died  in  infancy.  .    .    ,"* 

Not  alone  in  her  descendants,  but  also  in  her  ancestry  and 
collateral  relatives  does  this  woman  illustrate  the  influence 
of  defective  germ  plasm  in  a  family.  Of  twenty-seven  chil- 
dren, one  or  both  of  whose  parents  were  feeble-minded,  twen- 
ty-four showed  the  defect,  the  character  of  the  other  three 
being  unknown. 

The  following  eases  cited  by  Davenport  are  further  exam- 
ples of  the  blight  which  defective  inheritance  so  often  casts 
upon  a  human  life. 

This  case  "is  an  eleven  year  old  boy  who  began  to  steal  at 
3  years;  at  4  set  fire  to  a  pantry  resulting  in  an  explosion 
that  caused  his  mother 's  death ;  and  at  8  set  fire  to  a  mattress. 
He  is  physically  sound,  able  and  well  informed,  polite,  gen- 
tlemanly and  very  smooth,  but  he  is  an  inveterate  thief  and 
has  a  court  record.  His  older  brother,  14,  has  been  full  of 
deviltry,  has  stolen  and  set  fires  but  is  now  settled  down  and 
is  earning  a  living.  Their  father  is  an  unusually  fine, 
thoughtful  intelligent  man,  a  grocer,  for  a  time  sang  on  the 
vaudeville  stage ;  his  mother,  who  died  at  32,  is  said  to  have 
been  a  normal  woman  of  excellent  character.  There  is  how- 
ever a  taint  on  both  sides.  The  father's  father  was  wild 
and  drank  when  young  and  had  a  brother  w^ha  was  an  in- 
veterate thief.  The  mother's  father  was  alcoholic  and  when 
drunk  mean  and  vicious.  Some  of  the  mother's  brothers  stole 
or  were  sexually  immoral, 

"A  healthy  man  employed  on  a  railroad  as  a  fireman  and 
using  neither  alcohol  nor  tobacco  married  a  woman  who  was 
born  in  the  mountains  of  West  Virginia  near  the  Kentucky 
line  and  who  shows  many  symptoms  of  defectiveness.  She 
has  epileptic  convulsions  as  often  as  two  or  three  times  a 
week,  has  an  ungovernable  temper,  smokes,  chews  and  drinks, 
is  illiterate  and  sexually  immoral.  There  are  10  children,  of 
whom  something  is  known  about  seven.  One  died  early  of 
chorea,  one  of  the  others  seems  normal ;  one  has  killed  two 
men  including  a  policeman;  another  had  her  husband  killed 
and  lives  with  the  slayer;  one  was  an  epileptic  and  cigarette 
fiend,  convicted  of  assault ;  another  has  hysterical  convulsions 
and  is  afraid  in  sleep ;  while  still  another  has  migraine.  The 
combination  in  the  fraternity  of  migraine,  chorea,  hysteria, 
epilepsy  and  sexual  immorality  and  tendency  to  assault  is 
striking  and  appalling. 

"A  10  year  old  boy  who  was  precocious  as  a  raconteur  at 
22  months,  does  well  at  school  except  for  inattention ;  is  fond 
of  reading  and  athletics,  cheerful,  and  polite.    But  he  prefers 
* '"'American  Breeders  Magazine,"  Vol.  I,  pp.  176-8. 


272  Binlor/jf  in  Amrrica 

the  companionship  of  okler,  wild  boys  and  cannot  be  weaned 
from  thom.  lie  lies,  iniiis  up  accounts  in  his  parents'  name, 
is  acquiring  bad  sexual  habits,  and  runs  away  from  home. 
lie  has  two,  fine,  studious  brothers.  His  father  is  a  strong 
character  and  a  successful  lawyer,  his  mother  an  excellent 
woman,  intelligent  and  firm.  She  has  a  brother  who  left 
home  at  14  to  seek  a  life  of  adventure.  He  finally  settled 
down  to  a  steady  life.  Their  father's  father  was  erratic. 
He  loved  Indian  outdoor  life,  always  used  an  Indian  blanket 
and  at  over  70  years  swam  the  IMississippi  River.  He  traced 
back  his  ancestry  to  Pocahontas.  He  has  another  grandson, 
who  is  an  unruly  character  with  a  roving  disposition ;  he 
joined  the  navy  and  his  whereabouts  are  unknown ;  his  father 
was  a  lawyer  and  a  fine  character. 

"An  intelligent  physician  with  training  abroad  as  well  as 
in  this  country  and  of  a  good  family  (his  brother  is  a  college 
professor  and  his  father  a  Methodist  preacher)  married  a  lady 
of  good  family,  with  much  musical  talent,  but  subject  to 
migraine  and  formerly  to  chorea.  They  have  two  sons  born 
in  the  best  of  environments.  The  younger  is  still  in  the 
kindergarten,  seems  wholly  normal,  truth-telling  and  lovable ; 
the  other,  now  13,  developed  normally,  has  had  no  convulsions, 
and  lias  never  been  seriously  sick  and  ordinarily  sleeps  well. 
He  has  regular,  refined  features  and  a  normal  alert  attitude 
and  is  very  industrious.  He  attends  Sunday  school  regu- 
larly, has  excellent  talent  for  music.  At  3  years  of  age  he 
walked  to  a  nearby  railroad,  boarded  a  train  and  was  carried 
12  miles  before  the  conductor  discovered  him;  since  then  he 
has  run  away  very  many  times.  From  an  institution  for 
difficult  boys,  where  he  was  placed,  he  ran  away  13  times. 
He  escapes  from  his  home  after  dark  and  sleeps  in  neighbor- 
ing doorways.  His  mother  used  to  make  Saturday  a  treat 
day.  She  would  take  a  violin  lesson  with  him  and  spend 
the  afternoon  in  the  Public  Library  which  he  much  enjoyed 
but  he  would  slip  away  from  her  on  the  way  home  and  be 
gone  until  midnight.  He  is  an  unconscionable  liar.  He  con- 
tracts debts,  steals  when  he  has  no  use  for  the  articles  stolen 
and  has  been  convicted  for  burglary.  Much  money  and 
effort  have  been  spent  on  him  in  vain.  His  mother's  father 
(of  whom  he  has  never  heard)  was  a  western  desperado,  drank 
hard  and  was  involved  in  a  murder,  but  finally  married  a  very 
good  woman,  and  has  2  normal  daughters  in  addition  to  this 
boy's  mother."  ^ 

As  examples  of  the  inheritance  of  physical  defects  may  be 
cited  that  of  deaf -mutism,  hare  lip  and  cleft  palate,  imperfect 

"Davenport,  "Heredity  in  Kelation  to  Eugenics,"  pp.  85-90.  Bj  per- 
mission of  Henry  Holt  and  Company. 


Mendelism  273 

clotting  of  the  blood  resulting  in  the  persistent  bleeding  of 
wounds,  cretinism  or  infantile  imbecility  and  dwarfism,  and 
many  others. 

But  the  picture  has  also  a  brighter  side,  for  physical  and 
mental  ability  are  inherited  just  as  surely  as  are  their  oppo- 
sites.  The  families  of  the  Edwards,  the  Lees,  the  Corbins 
and  the  Fitzhughs  have  put  the  stamp  of  beauty  and  of 
strength  upon  the  face  of  America.  The  family  of  the  great 
musician  Bach  included  twenty  eminent  musicians,  and  twice 
as  many  of  lesser  eminence. 

Macaulay's  father  and  grandfather,  two  uncles,  a  cousin 
and  a  nephew  were  all  noted  writers.  The  records  of  the 
Pomeroy  family  date  back  to  1630.  "The  first  of  the  family 
in  America  was  Eltweed  Pomeroy  at  Dorchester  .  .  .  and 
later  at  Windsor,  Connecticut.  He  was  by  trade  a  black- 
smith, which  in  those  days  comprehended  practically  all 
mechanical  trades.  His  sons  and  grandsons,  with  few  excep- 
tions, followed  this  trade.  'In  the  settlement  of  new  towns 
in  Massachusetts  and  Connecticut  the  Pomeroys  were  welcome 
artisans.  Large  grants  of  land  were  awarded  to  them  to 
induce  them  to  settle  and  carry  on  their  business. '  '  The  pecu- 
liar faculty  of  the  Pomeroys  is  not  the  result  of  training  and 
hardly  of  perceptible  voluntary  effort  in  the  individual. 
Their  powers  are  due  to  an  inherited  capacity  from  ancestry 
more  or  less  remote,  developed  for  generations  under  some 
unconscious  cerebration.'  There  was  Setli  Pomeroy  (1706- 
1777)  an  ingenious  and  skillful  mechanic  who  followed  the 
trade  of  gunsmith.  At  the  capture  of  Louisburg  in  1745  he 
was  a  major  and  had  charge  of  more  than  twenty  smiths  who 
were  engaged  in  drilling  captured  cannon.  Other  members 
of  the  family  manufactured  guns  which  in  the  French  and 
Indian  wars  were  in  great  demand  and  in  the  Revolution, 
also,  the  Pomeroy  guns  were  indispensable.  'Long  before  the 
United  States  had  a  national  armory,  the  private  armories 
of  the  Pomeroys  were  famous.  There  was  Lemuel  Pomeroy, 
the  pioneer  manufacturer  of  Pittsburg,  stubborn  but  clear- 
headed, of  whom  a  friend  said :  '  There  would  at  times  be  no 
living  with  him  if  he  were  not  always  right. '  There  was  also 
Elisha  M.  Pomeroy  of  Wallingford,  a  tinner  by  trade.  He 
invented  the  razor  strop  and  profited  much  by  its  success. 
In  the  sixth  generation  we  find  Benjamin  Pomeroy  a  suc- 
cessful lawyer  entrusted  with  important  public  offices.  'But 
he  was  conscious  of  powers  for  which  his  law  practice  gave 
him  no  scope.  He  had  a  taste  for  mechanical  execution 
and  as  a  pastime  between  his  professional  duties  undertook 
the  construction  of  difficult  public  works — the  more  difficult 
the  better  he  liked  them.     The  chief  of  the  United  States 


274  Biology  in  America 

Topogiaphit'al  Engineers  was  a  friend  of  Mr.  Pomeroy  and 
repeatedly  eonsnlted  liim  in  emei'gencies  wlierein  his  extraor- 
dinary capacity  was  made  useful  to  the  government.  By 
him  were  constructed  on  the  Atlantic  coast  beacons  and 
various  structures  in  circumstances  tliat  had  baffled  previous 
attempts.'  The  value  to  this  country  of  the  mechanical  trait 
in  this  one  germ  plasm  can  hardly  be  estimated.  Especially 
is  it  to  be  noted  that,  despite  constant  out-marriages,  it  goes 
its  course  unreduced  and  unmodified  through  the  genera- 
tions. ""^ 

Well,  what  is  the  eugenist  "going  to  do  about  it?"  In 
the  first  place  gather  data  upon  which  to  base  a  constructive 
program.  While  our  knowledge  of  inheritance  in  plants  and 
animals  has  grown  by  leaps  and  bounds  in  the  past  twenty 
years,  and  data  concerning  human  inheritance  are  accumulat- 
ing rapidly,  the  science  of  genetics,  and  especially  eugenics 
is  yet  in  its  infancy.  Our  knowledge  of  human  inheritance 
is  still  very  fragmentary;  comparatively  few  characters  have 
yet  been  studied,  and  these  by  no  means  exhaustively.  Recog- 
nizing information  as  the  primary  need  of  the  social  student  of 
today,  the  Eugenics  Laboratory  in  London  and  the  Eugenics 
Record  Office  at  Cold  Spring  Harbor  are  devoting  their 
energies  chiefly  to  a  study  of  the  laws  of  human  inheritance, 
with  the  ultimate  view  of  formulating  from  those  laws  a  con- 
structive program  of  eugenics,  supported  by  a  public  opinion, 
alive  on  the  one  hand  to  the  menace,  and  on  the  other  to  the 
splendid  possibilities  of  human  inheritance. 

But  while  gathering  more  information  are  we  to  sit  idle 
and  not  use  the  information  which  we  have?  What  can  we 
"do  about  it"  now?  First  of  all,  we  need  more  sanity  and 
less  self-confidence,  more  cool  calculation  and  less  hot  enthu- 
siasm. The  advocates  of  the  "rabbit  theory"  of  society,  who 
cry  out  from  the  house-tops  against  the  suicide  of  the  race, 
should  realize  that  propagation  is  as  dangerous  as  propaganda 
if  the  subjects  thereof  are  unworthy  or  unfit.  On  the  other 
hand,  the  advocates  of  "birth  control"  should  not  forget  that 
"a  little  knowledge  is  a  dangerous  thing"  and  that  knowledge 
of  this  practise  by  the  selfish,  the  ignorant  or  the  unwise  might 
prove  to  be  a  match  in  the  hands  of  a  child. 

The  fundamental  principle  of  eugenics  is  the  promotion  of 
a  better  race  by  the  marriage  of  the  fit,  and  the  elimination 
of  the  undesirable  members  of  society  by  the  prevention  of 
their  increase.  But  in  a  matter  of  so  highly  personal  a  nature 
as  marriage,  where  personal  tastes  and  emotions  play  so  large 
a  part,  how  is  anything  like  scientific  control  possible?  The 
only  answer  is  that  it  is  not  possible,  nor  desirable.     If  men 

'  Davenport,   locus   citatus,   pp.   55-57. 


Mendelism  275 

and  women  chose  their  partners  as  they  choose  a  pet  dog 
or  a  suit  of  clothes,  the  divorce  courts  would  have  to  work 
overtime.  But  on  the  other  hand  no  one  has  the  right  to 
insure  his  own  temporary  happiness  at  the  risk  of  the  misery 
of  those  who  are  to  follow  him.  And  here  is  where  eugenics 
has  its  major  role  to  play — namely,  in  the  education  of  the 
youth  as  to  the  inflexibility  of  inheritance,  the  methods  of  its 
operation,  and  their  duty  to  generations  yet  unborn. 

The  rights  of  the  individual  form  one  of  the  corner  stones 
of  a  democracy,  while  those  of  society,  or  the  group  of  indi- 
viduals, form  the  other.  In  so  far  as  the  former  does  not 
conflict  with  the  latter  it  must  be  fully  insured  or  democracy 
becomes  an  empty  name,  but  no  man  has  a  right  to  personal 
freedom  when  that  freedom  encroaches  upon  the  welfare  of 
society,  and  one  of  the  functions  of  eugenics  is  to  preserve 
that  welfare  by  preventing  the  increase  of  the  feeble-minded, 
the  alcoholic,  the  sexually  immoral  and  the  diseased — or  in 
general,  the  unfit.  The  simplest  and  safest  way  in  fact,  is 
sterilization.  This  can  be  accomplished  by  a  very  simple  and 
harmless  operation  in  man,  requiring  only  a  few  minutes  of 
time  and  the  use  of  a  local  anesthetic.  In  woman  it  is  a  more 
serious  operation,  but  in  neither  case,  if  carefully  performed, 
is  it  dangerous  or  productive  of  evil  after-effects.  Needless 
to  say,  the  practise  of  sterilization  should  be  surrounded  by 
every  precaution  to  protect  the  rights  of  the  individual,  and 
should  not  be  practised  except  by  expert  and  responsible  sur- 
geons. Thus  far  eleven  states  have  sterilization  laws,  though 
but  few  operations  under  these  laws  have  as  yet  been  per- 
formed. In  some  instances  individuals  have  voluntarily  sub- 
mitted themselves  to  the  operation. 

The  first  of  these  to  be  adopted  was  the  Indiana  law,  which 
is  here  quoted:  "An  Act,  entitled,  An  act  to  prevent  pro- 
creation of  criminals,  idiots,  imbeciles,  and  rapists — providing 
that  superintendents,  or  boards  of  managers,  of  institutions 
where  such  persons  are  confined  shall  have  the  authority, 
and  are  empowered  to  appoint  a  committee  of  experts,  con- 
sisting of  two  physicians,  to  examine  into  the  mental  condi- 
tion of  such  inmates. 

"Whereas,  Heredity  plays  a  most  important  part  in  the 
transmission  of  crime,  idiocy,  and  imbecility; 

"Therefore,  Be  it  enacted  by  the  General  Assembly  of  the 
State  of  Indiana,  That  on  and  after  the  passage  of  this  act 
it  shall  be  compulsory  for  each  and  every  institution  in  the 
State,  entrusted  with  the  care  of  confirmed  criminals,  idiots, 
rapists  and  imbeciles,  to  appoint  upon  its  staff,  in  addition  to 
the  regular  institutional  physician,  two  (2)  skilled  surgeons 
of  recognized  ability,  whose  duty  it  shall  be,  in  conjunction 


276  Biology  in  America 

with  the  chief  physician  of  the  institution,  to  examine  the 
mental  and  physical  condition  of  such  inmates  as  are  recom- 
mended by  the  institutional  physician  and  board  of  managers. 
If,  in  the  judgment  of  this  committee  of  experts  and  the 
board  of  managers,  procreation  is  inadvisable,  and  there  is 
no  probability  of  improvement  of  the  mental  and  physical 
condition  of  the  inmate,  it  shall  be  lawful  for  the  surgeons 
to  perform  such  operation  for  the  prevention  of  procreation 
as  shall  be  decided  safest, and  most  etfective.  But  this  opera- 
tion shall  not  be  performed  except  in  cases  that  have  been 
pronounced  unimprovable:  Provided,  That  in  no  case  shall 
the  consultation  fee  be  more  than  three  (3)  dollars  to  each 
expert,  to  be  paid  out  of  the  funds  appropriated  for  the 
maintenance  of  such  institution. ' ' 

The  question  of  elimination  of  defectives,  by  preventing 
their  procreation,  leads  to  the  delicate  one  of  elimination  of 
human  misery  by  taking  the  life  of  children,  so  hopelessly 
deformed  or  diseased,  that  they  can  never  by  any  possible 
chance  be  anything  but  sources  of  suffering  to  themselves, 
and  of  unhappiness  to  their  friends.  The  practise  of  destroy- 
ing those  infants  considered  unlikely  to  develop  into  vigorous 
men,  and  good  soldiers  is  well  known  as  the  policy  of  Sparta 
in  ancient  Greece,  and  among  savages  infanticide  has  some- 
times been  practised  for  a  similar  reason.  In  India  the  kill- 
ing of  girl  babies  to  save  them  the  dishonor  of  remaining 
unmarried  or  of  marrying  below  their  caste,  as  well  as  to 
avoid  the  excessive  expense  incident  to  marriage  ceremonies, 
was  prevalent  among  many  tribes  previous  to  the  middle  of 
the  last  century,  when  it  was  terminated  by  the  British  Gov- 
ernment. Among  civilized  peoples  infanticide  is  generally 
regarded  as  a  crime  equal  to,  or  but  slightly  less  than  murder. 
Abortion,  unless  practised  to  save  the  life  or  health  of  the 
mother,  is  criminal,  though  of  a  much  lower  degree  than 
infanticide.  The  logic  of  a  distinction  between  a  foetus  a 
few  days  before  birth  and  a  baby  a  few  days  after,  is  some- 
what difficult  however  to  appreciate. 

The  reverence  for  human  life  has  even  extended  to  the  dead 
body,  so  that  in  the  early  days  of  anatomy,  cadavers  for  dis- 
section could  only  be  obtained  by  devious  means. 

The  sacredness  in  which  we  hold  life  has  led  us  to  take 
every  means  for  its  preservation,  even  to  abolition  in  many 
states  and  foreign  countries  of  capital  punishment,  the  forcible 
restraint  of  attempted  suicides,  and  the  most  careful  nurture 
of  helpless  cripples  and  hopeless  idiots.  Because  of  our 
reverence  for  human  life  we  sometimes  practise  the  most 
refined  cruelty  to  those  we  love  the  best,  a  cruelty  we  would' 
not  tolerate  for  a  moment  if  practised  upon  the  dumb  brute. 


Mendelism  277 

It  was  therefore  with  a  feeling  akin  to  horror  that  many- 
read  in  the  public  press  in  1915  of  the  action  of  Dr.  Haiselden 
of  Chicago;  who,  with  the  consent  of  the  child's  parents, 
refused  to  perform  an  operation  which  would  have  saved  to 
a  life  of  suffering,  an  infant,  which  by  his  refusal  was  allowed 
to  die.  This  question  however  is  not  one  of  eugenics  proper, 
although  closely  related  thereto.  But  it  is  one  which  the 
thoughtful  student  of  human  life  will  do  well  to  ponder 
carefully. 

And  yet  a  final  duty  of  the  eugenist  is  to  combat  those 
anti-social  measures  which  put  a  premium  on  celibacy,  and 
a  discount  on  parenthood,  such  as  the  payment  of  non-living 
wages  to  workmen,  the  industrialization  of  women,  the 
penalization  of  teachers  for  marriage  or  motherhood.  A  for- 
ward step  in  the  right  direction  has  been  the  payment  by  many 
states  of  mothers'  pensions,  while  further  action  should  be 
taken  to  relieve  the  mother  during  the  early  months  of 
maternity  from  the  necessity  of  bread  winning. 

We  have  come  already  a  long  way  in  the  paths  of  social 
righteousness,  but  the  way  is  never-ending  and  the  forces  of 
selfishness,  reaction  and  ignorance  beset  us  on  every  hand, 
so  that  it  behooves  us  to  gird  up  our  loins  in  order  that  we, 
like  Paul,  may  ' '  run  with  patience  the  race  that  is  set  before 
us." 


CHAPTER  XI 

Experimental  biology  continued.  Mechcmisni  versus  vitalism. 
Physico-chcmistnj  of  vital  processes,  metalolism  of  ani- 
mals and  plants. 

Is  tliere  one  law  for  the  living  and  another  for  the  dead, 
or  is  tlie  universe  a  unit  in  its  working  and  all  matter  gov- 
erned by  universal  law?  The  former  is  the  contention  of  the 
"vitalist,"  the  latter  of  the  "mechanist."  What  is  life? 
Is  it  some  inscrutable  process,  controlled  by  a  "vital  prin- 
ciple" operating  outside  the  realm  of  physics  and  of  chem- 
istry ?  Or  is  it  merely  a  special  expression  of  the  forces  which 
control  inorganic  matter?  Our  only  answer  to  these  ques- 
tions is  that  we  do  not  know.  Neither  the  substance  nor  the 
energ}'  of  life  has  ever  been  analyzed,  and  the  only  way  in 
which  we  can  identify  life  is  by  its  manifestations.  What 
are  these  manifestations,  and  what  light  if  any  do  they  throw 
upon  the  ultimate  nature  of  life  itself? 

Firstly,  what  is  the  stuff  of  which  living  things  are  made? 
An  analysis  of  living  substances  or  protoplasm  is  exceedingly 
difficult  if  not  impossible.  In  order  to  analyze  it,  it  must  be 
killed,  and  the  readiness  with  which  protoplasm  breaks  down 
into  innumerable  simpler  substances  leads  us  to  suspect  that 
after  protoplasm  is  killed  it  is  protoplasm  no  longer,  so  that 
we  are  analyzing  not  protoplasm  at  all,  but  something  else. 
Our  analyses  are  sufficient  to  show  us  however  that  proto- 
plasm contains  the  same  elements  of  which  inorganic  matter 
is  composed,  united  into  a  marvellously  complex  whole.  All 
life  is  "of  the  dust,  and  turn(s)  to  dust  again."  The  mani- 
fold varieties  of  life  which  we  know  lead  us  to  believe  in  as 
groat  a  variety  of  protoplasm  which  determines  this  variability 
in  living  things.  In  spite  of  its  variability  however  all  proto- 
plasm alike  contains  protein  consisting  of  carbon,  hydrogen, 
nitrogen,  oxygen  and  sulphur,  without  which  it  cannot  exist. 
Protein  however  is  founcl  outside  of  protoplasm  in  egg  albu- 
men for  example  and  in  the  various  albumens  and  globulins 
of  the  blood.  These  substances  while  protoplasmic  products 
are  not  protoplasm  itself ;  hence  we  see  that  in  its  composition 
at  least  living  matter  does  not  differ  fundamentally  from  non- 
living, since  both  contain  the  same  materials. 

278 


The  Living  Machine 


279 


One  of  the  most  characteristic  features  of  life  is  its  power 
of  waste  and  repair  and  growth.  It  is  folly  to  attempt,  as 
some  have  done,  to  compare  these  processes  in  their  entirety 
with  any  process  in  the  non-living  world.  There  is  nothing 
with  which  they  can  be  compared.  And  yet  if  we  analyze 
them  into  their  component  processes,  we  find  that  they  are 
composed  of  a  series  of  chemical  and  physical  reactions,  many 
of  which  at  least  can  be  exactly  reproduced  in  the  laboratory. 

In  the  warm  spring  days  when  the  remnants  of  last  j'car's 
crop  of  potatoes  in  the  cellar  start  to  sprout,  and  those  wliieh 
are  served  upon  your  table  have  an  unpleasant  sweetish  taste, 
you  are  the  victim  of  a  ferment  known  as  diastase,  of  wide- 


Diagram  illustrating  osmosis  through  an  egg  membrane.     Original. 


spread  if  not  universal  distribution  among  plants,  which 
changes  starch,  the  stored-up  food  stuff  of  the  plant,  into 
one  of  the  sugars.  When  the  maple  sugar  sap  is  flowing  in 
the  spring  we  know  that  a  similar  action  has  been  taking 
place  within  the  tree,  and  all  the  beauty  of  the  young  spring's 
growth  depends  upon  it.  A  similar  action  takes  place  in  our 
own  stomach,  under  the  influence  of  an  animal  ferment  known 
as  ptyalin,  and  present  in  the  saliva  of  many  mammals.  But 
a  similar  result  can  also  be  obtained  in  the  test  tube  of  the 
chemist  by  boiling  starch  in  dilute  acid. 

In  order  that  the  water  of  the  soil  with  its  dissolved  salts 
may  enter  the  root,  or  the  digested  food  stuffs  in  the  intestine 
pass  into  the  streams  of  blood  and  lymph,  the  process  of  os- 


280  Biology  in  America 

mosis,  or  the  passage  of  solutions  through  membranes  must 
occur.  But  if  the  shell  be  chipped  off  from  both  ends  of  a 
hen's  egg,  the  shell  membranes  being  left  intact  at  one  end, 
and  the  yolk  and  white  removed  from  the  other,  into  which  a 
glass  tube  is  sealed  Avith  a  few  drops  of  sealing  wax;  and  if 
now  the  egg  be  filled  with  a  solution  of  sugar,  and  then  im- 
mersed in  water,  until  the  water  is  at  the  same  level  with  the 
solution  in  the  tube,  the  latter  will  soon  be  seen  to  rise  due  to 
the  passage  of  water  through  the  egg  membrane  into  tlie  sugar 
solution;  while  more  slowly  the  sugar  will  ditt'use  in  the  re- 
verse direction.  Here  we  see  in  non-living  matter  the  same 
phenomenon  of  osmosis,  which  is  so  fundamental  a  factor  in 
all  living  processes. 

In  the  exchange  of  materials  between  the  cell  and  its 
environment,  its  membrane  determines  what  substances  shall 
enter  and  leave  the  cell.  Thus  an  uninjured  beet  may  be 
placed  in  water  without  losing  any  of  its  color.  But  cut 
the  beet  and  its  color  readily  diffuses  outward.  So  in  the 
absorption  by  roots  of  substances  from  the  soil  and  by  the 
walls  of  the  intestine  from  the  digested  food  stuffs,  the  cell 
membrane  exercises  what  is  known  as  "selective  absorption," 
taking  some  and  rejecting  others.  In  the  passage  of  sub- 
stances between  mother  and  child,  through  the  walls  of  the 
placenta,  the  cells  of  the  latter  exercise  a  selective  function, 
allowing  food  materials  and  oxygen  to  pass  from  mother  to 
child,  and  waste  materials  to  pass  in  the  reverse  direction. 
This  selective  activity  of  living  membranes  is  strikingly 
shown  by  experiments  on  barley  seeds,  which  are  not  killed 
by  sulphuric  acid  because  it  cannot  penetrate  them,  but  are 
destroyed  by  bichloride  of  mercury,  which  readily  enters. 

In  the  burning  coal  of  the  furnace  and  in  the  forest's 
decaying  logs,  one  of  the  final  products  of  combustion  or 
decay  is  carbon  dioxide.  So  too  when  we  exhale  the  carbon 
dioxide  from  our  lungs  we  are  casting  off  one  of  the  end 
products  in  the  combustion  or  oxidation  of  our  foods  and 
our  tissues. 

Throughout  the  entire  process  of  metabolism,  of  growth, 
repair,  decay,  the  body  of  animal  or  plant  is  a  physico- 
chemical  laboratory  in  which  are  taking  place  the  processes 
of  the  non-living  world. 

Another  characteristic  feature  of  living  things  is  their 
power  of  movement.  This  is  not  evident  at  firet  sight  in 
all  organisms,  notably  plants.  In  fact,  one  of  the  criteria 
formerly  presented  as  distinguishing  plants  from  animals  was 
the  fixity  of  the  former  as  compared  with  the  motility  of  the 
latter.  This  distinction  we  now  know  to  be  false  however, 
for  even  in  the  apparently  non-motile  plants  there  is  circu- 


The  Living  Machine  281 

lation  of  cell  sap,  and  movements  of  leaves  and  roots  in 
response  to  stimuli ;  while  among  animals,  the  attached  forms 
such  as  sponges,  sea  anemones,  barnacles,  etc.,  either  lack 
locomotive  power  or  possess  it  in  very  slight  degree. 

All  living  things  then  are  motile  to  greater  or  less  degree. 
But  is  this  quality  lacking  in  the  non-living  world  ?  Place  a 
diluted  drop  of  ink  under  the  microscope  and  it  becomes  a 
microcosm  of  violent  activity.  Wind  and  water  are  ever 
active.  The  earth  is  flying  through  space  at  the  rate  of  18i/^ 
miles  a  second,  and  the  universe  is  a  realm  of  eternal  motion. 
Light  and  sound  are  expressions  of  movement,  and  the  elec- 
tronic theory  of  matter  postulates  that  matter  itself  is  a 
cosmos  of  ceaseless  energy.  But  the  vitalist  tells  us  that 
living  matter  possesses  '"spontaneity,"  which  is  lacking  in 
the  non-living  world.  The  living  thing  moves  of  its  own 
''volition,"  the  non-living  only  under  the  influence  of  forces 
external  to  itself.  But  what  evidence  have  we  of  "volition" 
on  the  part  of  an  Amoiba  or  bacterium,  while  the  energy 
of  the  living  machine  is  as  truly  the  result  of  oxidation  of 
fuel  as  is  that  of  the  steam  turbine  or  the  automobile.  Any 
distinction  then  on  the  basis  of  motion  alone  between  the 
world  of  the  living  and  the  non-living  is  a  fallacy. 

Adaptation  is  one  of  the  most  characteristic  features  of 
life.  The  bird  and  bat  are  adapted  for  flight,  the  flsh  for 
swimming,  the  monkey  for  climbing:  one  need  not  enumerate, 
for  one  cannot  name  a  single  living  thing  which  is  not 
adapted  to  the  conditions  of  its  existence;  otherwise  it  would 
not  exist.  Adaptation  is  the  very  keynote  of  life,  and  the 
tablets  of  the  past  are  crowded  with  the  records  of  creatures, 
which,  serving  well  their  day  and  generation,  failed  to  adapt 
themselves  to  changing  conditions,  and  so  were  trampled 
under  foot  by  the  onrush  of  the  fit  in  the  bitter  struggle 
for  existence. 

But  are  living  things  alone  adapted  to  their  environment? 
Does  not  the  river  adapt  itself  to  its  channel,  the  lake  to  its 
basin,  and  the  gas  to  the  fonn  and  size  of  its  container? 
Ice  exists  in  winter  because  it  is  adapted  to  the  cold  and  dis- 
appears in  summer  because  it  is  not  adapted  to  the  heat. 
Adaptation  indeed  is  merely  an  expression  of  action  and  re- 
action, of  cause  and  effect.  But,  argues  the  vitalist,  these 
are  merely  examples  of  the  direct  physical  influence  of  one 
thing  upon  another,  while  life  adapts  itself  only  in  indirect 
and  as  yet  unknown  ways.  The  fact  of  adaptation  in  the 
inorganic  world  remains  however,  and  when  the  riddles  of 
life  have  been  solved  it  is  not  unlikely  that  the  process  of 
adaptation  of  living  things  can  be  resolved  into  simple 
physico-mechanical  terms,  just  as  surely  as  can  the  adjust- 


282  Biology  in  America 

ment  of  the  river  to  its  channel,  or  the  snow  drift  to  the 
wind. 

Yet  another  manifestation  of  life  is  its  irritability  or  power 
of  response  to  stimuli.  Examples  of  this  are  so  common  that 
it  is  merely  trite  to  repeat  them.  There  is  no  form  of  life 
so  primitive  or  so  sluggish  as  to  escape  this  universal  law. 
But  is  tliis  phenomenon  limited  to  life  alone?  Does  not  life- 
less matter  also  respond  to  stimuli,  or  changes  in  its  environ- 
ment? Examples  of  such  changes  must  occur  to  the  mind 
of  everyone — changes  in  volume  or  in  state,  whether  solid, 
liquid  or  gaseous,  in  response  to  changes  in  temperature  or 
pressure,  are  among  the  most  familiar  instances  of  these 
responses.  If  a  metal  be  heated  its  electrical  conductivity 
is  decreased,  sound  travels  faster  the  higher  the  temperature, 
while  atmospheric  conditions  will  materially  affect  the 
messages  flashed  from  the  wires  of  the  radio.  While  the 
responses  of  living  things  and  changes  in  their  environment 
are  infinitely  more  complex  and  indirect  than  are  those  of 
the  non-living,  yet  the  same  principle  holds  true  for  both, 
and  when  we  know  more  of  the  mechanism  of  life  it  may  be 
possible  to  resolve  its  complex  reactions  into  their  simpler 
terms. 

Yet  one  great  characteristic  of  life  remains,  namely,  repro- 
duction. The  development  of  a  human  being  with  his  myriad 
cells,  more  varied  in  form  than  the  manifold  parts  of  the 
most  complicated  machine,  ranging  in  size  from  the  tiny 
corpuscles  of  the  blood,  less  than  one  four-thousandth  of  an 
inch  in  size,  to  the  motor  nerve  cells  of  the  spinal  cord,  which 
may  reach  a  length  of  over  three  feet;  and  including  the 
intricate  structures  of  the  brain  by  which  are  performed  all 
the  wonderfully  complex  functions  of  the  human  body,  in- 
cluding the  as  yet  inscrutable  processes  of  thought ;  all  these 
coming  from  an  apparently  simple  cell  a  little  more  than  one 
one-hundredth  of  an  inch  in  size,  is  a  wonder  beside  which  the 
magic  of  an  Aladdin  or  the  miracles  of  holy  writ  fade  into 
ghostly  paleness.  The  enthusiast  in  the  ranks  of  the  mech- 
anists has  attempted  however  to  remove  even  this  most 
distinctive  feature  of  living  things,  by  showing  that  non- 
living matter  may  in  a  certain  sense  reproduce  itself,  as  new 
crystals  form  in  an  evaporating  salt  solution.  However  feeble 
such  a  comparison  may  be,  it  is  nevertheless  true  that  all 
phases  of  reproduction — the  growth  of  the  germ  cells,  their 
union,  the  entrance  of  the  spermatozoon,  the  division  of  the 
fertilized  egg,  the  growth  and  differentiation  of  the  tissues 
are  all  intimately  associated  with  physico-chemical  changes 
taking  place  in  these  cells,  and  can,  as  we  shall  see  later, 
to  a  certain  extent  at  least  be  induced  by  artificial  means. 


The  Living  MacJiinc  283 

"Whatever  the  answer  to  the  riddle  of  life  may  ultimately 
be  it  is  at  least  certain  that  our  present  most  hopeful  line 
of  attack  lies  in  the,  at  least  partially  known,  fields  of  physics 
and  chemistry,  rather  than  in  the  unknown  metaphysical  one 
of  ''vital  principles,"  "entelechies"  and  other  hypothetical 
factors.  What  information  then  does  the  bio-chemist  have 
to  give  us  which  may  help  us  in  the  solution  of  our  problem  ? 

The  writer  once  accompanied  a  class  of  school-boys  through 
a  Colorado  mine.  On  the  mine  track  stood  a  string  of  empty 
cars,  and  one  of  the  boys  asked  the  conductor  of  the  party 
what  kind  of  fuel  they  used  for  their  engines  in  the  mine. 
"Hay,"  replied  tlie  conductor,  which  somewhat  puzzled  the 
boys,  until  they  learned  that  mules  furnished  the  motive 
power  for  the  cars.  One  of  the  earliest  speculations  of  physi- 
ologists was  regarding  the  nature  of  animal  heat.  Some 
animals  (birds  and  mammals)  have  a  constant  body  tempera- 
ture which  is  usually  higher  than  that  of  their  surroundings. 
"What  is  this  heat,  and  whence  does  it  come?"  the  early 
investigators  asked  themselves.  It  was  at  first  supposed 
that  heat  was  a  substance  which  entered  and  left  the  body 
in  some  unknown  way.  Toward  the  beginning  of  the  eight- 
eenth century  speculation  began  to  call  experiment  to  its 
aid,  and  Mayow,  Boyle  and  Priestley  tried  keeping  small 
animals  in  closed  chambers,  with  the  result  that  they  soon 
died.  They  also  tried  introducing  lighted  candles  into  similar 
chambers  and  found  that  just  as  the  "flame  of  life"  was 
soon  extinguished,  so  too  the  candles  went  out,  if  denied  air. 
They  further  found  that  an  animal  could  not  live  so  long  in 
a  jar  in  which  the  air  had  been  exhausted  by  a  burning 
candle  as  in  one  in  which  the  air  was  fresh;  and  vice  versa 
the  candle  would  not  burn  where  an  animal  had  exhausted 
the  air  before  it,  nor  would  one  animal  live  as  well  in  a 
chamber  formerly  occupied  by  another,  or  one  candle  burn 
as  well  where  another  had  been  previously  burned,  as  in  one 
containing  air  which  had  not  been  used  up  previously.  These 
experiments  led  them  to  suspect  that  the  breathing  of  the 
animal  and  the  burning  of  the  candle  were  similar  processes. 

Soon  after  followed  Priestley's  discovery  of  oxygen  which 
he  called  by  the  sophisticated  title  of  dephlogisticated  air, 
from  the  Greek  word  phlogiston  or  inflammable.  Now  fol- 
lowed Lavoisier's  discovery  that  when  a  candle  was  burned, 
or  an  animal  breathed,  the  oxygen  or  dephlogisticated  air  of 
Priestley,  which  formed  one-fifth  of  the  volume  of  ordinary 
air,  was  converted  into  what  was  formerly  known  as  "fixed 
air,"  a  compound  of  carbon  and  oxygen.  Lavoisier  now 
assumed  that  the  heat  of  the  animal  body  was  produced  in 
a  manner  analogous  to  that  of  the  burning  candle,  namely 


284  Biology  in  America 

by  the  combustion  of  the  carbon  in  the  body,  or  its  union 
with  oxvf^en  to  j)ro(luee  carbon  dioxide.  In  support  of  this 
assumption  he  pointed  out  that  in  birds,  whose  temperature 
is  higher  than  that  of  mammals,  there  is  a  greater  production 
of  carbon  dioxide  in  respiration. 

To  test  tliis  hypothesis  Lavoisier  constructed  a  primitive 
calorimeter  for  measuring  the  heat  production  of  the  animal 
body.  This  consisted  essentially  of  two  chambers,  an  inner, 
for  holding  the  animal  whose  heat  production  was  to  be 
measured,  and  ^n  outer  of  double  walls,  the  space  between 
which,  as  well  as  that  of  the  outer  chamber  itself,  was  packed 
with  ice.  Knowing  the  amount  of  heat  required  to  melt  a 
given  quantity  of  ice,  and  measuring  the  carbon  dioxide  and 
water  produced  by  the  animal,  it  should  be  possible  to  deter- 
mine whether  the  respiration  of  the  animal  was  of  the  proper 
amount  to  account  for  the  heat  produced.  Without  going  into 
details  regarding  these  experiments  of  Lavoisier,  and  his  suc- 
cessors Dulong  and  Depretz,  it  is  sufficient  to  say  that  the 
results  of  these  early  experimenters  showed  a  very  close 
correspondence  between  the  heat  calculated  from  the  respira- 
tory products  formed,  and  the  actual  production  of  heat  in 
the  calorimeter  and  led  to  the  conclusion  established  by  later 
observers  that  the  production  of  energy  in  the  animal  body 
is  dependent  on  the  oxidation  of  the  food  consumed,  and 
further  that  conservation  of  energy  is  just  as  true  of  the 
latter  as  of  any  non-living  machine. 

The  work  of  these  early  experimenters  has  been  continued 
in  recent  years  by  Benedict  and  Atwater  at  the  Nutrition 
Laboratory  of  the  Carnegie  Institution  in  a  series  of  brilliant 
investigations  with  the  aid  of  a  very  ingenious  and  intricate 
respiration  calorimeter.  This  in  brief  consists  of  a  chamber 
large  enough  for  a  man  to  live  in  for  several  days  at  a  time, 
and  containing  apparatus  (i.  e.,  a  bicycle)  on  which  exercise 
may  be  taken.  The  chamber  is  constructed  of  a  double  metal 
wall  with  a  contained  air  space  and  is  surrounded  with  a 
double  wall  of  wood  containing  a  second  air  space,  while 
between  metal  and  wooden  walls  is  an  intermediate  air  space, 
the  whole  very  effectively  preventing  any  exchange  of  heat 
between  the  interior  and  exterior  of  the  chamber.  As  a  fur- 
ther precaution  to  prevent  such  exchange  of  heat  special 
electrical  devices  are  installed  for  keeping  the  two  walls  of  the 
metal  chamber  at  the  same  temperature,  and  any  difference 
in  temperature  between  them  is  recorded  on  a  galvanometer 
on  the  observer's  desk  in  the  laboratory.  Connected  with 
the  chamber  are  various  devices  for  measuring  the  intake  of 
oxygen,  the  outgo  of  carbon  dioxide  and  water,  the  heat  lost 
by  the  subject  during  the  experiment  and  the  amount  of 


The  Living  Machine  285 

energy  expended  in  muscular  activity.  To  illustrate  the 
extreme  care  taken  to  avoid  error  in  the  use  of  this  apparatus 
may  be  cited  the  precautions  used  in  measuring  the  amount 
of  heat  generated  by  the  subject  in  the  calorimeter.  This  is 
determined  by  reading  the  temperatures  of  a  stream  of  water 
which  circulates  through  coils  of  pipe  in  the  chamber.  To 
the  ordinary  person  it  would  seem  as  though  it  were  suffi- 
ciently accurate  to  read  these  temperatures  as  given  by 
accurate  thermometers.  But  in  order  to  eliminate  all  possible 
error  corrections  are  made  for  the  effect  of  pressure  of  water 
on  the  bulb  of  the  thermometer.  "Within  the  chamber  is  a 
folding  cot,  chair,  table  and  other  conveniences.  During  an 
experiment  the  entrance  to  the  chamber  is  tightly  sealed  by 
glass  which  serves  as  a  window,  while  a  small  opening  serves 
for  exchange  of  food,  water,  excreta,  etc.  A  telephone  en- 
ables the  occupant  to  talk  to  persons  on  the  outside.  The 
apparatus  is  so  delicate  that  the  slight  rise  in  temperature 
caused  by  the  subject  rising  from  his  chair  is  recorded  by  it. 

The  respiration  calorimeter  is  used  for  investigating  the 
many  intricate  problems  of  human  nutrition  and  especially 
for  determining  the  relation  between  different  kinds  of  food 
and  the  energy  furnished  by  them.  To  test  its  accuracy  its 
designers  performed  a  series  of  check  experiments  in  which 
alcohol  instead  of  human  tissue  was  burned,  and  the  amounts 
of  carbon  dioxide,  water  and  heat  produced,  and  oxygen  con- 
sumed, were  measured  and  compared  with  the  amount  re- 
quired by  calculation  from  the  amount  of  alcohol  used.  Four 
such  experiments  showed  an  average  difference  between  the 
calculated  and  experimental  results  of  less  than  one-half  of 
one  per  cent. 

Experiments  with  the  calorimeter  can  be  made  to  show  what 
proportion  of  the  energy  available  in  the  food  consumed  is 
used  in  the  work  done  by  the  subject.  It  is  a  fact  well  known 
to  all  mechanical  engineers  that  no  machine  can  utilize  all 
the  energy  of  its  fuel.  This  is  largely  due  to  loss  of  heat  by 
radiation  from  the  surface  of  the  machine  and  in  friction. 
Our  best  engines  can  use  perhaps  not  more  than  one-tenth 
of  the  energy  available  in  their  fuel.  In  this  respect  the 
human  machine  is  a  more  perfect  mechanism,  for  it  can  use 
about  15-20%  of  the  energy  available  in  its  fuel  (food)  for 
mechanical  (muscular,  nervous,  etc.)  work. 

The  subject  of  human  nutrition  is  one  to  fill  volumes  in 
itself.  We  can  only  note  here  in  passing  a  few  of  the  most 
interesting  and  important  results  obtained  from  experiments 
in  this  field. 

Two  of  the  perquisites  which  the  Englishman  of  past 
generations  has  regarded  as  his  inalienable  right  have  been 


286  Biology  in  America 

liis  meat  aiul  liis  ale,  and  his  descendants  on  this  side  of 
the  water  have  maintained  fairly  well  the  reputation  of  their 
ancestors.  But  "those  who  dance  must  pay  the  fiddler"  and 
higli  living  has  hrought  in  its  train  not  only  higli  grocer's, 
l)ut  high  doctor's  bills  and  mortality  rates  as  well.  The  advent 
of  meat  cards  and  meatless  days  during  the  war  brought 
about  a  cut  in  the  size  of  our  steaks  if  not  of  our  butcher's 
bills.  If  this  seeming  privation  teaches  us  that  an  excessive 
meat  diet  is  not  essential  to  our  health  and  happiness  the 
game  will  indeed  prove  ' '  worth  the  candle. ' '  But  there  were 
even  in  early  days  voices  raised  in  warning  against  prevalent 
excesses  in  diet.  One  of  these  was  the  plea  for  moderation 
in  eating  by  the  English  physician  Thomas  Cogan,  published 
in  159G  under  the  title  "The  Haven  of  Health,"  in  which  he 
says:  "The  second  thing  that  is  to  be  considered  of  meates 
is  the  quantitie,  which  ought  of  all  men  greatly  to  be  re- 
garded, for  therein  lyeth  no  small  occasion  of  health  or 
sickness,  of  life  or  death.  For  as  want  of  meate  consumeth 
the  very  substance  of  our  flesh,  so  doth  excesse  and  surfet 
extinguish  and  suffocate  naturall  heat  wherein  life  con- 
sisteth."  Again,  "Use  a  measure  in  eating,  that  thou  maist 
live  long :  and  if  thou  wilst  be  in  health,  then  hold  thine  hands. 
But  the  greatest  occasion  why  men  passe  the  measure  in 
eating,  is  varietie  of  meats  at  one  meale.  "Which  fault  is 
most  common  among  us  in  England  farre  above  all  other 
nations.  For  such  is  our  custome  by  reason  of  plentie  (as  I 
think)  that  they  which  be  of  abilitie,  are  served  with  sundry 
sortes  of  meate  at  one  meale.  Yea  the  more  we  would  wel- 
come our  friends  the  more  dishes  we  prepare.  And  when  we 
are  well  satisfied  with  one  dish  or  two,  then  come  other  more 
delicate  and  procureth  us  by  that  means,  to  eate  more  than 
nature  doth  require.  Thus  varietie  bringeth  us  to  excesse, 
and  sometimes  to  surfet  also.  But  Phisicke  teacheth  us  to 
faede  moderately  upon  one  kinde  of  meate  only  at  one  meale, 
or  at  leastwise  not  upon  many  of  contrarie  natures.  .  .  .  This 
disease,  (I  mean  surfet)  is  verie  common:  for  common  is  that 
saying  and  most  true:  That  more  die  by  surfet  than  by  the 
sword.  And  as  Georgius  Pictorius  saith,  all  surfet  is  ill,  but 
of  bread  worst  of  all.  And  if  nature  be  so  strong  in  many, 
and  they  be  not  sicke  upon  a  full  gorge,  yet  they  are  drowsie 
and  hcavie,  and  more  desirous  to  lo.yter  than  to  labor,  accord- 
ing to  that  old  master,  when  the  belly  is  full,  the  bones  would 
be  at  rest.  Yea  the  minde  and  wit  is  so  oppressed  and  over- 
whelmed with  excesse  that  it  lyeth  as  it  were  drowned  for  a 
time,  and  unable  to  use  his  force, "  ^ 

1  Quoted  from  Chittenden,  "  The  Nutrition  of  Man,  "pp.   166-7. 


The  Living  Machine  287 

In  recent  times  physiologists,  both  pseudo  and  scientific, 
including  a  great  variety  of  cranks  of  all  sorts  and  sizes, 
have  been  turning  their  attention  more  and  more  to  matters 
of  diet,  and  the  layman  is  beginning  to  learn  that  it  is 
possible  for  him  to  select  his  food,  not  only  with  respect  to 
price  and  palatability,  but  also  for  its  value  as  a  fuel  for 
the  human  machine.  The  principal  elements  in  human  diet 
are  proteins  (meat,  eggs  and,  to  a  less  extent,  milk,  grain  and 
vegetables),  carbohydrates  (sugar  and  starch)  and  fats.  One 
of  the  greatest  services  rendered  by  modern  students  of  human 
nutrition  has  been  to  show  that  a  high  protein  diet  is  not  only 
unnecessary,  but  actually  in  many  cases  detrimental  to  health. 
Studies  of  this  sort  have  been  largely  conducted  in  this  coun- 
try by  Professors  Chittenden  and  Fisher  at  Yale,  the  results 
of  two  of  the  most  striking  of  whose  experiments  are  here 
summarized.  The  first  of  these  was  conducted  upon  a  group 
of  thirteen  United  States  soldiers,  for  a  period  of  six  months, 
and  the  second  on  eight  college  athletes  for  five  months. 

The  ordinary  diet  of  the  soldiers  prior  to  the  experiment 
may  be  illustrated  by  the  following  average  day's  menu: 
Breakfast — Beefsteak  8  oz.,  gravy  2.4  oz.,  fried  potatoes  8.2 
oz.,  onions  1.2  oz.,  bread  5  oz.,  coffee  24  oz.,  sugar  0.6  oz. 
Dinner — Beef  6  oz.,  boiled  potatoes  12.3  oz.,  onions  2  oz., 
bread  8.2  oz.,  coffee  32.3  oz.,  sugar  1  oz. 
Supper — Corned  beef  6.9  oz.,  potatoes  6  oz.,  onions  0.7  oz., 
bread  5.5  oz.,  fruit  jelly  3.7  oz.,  coffee  15.0  oz.,  sugar  9.7  oz. 

During  the  experiment  the  amount  of  meat  was  gradually 
reduced  until  the  men  were  living  on  a  diet  of  which  the 
following  day's  menu  is  a  sample: 

Breakfast — Wheat  griddle  cakes  7  oz.,  syrup  1.7  oz.,  one  cup 
coffee,  with  milk  and  sugar,  12.3  oz. 

Dinner — Codfish  balls  (4  parts  potato,  1  part  fish,  fried  in 
pork  fat)  5.3  oz.,  stewed  tomato  7  oz.,  bread  2.6  oz.,  one  cup 
coffee  13.3  oz.,  apple  pie  3.3  oz. 

Supper — Apple  fritters  7  oz.,  stewed  prunes  4.4  oz.,  bread 
1.7  oz.,  butter  0.4  oz.,  one  cup  tea  12.3  oz. 

As  a  result  of  this  change  of  diet  some  of  the  men  showed 
a  slight  loss  of  weight  which  occurred  at  the  start,  and  in 
others  an  actual  gain  for  the  entire  period.  In  only  one  case, 
that  of  a  stout  man,  was  there  any  noticeable  decrease,  which 
in  his  case  was  to  his  advantage,  rather  than  the  reverse. 

Not  only  was  there  no  harmful  loss  of  weight,  but  the 
general  health  was  maintained  and  in  some  cases  improved. 
"Most  conspicuous,  however,  though  something  that  was 
entirely  unlocked  for,  was  the  effect  observed  on  the  muscular 
strength  of  the  various  subjects,"  which  showed  not  a  loss, 
but  on  the  contrary  a  decided  gain,  "and  furthermore,"  says 


288 


Biology  in  America 


Professor  Cliittenden,  "tlioro  was  a  noticoablc  gain  in  self- 
reliance  and  conrage  in  their  athletic  work,  both  of  Avhich 
are  likewise  indicative  of  an  improved  condition  of  the  body. 
How  far  these  improvements  are  attribntable  to  training  and 
to  the  more  regular  life  the  men  were  leading,  and  how  far 
to  the  change  in  diet,  cannot  be  definitely  determined.  AVe 
may  venture  the  opinion,  however,  .  .  .  that  the 


change  in 


A  Soldier  after  a  Six-Months'  Diet  Low  in  Meat 

After  Chittenden,  "The  Nutrition  of  Man." 

By  permission  of  F.  A.  Stokes   Company. 

diet  was  in  a  measure  at  least  responsible  for  the  increased 
efficiency.  As  the  writer  has  already  expressed  it,  there  must 
be  enough  food  to  make  good  the  daily  waste  of  tissue,  enough 
food  to  furnish  the  energy  of  muscular  contraction,  but  any 
surplus  over  and  above  what  is  necessary  to  supply  the^se 
needs  is  not  only  a  waste,  but  may  prove  an  incubus,  retard- 
ing the  smooth  working  of  the  machinery  and  detracting 
from  the  power  of  the  organism  to  do  its  best  work." 


The  Living  Machine  289 

Concerning  the  second  experiment  above  mentioned  Profes- 
sor Chittenden  says:  "Here,  again,  we  see  that  a  relatively 
small  intake  of  proteid  food  will  not  only  bring  about  and 
maintain  nitrogen  eqnilibrium  for  many  months,  and  probably 
indefinitely,  but  that  such  a  form  of  diet  is  equally  as  effective 
with  vigorous  athletes,  accustomed  to  strenuous  muscular  ef- 
fort, as  with  professional  men  of  more  sedentaiy  habits.  Fur- 
ther, these  many  months  of  observation  with  different  individ- 
uals all  lead  to  the  opinion  that  there  are  no  harmful  results  of 
any  kind  produced  by  a  reduction  in  the  amount  of  proteid 
food  to  a  level  commensurate  with  the  actual  needs  of  the 
body.  Body-weight,  health,  physical  strength,  and  muscular 
tone  can  all  be  maintained,  in  partial  illustration  of  which 
may  be  offered  two  photogi*aphs  of  one  of  the  eight  athletes 
taken  toward  the  end  of  the  experiment;  pictures  which  are 
certainly  the  antithesis  of  enfeebled  muscular  structure,  or 
diminished  physical  vigor." 

Similar  results  have  been  obtained  with  professional  men. 
Altogether  they  show  very  conclusively  the  possibility  of  not 
only  maintaining,  but  also  of  improving  human  health  with 
a  diet  relatively  low  in  proteid  matter. 

What  now  will  be  the  result  if  an  animal,  which  in  its 
natural  state  was  exclusively  carnivorous,  and  even  in  domes- 
tication is  still  largely  so,  be  fed  on  a  proteid-poor  diet? 
Some  of  the  earlier  experimenters  in  Europe  found  that  a 
reduction  in  the  meat  of  a  dog's  diet  resulted  in  gastro- 
intestinal disturbance  followed  by  death.  These  experiments 
however  were  conducted  with  dogs  kept  in  close  confinement 
and  as  Chittenden  says  "It  is  doubtful  if  there  is  full  appre- 
ciation of  the  possible  effect  of  monotony,  in  the  ordinary 
dietary  experiments  on  dogs.  Man  quickly  feels  the  effect; 
the  sportsman  camping  in  the  woods  by  brook  or  lake  enjoys 
his  first  meal  of  speckled  trout  and  has  no  thought  of  ever 
becoming  tired  of  such  a  delicacy;  but  as  trout  cooked  in 
various  ways  continue  to  be  placed  before  him  three  times  a 
day,  and  with  perhaps  very  little  else,  he  soon  passes  into  a 
frame  of  mind  where  salt  pork  would  be  a  luxury,  and  where 
he  would  prefer  to  go  hungry  rather  than  eat  the  delicacy, 
if  indeed  he  has  appetite  to  eat  anything.  Is  it  strange  that 
dogs  confined  in  cages  barely  large  enough  to  permit  of  their 
turning  around,  and  fed  day  after  day  and  month  after 
month  with  exactly  the  same  amount  of  desiccated  meat,  fat, 
and  rice,  should  show  signs  and  symptoms,  if  nothing  worse, 
of  disturbed  nutrition?  It  is  necessary  in  experiments  of 
this  kind  that  the  animals  be  confined  for  given  periods,  at 
least.  ...  It  is  possible,  however,  to  limit  the  time  of  close 
confinement  to,  say,  ten  consecutive  days,  this  to  be  followed 


290  Biology  in  America 

by  a  like  period  of  comparative  freedom,  thus  insuring  oppor- 
tunities for  an  abundance  of  fresh  air  and  exercise." 

In  order  to  test  the  effects  of  a  proteid-poor  diet  on  dogs 
living  under  conditions  as  nearly  ideal  as  possible  a  series  of 
experiments  were  carried  out  on  some  twenty  animals, 
some  of  these  lasting  an  entire  year,  ''AH  of  the  .  .  .  dogs 
.  .  .  were  fed  on  a  mixed  diet,  with  some  fresh  meat  each  day ; 
bread,  cracker  dust,  milk,  lard,  and  rice  being  the  other  foods 
drawn  upon  to  complete  the  dietary.  The  animals  were  fed 
twice  a  day,  each  meal  being  accurately  weighed  and  of  defi- 
'nite  chemical  composition.  A  large,  light,  and  airj^  room,  kept 
scrupulously  clean,  and  in  the  winter  time  properly  heated 
by  steam,  served  as  their  main  abiding  place.  In  this  room 
were  a  suitable  number  of  smaller  compartments,  the  walls 
of  which  were  composed  of  open  lattice  work  (of  iron),  so 
as  not  to  interfere  with  light  or  air,  and  yet  adequate  to  keep 
the  dogs  apart.  These  compartments  were  not  cages  in  the  or- 
dinary sense,  but  were  truly  large  and  roomy.  ...  In  pleas- 
ant weather,  immediately  after  their  first  meal,  the  dogs  were 
taken  out  of  doors  to  a  large  enclosure  near  by,  where  they 
were  allowed  perfect  freedom  until  about  four  o'clock,  when 
they  were  taken  in  for  their  second  meal  (between  four  and 
five  o'clock  in  the  afternoon).  The  outdoor  enclosure  was 
inaccessible  to  every  one  except  the  holder  of  the  key,  and 
the  dogs  while  there  were  wholly  free  from  annoyance.  Once 
every  month,  during  a  period  of  ten  consecutive  days,  each 
dog  was  confined  in  the  metabolism  cage  so  as  to  admit  of 
the  collection  of  all  excreta,  in  order  to  make  a  determination 
of  the  nitrogen  balance.  Practically,  therefore,  each  dog 
was  in  close  confinement  only  one-third  of  the  month,  the 
remaining  two-thirds  being  spent  in  much  more  congenial 
surroundings." 

While  details  regarding  all  of  these  experiments  cannot  be 
given  here  one  case  may  be  selected  as  an  example.  "The 
animal  employed  in  this  experiment  .  .  .  was  apparently  full 
grown,  but  was  thin  and  had  the  appearance  of  being  under- 
fed. At  first,  it  was  given  daily  172  grams  of  meat,  124  grams 
of  cracker  dust,  and  72  grams  of  lard.  .  .  .  (Later)  a  radical 
change  was  made  in  the  diet,  by  reducing  the  amount  of  meat 
to  70  gi-ams  daily ;  .  .  .  the  cracker  dust  and  lard  being  kept 
at  essentially  the  same  levels  as  before  .  .  .  the  dog  in  the 
meantime  gaining  in  body-weight.  ...  In  this  manner,  the 
experiment  was  continued  with  frequent  changes  in  the  char- 
acter of  the  diet,  but  always  maintaining  essentially  the  same 
(food)  values  .  .  .  (for)  just  eleven  months,  with  the  ani- 
mal at  the  close  of  the  experiment  still  gaining  in  body- 
weight,  .  .  .  and  with  every  indication  of  good  health  and 


The  Living  Machine 


291 


stren^h."  The  results  of  his  entire  series  of  experiments 
led  Chittenden  to  the  conclusion  that:  ''These  experiments 
on  the  influence  of  a  low  proteid  diet  on  dogs,  as  a  type  of 
high  proteid  consumers,  taken  in  their  entirety,  afford  con- 
vincing proof  that  such  animals  can  live  and  thrive  on  amounts 
of  proteid  and  non-nitrogenous  food  far  below  the  (usual) 
standards.  .  .  .  The  deleterious  results  reported  by  these  in- 
vestigators were  not  due  to  the  effects  of  low  proteid  or  to 
diminished  consumption  of  non-nitrogenous  foods,  but  are  to 
be  ascribed  mainly  to  non-hygienic  conditions,  or  to  a  lack 
of  care  and  physiological  good  sense  in  the  prescription  of  a 
narrow  dietary  not  suited  to  the  habits  and  needs  of  this 


Effect  of  Diet  on  Dogs 
Left — A  dog  fed  on  a  diet  containing  one-half  pound  of  meat  daily. 

Eight — The   same   animal   after   several  months   on   a   diet  with   less 
than  half  as  much  meat.     From  Chittenden,  "The  Nutrition  of  Man." 
By  permission  of  F.   A.  Stokes   Company. 

class  of  animals.  Further,  it  is  obvious  that  the  more  or  less 
broad  deductions  so  frequently  drawn  from  .  .  .  experiments 
(on  dogs)  .  .  .  especially  in  their  application  to  mankind, 
are  entirely  unwarranted  and  without  foundation  in  fact. 
Our  experiments  offer  satisfying  proof  that  not  only  can  dogs 
live  on  quantities  of  proteid  food  per  day  smaller  than  (are 
usually)  .  .  .  deemed  necessary,  and  with  a  fuel  value  far 
below  the  (usual)  standard  .  .  .  ;  but,  in  addition,  tliat  these 
animals  are  quite  able  on  such  a  diet  to  gain  in  body-weight 
.  .  .  ,  thereby  indicating  that  even  small  quantities  of  food 
might  suffice  to  meet  their  true  physiological  requirements. 
"The  results  of  these  experiments  with  dogs,   which  we 


292  Biology  in  America 

have  recorded  in  such  detail,  are  in  perfect  haiTDiony  with  the 
conclusions  arrived  at  by  our  experiments  and  observations 
with  man,  and  serve  to  strengthen  the  opinion,  so  many  times 
expressed,  tliat  the  dietary  habits  of  mankind  and  the  dietary 
standards  based  thereon  are  not  always  in  accord  with  the 
true  physiological  requirements  of  the  body. ' ' 

There  is  one  experiment  in  the  foregoing  series  regarding 
which  a  further  word  may  be  said.  In  this  experiment  a 
dog  which  had  been  fed  on  a  diet  of  meat,  milk,  bread  and 
lard  was  changed  to  a  diet  of  bread  and  lard  only,  the  food 
and  fuel  value  however  of  the  diet  remaining  unchanged. 
"In  four  days'  time  however  a  change  began  to  creep  over 
the  animal ;  the  appetite  diminished,  and  there  was  apparent 
a  condition  of  lassitude  and  general  weakness  which  deterred 
the  animal  from  moving  about  as  usual. 

"During  the  next  week  the  animal  grew  steadily  worse, 
and  would  eat  only  when  coaxed  with  a  little  milk  or  with 
bread  softened  with  milk,  the  diet  of  bread  and  lard  being 
invariably  refused.  There  was  marked  disturbance  of  the 
gastro-intestinal  tract;  bloody  discharges  were  frequent;  the 
mucous  membrane  of  the  mouth  was  greatly  inflamed  and 
very  sore ;  body-weight  fell  off,  and  the  animal  was  in  a  very 
enfeebled  condition.  This  continued  until  December  4,  with 
every  indication  that  the  animal  would  not  long  survive,  but 
by  feeding  carefully  with  a  little  milk  and  occasionally  some 
meat,  improvement  finally  manifested  itself,  and  by  December 
18  there  was  good  appetite,  provided  bread  was  not  con- 
spicuous in  the  food.  Body-weight  .  .  .  was  .  .  .  slowly  re- 
gained (until  finally)  ...  in  general  condition  there  was 
nothing  to  be  desired."  ^ 

Similar  results  have  been  obtained  by  Hopkins  and  Nevill 
who  kept  twenty-four  young  rats  on  a  diet  of  protein,  starch, 
lactose  (milk-sugar)  and  salts.  They  ate  well  and  took 
sufficient  food  to  supply  them  with  needed  energy,  but  soon 
ceased  to  grow  and  in  a  few  days  actually  began  to  lose 
weight,  fourteen  of  them  dying  in  forty  days.  With  six  of 
the  rats  there  was  added  to  the  diet,  after  the  decline  in  weight 
had  commenced,  a  small  portion  of  milk  daily,  which  was 
followed  by  an  immediate  improvement  in  health,  and  re- 
newed growth. 

There  are  certain  problematical  diseases  in  man,  which' 
may  be  due  to  a  lack  of  something  in  the  food.  Beri  beri,  a 
disease  common  among  Filipinos,  Japanese  and  East  Indians, 
and  characterized  by  paralysis,  swelling  and  degeneration  of 
the   muscles,    has   been   attributed   to   an   extensive   diet   of 

*The  foregoing  quotations  arc  from  Chittenden,  "The  Nutrition  of 
Man,"  pp.  187  et  sot].,  Ity  permission  of  Fred'd    A.  Stokes  Co. 


The  Living  Machine  293 

polished  rice  which  lacks  the  reddish  husk  of  the  kernel.  If 
fowls  are  fed  on  an  exclusive  diet  of  this  they  die  after  some 
weeks.  If  fed  on  unpolished  rice,  they  do  not  contract  the 
disease,  and  if  an  extract  of  the  husk  or  bran  be  injected  into 
fowls  ill  from  eating  the  polished  grain  they  will  recover. 
Similarly  men  who  eat  the  unpolished  rice  are  not  subject  to 
beri-beri.  It  seems  then  that  the  rice  husk  contains  some 
substance  which  is  essential  to  life. 

Pellagra,  a  disease  common  among  the  poorer  classes  in 
tropical  and  sub-tropical  countries  practically  throughout  the 
world,  is  characterized  by  weakness,  pains,  digestive  disturb- 
ances, skin  eruptions  and  mental  disorders,  terminating  in 
insanity  and  finally  death.  In  its  earlier  stages  the  disease 
is  recurrent,  appearing  each  spring  for  several  years  with 
increasing  severity  until  it  becomes  a  permanent  condition. 
It  has  been  ascribed  to  a  too  extensive  diet  of  corn  or  to  eating 
spoiled  corn.  It  has  also  been  laid  at  the  door  of  the  villains 
of  so  many  sanitary  (or  insanitary)  tragedies — the  insects. 
One  investigator  has  recently  attempted  to  find  an  hereditary 
basis  for  the  disease.  Whatever  the  ultimate  cause  it  is 
clearly  a  disease  of  disturbed  metabolism,  and  evidence  is 
accumulating  to  show  that  imperfect  diet  is  responsible. 

Scurvy  has  long  been  known  as  a  disease  of  mal-nutrition, 
common  especially  among  sailors,  who  were  forced  to  live  on 
a  diet  largely  of  salt  meat,  so  that  in  the  maritime  laws  of 
many  nations  captains  were  required  to  furnish  their  seamen 
with  a  ration  of  vinegar,  lime  juice  or  other  acid  as  a  pre- 
ventive. 

While  the  subject  of  human  nutrition  is  yet  in  its  infancy, 
especially  as  regards  our  knowledge  of  these  problematical 
substances,  which  are  essential  to  health,  and  to  some  of 
which,  especially  those  present  in  milk,  the  term  vitamine  has 
been  applied ;  the  evidence  is  clear  that  to  furnish  the  living 
machine  with  the  fuel  needed  for  its  proper  working,  it  is  not 
sufficient  merely  to  supply  the  necessary  material  for  energy, 
repair  and  growth,  but  that  other  things  are  needed  to  enable 
it  to  properly  utilize  this  fuel.  While  therefore  excesses 
in  eating  are  but  little  if  any  less  injurious  than  those  in 
drinking  or  other  indulgence,  there  is  no  place  in  the  regime 
of  the  sane  and  normal  individual  for  the  dietary  fads  and 
foolishness  which  some  enthusiasts  have  advocated  with  great 
eclat.  While  most  of  us  undoubtedly  eat  too  much  meat, 
there  is  small  excuse  for  adopting  a  strictly  vegetarian  diet. 
Our  teeth  are  made  for  service,  and  not  for  the  exclusive 
benefit  of  the  dentist,  but  while  thorough  mastication  is  un- 
doubtedly essential  to  a  ripe  old  age  with  good  digestion, 
most  of  us  will  hardly  find  it  necessary  to  chew  by  the  stop- 


294  Biology  in  America 

watch,  or  to  reflate  our  bites  as  we  do  our  setting-up  exer- 
cises. In  the  feeding  of  hens  for  egg  productivity  Pearl  has 
shown  that  hens  witli  a  mixed  diet,  from  which  they  were 
permitted  to  choose  at  will,  maintained  better  health  than 
those  limited  strictly  to  certain  articles.  ''Eeason  in  all 
things,  excess  in  none,"  is  a  fundamental  rule  for  sanity  in 
diet  as  in  other  of  our  life  activities. 

What  of  the  mechanism  whereby  this  wonderful  machine 
of  life  utilizes  its  fuel?  Herein  lies  one  of  the  fundamental 
differences  between  the  living  and  the  non-living  machine. 
"Whereas  the  latter  uses  its  fuel  solely  in  the  conversion  of 
potential  energy  into  heat  and  work,  the  former,  in  addition 
to  these  two  functions,  also  converts  some  of  its  fuel  into  its 
own  substance  to  take  the  place  of  worn-out  parts,  and  to 
build  new  parts  and  enlarge  those  already  formed  in  develop- 
ment and  growth.  We  have  already  seen  that  the  living 
engine  is  much  more  efficient  in  the  conversion  of  the  potential 
energy  of  its  fuel  into  work  than  is  the  non-living  machine. 
How  convenient  it  would  be  if  the  latter  like  the  former  were 
automatically  repaired  as  it  wore  out !  Given  a  good  machine 
to  start  with,  proper  fuel  and  draft,  and  preventing  anyone 
from  throwing  in  dirt  (disease)  and  the  living  machine  will 
run  without  repair  for  the  time  of  its  natural  life. 

How  is  this  done?  In  the  non-living  machine  the  process 
of  converting  fuel  energy  into  work  energy  is  comparatively 
simple.  The  carbon  of  the  fuel  is  in  such  shape  that  it  can'' 
be  more  or  less  directly  oxidized  to  carbon  dioxide,  and  heat 
energy  thereby  released.  But  in  the  utilization  of  the  food 
or  fuel  of  the  living  machine  a  large  number  of  intermediate 
steps  are  necessary,  which  steps  often  consist  of  a  cycle  of 
changes  which  are  partly  degenerative  (breaking  down  com- 
plex substance  and  thereby  releasing  energy)  and  partly 
constructive  (building  up  simpler  into  more  complex  sub- 
stance and  storing  energy  thereby).  The  food  as  taken  into 
the  body  of  most  animals  is  in  such  shape  that  it  cannot  be 
directly  burned  to  furnish  energy^  or  built  up  into  body 
substance.  While  our  knowledge  of  the  many  complicated 
changes  undergone  by  food  stuffs  in  the  animal  body  is  as 
yet  very  meagre,  we  have  nevertheless  enough  information  to 
enable  us  to  follow  in  a  general  way  these  changes.  Probably 
the  food  most  readily  convertible  into  energy  is  fat.  Some 
fat  is  an  exception  to  the  statement  made  above  that  food 
is  not  directly  convertible  into  energy.  The  Esquimaux  use 
seal  blubber  both  as  food  and  fuel  for  heating  their  igloos, 

*  I  refer  here  to  ordinary  conditions  of  combustion.  Any  food  sub- 
stance may  be  burned  in  a  special  apparatus  known  as  a  bomb  calorime- 
ter and  its  energy  content  thereby  determined. 


The  Living  Machine  295 

and  various  vegetable  oils  can  be  burned  in  a  lamp.  "When 
taken  into  the  digestive  tract  however  the  fat  is  not  usable 
as  fuel  any  more  than  any  other  food  substance,  but  must 
first  undergo  digestion. 

The  function  of  digestion  of  all  food  is  to  put  it  into  such 
shape  that  it  can  be  absorbed  by  the  blood  and  lymph  through 
the  walls  of  the  digestive  tract.  This  transfer  or  absorption 
of  the  food  through  the  latter  takes  place,  as  we  have  seen, 
by  a  process  of  osmosis.  The  food  as  eaten  is  not  ordinarily 
in  solution  and  cannot  be  passed  through  a  membrane  or 
dialyzed,  the  function  of  digestion  being  to  render  it  soluble 
and  dialyzable.  This  is  accomplished  by  a  process  known  as 
hydrolysis  which  consists  in  the  splitting  up  of  the  food  into 
simpler,  compounds  by  the  addition  of  water.  This  process 
is  effected  by  means  of  certain  remarkable  substances  formed 
by  all  animals  and  plants  and  known  as  enzymes  or  ferments. 
When  a  little  yeast  is  added  to  a  solution  of  sugar  and  certain 
salts  and  kept  at  a  proper  temperature,  bubbles  of  gas  (carbon 
dioxide)  soon  begin  to  rise  to  the  surface  of  the  solution. 
The  sugar  is  being  broken  down  into  two  simpler  substances, 
carbon  dioxide  and  alcohol,  by  the  ferment  secreted  by  the 
yeast  cells.  So  far  as  we  know  the  ferment  itself  does  not 
change,  but  acting  as  by  magic  affects  a  change  in  certain 
substances  with  which  it  comes  in  contact.  Yet  even  this 
remarkable  activity  of  the  living  cell  has  its  counterpart  in 
inorganic  nature.  If  hydrogen  and  oxygen  be  brought  to- 
gether at  ordinary  temperatures  there  is  "nothin'  doin'  " — 
to  use  the  English  language  up  to  date.  But  introduce  a 
little  finely  divided  platinum  into  the  situation,  and  under 
its  seemingly  magic  influence  combination  occure  and  drops 
of  water  form  where  before  there  was  but  gas.  The  heat 
generated  by  this  reaction  soon  raises  the  platinum  to  a  red 
heat  and  this  principle  was  employed  in  the  construction  of 
a  self-lighting  lamp,  in  which  a  jet  of  hydrogen  played  upon 
a  bit  of  spongy  platinum,  which  soon  heated — igniting  the 
gas.  The  platinum  here  is  known  as  a  catalyzer.  Its  action 
is  similar  to  that  of  the  ferment  since  it  in  some  way  brings 
about  a  change  in  other  substances,  without  itself  entering 
into  that  change.  The  activity  of  the  ferment-forming  cell 
is  responsible  to  itself  for  its  continuation,  for  when  the 
products  of  ferment  action  become  too  great  this  action  ceases, 
and  will  not  recommence  until  these  products  are  removed, 
or  at  least  lessened  in  amount. 

Among  vertebrate  animals  the  digestive  ferments  are 
formed  chiefly  by  the  stomach,  pancreas  and  intestine,  al- 
though the  liver,  and  in  some  instances  the  mouth  glands 
play  a  minor  part;  while  the  simplified  and  soluble  (digested) 


296  Biology  in  America 

food  stuffs  are  absorbed  mainly  at  least  by  the  walls  of  the 
intestine,  whence  they  are  carried  by  the  body  fluids  (blood 
and  lymph)  to  the  tissues  of  tlie  body,  where  probably  under 
the  influence  of  other  ferments  they  are  again  built  up  into 
complex  substances,  which  compose  the  protoplasm  of  the 
body  cells.*  Thus  the  kernel  of  the  wheat,  or  the  muscle  of 
the  beef,  is  iu  some  mysterious  way  transformed  into  the 
muscle  and  the  nerves,  the  blood  and  bone  of  the  animal 
which  consumes  them.  The  various  steps  in  the  digestive 
and  absorptive  processes  are  extremely  complicated  and  their 
character  is  not  fully  understood.  The  large  number  of  prod- 
ucts formed  in  tlie  digestion  of  the  proteid  molecule  form 
one  evidence  of  the  complex  nature  of  protoplasm.  Leaving 
out  of  consideration  the  simpler  processes  of  digestion  of 
starch,  sugar  and  fat,  and  dealing  with  proteid  digestion 
alone;  passing  over  also  the  many  and  complicated  stages  in 
the  journey  of  the  proteid  molecule  through  the  digestive 
tract,  we  come  to  the  end  products  of  digestion,  the  amino- 
acids  or  "l)uilding  stones  of  proteid,"  as  they  have  l)een 
called.  Tliese  amino-aeids  include  a  large  number  of  sub- 
stances, all  built  around  the  common  nucleus  of  NHo.  Witli 
these  as  a  basis  the  constructive  ferments  of  the  l)ody  build 
up  its  marvelously  complex  materials. 

A  comparison  of  the  animal  body  with  a  machine,  the  food 
of  the  former  corresponding  to  the  fuel  of  the  latter  is  only 
partially  exact,  for  in  the  machine,  as  we  have  seen,  the  fuel 
is  directly  consumed  to  furnish  energy,  while  in  the  animal 
the  change  of  food  energy  into  work  energy  is  effected  in 
part  only  through  the  medium  of  the  body  substance 
itself.  After  the  conversion  of  the  digested  food  stuffs  into 
the  protoplasm  of  the  l)ody  this  must  in  turn  be  broken  down 
through  the  action  of  the  oxydizing,  or  destructive  ferments, 
into  a  whole  series  of  decomposition  products,  of  gradually 
decreasing  complexity,  the  principal  end  results  being  carbon 
dioxide  and  urea. 

Some  of  the  food  stuffs,  notably  those  with  the  highest 
energy  content,  the  fats  and  carbohydrates,  and  to  a  less 
extent  the  proteids  also,  may  after  digestion  be  directly 
oxidized  to  furnish  energy;  or  may  in  the  case  of  fat  and 
glycogen  be  stored  by  the  body  as  a  reserve  supply  for  future 
need.  Thus  a  hibernating  animal,  such  as  a  bear,  during  the 
summer  lays  up  for  himself  a  bountiful  supply  of  fat  upon 
whieli  to  draw  during  the  long  winter's  fast.  This  storage 
of  energy  in  the  form  of  reserve  food  stuffs  by  the  living 

*Sueh  a  brief  statement  as  the  above  naturally  overlooks  the  many 
intermediate   steps   in   this  very   complicated   process. 


The  Living  Machine  297 

machine  finds  a  parallel  in  the  storage  of  electrical  energy 
in  a  storage  battery. 

Turning  from  the  world  of  animals  to  that  of  plants,  we 
find  in  the  latter  a  parallel  to  all  of  the  metabolic  processes 
of  the  former.  The  average  person  is  accustomed  to  think  of 
a  plant  in  terms  of  the  green  thing  which  he  finds  in  garden, 
field  or  forest.  But  when  we  go  a-hunting  mushrooms,  or 
poke  aside  the  rotting  remains  of  a  fallen  tree,  we  discover 
other  plants  which  live  a  different  sort  of  life  from  that  of 
tree  or  shrub  or  herb.  And  should  we  delve  yet  further  into 
Nature's  recesses,  and  penetrate  that  hidden  world  to  which 
the  microscope  gives  entrance,  we  should  discover  creatures 
concerning  whom  no  one  can  say  whether  they  are  plant  or 
animal.  Some  of  these  uncertain  forms  are  claimed  by  both 
botanist  and  zoologist  as  belonging  in  their  own  especial  field 
of  study,  for  in  some  respects  they  are  distinctly  animal,  in 
others  plant  in  nature,  as  we  have  already  seen  in  an  earlier 
chapter.  But  while  one  stands  at  the  portals  of  life  in  a 
realm  which  is  neither  plant  nor  animal ;  advancing  into  either 
kingdom  he  must  follow  ever  more  widely  diverging  paths; 
until  when  he  reaches  the  farthest  bounds  of  this  wonderful 
world  he  finds  its  two  kingdoms,  while  governed  by  the  same 
fundamental  laws,  nevertheless  differing  profoundly  in  their 
expression. 

Perhaps  the  most  fundamental  difference  between  the  higher 
plants  and  animals  is  in  their  metabolism.  "While  the  latter 
are  spenders,  the  former  are  hoarders  of  energy,  taking  raw 
materials,  carbon  dioxide  from  the  air  and  water  from  both 
air  and  soil,  and  from  these  constructing  by  the  energy  of  the 
sun,  acting  through  the  green  chlorophyl  of  leaf  and  stem, 
their  own  food-stuffs;  thereby  converting  the  radiant  energy 
of  sunlight  into  the  chemical  energy  of  sugar  and  of  starch. 
From  the  soil  and  air  the  plant  obtains  its  nitrogen,  and  from 
the  soil  the  other  inorganic  substances  which  it  needs  to  build 
its  protoplasm,  and  combining  these  in  some  as  yet  but  little 
understood  way,  with  the  sugar,  by  the  action  of  constructive 
ferments,  it  builds  up  its  protoplasm.  This  is  what  is  hap- 
pening in  the  blade  of  grass,  the  spreading  leaf  and  the  stag- 
nant pool,  covered  with  a  thick  green  scum,  a  little  chemical 
laboratory,  where  Nature  is  busily  at  work  making  sugar  and 
releasing  oxygen.  Some  day  perchance  the  chemist,  imitat- 
ing Nature,  will  learn  to  make  our  starch  and  sugar  for  us, 
and  bid  defiance  to  the  "man  with  a  hoe."  This  indeed  is 
the  possibility,  perhaps  not  immediate,  but  none  the  less  ulti- 
mate, of  the  studies  on  photosynthesis  now  under  way  at  the 
Desert  Botanical  Laboratory  of  the  Carnegie  Institution  at 


298  Biology  in  America 

Tucson,  Arizona,  whose  work  we  have  considered  in  a  previous 
chapter.  Synthetic  chemistry  may  well  doff  its  hat  and  bow 
low  before  the  greatest  creative  chemist  in  the  world — the 
green  plant. 

Tlie  world  today  hungers  and  thirsts  after  nitrogen.  We 
must  have  nitrogen  to  fertilize  our  fields,  in  order  that  we 
may  not  starve,  and  we  must  have  nitrogen  to  rend  asunder 
the  bowels  of  the  earth  and  lay  bare  the  treasures  hidden 
therein,  and  we  must  have  nitrogen  that  we  may  slaughter 
our  fellow  men.  So  we  have  cleaned  the  guano  beds  of  Chile, 
where  the  sea  fowl  have  been  laying  down  treasure  and  stench 
for  years  untold.  We  have  dug  deep  into  the  nitrate  beds 
of  Cliile  and  Peru,  and  today  we  are  harnessing  the  water- 
fall and  bidding  it  harvest  for  us  the  nitrogen  of  the  air. 
Meanwhile  the  silent  plant  has  been  putting  man 's  ingenuity 
to  shame,  and  in  its  laboratory  working  wonders,  whereat 
science  well  may  marvel.  Truly  should  man  "consider  the 
lilies  of  the  field. ' ' 

But  the  green  plant  is  not  unassisted  in  the  wonders  which 
it  works.  On  the  roots  of  plants  of  the  pea  family  occur  little 
swellings  or  "nodules"  which  are  fonned  by  bacteria  which 
have  the  power  of  extracting  the  nitrogen  from  the  air  in  the 
soil  and  using  it  to  build  their  own  bodies.  Hence  they  are 
known  as  the  "nitrogen-fixing"  bacteria.  As  these  bacteria 
die  they  give  to  the  soil  compounds  of  the  nitrogen  which  they 
have  taken  from  the  air.  Thus  it  is  that  peas  and  their 
relatives  such  as  beans  and  alfalfa  are  such  valuable  plants 
for  crop  rotation,  for  if  a  soil  from  which  the  nitrogen  has 
been  largely  exhausted  by  continuous  cropping  with  grain  be 
planted  for  a  year  or  two  to  beans  or  alfalfa,  the  nitrogen- 
fixing  bacteria  on  the  roots  of  the  latter  will  replace  the 
nitrogen  and  give  to  the  worn-out  soil  a  new  lease  of  life. 
But  what  share  does  the  bean  or  the  alfalfa  and  the  bacteria 
have  in  this  co-operative  association  ?  The  latter  during  their 
life  probably  absorb  sugars  and  other  substances  formed  in 
the  leaves  of  the  former  and  passed  down  into  the  roots,  while 
on  their  death  some  of  the  nitrogenous  material  formed  by 
the  bacteria  is  absorbed  Ijy  tlie  green  plant.  The  heirs  to 
the  riches  laid  up  by  these  two  industrious  partners  are  the 
plants  which  follow  the  peas,  beans  or  alfalfa  in  rotation. 
There  are  other  soil  bacteria  which  aid  the  farmer  by  changing 
the  ammonia  in  the  soil  into  nitrites  and  nitrates,  in  which 
form  it  becomes  available  as  food  for  the  green  plants,  while 
vice  versa  other  soil  bacteria  perform  exactly  the  reverse 
operation  and  change  nitrites  and  nitrates  into  ammonia. 
All  life  is  a  cycle.     No  sooner  does  one  agency  build  up  than 


The  Living  Machine  299 

another  tears  down,  and  so  it  goes,  in  the  lives  of  the  unseen 
bacteria  of  the  soil,  as  well  as  in  the  affairs  of  man. 

But  while  most  animals  and  plants  differ  so  widely  in  their 
metabolism,  fundamentally  their  ways  of  life  are  alike.  Both 
must  have  food,  from  the  combustion  of  which  their  energy 
is  derived,  and  from  which  their  wastage  is  replaced  and 
growth  material  obtained.  And  this  food  must  be  rendered 
soluble  and  dialyzable  in  order  that  it  may  pass  through 
membranes  which  surround  each  cell,  i.  e.,  must  be  digested. 
While  in  the  higher  animal  there  is  a  special  place  where 
digestion  and  absorption  occur  (the  digestive  tract)  and  the 
digestive  ferments  are  formed  by  special  glands  (liver,  pan- 
creas, etc.),  in  the  plant  there  is  no  such  specialized  tract  or 
glands  for  the  functions  of  digestion  and  absorption,  these 
taking  place  generally  in  the  leaves.  There  are  however  cer- 
tain specialized  tubes  of  cells  in  the  root  and  stem  which 
taken  together  form  "conducting  paths,"  for  the  water,  with 
its  dissolved  salts  ascending  from  the  soil,  and  the  sugar 
descending  from  the  leaves  to  root  and  stem,  there  to  be  stored 
as  starch  for  future  use.  And  after  digestion  the  food  must 
circulate  through  the  plant  to  all  its  parts,  and  be  built  up 
into  its  tissues  by  constructive  ferments  analogous  to  those 
of  animals. 

In  this  circulation  of  water  with  its  dissolved  substances 
through  root  and  stem  we  see  one  of  those  marvelous,  and 
as  yet  inexplicable  phenomena  of  life,  which  have  caused 
so  many  biologists  to  throw  up  their  hands  in  despair  and 
ascribe  to  life  some  occult  power  undiscoverable  by  the  sci- 
entific methods  of  the  physicist  and  chemist. 

From  the  leafy  surface  of  humblest  herb  and  mightiest  tree, 
transpiration  takes  place,  or  the  loss  of  water  absorbed  by  the 
roots  from  the  soil.  During  the  day  this  water  is  usually 
quickly  evaporated,  but  in  the  cooler  air  of  night  evaporation 
is  reduced  and  some  of  the  transpired  water  remains  as  dew 
upon  the  leaf.  The  pressure  lifting  the  water  from  the  soil 
to  the  leaf  may  be  as  great  in  some  cases  as  that  which  would 
be  exerted  on  the  earth's  surface  by  an  atmosphere  six  to 
eight  times  the  thickness  of  the  present  one,  a  pressure  suffi- 
cient to  support  a  column  of  water  between  two  and  three 
hundred  feet  high. 

Various  attempts  have  been  made  to  explain  the  rise  of 
sap  in  plants  but  as  yet  with  no  great  success.  The  evapora- 
tion from  the  leaves  and  the  absorption  of  water  by  the  cells 
are  the  principal  factors  claimed  as  causing  this  wonderful 
phenomenon.  Neither  factor  however  is  adequate,  and  the 
best  we  can  do  here,  as  in  so  many  other  cases,  is  to  confess 
our  ignorance,  and  press  onward  in  the  search  for  knowledge. 


300  Biology  in  America 

In  this  marvellous  laboratory  of  the  living  body  with  its 
countless  millions  of  little  test  tubes  or  cells,  and  its  manifold 
reagents,  many  of  which  we  do  not  know,  wonderful  reactions 
are  continually  taking  place,  whose  complexity  is  at  once 
the  joy  and  the  despair  of  the  chemist,  and  whose  study  is 
one  of  the  newest,  most  fascinating  and  withal  most  difficult 
fields  into  which  chemistry  has  been  privileged  to  enter.  And 
yet  marvelous  as  are  the  transformations  within  the  body 
of  the  living  being  they  are  all  without  exception  undoubtedly 
effected  by  physical  and  chemical  means. 


CHAPTER   XII 

Experimental  biology,  mechanism  versus  vitalism  continued. 
Tropisms,  iyistincts  and  intelligence.  H&rmanes.  Arti- 
ficial fertilization. 

But  can  physics  or  chemistry  explain  the  as  yet  unknown 
processes  of  nervous  action;  the  bewildering  pei-plexity  of 
the  instinct  of  bee  or  bird  or  beast,  or  the  yet  more  amazing 
intricacies  of  human  thought?  To  answer  this  question,  as 
indeed  to  solve  any  of  the  problems  of  living  matter  aright, 
it  is  essential  that  we  turn  to  the  lowest  rather  than  to  the 
highest  organisms,  to  those  which  present  to  us  in  their 
simplest  terms,  all  the  fundamental  processes  of  the  living 
thing.  If  the  extended  process  or  pseudopodium  of  an  Amoeba, 
one  of  the  simplest  types  of  living  things,  be  touched  with  a 
finely  drawn  out  thread  of  glass,  the  process  is  retracted  and 
the  direction  of  movement  of  the  animal  is  altered  thereby. 
If  on  the  other  hand  Amceba  comes  in  contact  with  some 
object,  which  serves  as  food,  it  reacts  positively  toward  it, 
thrusting  out  its  processes  and  engulfing  the  object.  Further- 
more Amceba  can  pursue  its  food,  so  that  to  the  observer  it 
seems  as  if  this  tiny  bit  of  protoplasm,  so  small  that  the 
largest  specimens  appear  to  the  naked  eye  as  mere  specks  of 
white,  were  endowed  with  a  sort  of  primitive  intelligence. 
This  pursuit  of  food  has  been  described  by  Jennings  as 
follows :  "I  had  attempted  to  cut  an  Amoeba  in  two  with  the 
tip  of  a  glass  rod.  The  posterior  third  of  the  Amoeba,  in  the 
form  of  a  wrinkled  ball,  remained  attached  to  the  body  only 
by  a  slender  cord,  the  remains  of  the  ectosarc.  The  Amceba 
began  to  creep  away,  dragging  with  it  this  ball.  I  will  call 
this  Amoeba  a,  while  the  ball  will  be  designated  b,  A  larger 
Amoeba  (c)  approached,  moving  at  right  angles  to  the  path 
of  the  first  Amoeba;  its  course  accidentally  brought  it  into 
contact  with  the  ball  b,  which  was  dragging  past  its  front. 
Amoeba  c  thereupon  turned,  followed  Amoeba  a,  and  began 
to  engulf  the  ball  b.  A  large  cavity  was  formed  in  the  an- 
terior end  of  Amoeba  c,  reaching  back  nearly  or  quite  to  its 
middle,  and  much  more  than  sufficient  to  contain  the  ball  b. 
Amoeba  a  now  turned  into  a  new  path;  Amceba  c  followed 
(4).      After    the    pursuit    had    lasted    for    some    time    the 

301 


302 


Biology  hi  America 


ball  b  had  become  completely  enveloped  by  Amoeba  c;  the 
cord  connecting  it  with  Amoeba  a  broke,  and  the  latter  went 
on  its  way  (at  5)  and  disappears  from  our  account.  Now 
the  anterior  opening  of  the  cavity  in  Amoeba  c  became  partly 
closed,  leaving  a  slender  canal    (5).     The  ball  b  was  thus 


Pursuit  of  Food  by  Amceba 
From  Jennings,  "Contributions  to  the  study  of  the  behavior  of  lower 
organisms."     Carnegie  Institution,  Publication  No.  16.     For  description 
see  text. 


completely  inclosed,  together  with  a  quantity  of  water.  There 
was  no  union  or  adhesion  of  the  protoplasm  of  b  and  c;  on 
the  contrary  (as  the  sequel  will  show  clearly)  both  remained 
quite  separate,  c  merely  inclosing  b. 

*'Now  the  large  Amoeba  c  stopped,  then  began  to  move  in 
another   direction    (5-6),    carrying   with   it   its   meal.    But 


The  Livhuj  Machine  303 

the  meal,  the  ball  b,  now  began  to  show  signs  of  life,  sent  out 
pseudopodia,  and  indeed,  became  very  active.  \Ve  shall 
henceforth,  therefore,  speak  of  it  as  Amu?ba  b.  It  began  to 
creep  out  through  the  still  open  canal,  sending  forth  its 
psetidopodia  to  the  outside  (7).  Thereupon  Am(eba  c  sent 
forth  its  pseudopodia  in  the  same  direction,  and  after  creeping 
in  that  direction  several  times  its  own  length,  again  c()ni|)l('tely 
inclosed  b  (7-8).  The  latter  again  partly  escaped  (D),  and 
was  again  engulfed  completely  (30).  Amoeba  c  now  started 
again  in  the  opposite  direction  (11),  whereupon  Amieba  b, 
by  a  few  rapid  movements,  escaped  entirely  from  tlie  posterior 
end  of  c,  and  was  free,  being  completely  separated  from  e 
(11-12).  Thereupon  c  reversed  its  course  (12),  crept  up  to 
b,  engulfed  it  completely  again  (13),  and  started  away. 
Amoeba  b  now  contracted  into  a  ball,  its  protoplasm  clearly 
set  off  from  the  protoplasm  of  its  captor,  and  remained  quiet 
for  a  time.  Apparently  the  drama  w^as  over.  Amoeba  c  went 
on  its  way  for  about  five  minutes,  without  any  sign  of  life  in  b. 
In  the  movements  of  the  Amoeba  c  the  ball  b  gradually  became 
transferred  to  the  posterior  end  of  c,  until  finally  there  was 
only  a  thin  layer  between  b  and  the  outer  water.  Now  b 
began  to  move  again,  sent  out  pseudopodia  to  the  outside 
through  the  thin  wall,  and  then  passed  botlily  out  into  the 
water  (14) .  This  time  Amoeba  c  did  not  return  and  recapture 
b.  The  two  Amoebae  moved  in  different  directions  and  re- 
mained completely  separated.  The  whole  performance  occu- 
pied, I  should  judge,  about  12  to  15  minutes  (the  time  was 
not  taken  till  several  minutes  after  the  beginning) . 

"After  working  with  simple  stimuli  and  getting  always 
direct  simple  responses,  so  that  one  begins  to  feel  that  he 
understands  the  behavior  of  the  animal,  it  is  somewhat 
bewildering  to  become  a  spectator  of  so  striking  and  com- 
plicated a  drama.  .  .  .  The  action  is  remarkably  like  that  of 
a  higher  animal.  Doubtless  we  must  assume  chemical  and 
mechanical  stimuli  as  directives  for  each  of  the  movements 
of  c,  but  the  analysis  so  obtained  seems  not  very  complete 
or  satisfactory. "  ^ 

Injurious  chemicals  cause  Amoeba  to  withdraw  from  them. 
Similarly,  if  the  water  on  one  side  of  an  Aiiueba  be  warmed, 
the  animal  will  contract  on  that  side,  and  thrusting  forth  its 
pseudopodia  on  the  other  side,  move  in  the  opposite  direction. 
If  a  weak  electric  current  be  passed  through  the  water  con- 
taining Amoeba,  its  behavior  is  similar  to  that  under  a  heat 
stimulus.  The  side  toward  the  anode  or  positive  pole  con- 
tracts, while  from  the  opposite  side  pseudopodia  are  extended, 

^Jennings,  "Contributions  to  the  Study  of  the  Behavior  of  Lower 
Organisms,"  Carnegie  Institution,  Publication  No.  16. 


304  Biolofjy  in  Am  eric, 

and  the  animal  moves  toward  the  cathode  or  negative  pole. 
Tlio  hrhavioi-  of  Amoeba  moreover  is  not  stereotyped,  l)ut  can 
be  adapted  to  suit  varying  conditions.  If  a  bright  light  be 
thrown  upon  it,  it  contracts  into  a  small  inactive  mass,  but 
after  a  time  the  psendopodia  are  again  thrust  out  and  activity 
resumed.  When  starved,  Amceba  l)e('omes  more  active  than 
usual,  while  after  a  heavy  meal  it  becomes  sluggish. 

"All  these  responses  are  purposive  in  that  they  are  adapted 
to  the  preservation  of  the  organism.  Simple  as  AuKcba  ap- 
parently is  it  manages  to  cope  very  effectively  with  the  condi- 
tions of  its  existence.  One  might  conceivably  construct  a 
machine  which  would  run  itself,  gather  tlie  food  needed  to 
supply  the  energy  used  in  its  workings,  avoid  automatically 
contact  with  obstacles  which  would  impair  its  running,  move 
away  from  regions  too  hot  or  too  cold  for  its  efficient  opera- 
tion, protect  itself  by  producing  coverings  in  unfavorable 
situations,  and  guide  itself  into  the  most  favorable  regions 
for  its  maintenance ;  but  Avhat  a  wonderfully  complicated 
mechanism  it  would  have  to  be!  Yet  a  simple,  apparently 
almost  structureless  mass  of  jelly  does  all  this  and  more. 
And  if  our  mechanism  had  the  property  of  repairing  its  own 
injuries  and  producing  other  pieces  of  mechanism  like  itself, 
its  structural  arrangements  would  be  almost  if  not  quite 
beyond  our  power  to  conceive.  One  cannot,  therefore,  but 
look  with  a  feeling  of  admiration  and  wonder  at  so  com- 
paratively simple  a  creature  as  Amoeba,  which  is  capable 
of  performing  so  much.  .  .  . 

"The  behavior  of  Amoeba  is  essentially  like  that  of  higher 
animals :  it  avoids  things  which  are  injurious ;  it  seeks  things 
Avhich  are  beneficial  and  it  adapts  its  behavior  to  new  condi- 
tions. Life  is  very  much  the  same  sort  of  thing  whether  in 
an  Amceba  or  a  man."  ^ 

One  must  not  however  be  too  sure  as  to  the  simplicity  of 
an  Am(pba.  While  to  the  eye  of  the  microseopist  it  ajijieai-s 
as  an  "almost  structureless  mass  of  jelly,"  nevertheless  the 
complexity  of  the  molecules  composing  this  jelly  is  such  as 
to  defy  analysis  by  the  most  skillful  chemist.  And  even  were 
it  possible  to  obtain  an  exact  analysis  of  the  Amoeba  molecules, 
the  number  of  atoms  composing  the  latter  is  so  great  as 
to  render  possible  several  million  combinations  of  these 
atoms,  each  in  a  different  way  and  each  possibly  resi)0]i- 
sible  for  every  ncAV  response  which  it  makes  to  its  sur- 
roundings. 

While  the  behavior  of  Amoeba  is  generally  such  as  to  benefit, 
rather  than  harm  it,  this  is  not  invariably  true  of  all  organ- 

Mlolinos,  "The  Evolulion  of  Aiiinial  Intelligence,"  pp.  70-71.  By 
permission  of  Henry  Holt  and  Company. 


The  Living  Machine  305 

isms.  Thus  a  one  por  cent  solution  of  morphine  attracts 
certain  bacteria  even  though  it  is  fatal  to  them.  This  is  an 
unusual  condition  however  as  morphine  is  a  substance  not 
encountered  in  nature  by  bacteria.  A  similar  behavior  is 
to  be  found,  as  we  shall  see  later,  in  higher  animals.  Nature 
sometimes  plays  the  role  of  the  enchantress  C'ii'ce  witii  the 
humblest,  as  well  as  the  proudest  of  her  creatures. 

A  step  hig:her  on  the  stage  of  life  we  come  to  Paramoecium, 
whose  acquaintance  we  have  already  been  privileged  to  make. 
Here  we  have  an  animal  with  definite  organs  of  locomotion 
(cilia)  arranged  in  definite  (spiral)  lines  upon  the  body;  "an 
oral  groove  or  food  trough,  leading  to  a  gullet  or  primitive 
digestive  tract,  a  definite  anal  spot  for  the  discharge  of 
undigested  materials,  specialized  organs  (contractile  vacuoles) 
for  excretion,  and  specialized  nuclei  which  play  a  complicated 
role  in  the  processes  of  metabolism  and  reproduction.  Para- 
mceeium  swims  in  a  spiral  path,  directed  by  the  spirally  ar- 
ranged cilia,  and  oblique  oral  groove.  Its  active  movement 
and  peculiar  form  have  caused  many  an  unhappy  hour  to 
the  tyro  in  biology.  If  one  place  a  drop  of  weak  acid  in  the 
dish  of  water  in  which  Paramcpcia  are  restlessly  zig-zagging 
to  and  fro,  they  will  be  found  after  a  time  to  have  gathered 
in  the  drop ;  while  vice  versa  a  grain  of  salt  will  soon  be  sur- 
rounded by  a  zone  of  water  free  from  Paramoecia  save  for  the 
dead  bodies  of  a  few,  which  have  ventured  too  near  the  fatal 
spot  and  failed  to  extricate  themselves  therefrom,  ere  death 
o'ertook  them. 

How  are  these  results  accomplished?  Are  Paramcecia  at- 
tracted by,  and  do  they  swim  into  the  drop  of  acid  because 
they  ''like"  it?  And,  similarly,  do  they  avoid  the  salt  be- 
cause they  "know  it  is  bad  for  them"?  Let  us  follow  their 
maneuvers  a  little  more  closely.  If  a  Paramoecium  in  swim- 
ming at  random  through  the  water,  happens  to  approach  a 
drop  of  acid  it  is  not  repelled  by  it,  and  hence  goes  into  the 
drop  if  its  direction  of  movement  happens  to  take  it  there; 
once  inside  the  drop  however  should  it  ''attempt"  to  escape 
it  cannot  do  so,  for  when  it  approaches  the  water  outside  the 
drop  it  is  seemingly  repelled  by  the  latter,  for  it  backs  up, 
turns  on  its  tail  and  swims  away.  Thus  it  can  enter  the 
drop  but  cannot  leave  it,  and  in  a  short  time  a  large  number 
of  Paramoecia  may  be  trapped  in  this  manner.  This  behavior 
of  Paramoecium  has  been  likened  by  Jennings  who  described  it, 
to  a  sort  of  "trial  and  error"  behavior,  similar  to  that  of 
the  dog  who  learns  to  open  a  gate  by  putting  his  paw  on  the 
latch,  as  a  result  of  numberless  fruitless  pawings,  in  an  at- 
tempt to  escape  from  the  yard  in  which  he  is  penned  up. 
Loeb  however  sees  in  this  behavior  something  yet  more  simple 


306  Biology  in  America 

than  doos  Jciiiiiiifrs;,  ascribing  tlio  backing  and  tnrning 
movement  of  tlie  animal  on  its  approach  to  au  unfavorable 
environment,  to  a  reversal  of  the  ciliary  movement  on  the  side 
stimulated,  and  to  the  asymmetrical  shape  of  the  body.  The 
controversial  pliase  of  the  snl)ject  is  one  which  does  not 
interest  tlie  general  reader;  the  important  point  is  that  a 
primitive  animal  like  Paramoecinm,  lacking  any  specialized 
sense  organs  or  nervous  system,  is  nevertheless  as  sensitive  to 
stimuli  as  the  higlier  organism,  with  its  indescribably  complex 
organs  of  sense,  and  intricate  maze  of  nervous  paths. 

Many  of  the  unicellular  organisms,  both  plant  and  animal, 
are  exceedingly  sensitive  to  light.  This  is  especially  well 
shown  by  the  ciliate  Stentor.  This  is  a  gourd-shaped  cell, 
completely  covered  with  cilia,  except  at  the  basal  end  or 
"foot"  by  means  of  which  the  animal  occasionally  attaches 
itself.  At  one  end  is  a  flattened  or  hollow  disk  surrounded 
by  a  band  of  strong  cilia  which  guide  the  food  to  a  depression 
in  the  tlisk,  the  mouth.  Close  to  the  outer  surface  of  the 
animal  are  a  number  of  delicate  contractile  fibrils  which  func- 
tion as  muscles,  in  which  respect  Stentor  shows  a  marked 
advance  in  structure  over  Paramnecium.  If  the  water  in  which 
this  ciliate  is  swimming  be  suddenly  illuminated,  the  animal 
reverses  its  movements,  turns  always  in  the  same  direction 
(in  respect  to  the  sides  of  the  body)  and  then  goes  ahead  once 
more.  This  reaction  may  be  repeated  a  number  of  times,  with 
the  final  result  that  the  animal,  through  a  series  of  ' '  trials  and 
errors"  is  finally  brought  into  a  region  of  less  light. 

Many  of  the  unicellular  plants  and  animals  are  provided 
with  little  spots  of  red  pigment  which  are  sensitive  to  light. 
In  these  forms,  which  belong  to  the  group  of  flagellates,  or 
forms  bearing  one  or  more  long,  whip-like  cilia,  and  many  of 
which  are  on  the  problematical  fence  between  plants  and 
animals,  light  reactions  are  well  marked.  The  reactions  may 
be  either  positive  or  negative,  vigorous  or  weak,  and  may  vary 
with  the  physiological  state  or  condition  of  the  organism  at 
different  times;  but  all  serve  to  bring  it  into  that  strength 
of  light  which  the  organism  "likes"  best,  i.  e.,  to  which  it 
is  best  adapted. 

We  are  accustomed  to  think  of  unicellular  organisms  as 
expressing  life  in  its  simplest  terras,  but  we  have  seen  never- 
theless that  many  of  them  are  indeed  very  complex  creatures, 
possessing  organs  of  locomotion,  digestion,  excretion,  contrac- 
tion and  even  in  some  cases  of  special  sense  ("eye  spots"). 
Kecently  Kofoid  and  his  students  working  at  the  University 
of  California  have  discovered  structures  in  certain  Protozoa 
which  they  believe  represent  a  primitive  nervous  system. 
These  are  delicate  fibrils  which  can  be  clearly  brought  out 


The  Living  Machine 


307 


by  appropriate  staining,  and  are  connected  on  the  one  hand 
with  the  tiagella  or  cilia  and  on  the  other  with  certain  deeply 
staining  granules  in  the  body  of  the  animal.  To  operate  on 
creatures  less  than  1/150  inch  in  length  is  a  surgical 
"stunt"  of  no  small  difficulty.  Yet  this  has  been  done  and 
these  delicate  fibrils  cut,  with  the  resultant  cessation  of  move- 
ment of  the  connected  fiagella.  It  is  clear  then  that  these 
fibrils  represent  a  primitive  nerve-muscle  structure  such  as 
occurs  in  more  diff'erentiated  form  in  some  of  the  simpler  of 
the  many-celled  animals. 

The  ability   of  higher  plants  to  respond  to  stimuli  is  a 


Compass  Plants  as  Seen  from  Different  Positions 
From  Kerner   (translation  by  Oliver),  "Natural  History  of  Plants," 
Henry  Holt  and  Company. 

Print  furnished    hii  Vnunnl   I. (intern  Slide  Couipmnj ,   Chicago. 

matter  of  common  knowledge.  We  place  a  i)lant  in  our  win- 
dow and  soon  leaves  and  stems  are  bending  toward  the  light. 
The  compass  plant  is  a  devoted  worshipper  of  the  sun.  In 
the  dawn  it  turns  its  opening  flowers  eastward  to  greet  the 
rising  sun,  while  at  eventide  they  face  the  west  attendant 
on  its  setting.  The  mold  Piloljolus  grows  upon  horse 
manure.  When  its  spores  ripen  they  are  thrown  by  the  plant 
with  considerable  force,  surrounded  by  the  spore  cases,  in 
the  direction  of  the  light.  Jf  a  little  fresh  horse  manure  be 
placed  in  a  box  with  a  small  window,  the  filaments  of  the 
mold  turn  toward  the  window,  and  as  the  spores  ripen 
they  are  thrown  in  their  cases  against  the  window  to  which 
they  adhere.     A  tree  is  felled  by  a  land-slide  or  a  tornado 


308 


Biology  in  America 


and  some  of  its  roots  are  left  embedded  in  the  ground.  Soon 
the  young  flexible  branches  turn  and  grow  upward  opposite 
to  the  direction  of  gravity.  Roots,  on  the  contrary,  when 
placed  in  a  horizontal  position,  or  inverted  so  as  to  point 
upward,  will  soon  respond  to  the  pull  of  gravity  and  grow 
downward.  A  seedling  is  suspended  with  its  rootlets  im- 
mersed in  a  stream  of  water,  and  soon  they  bend  and  grow 
against  the  current  of  the  stream.  Touch  the  leaves  of  the 
Mimosa  or  sensitive  plant  and  almost  immediately  the  paired 


MiNOSA  OK  Sensitive  Plant 
From  Kerncr   (translation  l)y  Oliver),  "Natural  History  of  Plants,' 
Henry  Holt  and  Company. 


lobes  of  the  leaflets  fold  together  and  the  leaf  itself  droops 
slightly,  soon  however  resuming  their  original  position  if  un- 
disturbed. 

The  flowers  of  some  plants  serve  as  insect  traps.  In  the 
sun  dew  (Drosera)  the  leaves  are  covered  with  numerous  little 
hairs  or  tentacles,  which  secrete  a  sticky  fluid,  v;hich  glistens 
in  the  sun  like  drops  of  dew,  whence  the  plant  derives  its 
common  name  of  "sun  dew."  Certain  glands  in  the  leaf 
secrete  a  digestive  enzyme  similar  to  the  pepsin  of  an  animal's 
stomach.     If  a  drop  of  rain,  or  a  grain  of  dust  blown  by 


The  Living  Machine 


309 


the  wind,  fall  on  the  leaf,  there  is  no  movement  of  the  ten- 
tacles or  secretion  of  digestive  fluid,  but  should  an  unlucky- 
insect  alight  on  a  sun  dew  leaf  attracted  by  the  honey-like 
drops  upon  the  tentacles,  they  bend  over  and  figuratively 
speaking  seize  upon  the  intruder,  while  the  edges  of  the  leaf 
fold  together,  thus  wrapping  the  leaf  about  its  body.  The 
digestive  glands  complete  the  tragedy  and  what  was  once  an 
insect  now  becomes  incorporated  in  a  leaf.  Here  we  find  a 
relatively  complex  series  of  reactions  co-ordinated,  or  working 
in  harmony,  in  an  organism  lacking  any  special  nervous  or 
co-ordinating  system  altogether. 


:.-->diL: 

-  -3 

^^^^^^^^^ 

•       F  1 

if 

i!5!^^^^^^" 

Sun  Dew  Leaf 
Showing    sticky    hairs    and    entrapped    insect.      From    Needham    and 
Lloyd,  "The  Life  of  inland  Waters,"   Comstock  Publishing   Company. 


Can  these  responses  of  the  unicellular  animals  and  plants  be 
explained  on  a  physico-chemical  basis?  This  the  leader  of 
the  mechanist  school  in  America,  Jacques  Loeb,  endeavors 
to  do  with  his  "forced  movement"  or  "tropism  theory'." 
According  to  this  theory  every  organism  is  in  a  state  of 
physiological  equilibrium  or  balance  with  respect  to  a  median 
plane  of  symmetry,  until  it  is  subjected  on  one  side  or  the 
other  to  a  stimulus,  such  as  heat,  light,  electricity,  etc. ; 
which  stimulus  induces  certain  physico-chemical  changes, 
differing  in  degree  on  either  side  of  the  body,  this  difference 
forcing  the  organism  to  respond  unequally  on  the  two  sides, 
and  then  perform  a  "forced  movement"  or  a  "tropism" 
(turning).     While  a  great  many  of  the  one-celled  organisms 


310 


Biology  in  America 


are  not  strictly  symmetrical  they  may  be  assumed  to  be  so 
for  the  purposes  of  the  theory.  Thus  if  a  Paramoecium  be 
acted  upon  by  an  electric  current  whose  direction  is  oblique 
to  the  long  axis  of  its  body,  the  cilia  on  the  side  toward  the 
negative  pole  beat  more  vigorously  than  do  those  on  the 
positive  side,  and  in  the  opposite  direction,  causing  the  animal 
to  turn  until  it  is  in  line  with  the  current  when  it  swims 
ahead,  toward  the  negative  pole.  The  stem  of  a  plant  turns 
toward  the  light,  or  bends  upward,  because  of  a  difference 
in  amount  of  chemical  substances  on  the  two  sides,  and  ''this 
causes  a  difference  in  the  velocity  of  chemical  reactions  be- 
tween (the  two  sides)."  The  organism  has  no  control  over 
its  behavior  but  is  so  to  speak  blown  about  "by  every  wind 
that  blows"  as  helplessly  as  a  derelict  ship  upon  the  sea. 


Sagging  in  a  Stem 
Due  to  unequal  growth  on  the  two  sides.     From  Loeb,  "Forced  Move- 
ments, Tropisnis  and  Animal  Conduct." 

By  permission  oj  J.  B.  Lippincott  Company. 

But  what  proof  have  we  that  such  chemical  changes  as  Loeb 
asvsumes  do  occur  in  the  organism?  If  we  suspend  a  stem 
of  a  plant  in  a  horizontal  position,  it  soon  bends  downward, 
taking  the  form  of  a  U.  This  bending  is  not  due  to  sagging 
of  the  stem  as  a  rope  sags,  but  rather  to  unequal  growth  of 
the  two  sides,  which  can  be  proven  by  marking  equal  dis- 
tances on  upper  and  lower  sides  by  lines  of  India  ink  and 
later  measuring  the  amount  of  growth  occurring  between 
the  marks.  If  the  amount  of  bending  in  such  a  stem  with 
leaves  attached  be  compared  with  that  in  a  stem  lacking 
leaves,  it  will  be  found  to  be  much  greater  in  the  former 
due  to  the  greater  amount  of  growth  material  available,  and 
similarly  there  is  greater  bending  in  a  stem  furnished  with  a 


The  Living  Machine 


311 


complete  leaf  than  in  one  with  a  leaf  which  has  been  partly 
cut  awa3^  "What  has  been  demonstrated  in  this  case  explains 
probably  also  why  the  apex  of  many  plants  when  put  into 
a  horizontal  position  grows  upward,  and  why  certain  roots 
under  similar  conditions  grow  downward.  It  disposes  also 
in  all  probability  of  the  suggestion  that  the  apex  of  a  posi- 
tively geotropic  root  has  'brain  functions.'  It  is  chemical 
mass  action  and  not  'brain  functions'  which  are  needed  to 
produce  the  changes  in  growth  underlying  geotropic  curva- 
ture. "^ 

Such  an  explanation  however  is  difficult  to  apply  to  many 


Eelative  Amount  of  Bending 
Due  to  unequal  growth  in  stems  with  and  those  without  leaves. 
Loeb,  "Forced  Movements,  Tropisms  and  Animal  Conduct." 
By  permission  of  J.  B.  Mppincott  Company. 


From 


of  the  reactions  of  a  Stentor  or  a  Paramoecium.  AVhile  the 
latter  animal  reacts  to  an  electric  current  by  a  cjifference  in 
the  beat  of  the  cilia  on  the  two  sides,  and  the  animal  is  thus 
turned  so  as  to  swim  with  the  current,  by  a  process  seem- 
ingly as  mechanical  as  that  of  turning  a  boat;  in  other 
cases,  as  when  running  into  a  salt  solution,  the  behavior  of 
Paramoecium  is  not  so  simply  explained,  for  in  this  circum- 
stance it  always  turns  in  the  same  direction,  regardless  of 
the  angle  at  which  it  meets  the  salt  current,  and  even  though 

*  Loeb,    "Forced    Movements,    Tropisms    and    Animal    Conduct,"    i)p. 
121-2.     By  permission  of  J.  B.  Lippincott  Company. 


312  Biology  in  America 

this  turning  may  bring  it  towards,  rather  than  away  from 
tlie  unfavorable  medium.  Its  behavior  in  this  case  is  fixed  in 
character,  and  not  so  clearly  mechanical  as  in  the  former 
case. 

A  remarkable  imitation  of  a  living  creature  responsive  to 
light  stimuli  has  been  invented  by  the  American  engineer 
John  Hays  Hammond,  Jr.  It  "consists  of  a  rectangular  box 
about  3  feet  long,  li/o  feet  wide  and  1  foot  high  mounted  on 
three  wheels,  two  of  which  are  geared  to  a  driving  motor, 
while  the  third  and  rear  wheel  can  be  turned  by  electro- 
magnets and  thus  serve  for  guiding  the  machine.  Two  5-inch 
condensing  lenses  on  the  forward  end  appear  very  much  like 
large  eyes. ' '  The  operation  of  the  machine  is  affected  through 
the  action  of  light  on  two  selenium  cells  controlling  electro- 
magnetic switches.  "When  one  cell  or  both  are  illuminated 
the  current  is  switched  on  to  the  driving  motor ;  when  one  cell 
alone  is  illuminated  an  electro-magnet  is  energized  and  aifects 
the  turning  of  the  rear  steering  wheel  .  .  .  thus  bringing  the 
shaded  cell  into  the  light.  As  soon  and  as  long  as  both  cells 
are  equally  illuminated  in  sufficient  intensity,  the  machine 
moves  in  a  straiglit  line  toward  the  light  source.  By  throw- 
ing a  switch  which  reverses  the  driving  motors,  the  machine 
can  be  made  to  back  away  from  the  light  in  a  most  surpris- 
ing manner. 

"Upon  shading  or  switching  off  the  light  the  'dog'  can  be 
stopped  immediately,  but  it  will  resume  its  course  behind  the 
moving  light  so  long  as  the  light  reaches  the  condensing 
lenses  in  sufficient  intensity.  Indeed,  it  is  more  faithful  in 
this  respect  than  the  proverbial  ass  behind  the  bucket  of 
oats.  To  the  uninitiated  the  performance  of  the  pseudo  dog 
is  very  uncainiy  indeed."* 

But  what  is  the  case  with  those  animals  with  a  nervous  sys- 
tem by  means  of  which  their  complex  functions  are  made  to 
work  in  orderly  fashion?  It  would  take  us  too  far  afi<'ld  to 
attempt  to  trace,  as  Professor  Parker  has  recently  done  in  his 
admirable  little  book  on  the  "Elementary  Nervous  System," 
the  relation  between  the  specialization  of  the  latter,  and  the 
(delicacy)  of  their  nervous  responses.  Suffice  it  to  say  that 
even  in  animals  with  a  highly  developed  nervous  system  such 
as  insects  the  responses  in  many  cases  at  least  appear  to  be 
purely  mechanical.  The  attraction  of  the  candle  flame  for 
the  moth  is  proverbial,  and  even  so  highly  organized  an  animal 
as  a  bird  fre(|uently  appears  to  be  as  much  a  creature  of  cir- 
cumstance as  the  moth,  for  birds  often  beat  themselves  to 
death  in  great  numbers  against  light-houses.  The  purely 
mechanical  response  of  an  animal  to  stimuli  is  beautifully 

^Mit'ssner,  "Electrical  Experimenter,"  Sept.,  1915,  p.  202. 


The  Living  Machine  313 

illustrated  by  the  behavior  of  the  caterpillar  of  the  butterfly 
(Porthesia  chrysorrhcea).  "This  butterfly  lays  its  eggs  upon 
a  shrub,  on  which  the  larvae  hatch  in  the  fall  and  on  which 
they  hibernate,  as  a  rule,  not  far  from  the  ground.  As  soon 
as  the  temperature  reaches  a  certain  height,  they  leave  the 
nest;  under  natural  conditions  this  happens  in  the  spring 
when  the  first  leaves  have  begun  to  form  on  the  shrub.  (The 
larvaB  can  however  be  induced  to  leave  the  nest  at  any  time 
in  the  winter  provided  the  temperature  is  raised  sufficiently.) 
After  leaving  the  nest,  they  crawl  directly  upward  on  the 
shrub  where  they  And  the  leaves  on  which  they  feed.  If 
the  caterpillars  should  move  down  the  shrub  they  would 
starve,  but  this  they  never  do,  always  crawling  upward  to 
where  they  find  their  food.  What  gives  the  caterpillar  this 
never-failing  certainty  which  saves  its  life  and  for  which  the 
human  being  might  envy  the  little  larva?  Is  it  a  dim  recol- 
lection of  experience  of  former  generations,  as  Samuel  Butler 
would  have  us  believe?  It  can  be  shown  that  this  instinct 
is  merely  positive  heliotropism  and  that  the  light  reflected 
from  the  sky  guides  the  animals  upward.  The  caterpillars 
upon  waking  from  their  winter  sleep  are  violently  positively 
heliotropic,  and  it  is  this  heliotropism  which  makes  the  ani- 
mals move  upward.  At  the  top  of  the  branch  they  come  in 
contact  with  a  growing  bud  and  chemical  and  tactile  influ- 
ences set  the  mandibles  of  the  young  caterpillar  into  activ- 
ity. If  we  put  these  caterpillars  into  closed  test  tubes  which 
lie  with  their  longitudinal  axes  at  right  angles  to  the  window 
they  will  all  migrate  to  the  window  end  where  they  will  stay 
and  starve,  even  if  we  put  their  favorite  leaves  into  the  test 
tube  close  behind  them.  These  larva?  are  in  this  condition 
slaves  of  the  light. 

* '  The  few  young  leaves  on  top  of  a  twig  are  quickly  eaten  by 
the  caterpillar.  The  light  which  saved  its  life  by  making  it 
creep  upward  where  it  finds  its  food  would  cause  it  to  starve 
could  the  animal  not  free  itself  from  the  bondage  of  positive 
heliotropism.  After  having  eaten  it  is  no  longer  a  slave  of 
light  but  can  and  does  creep  downward.  It  can  be  shown 
that  a  caterpillar  after  having  been  fed  loses  its  positive 
heliotropism  almost  completely  and  permanently.  If  we  sub- 
mit unfed  and  fed  caterpillars  of  the  same  nest  to  the  same 
artificial  or  natural  source  of  light  in  two  different  test  tubes 
the  unfed  will  creep  to  the  light  and  stay  there  until  tliey 
die,  while  those  that  have  eaten  will  pay  little  or  no  attention 
to  the  light.  Their  positive  heliotropism  has  disappeared 
and  the  animal  after  having  eaten  can  creep  in  any  direction. 
The  restlessness  which  accompanies  the  condition  of  starva- 
tion makes  the  animal  leave  the  top  of  the  branches  and  creep 


314  Biology  in  America 

downward — which  is  the  only  direction  open  to  it — where  it 
finds  new  young  leaves  on  which  it  can  feed.  The  wonderful 
hereditary  instinct  upon  wliicli  tlie  life  of  the  animal  depends 
is  its  positive  heliotropism  in  the  unfed  condition  and  the 
loss  of  this  heliotropism  after  having  eaten.  The  chemical 
changes  following  the  taking  up  of  the  food  abolish  the 
heliotropism  just  as  CO,  arouses  positive  heliotropism  in 
certain  Daphnia,"  ° 

Such  an  instinct  as  that  of  this  caterpillar  is  however  a 
relatively  simple  one.  Can  those  wonderfully  complex  in- 
stincts of  so  many  animals  which  are  connected  with  the  pro- 
duction and  care  of  the  young  be  likewise  relegated  to  the 
realm  of  the  purely  mechanical?  To  bring  the  reactions  of 
so  complex  an  organism  as  a  vertebrate  animal  with  its  highly 
developed  brain,  nerves  and  sense  organs  into  line  with  those 
of  a  unicellular  form  or  a  non-nervous  plant  in  the  present 
state  of  our  knowledge  is  a  matter  of  great  difficulty.  It  can 
be  shown  with  a  reasonable  degree  of  probability  however  that 
even  here  what  we  call  "instinct"  may  be  purely  a  response 
to  physical  or  chemical  stimuli,  modified  by  certain  substances 
secreted  by  the  body  and  known  as  "hormones"  from  the 
Greek  verb  hormao  to  excite. 

The  role  of  tliese  substances  and  the  bearing  which  they 
have  on  the  "mechanistic  conception  of  life"  we  shall  dis- 
cuss later,  merely  bearing  in  mind  their  existence  at  this 
point,  in  order  to  appreciate  what  follows.  ^ 

In  many  fish,  as  for  example  the  minnow  Fundulus,  the 
act  of  mating  consists  in  the  sexes  pressing  their  bodies  close 
together  in  such  a  way  that  as  the  eggs  are  laid  by  the  fe- 
male the  sperms  are  pressed  out  by  the  male  and  are  thus 
mixed  with,  and  fertilize  the  eggs  in  the  water.  That  this 
behavior  on  the  part  of  the  female  at  least  is  similar  to  a 
response  to  a  solid  object  is  shown  by  keeping  the  sexes  sepa- 
rate at  the  spawning  season,  in  which  case  the  female  will 
mate  with  the  glass  wall  of  the  aquarium,  when  she  happens 
to  come  in  contact  with  it.  This  reaction  is  usually  devel- 
oped only  in  the  spawning  season  through  the  influence  of 
the  hormones  secreted  at  that  time,  but  if  the  female  is  kept 
permanently  isolated  from  the  male  she  may  perform  this  act 
at  any  time  of  year. 

Loeb  quotes  the  late  Professor  Whitman  to  the  effect  that 
male  pigeons  isolated  from  the  females  will  attempt  to  mate 
with  any  solid  object  in  their  field  of  vision,  e.g.,  glass  bot- 
tles, and  even  with  objects  which  give  only  the  optical  im- 
pression of  a  solid,  namely  their  own  shadow  on  the  ground. 
And  Craig  has  shown  that  male  pigeons  under  these  eircum- 

"  Loeb,  locus  citatus,  pp.   161-2. 


The  Living  Machine  315 

stances  will  respond  to  a  human  hand.  ."  'The  dove  was  kept 
in  a  room  where  several  men  were  at  work,  and  he  directed 
his  display  behavior  toward  these  men  just  as  if  they  be- 
longed to  his  own  species.  Each  time  I  put  food  in  his  cage 
he  became  greatly  excited,  charging  up  and  down  the  cage, 
bowing  and  cooing  to  me,  and  pecking  my  hand  whenever  it 
came  within  his  cage.  From  that  day  until  the  day  of  his 
death,  Jack  continued  to  react  in  this  social  manner  to  hu- 
man beings.  He  would  bow-and-coo  to  me  at  a  distance,  or 
to  my  face  when  near  the  cage ;  but  he  paid  greatest  atten- 
tion to  the  hand — naturally  so,  because  it  was  the  only  part 
with  which  he  daily  came  into  direct  contact.  He  treated 
the  hand  much  as  if  it  were  a  living  bird.  Not  only  were 
his  own  activities  directed  toward  the  hand  as  if  it  were  a 
bird,  but  he  received  treatment  by  the  hand  in  the  same 
spirit.  The  hand  could  stroke  him,  preen  his  neck,  even  pull 
the  feathers  sharply.  Jack  had  absolutely  no  fear,  but  ran 
to  the  hand  to  be  stroked  or  teased,  showing  the  joy  that  all 
doves  show  in  the  attentions  of  their  companions.'  When 
this  pigeon  was  almost  a  year  old  it  was  put  into  a  cage  with 
a  female  pigeon,  but  although  the  female  aroused  the  sexual 
instinct  of  the  formerly  isolated  male  the  latter  did  not  mate 
with  her,  but  mated  with  the  hand  of  his  attendant  when  the 
hand  was  put  into  the  cage,  and  this  continued  throughout 
the  season.  Thus  the  memory  images  acquired  by  the  bird 
at  an  impressionable  age  and  period  perverted  its  sexual 
tropisms. ' '  '^ 

Light  response  is  a  common  phenomenon  among  the  fresh 
water  crustaceans.  During  broad  daylight  the  upper  levels 
of  a  lake  may  be  almost  uninhabited  by  these  little  animals, 
while  at  greater  depths  they  occur  in  large  numbers.  As 
night  comes  on  they  return  to  the  upper  regions  which  they 
have  deserted  by  day.  Loeb  has  shown  that  the  behavior  of 
some  of  these  animals  with  respect  to  light  can  be  totally 
changed  by  chemical  treatment.  Thus  the  fresh  water  Daph- 
nia,  Gammarus  and  other  Crustacea  when  in  a  condition  in 
which  they  do  not  respond  to  light  can  be  made  intensely 
positively  heliotropic  by  adding  some  acid  to  the  fresh  water, 
especially  weak  CO,.  If  carbonated  water  or  beer  be  added 
to  water  containing  some  of  these  animals  they  "will  collect 
in  a  dense  cluster  on  the  window  side  of  the  dish."  Other 
chemicals  including  alcohol  give  the  same  results.  The  light- 
minded  reader  may  be  inclined  to  draw  an  analogy  between 
this  behavior  and  the  tendency  of  some  individuals  to  enter 
into  close  communion  with  a  lamp  post  in  the  "wee  sma' 
hours."     The  alkaloids  caffein  and  strychnin  on  the  other 

'  Quoted  from  Loeb,  locus  citatus,  pp.  168-9. 


316  Biology  in  America 

hand  will  Tiiak(>  the  "fresh  water  Crustacean  Diaptomus  in- 
tensely nefjatively  heliotropie."  Changes  of  temperature  and 
osmotic  pressure  may  bring  about  similar  results. 

The  social  life  of  the  wasps,  bees  and  ants  has  long  been  a 
subject  for  wonder  and  admiration.  In  the  busy  ant  hive 
is  a  nest  full  of  conundrums  for  the  student  of  animal  be- 
havior, the  half  of  which  have  as  yet  scarcely  been  stated. 
The  life  of  these  social  insects  is  seemingly  so  complex  that 
we  are  accustomed  to  think  of  it  in  terms  of  human  life  and 
so  we  have  ''castes"  of  "drones"  '  and  "queens"  and  "work- 
ers." Some  of  these  latter  are  "soldiers,"  among  whom  we 
find  "scouts"  and  "officers,"  others  are  "nurees,"  still  oth- 
ers are  "harvesters"  whose  duty  it  is  to  fill  the  "granaries," 
while  yet  others  are  "slave-makers,"  whose  duty  it  is  to  go 
out  and  capture  "slaves."  Some  ants  play  the  part  of 
"thieves"  in  other  ants'  nests.  Yet  others  act  as  "hosts" 
entertaining  other  species  of  ants  as  "guests,"  while  some 
keep  aphids  which  they  milk  as  "cows."  Some  give  to  other 
ants  a  "shampoo,"  in  return  for  which  the  "delighted"  ant 
yields  a  drop  of  honey,  which  the  shampooer  licks  up  greed- 
ily. Ants  are  "brave"  and  fight  with  "ferocity,"  while  all 
are  "industrious"  and  endowed  with  "wisdom,"  Mark  Twain 
to  the  contrary  notwithstanding. 

Can  such  ' '  human ' '  behavior  be  removed  from  the  realm  of 
poetrj^  and  relegated  to  the  prosaic  one  of  purely  mechanical 
reflex  ? 

One  of  the  most  remarkable  periods  in  the  life  of  the  ant 
is  the  swarming  time,  w'hen  the  winged  males  and  "queens" 
perform  their  "nuptial"  flight,  rushing  forth  in  "ecstasy" 
from  their  nest  to  found  new  colonies.  After  this  flight  the 
males  die,  the  females  pull  off  their  wings  and  crawling  into 
the  ground  either  alone  or  accompanied  by  a  group  of  work- 
ers, settle  down  to  the  humdrum  duty  of  egg  laying.  Is  such 
behavior  a  response  to  a  purely  physical  or  chemical  stimu- 
lus? According  to  Loeb  this  "wedding  flight"  is  a  "helio- 
tropie phenomenon  presumably  due  to  substances  produced 
in  the  body  during  this  period,  .  .  .  (for)  at  a  certain  time 
— in  the  writer's  observation  toward  sunset,  when  the  sky  is 
illuminated  at  the  horizon  only — the  whole  swarm  of  males 
and  females  leave  the  nest  and  fly  in  the  direction  of  the 
glow"*  After  removing  her  wings  the  female  loses  her 
heliotropism  and  becomes  strongly  stereotropic,  responding 
to  touch  stimuli,  for  if  placed  in  a  dark  box  containing  folds 
of  cloth,  she  is  found  snugly  tucked  aw^ay  among  the  folds. 

'  This  term  belongs  of  course  properly  to  insects,  and  is  applied  sec- 
ondarilj'  to  man. 

'  Loeb,  locus  citatus,  p.  158. 


The  Living  Machine  317 

It  is  this  stereotropism  which  causes  her  to  seok  a  hidinj? 
place  ill  the  earth  wherein  to  lay  her  eggs.  This  explanation 
would  be  very  simple  and  satisfying  did  we  know  what  it  is 
which  makes  the  ant  at  one  moment  responsive  to  light  and 
at  another  to  touch.  "Presumably"  Locb's  explanation  is  cor- 
rect, but  so  long  as  it  is  founded  on  presumption  only,  it  can 
hardly  be  said  to  be  strictly  scientific. 

Professor  Vernon  Kellogg  has  however  made  some  observa- 
tions on  the  swarming  of  bees  which  prove  pretty  conclu- 
sively that  this  behavior  is  due  to  positive  heliotropism  in 
this  insect.  Professor  Kellogg 's  bees  were  kept  in  a  cloth 
jacketed  hive,  with  a  small  opening  at  the  bottom.  He  says, 
"Last  spring  at  the  normal  swarming  time,  while  standing 
near  the  jacketed  hive,  I  heard  the  excited  hum  of  a  begin- 
ning swarm  and  noted  the  first  issuers  rushing  pellinell  from 
the  entrance.  Interested  to  see  the  behavior  of  the  com- 
munity in  the  hive  during  such  an  ecstatic  condition  as  that 
of  swarming,  I  lifted  the  cloth  jacket,  when  the  excited  mass 
of  bees  which  was  pushing  frantically  down  to  the  small  exit 
in  the  lower  corner  of  the  hive  turned  with  one  accord  about 
face  and  rushed  directly  upward  away  from  the  opening 
toward  and  to  the  top  of  the  hive.  Here  the  bees  jammed, 
struggling  violently.  I  slipped  the  jacket  partly  on ;  the  ones 
covered  turned  down ;  the  ones  below  stood  undecided ;  I 
dropped  the  jacket  completely ;  the  mass  began  issuing  from 
the  exit  again ;  I  pulled  off  the  jacket,  and  again  the  whole 
community  of  excited  bees  flowed — that  is  the  word  for  it, 
so  perfectly  aligned  and  so  evenly  moving  were  all  the  indi- 
viduals of  the  bee  current — up  to  the  closed  top  of  the  hive. 
Leaving  the  jacket  off  permanently,  I  prevented  the  issuing 
of  the  swarm  until  the  ecstasy  was  passed  and  the  usual 
quietly  busy  life  of  the  hive  was  resumed.  About  three  hours 
later  there  was  a  similar  performance  and  failure  to  issue 
from  the  quickly  unjacketed  hive.  On  the  next  daj^  another 
attempt  to  swarm  was  made,  and  after  nearly  an  hour  of 
struggling  and  moving  up  and  down,  depending  on  my 
manipulation  of  the  black  jacket,  most  of  the  bees  got  out  of 
the  hive's  opening  and  the  swarming  came  off  on  a  weed 
bunch  near  the  laboratory.  That  the  issuance  from  the  hive 
at  swarming  time  depends  upon  a  sudden  extra-development 
of  positive  heliotropism  seems  obvious.  The  ecstasy  comes 
and  the  bees  crowd  for  the  one  spot  of  light  in  the  normal 
hive,  namely,  the  entrance  opening.  But  Avhen  the  covering 
jacket  is  lifted  and  the  light  comes  strongly  in  from  above 
— my  hive  was  under  a  skylight — they  rush  toward  tlie  top, 
that  is,  toward  the  light.  Jacket  on  and  light  shut  off  from 
above,  down  they  rush;  jacket  off  and  light  stronger  from 


318  Biology  in  America 

above  tliaii  })clo\v  and  tlicy  respond  like  iron  filings  in  front 
of  an  eleetromagnet  which  has  its  current  suddenly  turned 
on."« 

Our  knowledge  of  what  occurs  when  an  impulse  is  sent  over 
a  nerve  is  very  vague,  but  we  have  certain  knowledge  that 
physical  and  chemical  changes  take  place  in  nerve  cells  and 
fibers  coincident  with  such  impulses,  so  that  we  are  justified 
in  believing  that  these  impulses  are  physico-chemical  phenom- 
ena.    At    the    University    of    Chicago    a    young    Japanese, 
Tashiro,  a  few  years  ago  designed  a  very  delicate  little  in- 
strument which  he  calls  the  biometer,  or  measurer  of  life. 
By  means  of  this  instrument  he  is  able  to  detect  traces  of 
carbon  dioxide  as  small  as  one  thirty-millionth  of  an  ounce. 
If  a  living  nerve  fiber  be  placed  in  the  biometer  and  stimu- 
lated by  an  electrical  current  it  is  found  to  give  off  carbon 
dioxide  as  the  other  tissues  of  the  body  when  they  are  made 
to  work.     There  is  combustion  of  living  matter  then  when 
an  impulse  travels  along  a  nerve.     In  the  body  of  a  nerve 
cell    are   certain   peculiarly   staining  masses   known    as   the 
Nissl  bodies.     When  a  nerve  cell  is  stimulated  successively 
several   times   these   bodies  disappear.     Some   chemical   sub- 
stance has  been  consumed  in  the  activity  of  the  cell.    Nervous 
activity    develops    electrical    currents    which    can    be    meas- 
ured on  a  galvanometer,  and  with  very  delicate  instruments 
electrical  currents  can  even  be  detected  in  the  resting  nerve. 
The  impulse  is  not  instantaneous  but   requires  measurable 
time   for   its   transmission.      The    intensity   of   the    impulses 
can  be  measured,  as  one  measures  the  intensity  of  sound, 
light,  electrical  energ>^  or  other  physical  energy.     Nerve  ac- 
tion can  be  checked  by  means  of  suitable  chemicals   (anes- 
thetics), while  on  the  other  hand  certain  substances,  such  as 
sodium,   increase   it.     Anesthetics   may   produce   similar   ef- 
fects in  non-nervous  tissues  and  even  in  non-living  matter. 
Thus  Osterhout  has  shown  that  small  quantities  of  anesthet- 
ics in  the  sea  water  decrease  the  electrical  conductivity  of 
seaweed,  and  several  obseryers  have  shown  that  they  check 
the  passage  of  substances  through  cell  membranes.     If  char- 
coal made  from  blood  be  mixed  with  a  solution  of  oxalic  acid 
containing  free  oxygen,  the  acid  is  changed  to  carbon  diox- 
ide   and   water,   the   charcoal    acting   as   a    catalyzer.     This 
catalytic  power  of  the  charcoal  can  be  retarded  by  certain 
substances  (i.e.,  carbon  bisulphide)   which  act  as  anesthetics 
and  which  can  also  check  the  action  of  finely  divided  plat- 
inum in  the  separation   (catalysis)   of  hydrogen  peroxide  to 
w^ater  and  oxygen.     If  therefore  anesthetics  produce  effects 
in  non-nervous  and  even  in  non-living  substances  similar  to 

» Kellogg,  V,  "Some  Insect  Keflexes,"  "Science,"  XVIII,  pp.  693-4. 


The  Living  Machine  319 

those  which  they  produce  in  nerves,  we  have  good  reason  to 
believe  that  their  action  on  the  latter  is  similar  to  that  on 
the  former  or  that  the  prevention  of  nervous  action,  and 
therefore  that  action  itself  is  fundamentally  a  physico-chem- 
ical one. 

But  can  physics  and  chemistry  explain  all  the  complicated 
instincts  of  the  insect,  bird  and  mammal,  or  the  as  yet  un- 
solved riddle  of  human  thought?  Frankly  we  must  admit 
that  at  present  we  do  not  know.  According  to  Loeb  these 
are  merely  ''tropistic  reactions"  modified  by  "memory 
images,"  which  have  an  "orienting  effect"  upon  the  organ- 
ism, and  which  he  attempts  to  explain  by  an  illustration 
from  the  behavior  of  the  solitary  wasp  Ammophila,  which 
digs  a  hole  in  the  ground  in  which  to  lay  its  eggs. 

Ammophila,  a  solitary  wasp,  makes  a  small  hole  in  the 
ground  and  then  goes  out  to  hunt  for  a  caterpillar,  which, 
when  found,  it  paralyzes  by  one  or  several  stings.  The  wasp 
carries  the  caterpillar  back  to  the  nest,  puts  it  into  the  hole, 
and  covers  the  latter  with  sand.  Before  this  is  done,  it  de- 
posits its  eggs  on  the  caterpillar  which  serves  the  young  larva 
as  food. 

"An  Ammophila  had  made  a  hole  in  a  flower  bed  and  left" 
the  flower  bed  flying.  A  little  later  I  saw  an  Ammophila 
running  on  the  sidewalk  of  the  street  in  front  of  the  garden, 
dragging  a  caterpillar  which  it  held  in  its  mouth.  The 
weight  of  the  caterpillar  prevented  the  wasp  from  flying. 
The  garden  was  higher  than  the  sidewalk  and  separated  from 
it  by  a  stone  wall.  The  wasp  repeatedly  made  an  attempt 
to  climb  upon  the  stone  wall,  but  kept  falling  down.  Sus- 
pecting that  it  might  have  a  hole  prepared  in  the  garden, 
I  was  curious  to  see  whether  and  how  it  would  find  the  hole. 
It  followed  the  wall  until  it  reached  the  neighboring  yard, 
which  had  no  wall.  It  now  left  the  street  and  crawled  into 
this  yard,  dragging  the  caterpillar  along.  Then  crawling 
through  the  fence  which  separated  the  two  yards,  it  dropped 
the  caterpillar  near  the  foot  of  a  tree,  and  flew  away.  After 
a  short  zigzag  flight  it  alighted  on  a  flower  bed  in  which  I 
noticed  two  small  holes.  It  soon  left  the  bed  and  flew  back  to 
the  tree,  not  in  a  straight  line  but  in  three  stages,  stopping 
twice  on  its  way.  At  the  third  stop  it  landed  at  the  place 
where  the  caterpillar  lay.  The  catei-pillar  was  then  dragged 
to  the  hole,  pulled  into  it,  and  the  hole  was  covered  with  tiny 
stones  in  the  usual  Avay. ' '  ^° 

Aside  from  the  fact  that  we  have  no  explanation  of  the 
physico-chemical      processes     underlying     these     "memory 
images,"  it  is  difficult  to  apply  the  theory  to  many  of  the 
"Loeb,  locus  citatus,  p.  170. 


320  Biology  in  America 

common  reactions  of  higher  animals.  Can  "memory  images" 
teach  a  bird  liow  to  build  its  nest  for  the  first  time,  or  guide 
the  bees  in  the  eonstruetiou  of  theii*  wonderful  condjs?  Can 
tlieir  "oi-ientiug  effect"  explain  the  return  to  its  nest  of  the 
terns  'whieh  AVatson  carried  from  the  Florida  Keys  to  Cape 
Ilatteras,  a  distance  of  150  miles  from  their  houu\  into  a  re- 
gion never  before  visited  by  the  birds?  Possibly,  although 
it  requires  a  mighty  effort  of  the  imagination  to  unite  cause 
and  effect  in  this  instance.  But  it  is  easy  to  find  flaws  in 
any  theory  Avhieh  boldly  ventures  into  the  comparatively 
uncharted  sea  of  animal  reactions,  and  endeavors  tliere  to 
lay  down  a  course  which  we  may  in  safety  follow ;  so  let  us 
comfort  ourselves  with  believing  that  "free  will"  has  no 
place  in  science,  but  is  merely  an  expression  of  the  "verbal- 
ists," and  tliat  we  simply  "go  where  our  legs  carry  us,"  a 
theory  which  has  at  least  the  advantage  of  enabling  us  to 
smile  complacently,  while  ancient  preachers  hurl  their  an- 
athemas at  the  damned. 

We  have  spoken  above  of  certain  substances  secreted  by 
the  animal  body  and  known  as  hormones,  which  exercise  a 
determining  influence  in  animal  behavior.  What  are  these 
substances,  how  are  they  formed  and  what  role  do  they  play 
in  animal  physiology? 

The  recognition  of  the  value  of  various  organs  in  curing 
disease  goes  back  to  the  days  of  Hippocrates,  the  "father 
of  medicine,"  and  since  his  time  many  such  remedies  have 
been  proposed.  Thus  the  liver  of  the  pigeon  or  the  wolf  were 
used  in  cases  of  disease  of  the  liver,  the  rabbit's  brain  was 
given  for  tremors,  and  the  lung  of  the  fox  for  difficulty  in 
breathing.  The  testicles  of  the  donkey  or  the  stag  were  rec- 
ommended by  Pliny  foi-  the  renovation  of  the  debauchee,  and 
even  today  (castoreum)  a  preparation  obtained  from  the 
prei)utial  glands  of  the  beaver  is  sometimes  employed  for 
colic,  hysteria  and  other  disorders.  In  more  recent  days  the 
French  physiologist  Claude  Bernai'd  advanced  the  view  that 
all  tissues  give  some  secretion  to  the  blood,  which  is  of  use 
in  the  nutrition  of  the  body,  and  while  our  knowledge  of 
these  substances  is  as  yet  very  fragmentary,  their  great  im- 
portance in  the  life  of  the  animal  and  their  usefulness  in  the 
treatment  of  various  disorck'rs,  are  widely  recognized.  It  is 
known  for  example  that  diabetes,  which  is  marked  by  the 
presence  of  sugar  in  the  urine,  is  not  a  kidney  disorder,  but 
is  due  to  improper  actio]i  of  the  pancreas,  as  a  result  of 
which  a  specific  secretion,  passed  by  the  latter  into  the  blood 
stream  and  functioning  in  sugar  metabolism,  is  absent  or  re- 
duced in  amount. 

Imperfect  development  of  the  thyroid  gland  leads  to  the 


The  Living  Machine  321 

condition  of  under  development  both  mental  and  physical, 
which  is  known  as  cretinism  from  tlie  French  word  cretin. 
Feeding  the  extract  of  the  thyroid  gland  of  a  sheep,  or  the 
gland  itself,  either  raw  or  cooked,  results  in  great  increase  in 
growth  and  development  of  both  mind  and  body  in  such  cases. 
The  use  of  adrenalin  (extract  of  the  adrenal  ghmd  of  some 
animal)  is  a  common  practise  in  certain  diseases  and  in- 
juries as,  for  example,  asthma,  in  which  injections  of  the 
drug  relax  the  bronchial  muscles,  and  greatly  relieve  the  suf- 
ferer. Attached  to  the  lower,  central  part  of  the  brain  is  a 
small  gland,  the  pituitary  body,  which  some  enthusiastic  the- 
orists have  fancied  to  be  the  seat  of  the  soul.  If  this  gland 
be  partly  removed  from  a  young  puppy  it  ceases  to  grow  ex- 
cept for  the  accumulation  of  fat.  It  keeps  its  puppy  hair 
and  milk  teeth,  while  the  development  of  the  genital  organs, 
and  of  the  intelligence  is  much  retarded. 

After  partial  digestion  in  the  stomach,  the  food  is  further 
digested  in  the  upper  end  of  the  small  intestine.  The  di- 
gestive juices  come  in  part  from  the  liver  and  wall  of  the 
intestine  itself,  and  in  part  from  the  pancreas.  When  the* 
partly  digested  and  acid  food  passes  from  the  stomach  into 
the  intestine,  it  causes  the  pancreatic  juice  to  flow  as  auto- 
matically as  the  movement  of  the  piston  in  a  gasoline  engine 
causes  the  intake  of  gasoline  from  the  supply  tank.  The 
pancreas  is  activated  by  the  acid  food  in  the  intestine.  It 
was  formerly  supposed  that  this  activation  was  effected  by 
reflex  nerve  action,  but  we  now  know  of  an  entirely  differ- 
ent mechanism  for  this  function.  If  an  acid  extract  of  the 
lining  of  the  intestine  be  injected  into  the  blood  it  causes  the 
pancreas  to  secrete  its  juice  as  surely  as  does  the  presence 
of  acid  food  in  the  intestine ;  while  similar  extracts  of  other 
organs  have  no  such  effect.  Here  there  is  clear  evidence  of 
an  internal  secretion  formed  by  the  intestine,  which  reach- 
ing the  pancreas  via  the  blood  causes  the  latter  to  act.  A 
beautiful  example  of  the  chemical  control  of  bodily  func- 
tions. 

On  the  run  of  any  through  train  between  the  terminals 
of  a  great  trunk  line  there  is  a  change  of  engines  about  once 
every  200  or  250  miles.  Neither  engine  nor  crew  can  give 
as  effective  service  if  operating  for  greater  distances.  The 
non-living,  as  well  as  the  living  machine  needs  rest  after  a 
certain  period  of  work. 

Recently  the  well-known  surgeon,  Crile  of  Cleveland,  has 
advanced  an  interesting  theory  which  he  calls  the  "kinetic 
drive"  to  explain  the  running  down  of  the  human  mechan- 
ism. In  the  "kinetic  drive"  of  modern  life,  when  the  hu- 
man machine  is  being  driven  at  top  speed,  stored  or  poten- 


322 


Biology  in  Ame7'ica 


tial  eiierfry  is  convert chI  into  active  or  kinetic  energy,  and  the 
tissues  of  the  body  sutler  corresponding  loss.  According 
to  Crile  certain  pai-ts  of  the  brain  furnish  the  nervous  en- 
ergy, which  is  probably  identical  with  electrical  energy,  and 
wliich  controls  muscular,  and  otlier  activity.  The  adrenal 
ghiiids  furnish  adrenalin,  which  in  some  way  determines  the 
oxidation  processes  in  the  brain  to  which  the  nervous  energy 
is  due.  The  thyroid  gland,  which  Crile  calls  the  ''pace- 
maker" of  the  body,  furnishes  iodin  to  the  tissues  and  ren- 


Effect  of  the  Kinetic  Drive 

Photograph  of  a  sohlier  under  extreme  mental  and  physical  stress. 
From  Crile,  "  Tlie  Kinetic  Drive."  "Journal  of  the  American  Medical 
Association,"  Vol.  LXV. 

ders  them  more  permeable  to  the  nervous  impulses.  In  the 
conversion  of  energy  in 'the  body  certain  acid  waste  products 
are  formed  which  are  eliminated  by  the  liver,  kidneys  and 
lungs.  The  blood  is  thus  kept  alkaline,  in  Avhich  condition 
only  is  the  carriage  of  oxygen  to  the  tissues  possible. 

If  the  production  of  adrenalin,  the  secretion  of  the  ad- 
renal glands,  be  prevented,  either  by  removal  of  these  glands, 
by  cutting  the  nerves  which  supply  them  or  by  narcotizing 
the  latter  Avith  morphin,  activity  is  reduced.  On  the  other 
hand  administration  of  adrenalin  produces  results  similar  to 


The  Living  Machine 


323 


those  of  exertion,  emotion,  injury,  etc.,  all  of  which  lead 
to  increase  of  energy  change,  while  its  continual  adminis- 
tration leads  to  symptoms  of  exhaustion  siuih  as  disorders 
of  heart  or  kidney.     Excessive  doses  of  iodine  also  "cause 


Effect  of  the  Kinetic  Drive  on  The  Tissues  op  the  Body. 
Above,  left  to  right,  section  of  normal  cerobelhun,  adrenal  and  liver; 
below,  sections  of  the  same  organs  of  a  soldier  who  ' '  had  snffered 
from  hunger,  thirst  and  loss  of  sleep,  had  made  the  extraordinary  forced 
march  of  180  miles  from  Mons  to  the  Marne;  in  the  midst  of  the  great 
battle  was  wounded  by  the  explosion  of  a  shell;  lay  for  hours  awaiting 
help  and  died  from  exhaustion  soon  after  reaeliing  the  ambulance. ' ' 
From  Crile,  "The  Kinetic  Drive,"  "Journal  of  the  American  Medical 
Association,"  Vol.  LXV. 

all  the  phenomena  of  emotion  and  exertion,  and  inversely 
.  .  .  emotion,  infection,  exertion,  etc.,  cause  changes  in  the 
iodine  content  of  the  thyroid." 

The  results  of  the  kinetii;  diive  are  evident  in  changes  of 
the  tissues.     The  brain  of  a  man  who  has  died  from  exhaus- 


324  Biology  in  America 

tion  gives  a  very  different  picture  from  that  of  a  man  killed 
accidentally,  certain  of  the  cells  having  almost  disappeared 
in  the  forme?'.  The  injection  of  poison  (i.e.  diphtheria  toxin) 
into  a  dog-  will  produce  similar  changes  in  the  l)rain,  hut  these 
changes  can  he  in  large  measure  prevented  by  the  injection 
of  mori)hin  at  the  same  time  as  the  toxin,  the  former  check- 
ing the  nervous  action  induced  by  the  latter. 

"Never  before  has  there  been  such  an  opportunity  for 
studying  the  behavior  of  the  human  mechanism  uiidci-  the 
strongest  physical  and  psychic  stress  as  in  wari-ing  Europe 
today.  Tlioi-e  ol)servations  of  the  injured,  of  soldiers  in  the 
field,  of  ])i'isoners  and  of  refugees  gave  me  an  unparalleled 
opportunity  for  studying  the  human  kinetic  drive  on  a  vast 
scale.  The  illustration  shows  the  gross  effect  of  the  combina- 
tion of  extreme  emotion  and  exertion  as  they  are  manifested 
in  the  faces  and  bearing  of  Belgium  refugees  and  of  wounded 
soldiers. 

"Turning  now  from  the  individual  acutely  driven  by  in- 
jury, by  infection,  by  emotion,  let  us  consider  the  individual 
chronically  driven  by  the  stinuili  of  want,  ambition,  anger, 
jealousy  or  grief,  by  infection,  by  pain  and  by  autointoxica- 
tion. In  the  acute  kinetic  drive  the  individual  is  endan- 
gered by  death  from  exhaustion  or  from  acid  intoxication, 
whereas  in  the  chronic  drive,  the  danger  is  that  one  or  an- 
other of  the  overdriven  organs  or  tissues  may  be  perma- 
nently injured. 

"The  common  chronic  drives  are  mental  and  physical  over- 
work, chronic  infections,  excessive  diet  and  pregnancy,  the 
emotions  of  fear,  hate,  jealousy,  shame  and  despair,  and  for- 
eign proteins,  as  in  intestinal  stasis.  These  conditions  pre- 
sent every-day  problems  and  demand  but  little  discussion. 
Since  the  lesions  of  these  various  driving  causes  are  the  same, 
however;  since  infection,  emotion. and  overwork  produce  iden- 
tical end-effects;  since  usually  two  or  more  of  these  operate 
simultaneously,  and  since  the  emotional  states  are  most  amen- 
able to  control,  it  becomes  obvious  why  these  conditions  have 
often  been  controlled  by  means  which  have  apparently  no 
direct  therapeutic  value,  such  as  faith  in  the  physician,  travel, 
diversion,  prayer,  healing  springs,  philosophy  and  Christian 
Science.  Again  and  again,  in  the  domain  of  regular  medi- 
cine as  in  the  domain  of  irregular  medicine,  the  exclusion 
of  worry  has  relieved  the  drive  sufficiently  to  allow  the  body 
processes  to  overcome  the  primary  disease.  But  the  reverse  is 
true  also — innumerable  men,  under  tlie  strain  of  a  chronic 
drive,  are  pushed  beyond  the  narrow  limits  of  safety  by  the 
added  drive  of  grief,  worry  or  shame.  Is  it  not  possible  that 
when  it  is  understood  that  the  various  kinetic  stimuli  have 


The  Living  Machine  325 

interchangeable  physical  values,  the  game  of  health  will  be 
more  skilfully  played f"^^ 

Not  only  may  poisons,  emotion  and  fatigue  induce  the 
kinetic  drive,  but  surgical  shock,  while  the  patient  is  an- 
esthetized, coupled  with  the  terror  of  the  knife  before  the 
operation,  are  also  powerfidly  inducing  causes.  While  the 
jjatient  may  be  entirely  unconscious  during  the  operation, 
there  is  nevertheless  a  great  drain  upon  tlie  nervous  system 
induced  by  the  action  of  the  knife.  To  overcome  these  as 
much  as  possible  Doctor  Crile  takes  every  ])ains  to  render  the 
patient  mentally  at  ease  before  the  operation  and  block  the 
kinetic  drive  by  the  use  of  morphin  and  by  local  anesthesia. 
Doctor  Crile's  theory  and  this  operative  method  are  gen- 
erally known  as  that  of  "anoci-association,"  or  the  pre- 
vention of  the  exhaustion  of  nervous  energy  through  opera- 
tive shock.  Experiments  upon  which  it  is  based  have  led 
him  to  many  other  discoveries  in  the  field  of  operative  sur- 
gery, which  have  rendered  his  name  famous,  but  this  brief 
sketch  must  suffice  as  an  illustration  of  the  automatic  and 
mechanical  operation  of  the  human  machine. 

One  of  the  most  striking  examples  of  the  role  of  hormones 
or  internal  secretions  is  the  action  of  the  sex  glands  in  con- 
trolling both  body  form  and  mental  activity.  The  physical 
and  mental  changes  occurring  in  both  boj^s  and  girls  at  the 
time  of  puberty  are  too  well  known  to  require  even  passing 
mention  here,  while  the  dependence  on  the  proper  function- 
ing of  the  sex  glands  of  the  secondary  sexual  characters,  such 
as  the  horns  of  the  deer,  the  comb  and  feathering  of  the 
cock,  the  size  of  the  stallion,  and  innumerable  others,  is  equally 
familiar  to  everyone.  Horses  and  cattle  are  castrated  to  ren- 
der them  docile  and  serviceable  as  draft  animals,  and  the 
cock  is  castrated  in  order  that  he  may  take  on  more  flesh  and 
become  a  welcome  member  of  our  dinner  parties.  A  curious 
case  is  that  of  the  race  of  poultry  known  as  sebrights  where 
the  male  goes  masquerading  in  female  attire,  while  the  fe- 
male wears  the  habit  of  the  male.  Castration  of  either  sex 
of  these  chickens  results  curiously  enough  in  their  adoption 
of  their  proper  garb,  either  male  or  female. 

We  are  accustomed  to  think  of  the  control  of  mind  over 
matter  and  to  regard  the  processes  of  thought  as  transcend- 
ing the  bounds  of  the  purely  material  universe,  and  yet  where 
could  we  have  a  more  beautiful  example  of  the  chemical  (and 
therefore  purely  material)  control  of  living  processes,  men- 
tal as  well  as  physical,  tlian  in  the  case  of  the  hormones  or 
internal  secretions  of  the  animal  body? 

"Crile,  "Journal  of  the  Aiuerican  Medical  Association,"  LXV,  p. 
213  2. 


Sebright  Poultry 
Photoj^raplis    of    a    normal    scbrijjlit    cock     (ahovo),    Avhich    has    the 
plumage  of  the  hen,  and  castrated  cock  (below),  which  has  male  feathers. 
After  Morgan,  "Physical  Basis  of  Heredity." 

Courtesy   of  Professor  Morgan  and   the  J.   B.   Lipphuott  Company. 


326 


The  Living  Machine  327 

Of  all  the  features  characteristic  of  living  matter,  none  is 
more  so  than  reproduction.  Attempts  have,  it  is  true,  been 
made  to  compare  the  growth  of  many  crystals  of  salt  in  a 
concentrating  solution  with  this  miracle  of  life,  but  such  at- 
tempts sound  like  a  mere  play  upon  words.  There  is  noth- 
ing in  the  inorganic  world  in  any  way  comparable  to  this 
wonderful  phenomenon.  Here  then,  if  anywhere  in  the  world 
of  life,  we  should  tind  evidence  of  some  force  higher  than 
the  physical  forces,  did  any  such  exist.  But  what  do  we 
find?  We  have  seen  in  a  previous  chapter  that  the  method 
of  reproduction  (bi-sexual  or  parthenogenetic)  can  be  altered 
by  external  means;  furthermore  in  Hydra  it  can  similarly 
be  changed  from  asexual  (budding)  to  sexual.  In  some 
plants  likewise  the  kind  of  reproduction  may  be  determined 
by  external  factors.  But  beyond  the  mere  shifting  of  the 
mode  of  reproduction  by  physical  or  chemical  stimuli,  it 
has  been  found  that  the  process  of  sexual  reproduction  itself 
is  a  physico-chemical  one  and  can  be  accomplished  by  arti- 
ficial means.  In  the  first  place  the  attraction  between  the  sex 
cells  is  in  some  cases,  though  apparently  not  in  all,  a  chem- 
ical one.  If  a  capillary  glass  tube  containing  a  weak  solu- 
tion of  malic  acid  (the  acid  found  in  apples  and  other  fruits) 
be  placed  in  water  containing  the  sperms  of  ferns  and  mosses, 
the  latter  are  attracted  by  the  acid,  and  will  enter  the  tube 
in  great  numbers.  The  action  here  however  may  be  similar 
to  that  described  above  of  "trapping"  Paramoecium  in  a  drop 
of  acid.  With  the  spermatozoa  of  the  sea  urchin  however 
such  chemical  attraction  appears  not  to  exist.  The  union  of 
egg  and  sperm  in  cases  where  chemical  attraction  cannot  be 
proven  appears  to  be  due  to  chance.  It  is  a  well-known 
fact  that  it  is  very  difficult  to  cross  different  species  of  ani- 
mals, this  difference  indeed  being  made  the  basis  for  a  physi- 
ological definition  of  species,  those  animals  which  breed  to- 
gether and  produce  fertile  offspring  being  grouped  as  one 
species ;  and  those  which  do  not  interbreed,  or  do  not  at  least 
produce  fertile  offspring  being  classed  as  distinct.  In  lower 
animals  union  of  egg  and  sperm  of  different  species  may  be 
prevented  by  physical  differences  such  as  size,  or  -ihemical 
differences  may  prevent  the  development  of  an  egg  into  which 
by  chance  a  foreign  sperm  has  entered.  In  some  cases  it  is 
possible  to  fertilize  the  egg  of  species  A  with  the  sperm  of 
B,  but  the  reciprocal  cross  is  impossible.  Among  higher  types 
there  appears  to  exist  a  mutual  repugnance  to  union,  which 
effectually  bars  intermingling.  Yet  even  here  occasional  in- 
stances of  crossing  and  the  production  of  fertile  offs]iring 
are  known,  in  crosses  of  hares  and  rabbits,  various  species  of 
fish,  etc.     Crosses  between  members  of  widely  distinct  groups 


328  Biology  in  America 

of  animals  are  practically  unknown  in  nature,  and  yet  Loeb 
has  succeeded  in  cross  fertilizing  tlie  sea  urchin's  egg  with  the 
spenu  of  several  s])ecies  of  starfish  and  one  of  tlie  brittle 
stars,  by  simply  adding  a  little  sodium  hydroxide  or  car- 
bonate to  the  sea  water  containing  the  eggs. 

The  entrance  of  the  sperm  into  the  egg  induces  changes 
in  tlie  latter  which  can  likewise  be  induced  by  chemical 
means.  When  the  sperm  of  a  sea  urchin  strikes  the  egg  the 
two  adhere  to  each  other,  due  prol)al)ly  to  a  sticky  secretion 
of  the  latter.  A  few  moments  later  the  very  delicate  mem- 
brane surrounding  the  egg  is  pushed  off  from  the  surface 
and  considerably  thickened,  due  probably  to  absorption  of 
water.  The  cause  of  this  membrane  formation  (or  better, 
membrane  extrusion)  is  the  li(iuefying  of  the  surface  of  the 
egg  just  beneath  the  membrane  and  its  consequent  absorp- 
tion of  water.  Subsequent  to  this  membrane  formation  the 
sperm  head  or  nucleus  penetrates  still  farther  into  the  egg 
leaving  the  tail  adherent  to  the  egg  membrane,  while  the  egg 
nucleus  advances  to  meet  it,  the  two  fuse  and  fertilization^  is 
accomplished,  to  be  followed  shortly  by  the  division  of  the 
egg  into  first  two,  then  four,  eight,  sixteen  cells,  and  so  on. 
INlany  Avorkers  have  succeeded  in  imitating  the  processes  of 
fertilization  and  causing  the  eggs  of  a  large  number  of  spe- 
cies of  animals  to  develop  parthenogenetically  by  various 
methods  of  treatment.  In  the  case  of  the  sea  urchin  Loeb 
fii'st  treats  the  egg  with  some  chemical  (i.e.,  butyric  or  other 
monobasic  fatty  acid)  which  induces  membrane  formation, 
and  then  follows  this  treatment  by  placing  the  egg  in  sea 
water  containing  a  little  more  salt  than  usual,  or  into  nor- 
mal sea  water  lacking  oxygen.  The  two  procedures  are  es- 
sential to  development,  for  if  the  first  alone  be  employed  the 
egg  disintegrates  after  extruding  its  membrane,  without  fur- 
ther development.  A  similar  result  sometimes  occurs  when 
a  sea  urchin  egg  is  fertilized  by  starfish  sperm.  Here  the 
entrance  of  the  sperm  is  very  slow,  some  ten  to  fifty  min- 
utes compared  with  about  a  minute  in  the  case  of  sperm  of 
the  same  species.  In  the  former  case,  owing  no  doubt  to  the 
slow  penetration  of  the  spcimi,  the  latter  does  not  always  en- 
ter the  egg,  but  remains  attached  to  the  extruded  membrane. 
It  seems  therefore  that  the  sperm  secretes  two  distinct  sub- 
stances, one  of  which  causes  liquefaction  of  the  surface  layer 
of  the  egg,  with  consequent  al)sorption  of  water  and  extru- 
sion of  the  membrane,  while  the  other  causes  the  initial  de- 
velopment (division  of  the  egg)  to  ensue.  The  action  of  this 
second  substance  is  not  yet  clearly  understood  but  apart 
from  the  experiments  in  artificial  parthenogenesis  and  the 
occasional  cessation  of  devcloijuient  after  membrane  forma- 


The  Living  Machine  329 

tion  in  the  cross  fertilization  experiments  just  mentioned, 
there  are  numerous  other  evidences  of  the  action  of  two 
substances  in  fertilization.  If,  for  example,  the  sea  urchin 
egg  be  treated  with  the  sperm  of  sharks  or  roosters,  or  with 
the  blood  or  extracts  of  the  organs  of  some  invertebrates,  or 
the  blood  sera  of  cattle,  sheep,  pigs  or  rabbits,  membrane 
extrusion  is  induced  but  development  soon  ceases,  unless  the 
egg  be  transferred  to  a  strengthened  solution  of  sea  water, 
in  which  development  progresses  for  a  time  at  least.  The 
initial  effect  here  (membrane  extrusion)  is  the  same  as  that 
obtained  by  the  use  of  a  fatty  acid  in  artificial  partheno- 
genesis, the  second  effect  (division  of  the  egg)  being  obtained 
in  the  same  manner  in  both  cases.  There  are  many  other 
ways  in  which  eggs  can  be  made  to  develop  without  fertiliza- 
tion: brushing  the  surface  of  the  egg  with  a  tine  brush,  plung- 
ing it  for  a  few  moments  into  concentrated  sulphuric  acid 
and  pricking  the  egg  membrane  have  all  been  successfully 
employed.  The  egg  of  even  so  highly  organized  an  animal  as 
the  frog  has  been  made  to  develop  simply  by  pricking  the 
egg  membrane,  and  the  resulting  embryo  reared  to  the  adult 
state. 

What  more  striking  evidence  could  be  asked  of  the  physico- 
chemical  nature  of  life,  than  the  development  of  a  new  be- 
ing by  these  means  ? 

Far  distant  though  we  be  from  a  solution  of  the  "riddle 
of  life"  our  only  present  hope  of  ultimate  success  is  to  pro- 
ceed from  the  known  to  the  unknown,  working  on  the  hy- 
pothesis that  nature  is  a  unity  and  not  a  duality,  and  that 
the  same  fundamental  laws  control  organic  and  inorganic 
worlds  alike. 


CHAPTER  XIII 

Color  in  Nature.  Colors  of  floivcrs  and  the  inter-relation 
of  flowers  and  insects.  Colors  of  animals  and  their  physico- 
chemical  causes.  The  theories  of  protective  coloration,  warri- 
ing  and  alluring  colors,  mimicry  and  recognition  marks. 

But  few  American  naturalists  have  entered  the  broad  and 
fascinating  field  of  Nature's  colors.  The  subject  was  one 
of  intense  interest  to  Darwin  and  his  co-workers,  Wallace, 
Bates  and  Fritz  Miiller,  and  has  been  largely  developed  by 
the  recent  Darwinians  in  Germany  and  England.  A  few 
Americans  however  have  made  valuable  contributions  to  the 
subject  w4iich  w'e  shall  consider  in  this  chapter. 

What  is  the  cause  and  what  the  function  of  the  bewilder- 
ing array  of  colors  which  we  find  on  every  hand?  Are  they 
useful  to  their  possessors,  and  hence  preserved  through  se- 
lection, or  are  they  simply  an  expression  of  a  reckless  gener- 
osity of  Nature,  who  lavishes  her  gifts  with  wild  prodigality 
upon  her  creatures,  regardless  of  whether  they  are  bene- 
fited thereby  or  no?  In  the  case  of  chlorophyl,  the  green 
coloring  matter  of  leaves,  and  haemoglobin  to  which  the  red 
color  of  the  blood  is  due,  we  know  of  course  the  physiolog- 
ical value,  but  most  colors  (those  of  flowers  and  insects  for 
example)  are  of  uncertain  value,  although  many  very  pretty 
theories  have  been  invented  to  account  for  them. 

The  colors  of  flowers  are  formed  as  by-products  of  their 
metabolism.  Their  function  is  possibly  to  attract  insects  and 
thus  aid  in  their  fertilization.  We  have  all  of  us  been  fa- 
miliar since  childhood  with  the  "busy  little  bee,"  and  how_  it' 
"employs  each  shining  hour"  has  ever  been  set  before  us  for 
our  edification  and  emulation;  but  the  beautiful  manner  in 
which  Nature  has  fashioned  her  children,  both  bee  and  flower, 
for  the  accomplishment  of  her  "purpose"  is  not  so  familiar 
to  us  all.  To  attempt  to  recount  here  even  in  small  measure 
the  life  of  the  bee  would  carry  us  too  far  aside  from  our 
main  theme,  and  would  moreover  be  a  thankless  task  for  one 
following  in  the  footsteps  of  a  Maeterlinck  or  a  Fabre.  We 
may  however  pause  for  a  moment  to  consider  the  relation 
between  a  single  sort  of  bee  and  a  single  kind  of  flower,  in 
order  to  gain  some  notion  of  the  wonderful  co-adaptation 

330 


Color  in  Nature 


331 


existing  between  them.  The  body  of  a  worker  honey  bee, 
which  gathers  the  honey  and  the  pollen  for  the  hive,  and 
performs  all  the  other  "chores"  of  the  bee  community,  such 
as  those  of  nurse  maid,  house  cleaner,  biitler,  architect,  po- 
liceman, and  even  executioner  and  undertaker,  is  clothed 
with  numerous  branched  hairs,  to  which  the  pollen  adheres 
as  &e  bee  goes  crawling  about  in  the  cups  of  the  flowers 
which  it  visits.  On  one  of  the  joints  of  the  middle  leg  of 
the  bee  is  a  groove,  overhung  by  rows  of  stiff  bristles,  form- 
ing the  "pollen  basket,"  while  another  joint  of  the  same  leg 
carries  several  rows  of  bristles  or  "pollen  combs,"  by  means 
of  which  the  pollen  is  combed  out  of  the  hairs  and  trans- 
ferred to  the  pollen  basket  where  it  sticks  in  the  form  of  a 
large   ball.     The   "basket"   enables  the  bee  to    carry   more 


Eelation  of  Bee  and  Flower,  a  Salvia. 

1,  flower  parts  in  usual  position;  2,  anthers  ereet;  3,  anthers  tipped 
down;  4,  bee  entering  flower;  5,  flower  with  extruded  style.  From 
Kellogg,   after  Lubbock. 

pollen  to  its  hive  than  it  could  if  it  depended  solely  on  the 
hairs  for  this  purpose.  A  part  of  the  bee's  esophagus  is 
enlarged  to  form  a  "honey  sac"  in  which  is  stored  the  nec- 
tar which  it  sucks  from  the  flowei-s,  and  which  in  the  hive 
is  evaporated  to  form  the  honey. 

As  the  bee  goes  buzzing  about  from  flower  to  flower,  in 
search  of  nectar,  some  of  the  pollen  from  one  flower  is  trans- 
ferred to  another,  and  fertilization  is  thus  effected.  The 
manifold  modifications  of  various  types  of  flowers  to  ensure 
transference  of  pollen  by  insects,  and  to  admit  only  those 
species  which  will  pay  for  their  supply  of  honey  by  trans- 
ferring pollen,  the  insect  Bolsheviki  and  I.W.W.'s,  which 
would  appropriate  the  honey  but  carry  no  pollen  in  return, 


332  Biology  in  America 

being  debarred  from  entrance,  are  so  numerous  and  won- 
derful as  to  need  for  their  description  a  volume  in  itself. 
We  must  content  ourselves  with  a  single  instance. 

In  one  of  tlie  Salvias  (S.  officinalis)  the  stamens  ripen 
before  the  pistil,  so  tliat  the  flower  cannot  fertilize  itself 
with  its  own  pollen/  Tlie  corolla  of  the  flower  consists  of 
two  lobes  or  lips,  an  upper  and  a  lower,  the  former  enclos- 
ing the  style  and  stamens  and  the  lower  serving  as  a  landing 
stage  for  insect  visitors.  Before  the  ovary  ripens  the  style 
is  withdrawn  within  the  upper  lobe  of  the  corolla,  as  shown 
at  1  in  the  preceding  figure;  after  ripening  it  hangs  down 
over  the  lower  lip,  5.  In  the  former  position  it  is  not  ordi- 
narily toiiclied  l)y  an  insect  entering  the  flower,  while  in  the 
latter  it  obviously  must  be.  The  functional  stamens  are  two 
in  number,  placed  close  together  at  the  base  of  the  hood. 
Each  stamen  bears  two  anthers,  separated  by  a  long  connec- 
tive, which  stands  upright  beneath  the  hood.  The  lower 
pair  of  anthers  contain  little  or  no  pollen,  while  the  upper 
pair  are  full  of  it.  If  a  bee  alights  on  the  lower  lip  and 
attempts  to  make  his  way  into  the  flower  tube,  where  the  nec- 
tar is  hidden,  his  head  must  first  of  all  encounter  the  lower 
pair  of  partly  developed  anthers.  As  these  are  pushed  before 
him  in  his  effort  to  enter,  the  upper  pair  are  swung  down 
upon  their  hinge,  striking  the  bee's  back  and  depositing 
thereon  their  load  of  pollen.  Thus  the  bee,  visiting  this 
Salvia,  is  either  besprinkled  with  pollen  to  be  carried  to  an- 
other flower,  or  deposits  some  of  its  pollen  upon  the  hanging 
styles  ready  to  receive  it,  according  to  the  stage  of  develop- 
ment of  ovaries  and  stamens. 

The  question  of  the  part  played  by  flower  color  in  these 
transactions  is  very  perplexing,  and  calls  for  much  more  in- 
vestigation. Some  authors  maintain,  while  others  deny,  the 
power  of  insects  to  distinguish  color,  and  more  especially 
to  discriminate  between  color  i)atterns  in  flowers.  An  in- 
sect's power  of  sight  is  probably  very  limited,  so  that  its 
distinction  of  the  form,  and  possibly  also  of  the  color  of 
flowers  at  any  considerable  distance  is  doubtful.  There  are 
however  some  very  clear  experiments  showing  ability  on  the 
part  of  insects  to  distinguish  color,  but  the  whole  question  is 
still  very  doubtful. 

Animal  colors  fall  into  two  classes — the  chemical  and  the 
physical,  or  a  combination  of  the  two.  The  chemical  colors 
are  due  to  pigments  diffused  inainly  through  either  the  sur- 

'  In  sonic  species  of  plants  tlic  flowers  are  on  the  contrary  so  con- 
structed as  to  insure  self-fertilization.  The  whole  question  of  the  in- 
fluence of  inbreedinjj  upon  virility  in  both  plants  and  animals  is  very 
uncertain  at  the  present  time.     See  page  85. 


Color  in  Nature  333 

face  cells,  the  cnticula  or  elsewhere,  or  else  lodged  in  spe- 
cial cells  knowu  as  chroniat()j)hores,  the  absorption  of  cer- 
tain rays  of  light  by  these  pigments,  and  the  reflection  of 
their  complementary  rays  causing  the  various  colors.  Pig- 
ments develop  through  the  action  of  an  oxidizing  ferment 
upon  a  color-forming  substance  or  chromogen,  and  numy 
different  pigments  may  be  merely  different  stages  in  the  mcxli- 
fication  of  a  single  chromogen.  Thus  the  brown  and  black 
pigments  of  animals  pass  through  yellow,  orange  and  red 
stages,  before  attaining  their  final  color. 

The  influence  of  external  factors  in  producing  more  or 
less  permanent  color  changes  in  animals  has  been  discussed 
in  a  previous  chapter,  dealing  with  the  influence  of  the  en- 
vironment upon  the  development  of  the  individual.  Tem- 
porary changes  in  the  hue  or  color  of  animals  may  resultin 
response  to  external  stimuli.  The  chameleon  is  the  class- 
ical example  of  this.  Temperature  and  light  appear  to  be 
the  controlling  stimuli  although  their  effects  differ  in  differ- 
ent species.  Fear  may  affect  the  color  of  an  animal.  Thus 
it  is  possible  to  cause  a  frog  to  "turn  pale  with  fear"  by 
continually  disturbing  it  with  a  stick  or  otherwise.  The  color 
changes  in  these  cases  are  due  to  changes  in  the  distribution 
of  the  granules  of  pigment  in  the  chromatophores ;  when  the 
pigment  is  distributed  throughout  the  cell  the  color  is  darker, 
when  concentrated  around  the  nucleus  the  reverse  is  true. 

One  of  the  most  remarkable  cases  of  color  adaptation 
known  is  that  of  the  flatfish.  Symmetrical  both  in  form  and 
color  in  its  early  stages  this  fish  soon  turns  on  its  side  and 
thereafter  lies  on  the  bottom  of  the  sea.  Accompanying  this 
change  in  life  the  eyes,  fins  and  mouth  shift  to  the  upper 
side  of  the  body,  and  the  lower  side  loses  its  color.  But, 
as  the  English  naturalist  Cunningham  has  shown,  the  color 
will  return  to  the  lower  side  in  fish  kept  in  an  a<iuarium 
which  is  lighted  from  below.  Living  on  tlie  bottom  the  flat- 
fish finds  itself  from  time  to  time  on  differently  colored  back- 
grounds, now  on  white  and  now  on  dark  sand,  and  again 
on  gravel  of  various  shades  and  patterns.  Tn  an  extensive 
series  of  experiments  Sumner  has  shown  tliat  this  species 
adjusts  its  color  to  match  that  of  its  background  with  won- 
derful accuracy;  and  that  further  this  change  is  affected  in 
some  unknown  way  through  the  nervous  system  in  response 
to  sight,  for  if  the  eye  be  removed  the  power  of  adjustment 
is  lost  with  it. 

The  physical  colors  of  animals  are  due  to  the  form  of  the 
body  surface,  causing  refraction  and  the  fornuition  of  "me- 
tallic" coloring,  or  interference  of  the  reflected  light  rays, 
thus  producing  the  wonderful  iridescence  characteristic  of 


334 


Biulogy  in  America 


many  boetlos  and  birds.  Metallic  colors  and  iridescence  are 
generally  super-imposed  on  pigment  color  producing  a  com- 
pound eil'ect,  white  being  the  only  purely  physical  color  that 
we  know  in  animals. 

The  functions  of  animal  colors  are  doubtless  manifold,  but 
concerning  them  our  knowledge  is  unfortunately  very  frag- 
mentary. Omitting  those  internal  i)igments  such  as  haemo- 
globin, bile  pigments  and  the  like,  which  are  intimately  re- 
lated to  the  physiology  of  the  animal,  and  pigments  derived 
from  tlie  animal's  food,  such  as  the  green  or  yellow  color  of 
some  caterpillars  fed  on  green  leaves  or  yellow  flowers  re- 


One  of  the  Flatfishes 
Animals  having  remarkable  powers  of  adjusting  their  appearance  to 
the  bottom  on  which  they  lie.     The  same  fish  jjhotographed  on  different 
backgrounds. 

Courtesy  of  Dr.  F.  B.  Sumner. 

spectively ;  and  considering  surface  color  only,  we  are  struck 
with  the  apparent  lack  of  any  physiological  use  of  such  color. 
One  might  expect  arctic  animals  to  bo  black  so  as  to  absorb 
the  maximum  of  heat  energy  from  the  sun,  and  tropical  ani- 
mals to  be  white,  thereby  reflecting  the  sun's  rays  and  avoid- 
ing absorption  of  heat;  but  the  reverse  is  true  of  the  for- 
mer, Avhile  the  latter  are  widely  variable  in  color. 

How  then  may  the  multitude  of  colors  and  markings  in  ani- 
mals be  explained?  The  follower  of  Danvin  bases  his  an- 
swer on  the  efficacy  of  selection  in  preserving  those  forms 


Color  in  Nature 


335 


whicli  are  best  adapted  to  their  environment.  AVith  seleetion 
then  as  a  framework  a  number  of  theories  have  been  ad- 
vanced in  explanation  of  animal  colors. 

The  first  of  these  is  that  of  protective  color  which  may  be 


Protective  Form  and  Color  in  Animals 

A.  Woodcock  on  her  nest.     From  a  photograph  by  Dugniore. 

B.  Night   hawk   on    a    log. 

C.  Toad   on  ground. 
1).  Tree  toad  on   hark. 

E.  Tree  lizards  on  oak  bark. 

F.  Caterpillar   on  twig. 

From    Metcalf ,   ' '  Organic    Evolution. ' ' 

By  permission  of  the  Macmillan  Company. 

either  general  or  specific.  '^ Camouflage"  is  not  a  new  art 
to  animals,  and  man  in  adapting  it  to  his  own  use  has  been' 
merely  following  the  advice  of  Solomon,  and  learning  wis- 
dom from  the  humbler  creatures  of  field  and  forest.  The 
existence  of  a  close  resemblance  between  many  animals  and 


3.1G 


Biolof/ii  i)i  America 


A  Leap  Insect 
Courtesy  of  the  U.  S.  Bureau  of  Entomology. 

their  backgroinid  must  be  evident  to  anyone  who  has  ever 
wandered  afield  in  search  of  Nature's  creatures.  Whoever 
is  skeptical  as  to  this  statement  may  readily  verify  it  by  a 


Group  of  Walking  Stick  Inskcts 
Courtesy  of  the  U.  S.  Bureau  of  Entomology. 

search  for  the  "peeper,"  the  first  of  the  frog  orchestra  to 
give  melody  to  our  marshes  in  the  spring.  Or  let  him  look 
for  a  grasshopper  after  it  lias  jumped,  for  a  night  hawk  on 


Color  in  Naturo 


337 


the  ground  or  a  tree  toad  on  bark.  But  yet  more  striking 
examples  of  i)rote(dive  eolor  are  furnished  l)y  those  ani- 
mals whicli  closely  resemble  some  particular  object.  There 
are  certain  caterpillars  commonly  known  as  "measuring 
worms"  which  progress  by  a  series  of  looping  movements, 
first  attaching  themselves  by  the  fore  feet  and  then  drawing 
up  the  hind  feet,  thus  forming  a  loop  of  the  body  between. 
Sometimes  these  attach  themselves  to  a  twig  by  the  hind 
feet,  extending  the  body  in  the  air,  when  they  almost  exactly 
imitate  a  dead  twig.     In  our  Southern  States  is  found  the 


Dead  Leaf  Butterfly 

Left,  with  wings  folded;  right,  expanded.     Original  photograph  from 
a  preparation  by  Kny-Schcercr  Company. 


"walking  stick"  insect,  a  creature  with  slim  body  and  long 
legs,  which  when  resting  upon  a  dead  branch  merges  with  its 
twigs  so  closely  as  to  appear  like  part  of  them.  One  species 
of  moth,  resting  on  the  edge  of  a  leaf,  is  almost  indistin- 
guishable from  the  dry,  curled  u])  edge  of  that  same  leaf; 
while  another  resembles  a  bit  of  bird's  dung  so  closely  as 
to  deceive  any  but  the  most  careful  observer. 

But  the  most  beautiful  example  of  animal  "camouflage" 
is  furnished  by  the  "dead  leaf"  butterfly,  Kallima,  of  the 
East  Indian  jungle.  When  in  flight  this  butterfly  is  a  beau- 
tiful creature  with  blue  and  orange  wings;  but  when  at 
rest,  with  the  wings  folded  together  above  the  body,  it  imi- 
tates a  dead  leaf  so  closely,  even  to  the  minute  details  of 


338 


Jiiolofjy  in  America 


mid-rib  and  veins,  as  to  deceive,  at  a  little  distance,  the 
closest  observer.  AVben  in  t\i^ht  the  Ixitterfly  is  a  striking 
object,  bnt  let  it  aliy:lit,  and  lo,  it  vanishes  i'roni  si<j;lit  as 
suddenly  and  completely  as  though  the  earth  had  swallowed 
it  up. 

Hut  some  animals,  who  liave  no  enemies,  unless  it  be  man, 
wiio  has  appeared  on  the  scene  of  action  only  recently,  in 
terms  of  biological  time,  closely  resemble  their  surroundings. 
Perhaps  the  most  notable  example  of  this  is  the  polar  bear, 
who  lives  among  the  snows  and  ice  fields  of  the  Arctic.  His 
color  is  readily  explained,  according  to  the  Darwinians,  on 
the  assumption  of  an  aggressive  resemblance.  If  the  seal, 
upon  which  the  hviw  preys,  cannot  see  the  latter  as  he  ap- 


Imitation  of  an  Orchid   (left)   by  a  Mantis    (right) 
Courtesy  0}  Thomas  Y.   Croicell  Publishing  Company. 


proaches  lie  Avill  be  more  readily  caught,  so  that  in  this  way 
a  resemblance  to  liis  surroundings  is  of  advantage  to  the 
bear. 

Closely  allied  to  this  theory  is  that  of  alluring  resem- 
blance, according  to  whicli  certain  animals  play  the  part  of 
a  "wolf  in  sheep's  clothing."  One  of  the  worst  of  these 
hypocrites  is  the  Indian  mantis,  which  so  closely  resembles 
an  orchid  blossom  as  (supposedly)  to  attract  unwary  insects, 
who,  alighting  on  it  in  search  of  honey,  thereby  come  to  an 
untimely  end. 

But  by  no  means  all  animals  are  thus  protectively  colored. 
Some  on  the  contrary  are  so  conspicuous  that  it  seems  as 
if  Nature  had  intentionally  singled  them  out  for  objects  of 
remark.  The  monarch  butterfly  in  his  brilliant  livery  of 
black  and  orange,  the  skunk  in  striking  garb  of  black  and 


The  Skunk 
An   example   of   "warning   color"   among   mammals. 
Courtesy   of  the  Conrad  Lantern  &lide  Company,   Chicago. 


PORKFISH 
One  of  the  many  strikingly  marked  and  colored  fish  of  the  tropica, 
whose   colors   and   markings   have   been   supposed   to    liave   warning   sig- 
nificance. 

Courtesy  of  Professor  W.  II.  Lonijley. 

339 


340 


Biology  in  America 


w 

^iltf 

^t             T^  ...^^amm'^m 

w^^^^^^^KBf IS  11^  i'^XNuoI^Bb 

Mimicry  op  the  Monarch  (left)  by  the  Viceroy  Butterfly  (right) 
Pliotos  from  water  color  drfiwings  by  Mrs.  Edith  Eicker.     From  Bulle- 
tin University  of  Montana,  Biological  Series  No.  5. 

white,  and  the  coral  reef  fish  of  the  tropics  with  their- ''coats 
of  iiiaiiy  colors,"  all  seem  designed  to  attract,  rather  than  de- 
tract attention.  To  explain  such  facts  as  these  a  new  theory 
was  necessary,  and  so  Wallace  suggested  that  these  conspicu- 
ous colors  were  developed  as  a  danger  signal  to  the  ene- 
mies of  their  possessors,  warning  them  of  an  unpleasant  taste, 
or  odor,  or  other  disagreeable  feature  pertaining  to  the  lat- 


Bumblebee   (left)    Mimicked  by  Fly    (right) 

Photos    from    water    color    drawings    by    Mrs.    Edith    Eicker. 
Bulletin  University   of  Montana,  ^Biological  Series  No.  5. 


From 


ter.  Thus,  according  to  the  theory,  the  black  and  white 
stripes  of  the  skunk  serve  as  a  pictorial  warning  to  his  ene- 
mies to  stop,  look  and  sniff'  before  crossing  his  track.  This 
theory  is  known  as  that  of  warning  color. 

One  of  the  most  remarkable  of  color  phenomena  in  ani- 
mals is  that  known  as  mimicry.  In  some  cases  there  occurs 
a  resemblance  so  close  as  to  amount  almost  to  identity  be- 
tween two  species  belonging  to  totally  distinct  genera,  fam- 


Mimicry  in  Butterflies 
At  the  left  a  series  of  stinking  or  unpalatable  forms,  the  "models"; 
with  a  series  of  imitators  or  "mimiL-s"  at  the  rJght.     From  a  prepa- 
ration by  Kny-Scheerer  Company. 


Mimicry  of  Leap-Cutting  Ant  by  a  Tree-Hopper 

From  Romanes,  ''Darwin  and  after  Darwin." 

B}i  permission  of  the  Open  Court  J'ublisliiinj  Company. 


341 


342  Biology  in  Amci'ica 

ilies,  or  even  orders  of  animals.  The  "monarch"  butterfly 
already  mentioned  is  imitated  by  the  "viceroy,"  a  species 
belonging  to  another  genns.  In  South  and  Central  America 
occur  groups  of  inedible  butterflies,  the  Ileliconidte  and 
Danaida,',  which  are  imitated  by  various  species  of  edible 
butterflies  and  moths,  mostly  the  Pierida?,  the  chief  repre- 
sentative of  which  in  the  United  States  is  the  common  cab- 
bage butterfly.  jNIany  a  fly  has  adopted  the  habit  of  a  wasp 
or  a  bee,  and  the  resemblance  is  so  perfect  that  only  the 
closest  scrutiny  reveals  the  deception.  But  perhaps  the  most 
curious  of  Nature's  masquerades  is  that  played  by  an  ant 
and  a  "tree-hopper"  in  the  Amazon  region,  the  latter  very 
closely  imitating  the  former  as  it  carries  on  its  back  a  leaf, 
which  it  has  cut  for  food. 

Why  all  this  counterfeiting  in  nature?  Of  what  advan- 
tage is  it  to  two  animals  to  be  almost  exact  replicas  of  one 
another?  Or  is  it  counterfeiting?  JMay  not  these  remark- 
able resemblances  be  mere  accidents  of  variation,  after  all? 
The  Darwinians  are,  as  usual,  ready  with  an  answer.  Ac- 
cording to  Bates,  a  very  real  advantage  in  the  life  and  death 
struggle  of  the  animal  world  is  afforded  certain  innocuous 
species  by  their  resemblance  to  other  species  which  are  pro- 
tected from  their  enemies  by  foul  taste,  or  odor,  or  other 
unpleasant  quality.  A  bird  which  has  learneil  to  respect  a 
wasp  by  reason  of  its  sting,  will  be  very  wary  about  seizing 
a  fly  which  resembles  a  wasp,  even  though  the  former  might 
prove  a  delicious  morsel,  did  the  bird  only  know  it,  while* 
the  "tree-hopper"  is  protected  by  its  reseml)lan('e  to  a  leaf- 
cutting  ant,  because  of  the  bitter  taste  of  the  latter. 

Occasionally  two  species  of  insects,  each  protected  by  some 
disagreeable  quality,  resemble  each  other.  What  advantages 
here,  if  both  are  self-protected  species,  in  mutual  resemblance 
between  them?  But  the  staunch  Darwinian  is  at  no  loss 
for  an  explanation ;  for,  he  argues,  if  two  unpleasant  insects 
look  alike,  their  enemies  will  have  only  one  pattern  of  color 
to  learn  in  order  to  avoid  them  both;  whereas  if  they  each 
had  a  different  pattern  they  would  have  two  patterns  to  learn, 
and  in  doing  so  would  sacrifice  twice  as  many  insects  as  under 
the  present  arrangement. 

There  are  a  few  species  of  animals  which  wear  a  white 
patch  on  the  rump  or  tail ;  for  example,  the  white  tail  of 
some  species  of  deer  and  rabbits  and  the  white  rump  patch  of 
the  antelope.  Could  anything  so  conspicuous  be  without* 
significance?  Certainly  not,  according  to  the  Darwinians, 
for  were  it  not  for  such  "recognition  marks,"  how  could  the 
young  follow  their  mother  or  the  herd  its  leader,  when  pur- 
sued by  some  swift  and  savage  foe? 


Color  in  Nature 


343 


There  are  yet  other  instances  of  striking  color  which  are 
not  covered  by  any  of  the  explanations  which  we  have  given 
so  far.  "Why  should  the  males  of  many  birds  be  so  si)lendidly 
attired  that  "even  Solomon  in  all  his  glory  was  not  arrayed 
like  one  of  these";  while  the  females  mnst  be  satisfied  with 
a  modest  coat  of  drab  or  brown?  The  male  scarlet  tanager 
in  flashing  lively  of  black  and  scarlet,  the  male  of  the  rose- 
breasted  gi'osbeak  with  its  breast  of  gorgeous  rose,  and  the 
saucy  little  male  goldflncli  in  coat  of  black  and  yellow,  are 


m    '"1 

m- 

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^^^^^^?^^S2iAlH 

yr^ 

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■.r^-  ■•:•'  i/A":^ 

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IMIt.       ■ 

The  Antelope 
Which  carries  a  recognition  mark  ui)ou  its  rump.     A  vanishing  species 
which  once  thronged  our  western  plains.- 

Courtesy  of  the  National  Zoiilof/ical  Park. 

among  the  most  striking  and  beautiful  objects  in  nature ;  while 
the  females  must  be  content  with  quiet  colors,  remU'ring  them 
wholly  different  in  appearance  from  their  mates.  Once  again 
the  Darwinian  comes  to  rescue  us  from  our  dih-mma  witli 
his  theory  of  sexual  selection,  which  was  proposed  auii  ably 
defended  by  Darwin  himself  in  his  "Origin  of  Species." 

"This  form  of  selection  depends,  not  on  a  struggle  for 
existence  in  relation  to  other  organic  beiiig-s  or  to  external 
conditions,  but  on  a  struggle  between  the  indivitluals  of  one 
sex,  generally  the  males,  for  the  possession  of  the  other  sex. 


344 


Biology  in  America 


The  result  is  not  death  to  the  unsuccessful  competitor,  but 
few  or  no  offspring.  .  ,  .  Generally,  the  most  vigorous  males, 
those  whicli  are  best  fitted  for  their  places  in  nature,  will 
leave  most  progeny.  But  in  many  cases,  victory  depends  not 
so  much  on  general  vigor,  as  on  having  special  weapons,  con- 
fined to  the  male  sex.  A  hornless  stag  or  spurless  cock  would 
have  a  poor  chance  of  leaving  numerous  offspring.  Sexual 
selection,  by  always  allowing  the  victor  to  breed,  might  surely 
give  indomitable  courage,  length  to  the  spur,  and  strength 


Male  and  Female  Wood  Ducks 
Showing   sexual   differences   in  color,  from   an   illustration   by   Louis 
Agassiz  Fuertes. 

Courtesy  of  the  U.  8.  Bureau  of  Biological  Survey. 

to  the  wing  to  strike  in  the  spurred  leg,  in  nearly  the  same 
manner  as  does  the  brutal  cockfighter  by  the  careful  selection 
of  his  best  cocks.  How  low  in  the  scale  of  nature  the  law 
of  battle  descends,  I  know  not;  male  alligators  have  been 
described  as  fighting,  bellowing,  and  whirling  around,  like 
Indians  in  a  war-dance,  for  the  possession  of  the  females; 
male  salmons  have  been  observed  fighting  all  day  long;  male 
stag-beetles  sometimes  bear  wounds  from  the  huge  mandibles 
of  other  males;  the  males  of  certain  hymenopterous  insects 
have  been  frequently  seen  by  that  inimitable  observer  M, 
Fabre,  fighting  for  a  particular  female  who  sits  by,  an  ap- 


Sexual  Difference  in  Beetles 
The   males   to   the   left,   and    females   to   the   right.     From    Darwin's 
"Descent  of  Man,"  D.  Applet  on  and  Company. 


Sexual  Difference  in  Fish 

The   male    above,    the   female   below.      From   Darwin's    "Descent   of 
Man,"  D.  Appleton  and  Company. 

345 


346  Biology  in  America 

parently  unconcerned  beholder  of  the  struggle,  and  then  re- 
tires with  the  conqueror.  The  war  is,  perhaps,  severest  be- 
tween tlie  males  of  polygamous  animals,  and  these  seem 
oftenest  provided  with  special  weapons.  The  males  of  car- 
nivorous animals  are  already  well  armed ;  though  to  them  and 
to  others,  special  means  of  defense  may  be  given  through 
means  of  sexual  selection,  as  the  mane  of  the  lion,  and  the 
hooked  jaw  to  the  male  salmon;  for  the  shield  may  be  as  im- 
portant for  victory  as  the  sword  or  spear. 

Amongst  birds,  the  contest  is  often  of  a  more  peaceful 
cliaracter.  All  those  who  have  attended  to  the  subject,  be- 
lieve that  there  is  the  severest  rivalry  between  the  males  of 
many  species  to  attract,  by  singing,  the  females.  The  rock- 
thrush  of  Guiana,  birds  of  paradise,  and  some  others,  congre- 
gate ;  and  successive  males  display  with  the  most  elaborate 
care,  and  show  off  in  the  best  manner,  their  gorgeous  plumage ; 
they  likewise  perform  strange  antics  before  the  females,  which 
standing  by  as  spectators  at  last  choose  the  most  attractive 
partner.  Those  who  have  closely  attended  to  birds  in  con- 
tinement  well  know  that  they  often  take  individual  prefer- 
ences and  dislikes :  thus  Sir  R.  Heron  has  described  how  a 
pied  peacock  was  eminently  attractive  to  all  his  hen  birds. 
I  cannot  here  enter  on  the  necessary  details;  but  if  man  can 
in  a  short  time  give  beauty  and  an  elegant  carriage  to  his 
bantams,  according  to  his  standard  of  beauty,  I  can  see  no 
good  reason  to  doubt  tliat  female  birds,  by  selecting,  during 
thousands  of  generations,  the  most  melodious  or  beautiful 
males,  according  to  their  standards  of  beauty,  might  produce 
a  marked  effect. ' '  - 

These  various  theories  of  animal  color  are  unfortunately 
mainly  founded  on  an  "anthropomorphic"  basis.  If  it  is 
difficult  for  us  to  discover  the  frog  in  the  grass  or  a  lizard 
on  a  stump,  assuredly  it  must  be  so  likewise  to  the  natural 
enemies  of  these  creatures.  If  a  butterfly  or  a  toad  has  a 
foul  taste,  or  an  unpleasant  odor  to  man,  it  must  imj)ress 
its  enemies  with  the  same  unpleasant  feature.  If  the  white 
tail  of  the  rabbit  renders  him  easier  for  us  to  follow  as  he 
dashes  away,  it  must  also  aid  the  young  in  their  flight  to 
keep  near  the  mother.  It  does  not  follow  however  that  be- 
cause an  object  is  difficult  for  man  to  see,  it  is  likewise  difficult 
for  the  eye  of  bird  or  beast  to  follow  it,  or  because  another 
object  is  unpleasant  to  man's  senses,  that  it  is  also  unpleasant 
to  those  of  the  creatures  of  the  wild. 

Recent  experiments  tend  in  particular  to  refute  the  theory 
of  warning  color.     This  is  based  very  largely,  though  not 

=■  Darwin,  "Origin  of  Species,"  6th  eel.,  pp.  108-109.  By  permission 
of  D.  Appleton  and  Company. 


Color  in  Nature  347 

exclusively  on  the  colors  of  certain  butterflies,  whose  natural 
enemies  are  assumed  to  be  birds,  to  which  they  arc  supposedly 
obnoxious  through  unpleasant  taste  or  odor.  Two  distinct 
assumptions  are  involved  in  the  theory — first  that  butterflies 
are  the  natural  prey  of  birds,  and  second  that  certain  species 
are  avoided  by  the  latter  by  reason  of  some  unpleasant 
characteristic.  The  first  of  these  hypotheses  is  founded  on 
very  slender  evidence.  There  are,  it  is  true,  a  few  scattered 
records  of  birds  feeding;  on  butterflies  in  nature,  but,  consider- 
ing the  extent  to  which  birds  and  butterflies  have  been  studied 
in  the  field,  these  records  are  few  and  far  between.  But, 
confronted  by  the  paucity  of  evidence  in  one  direction,  the 
ever  facile  mind  of  the  Darwinian  turns  immediately  in  an- 
other. Butterflies  carry  with  them,  he  maintains,  evidence 
of  the  peril  in  which  they  live,  in  the  form  of  nicks  in  the 
hind  wings;  which,  since  they  frequently  have  the  form  of 
a  bird's  beak,  must  be  the  result  of  unsuccessful  attacks  by 
birds,  from  which  the  butterflies  have  made  hairbreadth 
escapes.  But  if  one  studies  a  series  of  butterflies  taken  in 
late  summer  or  early  autumn,  he  will  probably  find  the  wings 
of  nearly  all  of  them  torn  and  broken  in  such  a  way  that 
only  a  little  Darwinian  imagination  is  required  to  conjure 
up  out  of  all  these  tattered  wings  a  tale  of  the  tragedies 
which  might  have  been.  The  more  natural  interpretation  is 
however  that  the  butterflies'  wings  merely  show  the  result 
of  the  wear  and  tear  of  a  summer's  flight  through  field  and 
thicket. 

If  butterflies  are  the  natural  prey  of  birds  an  examination 
of  their  stomachs  should  prove  it.  Such  examinations  have 
been  made  for  many  years  by  the  U.  S.  Biological  Survey, 
in  the  study  of  the  relation  of  birds  to  agriculture,  but  out  of 
some  80,000  examinations  made  butterfly  remains  have  been 
found  in  but  very  few. 

The  second  point  involved  in  the  theory  has  rather  more 
evidence  in  its  support.  There  are  a  number  of  observations 
on  record  of  birds  refusing  the  strikingly  colored  and  evi- 
dently distasteful  species  of  butterflies.  These  observations 
cover  not  merely  butterflies  but  other  insects  also. 

But  there  is  also  much  evidence  to  the  contrary.  Thus 
Judd,  in  a  number  of  feeding  experiments,  has  shown  that 
obnoxious  forms  such  as  various  species  of  bugs  (TIemiptera) 
whether  warningly  colored  or  not  are  occasionally  eaten,  as 
well  as  stinging  insects  such  as  bees.  Judd's  results  must 
however  be  accepted  with  caution,  having  been  obtained  with 
caged  birds.  It  is  not  certain  that  captive  animals  show 
normal  tastes.  In  some  of  my  own  experiments  I  have  found 
that  young  birds  will  eat  almost  anything  which  is  offered 


348  Biolofjy  in  America 

them,  and  in  some  cases  will  pick  up  bits  of  leaves,  etc.,  which 
never  in  any  likelihood  form  part  of  their  normal  food  under 
mitural  conditions.  Stomach  examinations  however  show 
that  supposedly  disagreeable  insects  form  a  considerable  part 
of  birds'  food.  Thus  hairy  caterpillars,  stinging  bees  and 
wasps,  ants  and  species  of  foul-tasting  or  smelling  bugs  and 
beetles  are  eaten  by  a  great  variety  of  birds. 

Greater  doubt  is  cast  upon  the  theory  of  warning  color  by 
the  work  of  Reighard  at  the  Dry  Tortugas.  These  are  isolated 
groups  of  coral  islands  lying  off  the  Florida  coast,  and  sur- 
rounded by  coral  reefs.  Inhabiting  these  latter  are  many 
species  of  brilliantly  colored  fishes,  which  supposedly  come 
within  the  category  of  warningly  colored  forms.  Living  in 
the  same  reefs  is  a  predaceous  fish,  the  gray  snapper.  Reig- 
hard has  shown  that  the  brilliantly  colored  fishes  of  the  reefs 
are  readily  eaten  by  the  snapper,  once  they  are  outside  the 
protection  of  the  reefs.  That  the  snappers  can  distinguish 
different  colors  how^ever  and  can  learn  to  associate  them  with 
unpleasant  tastes  was  proved  by  attaching  the  stinging  ten- 
tacles of  a  jellyfish  (Cassiopea)  to  a  small  fish  upon  which 
the  snappers  commonly  feed,  and  coloring  the  prey  red. 
After  several  unpleasant  experiences  the  snappers  learned 
to  leave  the  red  fish  severely  alone,  whether  with  or  without 
the  tentacles  attached,  while  they  took  fish  which  were  colored 
white  even  though  the  stinging  tentacles  were  attached  to 
them. 

Longley  also  has  made  extensive  studies  of  these  fishes,  as 
a  result  of  which  he  finds  that  the  apparently  conspicuous 
and  contrasting  colors  of  so  many  coral  reef  fishes  are  really 
protective,  harmonizing  their  possessors  with  their  surround- 
ings and  have  no  relation  to  warning  color  whatever.  Long- 
ley  strongly  inclines  to  the  hypothesis  of  Thayer  that  the 
greater  the  contrasts  in  an  animal's  color,  the  more  readily 
will  it  harmonize  with  its  background,  a  principle  most 
strikingly  illustrated  in  the  bizarre  effects  of  our  camouflaged 
ships  in  the  recent  war. 


CHAPTER   XIV 

Aquatic  hiologij.  Oceanography,  life  of  the  sea  and  its 
environment.  Biology  of  inland  waters.  Methods  of 
studying  aquatic  life. 

The  development  of  aquatic  biology,  especially  of  its  marine 
phase,  both  here  and  abroad,  has  gone  very  nearly  hand  in 
hand  with  the  development  of  interest  in  the  fisheries".  Per- 
haps nowhere  else  in  biology  has  there  been  a  better  recog- 
nition of  the  dependence  of  commercial  interest  upon  scientific 
knowledge —  of  the  national  stomach  ii])on  the  national  brains. 
The  recognition  of  this  fact  in  Europe  led  to  the  establishment 
of  the  marine  stations  at  Kiel,  Lowestoft,  Boulogne  and  else- 
where, and  to  the  development  of  the  International  Council 
for  the  Investigation  of  the  Sea,  conducted  jointly  by  Great 
Britain,  Norway,  Sweden,  Denmark,  Holland,  Germany, 
Belgium  and  Russia,  an  enterprise  which  before  the  great 
war  was  achieving  results  of  vast  scientific  and  practical 
value,  and  which  it  is  to  be  hoped  will  soon  be  re-established, 
following  the  advent  of  peace. 

The  earliest  attempts  at  exploration  of  the  sea  were  obser- 
vations on  currents,  tides,  waves  and  temperature.  Tliere 
were  however  occasional  efforts  to  determine  the  depth  of  tjie 
ocean  by  the  earlier  navigators,  some  of  them  undertaken 
with  very  ingenious,  but  not  very  successful  apparatus. 

The  first  map  of  the  Gulf  Stream  was  published  by  Ben- 
jamin Franklin  in  1770,  and  a  few  years  later  temperature 
observations  along  the  north  Atlantic  coast,  were  made  by 
the  Englishman,  Blagden. 

The  U.  S.  Exploring  Expedition  in  1839-42,  under  the 
direction  of  Captain  AVilkes,  accomi)anied  by  the  geologist 
Dana,  made  a  number  of  deep-sea  dredgings.  The  U.  S. 
Coast  Survey  has  made  important  contributions  to  our  knowl- 
edge of  the  sea  since  the  early  part  of  the  last  century  and 
the  first  successful  apparatus  for  deej)  sea  sounding  was 
devised  by  Midshipman  Brooke  of  the  U.  S.  Navy.  As  the 
result  of  dredgings  conducted  by  tlu^  Survey  off  the  coasts  of 
Florida  and  Cuba  between  1867  and  1870,  uuder  the  direction 
of  the  elder  Agassiz,  he  reached  tlie  conclusion  that  former 
oceanic  and  continental  areas  were  similar  to  those  of  the 

349 


350 


Biology  in  America 


prosojit.  Expoditioiis  hy  several  sliii)s  of  tlie  U.  S.  Navy 
and  Coast  ►Survey  during  tlie  latter  iialf  of  the  last  century- 
have  made  valuable  additions  to  our  knowledge  of  the  sea, 
among  Avhieh  may  be  mentioned  the  cruises  of  the  "Blake" 
in  th(>  ('ari))beaii  Sea  and  tlie  Gulf  of  Mexico  from  1877  to 
18SU  under  the  direction  of  the  late  Alexander  Agassiz,  of 
the  ]\Iuseum  of  Comparative  Zoolog;\^  of  Harvard.  University, 
and  son  of  the  great  Swiss-American  naturalist. 

The  establishment  of  the  U.   S.  Fish  Connnission  in  1871 
early  led  to  marine  expeditions  conducted  under  its  auspices. 


The  ' '  Albatross  ' '  of  the  U.  S.  Bureau  op  Fisheries. 

The  pioneer  American  vessel  engaged  in  oceanography.  She  was  in 
charge  of  Alexander  Agassiz  during  his  cruises  on  the  Pacific  and  has 
added  much  to  our  knowledge  of  the  fisheries  of  the  Pacific  Coast,  espe- 
cially Alaska.  After  Smith,  in  Bulletin  of  the  U.  S.  Bureau  of  Fisheries 
for  1908. 


although  partly  financed  by  private  money.  The  Commission 
was  at  first  dependent  upon  vessels  loaned  to  it  by  the  U.  S. 
Revenue  Cutter  Service,  the  Navy,  and  the  Coast  Survey, 
but  in  1880  it  accpiired  for  its  own  use  the  steamer  "Fish 
Hawk,"  which  has  since  then  been  used  on  the  Atlantic  coast, 
partly  for  scientific  investigations  and  partly  as  a  floating 
fish  hatchery;  and  two  years  later  the  "Albatross,"  which 
has  been  mainly  employed  in  scientific  and  practical  investi- 
gations on  the  Pacific  Ocean,  but  during  the  recent  war  was 
in  naval  service  on  the  Atlantic,  and  is  at  present  temporarily 
out  of  commission  at  Baltimore. 

Much  of  the  hazard  of  the  fisherman's  trade  is  due  to  the 


Life  of  the  Waters  351 

dangerous  construction  of  his  craft.  In  order  to  minimize 
so  far  as  possible  this  danger  the  Commission  constructed  a 
model  fishing-  schooner,  the  "Grampus,"  designed  to  overcome 
some  of  the  defects  in  the  okler  type  of  boat  hitherto  in  use. 
The  construction  of  this  vessel  has  largely  revolutionized 
that  of  the  New  England  fishing  boats  and  some  idea  of  its 
influence  in  the  saving  of  wealth  and  life  may  be  gained  by 
comparing  the  loss  of  82  vessels  from  Gloucester  alone  during 
the  decade  previous  to  1883,  at  a  cost  of  $400,000  and  895 
lives,  with  that  of  the  period  from  1898-1907,  in  which  only 
one-fourth  as  many  vessels  and  lives  were  sacrificed.  Besides 
serving  as  a  model  fishing  boat,  the  ''Grampus"  has  also  been 
used  in  scientific  investigations  along  the  Atlantic  coast. 

In  addition  to  tlie  more  extended  researches  of  the  "Alba- 
tross" in  the  Pacific  considerable  local  work  has  been  done  by 
the  boats  of  the  marine  station  of  the  University  of  California, 
now  known  as  the  Scripps  Institution,  and  some  desultory 
observations  have  been  made  by  occasional  workers  elsewhere. 
There  has  been  however  no  systematic  or  concerted  program 
by  American  workers  in  the  great  field  of  oceanography 
similar  to  that  undertaken  by  the  European  countries  already 
mentioned  prior  to  the  war,  a  neglect  which  is  scarcely 
pardonable  in  view  of  the  richness  and  extent  of  our  oceanic 
domain,  the  ever-growing  cry  for  food,  and  the  financial 
resources  of  our  nation  both  public  and  private.^ 

The  biology  of  inland  waters  has  also  been  largely  depend- 
ent upon  economic  interests,  in  part  those  furthered  by  the 
Bureau  of  Fisheries,  and  in  part  by  various  state  surveys. 

The  work  of  the  oceanographer'  as  related  to  biology  is 
concerned  with  investigating  the  physical  and  chemical  con- 
ditions of  life  in  the  sea,  and  in  determining  how  marine  life 
is  related  to  these  conditions.  The  economic  phase  of  the 
science  deals  with  those  forms  useful  to  man  for  food_  or 
otherwise,  in  their  relation  to  their  environment  both  physical 
and  biological,  and  endeavors  to  discover  the  best  meansof 
obtaining,  protecting  and  increasing  them.  A  consideration 
of  this  latter  phase  may  best  be  left  to  another  chapter. 

In  a  review  like  the  present  we  must  needs  pass  over  much 
that  is  interesting  and  important  in  this  great  field,  touching 
briefly  however  on  some  of  its  most  salient  features. 

If  one  were  to  construct  a  model  of  the  earth  with  a 
diameter  of  six  feet,  a  scratch  on  the  surface  of  the  globe, 
about  one-tenth  of  an  inch  deep  would  represent  the  greatest 
irregularity  of  the  earth's  surface,  from  the  summit  of  Mt. 
Everest,  rearing  its  yet  unconquered  front  nearly  six  miles 
into  the  clouds,  to  the  abysmal  depth  of  31,614  feet  or  2,600 
»  Plans  are  at  present  on  foot,  looking  toward  such  an  end. 


352 


Biology  in  Americo. 


feet  greater  than  the  height  of  Everest,  which  is  the  greatest 
depth  yet  recorded  in  any  ocean.  This  deptli  was  found  by 
tlie  U.  !S.  8.  "Nero,"  in  the  north  raeiiic  near  the  island  of 
Guam. 

The  floor  of  the  ocean  is  covered  with  fine  ooze  composed 
largely  of  the  fragments  of  shells  of  many  kinds  of  animals 
and  some  plants,  predominant  among  which  in  many  places 


wm 

^d//.J^,. 

« 

1     ■.  -^SIB 

o 

H^k^R 

■               •         ,--  t      ' 

"4 

Hipwil  ■:  jggggi 

r-^ 

t'^'- 

■         / 
^               /         - 

E^KKm'^^/^^^B^&^b 

1* 

.•*-J- 

.    :  ! 

■<^   .    \ 

A  Eadiolarian 
Courtesy  of  the  American  Museum  of  Natural  History. 

are  the  minute  and  wonderfully  sculptured  shells  of  uni- 
cellular animals,  Radiolaria,  and  Foraminifera,  which  in  life 
are  floating  at  the  surface  of  the  sea.  The  shells  of  these 
minute  creatures  often  make  up  so  large  a  part  of  the  bottom 
deposits,  that  the  latter  are  named  from  them.  One  of  the 
commonest  of  them  is  Globigerina,  which  has  given  its  name 
to  extensive  bottom  deposits  in  the  sea.  The  shells  of 
certain  small  species  of  molluscs,  the  pteropods  or  "wing- 


Life  of  Ike  Waters  353 

feet,"  so  named  from  the  wiiig-like  expansions  of  the  muscuhir 
foot  whicli  protrnde  from  Uie  shell  and  by  means  of  whieh 
they  swim,  make  up  the  great  mass  of  tlie  ooze  in  other  places, 
hence  the  name  pteropod  ooze,  while  the  marvellously  beau- 
tiful little  diatoms,  so  named  from  Ihe  two  parts  of  the  shell, 
which  fit  together  like  the  two  halves  of  a  pill  box  predominate 
in  other  places,  producing  the  diatom  ooze,  which  is  com- 
mon in  the  circumpolar  regions,  both  north  and  south. 

Not  only  do  the  shells  of  animals  and  plants  settle  to  the 
ocean  floor,  but  contained  within  these  shells  are  their  dead 
bodies,  which  serve  as  food  for  bottom  living  animals,  whose 
digestive  tracts  are  found  full  of  mud  from  which  the  suitable 
food  material  is  digested  and  absorbed,  the  greater  amount 
being  discharged  as  waste.  It  is  thus  that  oysters  and  clams 
are  nourished,  and  as  we  enjoy  our  "bluepoints"  and  "little 
necks,"  on  the  half  shell,  we  may  relish  them  all  the  more 
to  know  that  we  too  are  scavengers  of  the  sea. 

Far  to  the  eastward  from  our  southern  coast  extends  the 
"Sargasso  Sea,"  so  called  from  the  sargassum  weed,  which 
floats  in  great  masses  at  the  surface  of  the  ocean,  and  is  borne 
out  from  the  warm  waters  of  the  Gulf  of  Mexico  by  the  Gulf 
Stream  to  the  northeast.  Making  its  own  food  from  the 
inorganic  materials  in  the  sea,  by  means  of  the  action  of 
sunlight  on  its  chlorophyl,  it  contributes  largely  through  its 
death  and  decay  to  the  food  supply  for  animals  upon  the 
ocean  floor.  Then  too  organic  dust,  containing  the  decayed 
remains  of  land  plants  and  animals,  is  carried  by  wind  and 
current  far  from  land  and  gradually  settles  to  the  bottom 
as  it  goes.  How  far  this  detritus  may  be  carried  out  to  sea 
we  do  not  know.  It  probably  varies  greatly  in  different 
oceans,  dependent  on  wind  and  current.  Volcanic  dust 
however  has  been  carried  around  the  world. 

What  are  the  conditions  of  life  for  the  "dwellers  in  the 
deep"?  How  do  they  "live  and  move  and  have  their  being" 
in  the  abysmal  depths  of  the  sea?  While  by  far  the  greater 
number  of  marine  organisms  are  found  in  comparatively  shal- 
low water,  or  floating  and  swimming  freely  at  the  surface, 
there  are  a  few  "dwellers  in  darkness,"  who,  in  the  struggle 
for  existence,  have  sought  out  the  "fathomless  depths"  as 
an  abiding  place,  there  to  live  their  lives  unknown,  save  when 
the  trawl  of  the  explorer  brings  them  forth  from  their  retreat. 

Even  at  depths  of  over  24,000  feet  life  has  been  found 
within  the  sea.  At  such  a  depth  any  object  is  under  a  pres- 
sure of  over  10,000  pounds  per  square  inch.  The  pressure 
on  the  ordinary  concrete  foundation  for  a  bridge  pier  or  a 
New  York  "skyscraper"  is  only  350  pounds  per  square 
inch,  so  that  some  of  the  inhabitants  of  the  sea  have  to 


'J 


354 


Biology  in  America 


sustain  roufjlily  llircc  times  the  pressure  on  the  foundations 
of  the  Woohvorfli  Building  or  the  Metropolitan  Life.  To 
withstand  such  a  pressure  tlie  body  of  an  animal  would  have 
to  be  surrounded  by  an  exceedingly  strong  shell,  or  else  it 
must  be  of  such  a  character  that  the  pressure  is  easily  ren- 
dered the  same  Avithin  and  without.  The  latter  method  is 
the  one  Avhich  Nature  has  adopted,  and  the  bodies  of  deep 
sea  animals  are  so  soft  and  permeable  that  they  lose  their 


Deep  Sea  Fishes  as  Seen  Against  a  Light  Background. 

Photograph  of  a  group  in  the  American  Museum  of  Natural  History 
in  New  York. 

Courtesy  of  the  Museum. 


are 


shape   very   easily   when   brought   to    the   surface    and 
consequently  hard  to  preserve  in  their  natural  form. 

Below  depths  of  three  thousand  feet  light  is  virtually  absent 
in  the  sea.  Animals  therefore  living  below  this  comparatively 
shallow  depth  are  in  perpetual  darkness,  save  for  such  light 
as  they  themselves  generate.  Many  of  these  deep  sea  forms 
carry  their  own  lanterns  about  w'itli  them  in  the  form  of 
phosphorescent  organs.  The  firefly  is  an  object  of  common 
experience  to  many  a  country  dweller,  but  only  the  ocean 
voyager  or  the  inhabitant  of  its  shores,  who  has  seen  the 


Life  of  the  Waters 


355 


crest  of  a  wave  break  into  myriad  opalescent  drops,  can  fully 
appreciate  the  beauty  and  the  wonder  of  this  strange,  un- 
canny light.  The  physiology  of  light  production  in  animals 
is  not  yet  well  understood.  It  is  known  to  be  due  however 
to  some  secretion  which  combines  readily  with  oxygen,  this 
action  producing  the  light.  Phosphorescence  is  by  no  means 
limited  to  deep  sea  animals,  nor  do  all  of  the  latter  possess  it. 
One  of  the  most   interesting  cases  of  light   production  is 


Deep  Sea  Fishes  as  Seen  Against  a  Dark  Background 
Photograph  of  a  group  in  the  American  Museum  of  Natural  History 


in  New  York. 


Courtesy  of  tfie  Museum. 


that  of  the  deep  sea  angler  fish,  Gigantactus,  where  the  snout 
is  modified  to  form  a  luminous  organ,  suspended  on  a  stalk 
above  the  head  of  the  fish.  This  organ  is  supposed  to  act 
as  a  lure  to  attract  smaller  fish  which  readily  fall  victims 
to  the  angler's  appetite. 

The  occurrence  of  eyes  in  deep  sea  fishes  foniis  a  very 
perplexing  problem.  In  some  the  eyes  are  large,  and  in  others 
extremely  small  or  entirely  lacking.  By  analogy  with  the 
cave  dwellers  among  land  and  fresh  water  animals,  we  sliould 
expect  the  deep  sea  fishes  to  be  blind.     But  on  the  other  hand 


356 


Biology  in  America 


Two  Dknizens  of  the  Deep 
Left.     An  angler  fish  which  carries  a  lure  on  its  head  to  entice  its 
prey   within   reach   of   its   capacious  jaws.      From   the   "National   Geo- 
graphic  Magazine,"  Vol.   21. 

Right.      Chiasinodus   niger,   champion    cannibal    among   fishes.      From 
Murray,   "Depths   of    the    Ocean," 

By  permission  of  the  Macmillan  Company. 

of  what  advantage  would  it  be  to  a  species  of  fisli  to  have 
light  forming  organs,  and  no  means  of  seeing  them?  The 
whole  question  of  sight  organs  and  light  production  by  deep 
sea  forms  is  a  veritable  ' '  Chinese  puzzle, ' '  which  no  one  has 
yet  had  ingenuity  enough  to  solve.     It  is  not  merely  a  ques- 


GiANT  Squid 

And   skin  of  Avhale   showing   marks  of   giant   squid  tentacles.     From 
Murray,  ' '  Depths  of  the  Ocean. ' ' 

Bj/  permission  of  the  Macmillan  Company. 


Life  of  the  Waters 


357 


tion  of  two  animals  of  the  same  species  seeing  and  recognizing 
one  another;  but  of  one  species  finding  its  prey  and  another 
escaping  from  its  enemies ;  while  in  many  cases  light  produc- 


The  Portuguese  Man  of  War,  an  Animal  "U-Boat  " 
The  balloon-like  float  filled  with  gas  secreted  by  its  walls  floats  at  the 
surface  of  the  sea,  so  that  the  colony  is  carried  hither  and  yon  by  wind 
and  tide.  Each  of  the  thread-like  processes  pendent  from  the  float  is 
an  individual  member  of  the  colony  having  its  own  special  function  to 
perform,  some  having  stinging  cells  for  capture  of  prey,  others  serving 
as  feelers  and  still  others  as  feeders,  the  mouths  and  stomachs  of  the 
colony.  By  contraction  of  the  float  the  gas  is  expelled  and  the  animal 
can  submej-ge.  A  southern  form,  it  is  often  curried  by  the  Gulf  Stream 
into  the  North  Atlantic. 

Courtesy  of  the  Amcfican  Museum  of  Xatural  Hustory. 


tion  may  be  purely  incidental  to  other  processes  in  the  life 
of  the  animal.  And  furtlicr,  the  same  ends  are  attained  in 
different   ways   in   different   species.     Nature   knows   "more 


358  Biology  in  America 

than  one  way  to  kill  a  cat,"  and,  vice  versa,  to  save  its  life 
and  preserve  its  kind. 

The  depths  of  the  sea  are  the  scene  of  many  a  drama. 
If  Science  but  had  the  key  to  Davy  Jones'  Locker,  what  a 
wealth  of  secrets,  tragic  as  well  as  comic,  she  might  reveal! 
There  is  the  fate  of  the  flatfish  who  fell  over  on  his  side 
before  he  grew  up,  and  remained  lop-sided  ever  after.  And 
there  is  the  champion  cannibal  of  the  animal  world,  Chias- 
modus  niger,  who  swallowed  his  elder  brother,  acquiring 
thereby  a  portly  figure  of  which  the  most  accomplished  gour- 
mand might  well  be  proud. 

Many  a  terrific  battle  has  been  fought  upon  the  sea — 
titanic  struggles  of  giant  squids  and  mighty  whales,  battling 
to  the  death.  Some  of  these  squids  have  a  spread  of  tentacles 
of  over  eighty  feet,  and  the  whales,  which  are  probably  the 
invariable  victors  in  these  encounters,  bear  with  them  well- 


Velella 

Ori^jinal  from  a  specimen  in  the  zoological  collection  of  the  Univer- 
sity of  North  Dakota. 

earned  decorations  as  evidence  of  their  prowess,  in  the  form 
of  circular  scars  left  upon  the  skin  by  the  suckers  of  the 
squid. 

Floating  at  the  surface  of  the  sea  is  a  host  of  beings  large 
and  small,  "creatures  of  circumstance"  driven  hither  and 
yon  by  "every  wind  that  blows."  Delicately  tinted  jelly- 
fish, Velellas  with  their  tiny  sails,  the  "Portuguese  Man  of 
War"  with  its  balloon-like  float  and  its  vicious  stinging 
tentacles  trailing  below,  the  rotund  sunfish,  and  a  legion  of 
crustaceans,  molluscs  and  many  others,  live  at  or  near  the 
surface.  What  enables  them  to  float  so  easily?  Some  are 
lighter  than  the  water,  as  the  jellyfish  and  the  sunfish,  with 
its  jacket  of  fat  beneath  the  skin.  Still  others  have  floating 
sacks  or  bladders  containing  gas,  like  the  "Portuguese  Man 
of  War,"  while  others  still,  the  great  majority,  have  pro- 
jections of  some  sort,  which  increase  their  "specific  surface," 
i.  e.,  the  ratio  between  surface  and  weight,  and  hinder  their 
sinking.     A  tin  plate  will  sink  slower  than  a  leaden  bullet 


Above.     An  Ocean  Sunfish.     Photo  by  C.  H.  Townsend. 
By  permission    of   the  New    York  Zoological   Society. 
Below.      A    Crustacean    Lakva,    slio\vin<f    flotation    spines. 
Steuer,  after  Glaus. 


Prom 


35ii 


360  Biology  in  America 

of  equal  weight,  and  a  feather  or  sheet  of  paper  falls  more 
slowly  through  the  air  than  a  tiny  lead  shot,  which  weighs 
no  more.  Wonderfully  varied  and  beautiful  are  the  devices 
with  wliich  Nature  has  furnished  both  plants  and  animals  to 
buoy  them  in  the  water.  JNIany  diatoms  are  provided  with 
long  and  exceedingly  fine  spines.  The  Radiolaria  previously 
mentioned  also  have  numerous  spine-like  processes  projecting 
from  their  shells.  Many  molluscs  have  plate  or  wing-like 
extensions  of  body  or  shell,  secretions  of  slime,  or  air  cham- 
bers which  aid  in  flotation.  But  perhaps  the  most  beautiful 
floating  structures  in  the  animal  kingdom  are  found  in  the 
Crustacea  where  antenna,  feet  and  tail  may  be  greatly  length- 
ened and  finely  branched,  forming  long,  feathery  processes 
which,  when  extended,  offer  great  resistance  to  the  water  and 
serve  admirably  in  keeping  the  animals  afloat. 

AVhile  many  marine  animals,  and  the  same  is  true  of  fresh 
water  forms,  are  inactive  swimmers,  floating  idly  at  the  sur- 
face of  the  sea ;  or  living  a  monotonous  existence  hidden  away 
in  some  obscure  niche  of  coral  reef,  or  groveling  on  the  ocean 
floor ;  there  are  others,  mariners  bold,  who  fare  forth  in  quest 
of  prey,  making  long  journeys  across  the  sea.  Naturally  the 
chief  of  these  are  the  whales  and  fishes,  most  of  whom  are 
powerful  swimmers,  which  follow  their  food  from  place  to 
place  and  whose  presence  can  usually  be  predicted  from  the 
presence  of  the  latter. 

Experimental  evidence  of  the  migration  of  fishes  has  been 
obtained  in  recent  years  by  the  International  Council  for 
the  Investigation  of  the  Sea  by  marking  fish,  and  then  record- 
ing so  far  as  possible  the  number  of  marked  fish  caught. 
This  has  also  been  practised  on  our  Pacific  salmon  and  a 
similar  method  has  been  employed  by  American  ornithologists 
for  studying  the  migration  of  birds.  This  has  been  employed 
especially  in  studying  the  spawning  migration  of  fish,  and  it 
has  been  shown  for  example  that  the  Iceland  plaice  mi- 
grate hundreds  of  miles  to  and  from  their  spawning 
grounds. 

In  1888  and  '98  two  whales  were  taken  off  the  coast  of 
northern  Norway,  each  of  which  contained  bomb  lances  of 
American  manufacture.  These  lances  had  evidently  been 
used  by  American  whalers,  which  do  not  ordinarily  cruise 
off  the  Norwegian  coasts,  and  the  capture  of  whales  contain- 
ing these  lances  in  Norway  is  probable  evidence  of  ioug 
journeys  made  by  them. 

Even  more  interesting  than  the  more  or  less  sporadic  move- 
ments of  aquatic  animals  in  search  of  food  are  their  periodic 
journeys  to  and  from  their  spawning  grounds.  The  annual 
run   of  the  salmon,   wliieh    is  described  in  another  chapter. 


Life  of  the  Waters  361 

produces  one  of  the  principal  industries  of  the  Pacific  Coast, 
while  the  migration  of  the  shad  in  the  rivers  of  the  Atlantic 
Coast,  in  former  days  brought  wealth  to  the  fisherman,  and 
delight  to  the  palates  of  those  fortunate  enough  to  feast  on 
this  delicious  food.  Now  unfortunately  owing  to  various 
factors  this  fishery  is  much  decreased. 

The  underlying  cause  of  these  breeding  migrations  of  fish 
is  still  as  much  an  unsolved  problem  as  is  that  of  bird  migra- 
tion. We  have  already  seen  the  profound  influence  which 
internal  secretions  exercise  upon  the  metabolism  and  growth 
of  animals.  We  have  also  seen  how  external  chemical  agents 
may  influence  the  reactions  of  animals  (i.  e.,  light  responses 
of  Daphnia,  etc.).  The  cause  therefore  of  these  movements 
of  certain  fish  is  undoubtedly  to  be  sought  in  the  action  of 
a  secretion  of  the  sex  glands  causing  primarily  restlessness 
and  movement  from  place  to  place  on  the  part  of  the  fish, 
and  secondarily  a  change  in  response  to  the  chemical  environ- 
ment. Thus  the  ripening  of  the  sex  cells  in  an  adromous  fish 
such  as  salmon  and  shad  with  the  coincident  formation  of 
some  internal  secretion  by  the  sex  glands,  probably  induces 
restless  wanderings  on  the  part  of  the  fish,  in  the  course  of 
which  they  come  into  regions  of  fresh  water  discharged  by 
some  river.  Turning  in  the  direction  whence  the  fresh  water 
comes,  they  are  guided  to  the  mouth  of  the  river,  which  they 
ascend,  due  to  their  inclination  to  swim  against  the  current. 
The  restlessness  which  bring-!  them  originally  into  fresher 
water  finds  further  expression  in  the  leaping  of  the  salmon 
when  they  encounter  a  fall  on  their  course  up  stream.  This 
instinct  develops  even  in  fish  which  have  been  kept  from 
birth  to  maturity  in  ponds,  for  such  salmon  have  been  known 
to  leap  out  of  the  water  onto  the  bank  to  die. 

After  spawning  and  cessation  of  the  internal  secretion  the 
fish  lose  their  tendency  to  swim  up  stream,  and  are  either 
carried  helplessly  down  by  the  current,  dying  as  they  go, 
in  the  case  of  the  adult  salmon  on  our  Pacific  Coast,  or  in  tlie 
case  of  the  young  salmon  and  the  young  and  adults  of  other 
fish  (sturgeon,  shad  and  Penobscot  salmon)  they  swim  with 
the  current  back  to  their  home  in  the  sea. 

Eels  have  a  different  history,  living  in  fresh  Avaters  and 
descending  the  rivers  to  the  sea  to  spawn.  The  mysterious 
habits  of  the  eel  have  given  rise  to  some  very  curious  tales  of 
early  writers,  according  to  whom  eels  are  spontaneously 
generated  in  mud  and  elsewhere,  or  are  formed  from  horee 
hair,  old  eel-skins,  etc.  After  spending  several  years  in  fresh 
water,  the  ripening  of  the  sex  organs  probably  induces  the 
wandering  habit  in  the  eel,  and  it  descends  the  river  to  the 
ocean,  where  it  spawns  in  realms  unknown,  but  in  any  event 


WM^Kf-A, 

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m   t '  "1^1^  ftrB^ 

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1:* 

Salmon  at  Base  of  Falls  En  "Route  to  Their  Breeding  Grounds  in 

Alaska 


"Caught  in  the  Act,"  a  Leaping  Salmon 
Courtesy  oj  the  U.  8.  Bureau  of  Fisheries. 


362 


Life  of  the  Walcrs  363 

in  water  more  than  15,000  feet  deep.^  Where  the  eggs  are  laid 
IS  not  known,  but  they  hatch  at  the  surface  of  the  sea,  into 
ribbon-shaped,  transparent  Iarva3  of  about  the  thickness  of 
a  visitmg  card.  After  about  a  year's  time,  during  which 
they  are  said  to  take  no  food,  the  larvfe  lose  their  ribbon 
shape  and  assume  the  eel-like  form.  They  now  approach  the 
coasts  and  ascend  the  rivers  in  large  numbers,  forming  what 
are  known  as  the  "eel-fares"  of  late  winter  or  early  spring. 
Like  the  Pacific  salmon,  the  adults  die  after  spawning, 
though  the  manner  of  their  demise  is  unknown. 

But  the  spawning  and  feeding  migrations  of  marine  animals 
are  not  their  only  active  movements.  Many  species  seek  the 
deeper  layers  by  day,  coming  to  the  surface  at  night.  The 
depth  of  this  diurnal  movement  varies  for  different  species, 
but  does  not  in  general  exceed  100  to  150  feet.  In  some 
species,  the  wandering  habit  is  restricted  to  the  young,  while 
in  others  migrations  are  performed  by  the  males  only.  Similar 
diurnal  movements  occur  in  fresh  water  animals,  as  already 
noted. 

There  are  also  many  species  in  which  the  young  are  found 
at  one  level,  while  the  adults  occur  at  some  other.     This  is 
notably  true  of  many  bottom-living  fishes,  such  as  the  cod 
and  halibut,  Avhose  eggs  and  young  are  found  only  at  the 
surface.     Here  it  may  be  that  differences  in  specific  gravity 
at  the  different  ages  explain  these  differences  in  distribution. 
A  word  here  may  not  be   amiss   as  to   the  tools   of  the 
oceanographer.     By  what  means  has  our  knowledge  of  the 
depths  of  the  sea  been  obtained?     In  the  study  of  oceanog- 
raphy,  as  indeed  in  many  other  of  the   complex  fields  of 
modern  science,  the  biologist  must  be  a  physicist  and  chemist 
as   well.     One    of   the   most    important    implements    of   the 
oceanographer  is  his  sounding  line.     This  is  used  not  alone 
for  measuring  depth  but  for  carrying  instruments  of  various 
sorts.     In  the  earlier  deep  sea  expeditions,  notably  those  of 
the  British  ship  "Challenger"    (1872-76)    rope  lines  were 
used  for  sounding.     On  account  of  the  heavy  strain    (the 
weight  of  20,000  feet  of  the  line  itself  in  water  was  nearly 
250  pounds)    a  rope  one  inch  in   circumference  was  used. 
The  necessary  length  of  this  rope  (over  30,000  feet)  rendered 
it  awkward  to  handle  and  necessitated  large  space  for  its 
accommodation.     For  trawling  still  heavier  lines  (up  to  three 
inches  in  circumference)  were  required,  which  were  still  more 
difficult  to  handle  and  to  store.     At  the  time  of  the  "Chal- 
lenger"  expedition.  Sir  AVilliam  Thompson    (Lord  Kelvin) 

"Recently  the  Danish  oceanographer,  Johannes  Schmidt,  has  appar- 
ently discovered  the  spawning  grounds  of  both  European  and  American 
eels  southwest  of  the  Bermuda  islands. 


364 


Biology  in  AmcTica 


was  designing  a  sounding  machine  to  be  employed  with  wire 
line,  but  wire  was  first  actually  used  for  this  purpose  by 
two  American  captains,  Belknap  and  Sigsbee,  of  the  explor- 
ing vessels,  "Tuscarora"  and  "Blake"  respectively.  They 
employed  piano  wire  about  one-tenth  of  an  inch  in  circum- 
ference, Avith  an  obvious  saving  of  space.  For  trawling 
Sigsbee  used  a  wire  rope  made  up  of  forty-two  piano  wires 
twisted  about  a  tarred  rope  at  the  center. 

For  sounding  at  great  depths  a  heavy  weight  is  necessary 
to  hold  the  line  plumb  against  the  currents  of  the  sea  and 


Sigsbee  Sounding  Machine  in  Use  on  the  "Albatross" 
Courtesy  of  the  U.   S.  Bureau  of  Fisheries. 


the  drift  or  swing  of  the  ship  even  when  at  anchor,  and  this 
descends  at  a  rapid  rate.  With  a  weight  of  thirty  to  forty 
pounds,  the  line  runs  out  at  the  rate  of  about  seven  feet  a 
second,  while  with  weights  up  to  four  or  five  hundred  pounds, 
which  are  employed  in  deep  sounding,  the  speed  is  much 
greater.  The  depth  is  determined  from  the  number  of  revo- 
lutions of  the  wheel  which  carries  the  line,  and  the  end  of 
the  sounding  is  noted  by  the  sudden  slackening  of  the  speed 
of  the  line  in  its  descent.  This  point  is  naturally  very  difficult 
to  observe  in  a  rapidly  moving  line.  To  overcome  this  diffi- 
culty sounding  machines  of  various  types  have  been  devised, 
all  of  them  founded  on  the  principle  of  Lord  Kelvin's  original 


Life  of  the  Vi^aicrs  365 

machine,  in  which  a  counter-weight  serves  to  check  quickly 
the  speed  of  the  wire,  when  the  sounding  weight  reaches  tlie 
bottom.  The  types  empk)yed  by  the  " Albatro.ss"  and  otiicr 
vessels  of  the  U.  S.  Bureau  of  Fisheries,  in  which  adjustable 
spnngs  are  used  as  brakes,  instead  of  counter-weights,  are 
known  as  the  Sigsbee  and  Tanner  machines  from  their 
designers,  Commanders  C.  D.  Sigsbee  and  Z.  L.  Tanner  of 
the  U.  S.  Navy.  These  springs  also  serve  as  "accumulators" 
to  relieve  sudden  strains  on  the  sounding  line,  due  to  tossing 
of  the  ship  in  rough  weather. 

Another  means  of  checking  the  descent  of  the  line  is  the 
detachment  of  the  sinker  when  the  bottom  is  reached.  This 
is  usually  accomplished  by  means  of  a  catch  to  which  the 
sinker  is  attached.  While  the  sounding  line  is  taut  this 
catch  is  automatically  held  in  place,  but  when  the  former 
is  slackened  the  catch  drops,  releasing  the  sinker  and  thereby 
relieving  the  pull  on  the  line. 

For  taking  samples  of  the  bottom  there  is  frequently 
attached  below  the  sounding  weight  a  metal  tube  lined  with 
tallow,  which  is  driven  into  the  bottom  by  the  impact  of  the 
sinker,  and  when  drawn  up  retains  some  of  the  bottom 
material  adherent  to  the  tallow.  Some  samplers  are  made 
with  valves  at  the  upper  and  lower  ends  of  the  tube,  which 
are  automatically  closed  when  the  sample  is  taken,  thereby 
preventing  the  escape  of  the  catch.  For  taking  larger  sam- 
ples of  the  bottom,  devices  similar  to  the  ordinary  grapple- 
dredge  used  in  excavation  work  are  sometimes  employed. 

The  measurement  of  ocean  currents  is  made  with  various 
types  of  current  meters,  some  of  which  are  constructed  on 
the  principle  of  the  instrument  used  by  the  U.  S.  AVeather 
Bureau  for  measuring  the  velocity  and  direction  of  the  wind. 
These  carry  a  vane  or  rudder  for  holding  the  meter  in  line 
with  the  current,  and  a  series  of  revolving  cones,  the  number 
of  revolutions  of  which  are  transmitted  by  a  telephone  to 
the  ear  of  the  observer  at  the  surface,  and  from  their  mimber 
per  minute  the  velocity  may  be  computed.  In  the  Eckman 
current  meter  named  from  the  Swedish  naturalist,  V.  W. 
Eckman,  which  is  much  in  use,  both  here  and  abroad,  the 
velocity  of  the  current  is  registered  by  the  revolutions  of  a 
propeller,  connected  to  a  dial  whose  hands  are  turned  by  a 
set  of  cog-wheels,  and  the  direction  recorded  by  means  of  a 
magnetic  needle,  a  box  divided  into  thirty-six  compartments, 
and  a  tube  full  of  shot  connected  to  one  of  the  cog  wheels 
of  the  dial.  As  the  latter  turns  it  feeds  the  shot  into  the 
needle  box  where  it  falls  onto  the  middle  of  the  needle,  and 
then  runs  through  a  groove  to  drop  into  one  of  the  thirty- 
six  compartments,  depending  upon  the  position  of  the  needle 


366  Biology  in  America 

in  the  box.  Thus  the  direction  of  the  current  with  reference 
to  the  magnetic  meridian  is  recorded  by  the  number  of  shot 
in  the  different  compartments  of  the  needle  box. 

The  early  occanographers  attempted  to  determine  tempera- 
tures in  the  depths  of  the  sea  either  by  bringing  up  a  sample 
of  water  from  any  given  level  in  an  insulated  container  and 
recording  the  temperature  of  the  sample  on  the  deck  of  the 
ship;  or  by  insulating  the  thermometer  itself  so  that  it  ac- 
quired the  temperature  of  the  water  very  slowly,  leaving  it 
for  a  time    (several  hours)    at  the   desired  level  and   then 
hauling  it  up  very  quickly,  so  that  its  temperature  would 
change  but  slightly,   if  at  all,  in  the   ascent.     The  former 
method  of  taking  temperatures  was  employed  by  Nansen  on 
his  polar  expeditions  and  is  still  used  to  some  extent,  but 
the  principal  method  at  the  present  time  is  the  use  of  some 
type  of  deep  sea  thermometer,  which  shall  record  the  tem- 
perature at  a  given  depth,  and  give  the  same  reading  when 
drawn  to  the  surface.     One  of  the  earlier  types  of  instru- 
ment employed,  and  the  one  used  by  the  "Challenger"  expedi- 
tion, was  a  modification  of  the  ordinary  maximum  and  mini- 
mum air  thermometer.     For  moderate  depths,   or  in  cases 
where  the  temperature  changes  uniformly  from  the  surface 
downward,  this  type  of  instrument  gives  fairly  satisfactory 
results ;  but  for  great  depths,  where  the  temperature  does  not 
change  uniformly  from  top  to  bottom,  the  results  are  un- 
reliable. 

The  later  types  of  instrument  used  are  all  constructed  on 
essentially  the  same  principle.  They  consist  of  a  thermometer 
with  a  neck  which  is  twisted  and  very  narrow  just  above  the 
mercury  bulb.  This  is  enclosed  in  a  jacket  of  very  heavy 
glass  hermetically  sealed  for  protection  against  the  enormous 
water  pressure  at  gi'eat  depths,  the  mercury  bulb  being  sur- 
rounded by  a  special  mercury  jacket  so  that  heat  may  be 
rapidly  conducted  between  the  former  and  the  water.  After 
lowering  the  thermometer  to  any  given  depth,  it  is  reversed, 
or  turned  upside  down  by  a  special  mechanism,  when  the 
mercury  column  breaks  at  the  constricted  point  and  drops 
to  the  opposite  end  of  the  tube,  where  the  reading  is  given 
on  a  standardized  scale.  Before  reversal  the  mercury  can 
pass  up  or  down  the  tube  through  the  constricted  neck  de- 
pendent on  the  raising  or  lowering  of  the  temperature ;  but 
after  reversal  and  consequent  breaking  of  the  mercury  column, 
no  more  mercury  can  pass  through  and  the  reading  gives  the 
true  temperature  except  for  a  correction  which  has  to  be 
made.  During  the  ascent  of  the  thermometer,  if  the  difference 
in  temperature  between  air  and  water  be  considerable  there 
will  be  a  slight  change  in  the  volume  of  the  broken  off  column 
of  mercury  and  the  reading  will  not  be  strictly  accurate.    A 


Life  of  the  Waters  HGT 

correction  can  be  made  for  this  error  however  if  the  tem- 
perature (liiference  be  known,  and  so  in  one  of  the  best 
types  of  instrument  an  accessory  thermometer  is  mounted 
alongside  the  principal  one,  and  thus  tlic  < liiference  in  1cm- 
perature  between  the  water  and  tlie  air  at  the  moment  of 
reading  can  be  taken  and  the  correction  applied. 

The  reversal  of  the  deep  sea  tliermometer  is  effected  eitlier 
by  means  of  a  small  propeller  wliich  commences  to  revolve  at 
the  moment  of  raising  the  thermometer,  or  more  usually  by 
means  of  a  weight  or  "messenger"  whicli  is  dropped  down 
the  line  and  trips  a  catch,  releasing  a  spring  .and  upsetting 
the  ttermometer. 

An  estimation  of  the  light  penetrating  the  ocean  may  be 
made  by  lowering  a  white,  or  variously  colored  disk  and 
noting  the  point  at  whicli  it  disappears,  and  vice  versa  by 
raising  it  from  lower  depths  and  noting  the  depth  at  which 
it  can  first  be  seen.  By  taking  the  mean  of  these  two  read- 
ings, and  comparing  it  with  some  empirical  standard,  an 
estimate  may  be  made  of  the  transparency  of  the  water. 
Electric  lights  are  also  employed  for  this  purpose.  A  better 
method  is  the  use  of  a  photometer.  Various  types  of  these 
are  employed,  mainly  designed  on  the  principle  of  exposing 
photographic  plates  or  films  contained  in  a  water-tight  holder 
for  varying  periods  of  time  and  noting  the  density  of  the 
exposure  after  development.  By  comparing  the  density  of 
these  exposures  with  a  standard  set  made  in  the  air  for 
different  lengths  of  time,  and  taking  into  account  the  angle 
of  the  sun's  rays  with  the  horizontal  and  the  turbidity  and 
color  of  the  water,  an  estimate  may  be  obtained  of  the  in- 
tensity of  the  total  illumination  at  various  depths.  If  it  is 
desired  to  determine  the  relative  penetration  of  different 
rays  of  light  (red,  green,  blue),  plates  of  colored  glass,  with 
a  known  capacity  for  absorbing  (and  therefore  cutting  off 
from  the  plate  or  film)  certain  rays  and  admitting  their 
complementary  rays,  may  be  placed  over  it.  Such  an  appa- 
ratus is  crude  at  best,  and  it  remains  for  the  investigator  of 
the  future  to  devise  a  machine  presumably  of  electrical  con- 
struction, which  will  give  an  accurate  determination  of  the 
light  at  different  depths  in  the  sea."''"  Even  with  the 
crude  apparatus  thus  far  devised  however  many  interest- 
ing results  have  been  obtained.  The  depth  to  which  light 
penetrates  the  sea  has  already  been  mentioned.  It  has  also 
been  found  that  night-time  comes  much  sooner  for  the  chil- 
dren of  the  sea  than  for  those  of  the  air,  for  when  the  sun 
is  yet  many  degrees  above  the  horizon,  the  surface  of  the 
water  acts  as  a  mirror  and  totally  reflects  its  rays.     The 

=''Sucli  apparatus  has  been  devised,  but  has  not  yet  come  into  general 
use. 


368 


Biologij  in  America 


reflection  too  is  greater  the  greater  the  depth,  so  that  at 
depths  of  a  few  hundred  feet  daylight  may  last  but  a  few 
minutes,  wliile  at  de])ths  of  more  than  3,000  feet  is  a  realm 
of  perpetual  niglit.  The  character  of  the  sea  also,  whether 
smooth  or  rough,  materially  affects  the  results — the  rougher 
the  surface,  the  greater  the  number  of  mirrors,  placed  at  many 

and  eonstantly  changing  angles, 

and  the  greater  the  reflection  of 
the  light. 

In  collecting  samples  of  water 
from  various  depths  of  the  sea 
for  chemical  analysis,  o'r  for 
studying  the  microscopic  life 
which  it  contains,  various  types 
of  "water  bottles"  are  em- 
ployed. These  can  be  closed  at 
the  desired  depth  and  the  con- 
tained sample  then  drawn  to  the 
surface  for  examination.  The 
type  in  most  common  use  at 
present  is  the  Eckman  bottle, 
another  piece  of  apparatus  de- 
signed by  the  naturalist,  V.  W. 
Eckman,  to  whom  reference  has 
already  been  made.  This  is  a 
reversible  instrument  consisting 
essentially  of  a  metal  cylinder 
with  two  lids.  In  lowering  the 
cylinder  the  two  lids  are  held 
open  so  that  water  can  pass 
freely  through  it.  After  it  has 
reached  the  desired  depth  a  mes- 
senger is  sent  down  the  line  re- 
leasing a  catch,  when  the  cyl- 
inder upsets  itself  by  its  own 
weight  and  the  lids  are  auto- 
matically closed  at  the  same  time. 
Held  in  the  frame  beside  the 
water  bottle  is  a  reversible  ther- 
mometer, so  that  the  apparatus  serves  for  taking  water  samples 
and  temperatures  at  the  same  time.  A  second  messenger 
may  be  attached  to  the  bottom  of  the  frame  in  such  a  way 
ihi\\  when  the  first  messenger  reverses  the  bottle,  the  second 
messenger  is  released,  which  in  its  turn  reverses  a  second 
bottle  and  thermometer  at  a  loAver  level,  and  so  on.  In  this 
way  a  number  of  simultaneous  observations  may  be  made 
on  a  single  line. 


JiiGELow   Water  Bottle 

With     deep     sea     thermometer 
reversed  at  the  right,  and  ' 
sengcr"  at  top. 

CourtvHji  of  flir 

V.   S.   liurcau   o}  Fisheries. 


mes- 


Life  of  the  Waters 


369 


And  liovv  does  the  biologist  obtain  his  knowledge  of  the 
denizens  of  the  deep,  of  their  comings  and  goings,  their  num- 
bers and  their  whereabonts?  The  science  of  oceanography 
goes  back  to  the  earliest  days  when  men  went  "down  into  the 
sea  in  ships"  and  east  their  nets  into  the  great  waters, 
and  the  earliest  instrnnicnts  of  the  oceanographer  were  the 
compass,  the  plnmmet,  tlie  seine  and  the  trawl.  From  all 
depths  of  the  ocean  are  bronght  forth  creatures,  great  and 
small.     With  harpoon  and  bomb   lance,  with   heavy  dredge 


Blake  Deep  Sea  Trawl 
Courtesy  of  the  U.  S.  Bureau  of  Fislieries. 


and  trawl,  with  hand  line,  seine  and  nets  innumerable,  down 
to  those  of  the  finest  gauze  used  for  sifting  the  whitest  of 
our  flours,  man  has  searched  the  seven  seas  from  top  to 
bottom  and  from  pole  to  pole  in  quest  of  hidden  treasure. 

The  inhabitants  of  the  ocean  floor  are  brought  up  from 
their  hiding  place  by  means  of  dredge  and  trawl.  The  dredge 
is  essentially  a  long  rake  or  hoe  attached  to  a  stout  iron  frame, 
with  a  bag  of  steel  or  twine  netting  projecting  beiiind.  If 
the  latter,  it  may  be  protected  by  an  external  covering  of 
canvas  open  behind.  As  the  toothed  or  straight  bar  which 
acts  as  rake  or  hoe  is  dragged  over  the  bottom,  it  scrapes 


370  Biology  in  America 

up' the  surface  of  the  hitter,  wliieh  is  caught  by  the  bag,  the 
size  of  ()I)j('('ts  retained  de])ending  upon  its  size  of  mesh. 
The  grai)i)le-dre(lge  or  scoop  may  also  be  employed  for  this 
purpose,  with  tlie  advantage  of  deeper  penetration  and  con- 
sequent capture  of  burrowing  animals  which  might  escape 
the  ordinary  diedge.  The  trawl  is  constructed  on  much  the 
same  plan  as  the  dredge  except  that  it  is  designed  to  skim 
over  the  bottom  taking  those  animals  which  live  on,  rather 
than  in  the  latter.  This  is  effected  by  supporting  the  bag, 
made  of  fish  netting  in  the  trawl,  on  runners  like  those  of  a 
sled,  whicli  slide  over,  rather  than  penetrate  into  the  bottom. 
The  smaller  dredges  in  shallow  water  are  operated  by  hand, 
but  for  the  larger  apparatus,  which  may  bring  up  tons  of 
material  at  one  haul,  heavy  lines  and  steam  winches,  operated 
on  the  deck  of  a  large  vessel  are  essential. 

For  collecting  the  organisms  present  in  the  different  levels 
of  the  sea  a  large  variety  of  appliances  have  been  devised, 
the  details  of  which  are  too  many  and  too  intricate  to  describe 
here.  For  merely  qualitative  work,  that  is,  for  determining 
the  kinds  of  organisms  present  at  different  depths,  the  appli- 
ances are  relatively  simple.  Surface  collections  are  made  with 
tow-nets,  of  materials  of  various  degrees  of  fineness,  from 
coarse  fish  netting  down  to  number  20  silk  bolting  cloth, 
with  spaces  only  1/400  of  an  inch  in  diameter.  These  are 
usually  of  conical  shape,  with  a  large  metal  hoop  at  the 
opening  and  a  small  metal  cup  or  bucket  at  the  lower  end, 
for  holding  the  catch  as  the  net  is  towed  through  the  water. 
For  collections  at  lower  levels  similar  nets  may  be  lowered 
to  any  desired  depth  and  held  horizontally  while  towed,  by 
a  weight  attached  to  the  tow-line  .iust  in  front  of  the  net. 
Or  several  of  them  may  be  attached  to  one  main  line  at  any 
desired  points  by  means  of  side  lines,  the  main  line  being 
carried  down  by  a  weight  attached  to  its  lower  end.  The 
kinds  of  organisms  present  at  different  levels  may  also  be 
roughly  determined  by  lowering  tow  nets  to  different  depths 
and  drawing  them  vertically  to  the  surface  and  then  com- 
paring the  catches  taken  in  each.  If,  for  example,  certain 
organisms  are  present  in  the  deeper  hauls,  which  are  absent 
in  the  shallower  ones,  it  may  safely  be  inferred  that  these 
occurred  only  in  the  lower  levels.  The  relative  abundance 
of  organisms  at  different  depths  may  also  be  roughly  deter- 
mined in  this  way. 

Both  of  these  methods  however  are  open  to  the  objection 
that  the  nets  catch  not  only  the  organisms  present  at  the 
particular  depth  whicli  it  is  desired  to  study,  but  also  at 
all  depths  intermediate  between  it  and  the  surface,  as  the 
nets  are  draAvn  in.     To  overcome  this  difficulty  various  types 


Life  of  the  Waters 


371 


of  closing  nets  have  been  designed,  so  constructed  that  they 
can  be  lowered  closed  to  the  desired  depth,  and  then  opened, 
either  automatically  by  the  pull  on  the  net  itself,  or  by  a 
messenger  sent  down  a  cable,  and  closed  again  by  a  mes- 
senger, after  Avhich  they  are  drawn  to  the  surface  without 
danger  of  mixing  the  catch  with  organisms  present  at  other 
levels. 

For  qualitative   work  the   loss   of  a  few   organisms  is   a 
matter  of  small  consequence,  and  accordingly  the  net  bucket 


Tow-Nets 

In  use  on  the  ' '  Albatross ' '  of  the  U.  S.  Bureau  of  Fisheries. 

Courtesy  of  the  liiircau. 


is  a  simple  affair  merely  screwed  into  a  ring  at  the  loWer  e'lld 
of  the  net,  or  tied  into  the  net  itself.  But  for  quantitative 
work  every  organism  possil)le  must  be  saved,  and  the  bucket 
is  accordingly  more  complicated,  is  readily  detacliable  from 
the' net,  and  can  then  be  opened  and  drained  into  the  con- 
tainer for  receiving  the  catch. 

The  problem  of  determining  the  number  of  organisiiis 
present  in  a  given  volume  of  water,  at  any  given  time  and 
place,  is  one  of  the  most  important,  and  withal  difficult  prob- 
lems in  oceanography.  The  quantitative  study  of  the  animals 
and  plants  in  the  sea  is  essential  to  a  knowledge  of  their  rate 


372  Biology  in  America 

of  reproduction,  their  increase  or  decrease  under  varying 
conditions  of  environment  and  their  movements  from  place 
to  place.  It  is  essential,  not  alone  to  a  science  of  the  sea, 
but  also  to  a  knowledge  of  its  economic  resources  and  the 
best  means  of  their  utilization. 

The  dependence  of  tish  and  other  animals,  which  man 
appropriates  to  his  own  use,  upon  the  lower  forms  of  life 
within  the  sea  is  matter  of  common  knowletlge.  On  our 
Atlantic  Coast  is  an  industry  with  a  value  in  round  iinmbcrs 
of  $3,7UU,U(JO  annually,  and  giving  employment  to  5894  people, 
the  menhaden  fishery.  The  menhaden  produces  6,600,000 
gallons  of  oil  every  year  which  is  used  in  making  paint  and 
varnish  and  for  other  purposes.^  After  the  oil  has  be?n 
extracted  from  the  fish  their  remains  are  dried  and 
ground  up  for  fertilizer.  They  are  also  eaten  to  some  extent. 
Professor  Peck,  in  his  study  of  the  food  habits  of  this  fish  sev- 
eral years  ago,  found  that  it  fed  exclusively  on  the  minute 
plants  and  animals  fioating  in  the  water.  In  feeding,  the 
menhaden  swims  through  the  water  with  open  mouth,  at  the 
rate  of  about  two  feet  per  second;  and  as  it  does  so  the  water 
is  filtered  through  the  gills  which  form  a  fine  sieve,  allowing 
the  water  to  pass  freely  but  straining  out  the  small  organisms 
it  contains,  which  are  swallowed  by  the  fish.  In  this  way  it  fil- 
ters about  seven  gallons  of  water  per  minute,  obtaining  from  it 
about  a  cubic  inch  of  food  material  in  five  minutes.''  From 
this  it  may  readily  be  seen  that  the  size  of  a  menhaden's  meal 
is  limited  only  by  its  industry  in  eating  it.  The  abundance 
of  oil  in  this  fish  is  due  to  its  food,  and  thus  we  have  a 
beautiful  example  of  the  value  to  man  of  the  unseen  and 
often  unconsidered  wealth  of  the  waters. 

The  menhaden  is  not  a  large  fish,  weighing  but  little  over 
a  half  pound  on  the  average,  but  one  of  the  giants  of  the  sea, 
the  blue  whale,  which  reaches  a  length  of  nearly  ninety  feet 
and  an  estimated  weight  of  seventy-five  tons,  and  is  probably 
the  largest  animal  which  ever  lived,  is  likewise  dependent  on 
the  small  creatures  of  the  sea  for  its  food.  The  fast  vanish- 
ing whalebone,  which  in  years  gone  by  played  so  large,  a 
part  in  shaping  the  fate  as  well  as  form  of  women,  is  obtained 
from  the  massive  plates  of  bone-like  baleen  which  fringe  the 
palate  of  this  and  some  other  whales,  and  serve  them  as  a 
strainer  by  means  of  which  they  obtain  their  food.  The 
whale  in  feeding  takes  a  few  barrels  of  water  into  its  capacious 
mouth ;  then  as  the  mouth  is  closed  and  the  tongue  raised  the 

»Data  for  1912  from  U.  S.  Bur.  Fish.  Doc,  No.  811,  1917. 

*  This  amount  was  estimated  by  Professor  Peck  in  the  month  of  July 
at  the  mouth  of  the  Acushnet  River  at  New  Bedford,  Mass.  It  would 
naturally  vary  greatly  at  different  seasons  and  in  different  places. 


Life  of  ike  Waters  373 

water  is  forced  out  through  the  baleen  sieves,  while  the  little 
animals  it  contains  are  held  and  then  swallowed  by  the  whale. 
The  mouth  of  a  whalebone  whale  is  a  wonderfully  efficient 
mechanism.  Were  the  whalebone  stiff  and  inelastic,  retain- 
ing a  fixed  position  in  the  mouth  of  the  whale,  when  the 
mouth  was  opened  there  would  be  left  a  wide  space  for  tlie 
escape  of  the  water  between  the  strainer  and  tlie  lower  jaw. 
But  the  plates  are  both  pliable  and  elastic  fohliiig  backward 
in  the  mouth  when  the  jaws  are  closed  and  springing  into 
position  when  these  are  opened  "like  a  bent  bow,"  thus 
closing  completely  the  mouth  opening.  But  the  tips  of  the 
plates  are  thin  and  easily  bent,  and  were  they  not  protected 
in  some  way  might  be  bent  outward  by  the  force  of  the  water 
when  the  jaws  are  closed,  allowing  some  of  its  contents  to 
escape.  To  guard  against  such  a  mishap  Nature  has  pro- 
vided the  whale  with  a  large  lower  lip,  which  overlaps  the 
tips  of  the  plates  and  holds  them  in  place. 


Jaws  of  Whalebone  Whale 
From   Sedgwick  after  Cuvicr  in  "  Eegne   Animal." 

Even  man  has  tried  the  plankton  of  the  sea  and  found  it 
good,  as  testified  by  no  less  a  personage  than  tlie  Prince  of 
Monaco  himself,  who  found  that  the  plankton  c()})epods,  wlien 
roasted  in  butter,  made  very  good  patties. 

About  thirty  years  ago  it  occurred  to  the  German  zoijhtgist, 
Hensen,  to  study  the  productivity  of  the  sea  as  a  source  of 
human  wealth,  much  as  one  would  study  the  productivity  of 
the  land,  llensen  thought  of  this  productivity  in  terms  of 
the  smaller  forms  (chiefly  microscopic)  of  plant  and  animal 
life,  which  constitute  the  food  of  fish,  and  which  he  named 
plankton  from  the  Greek  word  planktos,  wandering.  In  order 
to  study  its  abundance,  he  constructed  a  net  which  is  known 
from  its  inventor  as  the  llensen  net.  This  consists  of  an 
inverted  canvas  half  cone  at  the  top  supported  by  two  rings, 


374 


Biology  in  America 


to  tlie  lower  and  larger  of  which  is  attached  the  net  proper, 
composed  of  fine  bolting  cloth,  and  terminating  below  in  the 
detachable  bucket  which  receives  the  catch.  To  relieve  the 
strain  on  tlie  silk  this  bucket  may  be  supported  by  strings 
attached  to  the  larger  ring  above  and  the  silk  may  be  sur- 
rounded by  netting  to  protect  it  from  injury.  The  object 
of  the  inverted  cone  is  to  insure  the  passage  of  all  the  water 
through  the  net  which  enters  its  mouth,  a  large  part  of  which 
would  otherwise  flow  over  the  edge  of  the  net,  rather  than 


Hensen's  Net 
For  collecting  plankton  in  the  sea.     From  Steuer  after  Chun. 


through  its  meshes,  due  to  the  resistance  of  the  latter  to  the 
water.  By  lowering  the  net  a  given  distance  and  then  hauling 
it  to  the  surface  Hensen  expected  to  filter  all  but  the  most 
minute  organisms  out  of  a  column  of  water,  whose  height 
was  the  length  of  the  vertical  haul,  and  whose  diameter  was 
the  diameter  of  the  net  opening.  In  this  way  he  attempted 
to  compute  the  number  of  organisms  present  beneath  any 
given  area  of  the  sea's  surface  down  to  any  given  depth. 
Experiments  have  shown  however  that  not  all  of  the  water 
assumed  to  pass  through  the  net  does  pass  through,  and  that 


Life  of  the  Waters  375 

further  this  amount  is  a  variable  quantity  depending  on  the 
rate  at  which  the  net  is  hauled  through  the  water,  the  extent 
to  which  it  has  been  used  and  various  other  factors,  all  of 
which  introduce  an  error  which  is  inconstant  and  is  not 
exactly  known. 

Many  kinds  of  quantitative  plankton  nets,  both  open  and 
closing,  have  been  designed  since  Hensen's  original  device 
was  conceived.  They  are  all  however  subject  to  the  same 
errors  as  is  Ilensen's  net,  and  for  exact  work,  especially  on 
the  smallest  forms  or  nanno-plankton  (from  the  Greek  word 
meaning  dwarf)  are  very  unreliable. 

To  obviate  the  uncertainty  of  the  net  method  in  quanti- 
tative plankton  work,  the  water  bottle  described  above  has 
been  used  for  small  samples,  while  larger  samples  have  been 
pumped  from  shallow  depths  and  the  water  strained  through 
a  net  to  concentrate  the  catch.  The  former  method  is  open 
to  the  objection  that  a  small  sample  is  not  necessarily  repre- 
sentative of  a  large  area,  as  the  organisms  (especially  the 
larger  ones)  may  vary  in  abundance  from  place  to  place, 
while  the  pump  method  is  only  applicable  to  shallow  depths, 
because  of  the  great  amount  of  hose  required  at  lower  levels, 
and  is  furthermore  subject  to  one  of  the  errors  involved  in 
tlie  net  method,  namely  that  the  smallest  organisms  in  large 
measure  press  through  the  net,  while  a  further  error  is 
involved  in  the  tendency  of  many  actively  swimming,  though 
minute  animals,  to  swim  away  from  the  suction  current 
created  by  the  pump,  and  thereby  give  the  eager  and  hard- 
working biologist  the  slip.  For  great  depths  and  large  catches 
therefore  the  net  method,  with  all  its  faults,  is  the  only  prac- 
tical one  as  yet  devised. 

But  having  made  his  collections  how  does  the  biologist 
determine  the  number  of  organisms  which  they  contain?  To 
do  this  the  method  in  use  among  physicians  for  counting 
the  corpuscles  in  the  blood  has  been  adopted.  Knowing  the 
amount  of  water  filtered  through  the  net,  the  catch  is  brought 
to  a  known  concentration,  say  1/50  or  1/100  part  of  tlie 
former,  and  a  small  quantity  (usually  one  cubic  centimeter) 
of  the  latter  is  placed  in  a  glass  cell  on  the  stage  of  the  micro- 
scope, and  the  total  number  of  organisms  (in  the  case  of  the 
larger  forms)  is  counted.  In  the  case  of  the  very  small 
organisms,  such  as  the  unicellular  forms,  the  number  present 
in  several  small  parts  of  the  cell  is  counted  and  by  averaging 
these  and  multiplying  by  the  ratio  between  the  area  of  the 
cell  and  the  total  area  of  the  parts  counted,  the  number  con- 
tained in  the  former  can  be  estimated  with  a  fair  degree  of 
accuracy.  The  size  of  the  parts  is  determined  by  means  of 
squares  ruled  on  a  small  disk  of  glass  in  the  eye-piece  of  the 


376  Biology  in  America 

microscope,  each  square  covering  a  known  area  of  the  cell 
at  a  given  magnification.  Suppose,  for  example,  the  amount 
of  water  filtered  through  the  net  to  have  been  1,000,000  cubic 
centimeters  (rougiily  1100  quarts)  and  tiiat  the  catch  is  con- 
tained in  100  cubic  centimeters  of  fluid.  Suppose  further 
that  file  volume  of  the  cell  is  one  cubic,  and  its  area  ten  square 
centimeters,  and  the  area  of  each  one  of  ten  parts  counted  is 
1/10  of  a  square  centimeter.  If  these  ten  parts  contain  100 
specimens  of  some  species,  then  the  number  of  individuals 
of  that  species  in  the  1,000,000  cubic  centimeters  strained  by 
the  net  would  be  100  (number  of  individuals  counted) 
X  [10-^  (10  X  1/10)]  (ratio  of  total  cell  area  to  area  in 
which  specimens  were  counted)  X  100  -^  1  (ratio  of  volume 
of  concentrated  catch  to  volume  of  cell)  =  100,000,  or  one  in 
every  ten  cubic  centimeters  of  the  water  filtered;  assuming 
of  course  that  the  organisms  are  uniformly  distributed 
through  the  concentrated  sample  and  through  the  counting 
cell,  an  assumption  which  is  only  approximately  true.  The 
method  of  counting,  like  that  of  collecting,  is  subject  to  a 
large  error  and  the  whole  method  is  necessarily  a  very  approxi- 
mate one.  In  the  case  of  larger  forms,  which  can  readily  be 
seen  with  the  naked  eye,  such  as  shrimps,  jellyfish  and  small 
fish,  and  which  are  never  very  numerous  in  these  quantita- 
tive collections,  the  number  taken  in  the  entire  catch  is  gen- 
erally counted. 

For  counting  the  very  minute  animals  and  plants,  if  they 
are  abundant,  a  more  accurate  method  is  the  use  of  the 
centrifuge,  by  which  all  of  the  organisms  may  be  obtained 
in  the  concentrate,  if  the  speed  of  the  centrifuge  be  sufficiently 
high  and  the  time  of  centrifuging  long  enough.  Centrifuges 
are  now  made  which  will  run  at  a  speed  of  3,000-4,000  revolu- 
tions per  minute  and  carry  100  cc.  of  water.  In  general  how- 
ever the  centrifuge  method  is  applicable  only  for  the  study 
of  the  most  minute  organisms  in  small  samples  of  water. 
For  general  quantitative  studies  of  the  organisms  present 
in  the  sea  it  is  quite  impracticable. 

Yet  another  method  of  determining  the  number  of  organ- 
isms present  in  water,  is  the  Sedgwick-Rafter  method,  so 
named  from  Professor  Sedgwick  of  the  Massachusetts  Institute 
of  Technology,  the  Avell-known  sanitary  biologist,  and  JMr. 
Geo.  W.  Rafter,  C.  E.  This  has  been  employed  quite  exten- 
sively for  studying  the  organisms  (especially  the  microscopic 
plants)  present  in  drinking  waters.  In  this  method  a  given 
quantity  of  water,  usually  about  a  pint,  is  filtered  through  a 
plug  of  fine  sand  about  three-fourths  of  an  inch  deep,  which 
is  held  in  the  funnel-shaped  end  of  a  tall,  narrow  cylinder 


Life  of  the  Waters  377 

by  a  perforated  cork  covered  with  a  circle  of  fine  bolting 
cloth.  After  the  water  has  been  concentrated  to  1/50  or 
1/100  part  of  its  original  volume,  the  cork  is  removed,  the 
sand  washed  and  the  washings,  containing  the  organisms  to 
be  counted,  preserved.  Tliis  method,  like  all  others,  has 
its  advantages  and  disadvantages,  principally  tlie  latter,  but 
for  general  purposes  is  perhaps  as  little  objectionable  as  any. 

But  the  biologist  relies  not  alone  upon  devices  of  his  own 
cunning.  In  his  search  for  the  creatures  of  the  sea  he  employs 
the  whale  as  a  retriever  and  in  its  capacious  maw  finds  stores 
of  undigested  information.  The  most  primitive,  but  withal 
the  most  efficient  plankton  trap  known,  is  the  phaiynx  of 
the  ascidian  or  sea  squirt,  which  is  perforated  by  numerous 
minute  openings  through  which  water  is  strained,  the  animals 
and  plants  which  it  contains  being  retained  in  the  pharynx  to 
serve  as  the  animal 's  food.  By  studying  the  stomach  contents 
of  these  forms  much  has  been  learned  of  the  microscopic  life 
of  the  sea. 

In  studies  of  fresh  water  life  many  appliances  are  used 
similar  to  those  employed  for  marine  work,  and  but  few  of 
a  special  type  are  required.  The  methods  employed  here  are 
necessarily  simpler  than  those  used  in  investigation  of  the 
sea,  with  its  profound  depths,  its  mighty  waves  and  powerful 
currents.  In  work  upon  large  bodies  of  fresh  water  however 
such  as  our  Great  Lakes,  conditions  are  found  resembling  in 
many  ways  those  of  the  sea,  and  here  especially  must  the 
methods  and  apparatus  of  the  oceanographer  be  largely  re- 
sorted to.  Such  apparatus  as  is  peculiar  to  fresh  water 
research  is  described  in  various  technical  and  special  works, 
and  does  not  call  for  special  mention  here. 

Fresh  water  studies  in  the  United  States,  apart  from  those 
of  the  most  general  character,  have  been  prosecuted  mainly 
by  the  Massachusetts  State  Board  of  Health,  and  the  water 
works  department  of  Boston,  Mass.,  and  Brooklyn,  N.  Y., 
the  U,  S.  Bureau  of  Fisheries,  the  Illinois  State  Laboratory 
of  Natural  History  and  the  Natural  History  and  Geological 
Survey  of  Wisconsin,  The  first  two  of  these  agencies  have 
studied  the  drinking  waters  of  their  respective  eonnnunities 
primarily  from  the  sanitary  standpoint;  the  Bureau  of 
Fisheries  is  interested  primarily  in  the  commercial  utilization 
of  our  aquatic  resources,  while  the  other  institutions  have 
approached  their  problems  from  primarily  tlie  i)urely  scien- 
tific angle  with  secondary  reference  to  the  practical  results. 

We  are  accustomed  to  think  of  the  suitability  of  water  for 
drinking  and  general  domestic  purposes  in  terms  of  bacterial 
and  chemical  character,  overlooking  the  fact  tiiat  there  are 


378  Biology  in  America 

many  plants  other  than  the  bacteria  which  may  render  water 
unsuitable  for  consumption  or  other  household  uses.  Ani- 
mals too,  especially  mosquito  larvas,  present  in  drinking 
waters,  may  play  an  important  role  in  human  health.  At 
various  times  the  people  of  Boston  have  noticed  an  odor  of 
cucumbers  in  their  drinking  water.  However  delectable  the 
odor  of  cucumbers  may  be  in  a  salad,  the  inconsistency  of 
human  nature  is  such  that  Boston  people  strongly  objected 
to  it  in  their  drinking  water,  the  more  so  as  it  suggested  cer- 
tain unsavory  things  such  as  garbage  cans,  or  a  vegetable  push 
cart  in  Salem  Street.     Investigation  proved  however  that  the 


Synura 
Which  imparts  the  odor  of  cucumbers  to  water.     From  Conn,  "Pro- 
tozoa of  Connecticut. ' ' 

cucumber  was  entirely  blameless  in  the  matter,  the  guilty 
party  being  an  innocent  looking  little  animal,  the  protozoan 
Synura.  Professor  Whipple  has  compiled  a  list  of  twenty- 
two  unicellular  plants  and  animals  which  are  responsible  for 
various  odors  in  water,  ranging  all  the  way  from  the  delicate 
perfume  of  the  violet  to  the  disgusting  smell  of  the  piggery. 
Some  organisms  indeed  run  the  whole  gamut  of  odor,  de- 
pending on  the  number  present  and  the  amount  of  decom- 
position, from  the  odor  of  a  violet  or  a  geranium  to  that  of 
a  fish,  or  from  the  smell  of  newly  cut  grass  or  corn  to  that  of 
the  pig-pen.  "Things  are  not  always  what  they  seem."  On 
one  occasion  seven  out  of  ten  people  declared  that  highly  di- 
luted kerosene  smelled  like  perfumery,  which  observation  may 
be  interpreted  either  as  a  libel  on  certain  "perfumery"  or 

vice  versa. 

■When  the  shirt  of  your  bosom  returns  to  you  an  hour  be- 
fore dinner  stiff  and  glossy,  but  with  dull  brown  stains  upon 
■it,  do  not  blame  the  Chinaman  or  the  laundry  maid;  go  rather 


Life  of  ike  Waters  379 

to  headquarters  and  call  the  culprit  Crenothrix  before  the 
bar  of  outran:ed  ])rivate  opinion.  This  is  a  mieroscopic  fila- 
meiitous  plant  allied  to  the  bacteria,  which  sometimes  devel- 
ops extensively  in  water  pipes  and  deposits  iron  in  its  sheaths, 
and  to  which  the  stains  on  clothes  are  sometimes  due. 

The  work  of  the  sanitary  biologist  in  connection  with  waters 
for  drinking  and  other  domestic  uses  has  been  to  ascertain 
the  effect  of  various  organisms  present  in  the  water,  and 
the  means  of  control  and  removal  of  those  which  are  in- 
jurious. But  it  would  take  us  too  far  afield  to  go  into  this 
subject,  which  is  largely  a  technical  one  of  sanitary  engineer- 
ing. 

The  work  of  the  Bureau  of  Fisheries,  being  primarily  of 
an  economic  character,  may  perhaps  best  be  discussed  "else- 
where, which  leaves  us  the  more  purely  scientific  phases  of 
fresh  water  biology  for  consideration  here.  The  problems 
of  the  biologist  who  studies  the  life  of  inland  waters,  are 
much  the  same  as  those  of  the  biologist  upon  the  sea.  His 
work  is  to  ascertain  the  kinds  of  life  inhabiting  these  waters 
and  their  abundance  and  behavior  in  relation  to  their  en- 
vironment.  His  first  undertaking  then  is  to  study  the  physi- 
cal and  chemical  character  of  inland  w^aters  and  to  deter- 
mine the  species  of  their  animal  and  plant  iidiabitants,  while 
secondarily  there  opens  up  to  him  a  vast  field  of  questions 
relative  to  the  structure,  nutrition,  reproduction  and  move- 
ment of  these  inhabitants,  and  the  way  in  which  their  activi- 
ties are  related  to  the.  various  factors  in  their  environment. 
Most  of  these  problems  find  a  place  as  well  in  other  fields  of 
biology  to  which  reference  has  been  made  elsewhere.  AVe 
may  here  consider  a  few  which  belong  especially  in  this  dis- 
tinctive field. 

In  the  yearly  life  of  lake  or  river  there  occurs  a  cycle  of 
changes  even  more  marked  than  those  of  the  ocean.  During 
the  warm  bright  months  of  summer  the  plants  and  animals 
enjoy  the  heyday  of  their  existence  and  may  uudtiply  so 
rapidly  that  the  water  appears  "soupy"  from  them.  Espe- 
cially is  this  true  of  the  algae,  which  may  form  a  thick  green 
scum  on  the  surface  of  lake  or  pool.  But  with  the  advent 
of  the  cold,  when  lakes  and  ponds  pass  into  a  period  of  win- 
ter "sleep,"  the  life  which  they  contain  seems  almost  to 
vanish,  so  that  where  in  summer  one  might  find  a  thousand 
individuals  of  animal  or  plant,  in  winter  he  may  find  one  or 
two  or  even  none  at  all.  At  this  time  changes  occur  in  the 
water  which  may  have  a  profound  (even  a  life  and  death) 
influence  in  the  life  of  its  inhabitants.  AVhen  a  lake  is  frozen 
over  to  a  thickness  of  several  feet,  and  when  on  top  of  the  ice 
sheet  is  laid  a  blanket  of  snow,  several  more  feet  thick,  the 


380  Biology  in  America 

oxygen  content  of  the  water  may  be  so  reduced  as  to  smother 
many  of  its  inliabitants.  Tlic  sliores  of  shallow  lakes  in  the 
north,  after  an  unusually  lonji',  hard  winter,  may  be  lined 
in  spring  with  the  deca3'ing  bodies  of  hosts  of  fish,  which 
have  thus  perished.  For  aquatic  animals  require  fresh  air 
as  well  as  those  who  inhabit  terra  firma,  or  rather  the  oxygen 
which  is  dissolved  in  the  water  from  the  air.  At  least  most 
of  them  do.  Professor  Juday  at  Wisconsin  has  however  re- 
cently made  the  very  interesting  claim  that  many  species  of 
animals,  Pi-otozoa,  worms,  insect  larvfe  and  even  molluscs 
may  inhabit  the  oxygen-free  ooze  at  the  bottom  of  lakes. 
While  Professor  Juday 's  observation  needs  confirmation, 
there  is  no  question  that  many  aquatic  animals  can  live  in 
water  with  a  very  low  oxygen  content.  This  does  not  mean 
however  that  they  are  living  without  oxygen,  which  is  a  sine 
qua  nan  for  all  living  things,  but  merely  that  they  obtain 
it  in  some  other  way,  possibly  through  breaking  down  oxy- 
gen-containing substances  in  the  water,  or  it  may  be  directly 
from  their  food. 

Another  effect  of  winter  upon  shallow  lakes  is  the  con- 
centration of  dissolved  substances  in  the  lower  levels.  When 
ice  forms  on  the  surface  of  water,  any  substances  dissolved 
in  the  latter  are  in  some  mysterious  way  filtered  out  of  the 
freezing  water  and  as  a  result  become  more  concentrated  in 
the  unfrozen  water,  and  very  much  less  so  in  the  ice,  sea  ice 
containing  only  about  one-fifth  as  much  salt  as  sea  w^ater. 
This  increase  in  concentration  of  the  salt  content  of  brackish 
lakes  in  winter  may  materially  affect  the  life  which  they 
contain,  and  may  even  be  a  crucial  factor  in  determining  the 
presence  of  various  species  of  animals  in  the  water.  In 
Devils  Lake,  North  Dakota,  we  have  a  fine  example  of  one 
of  these  shalloAv,  brackish  lakes,  which  are  characteristic  of 
much  of  our  western  territory.  It  has  a  maximum  depth  of 
not  more  than  eighteen  feet,  while  much  of  the  lake  is  so 
shallow  that  it  freezes  solidly  in  winter.  In  earlier  days 
when  the  lake  was  deeper  it  abounded  in  pickerel,  and  in 
recent  years  many  efforts  have  been  made  to  restock  it.  In 
many  of  these  experiments  fish  were  kept  alive  for  weeks 
during  the  summer,  but  with  one  or  two  possible  exceptions 
no  results  of  these  experiments  were  evident  the  following 
spring.  The  probable  explanation  of  these  failures  is  that 
the  lake  had  about  reached  that  degree  of  concentration  (14,- 
000  parts  of  solids  in  1,000,000  parts  of  water)  which  the  ex- 
perimental fish  can  stand,  and  that  with  a  considerable  increase 
in  this  concentration  in  winter,  due  to  a  three-foot  layer  of 
ice,  they  were  unable  to  survive. 

Not  alone  are  dissolved  substances  separated  from  freezing 


Life  of  Ike  Waters  381 

water,  but  bacteria  also  suffer  a  "freeze  out,"  so  that  ice  har- 
vested from  sewage-contaminated  water  may  be  fit  for  drink- 
ing. Analyses  made  by  the  Massachusetts  State  Koai-d  of 
Health  and  the  North  Dakota  Public  Health  Laboratory  have 
shown  that  clear  ice  taken  from  polluted  water  may  contain 
as  low  as  1%  of  the  number  of  bacteria  present  in  the  water. 
This  is  not  true  in  all  cases  however  as  there  are  many  fac- 
tors influencing  the  result. 

Small  bodies  of  water  may  undergo  other  changes  than 
those  due  to  cold  and  heat,  freezing  and  thawing.  Many 
pools,  formed  in  spring  from  rain  or  melting  snow,  and 
swarming  with  life  in  the  early  months  of  summer,  dry  up 
completely  during  late  summer  or  early  autumn,  with  re- 
sultant destruction  of  the  life  which  they  contain,  except 
those  forms  which  are  able  to  survive  long  periods  of  drouth 
with  consequent  extremes  of  heat  and  cold. 

But  in  spite  of  the  destruction  of  life,  which  occurs  in 
these  temporary  ponds  each  year,  every  succeeding  year  they 
are  swarming  with  living  things  again  as  though  nothing 
had  happened.  What  has  become  of  this  life  meanwhile,  and 
how  is  its  cycle  maintained  in  winter  when  Jack  Frost  seizes 
the  waters  of  the  North  in  his  icy  grasp  ? 

Some  aquatic  animals  and  plants  can  over-winter  in  their 
ordinary  condition,  their  rate  of  increase  being  merely  slowed 
down  temporarily.  Many  fresh  water  copepods  may  be 
found  beneath  the  ice  in  winter  oftentimes  even  carrying  eggs, 
and  consequently  actively  reproducing.  Fresh  water  beetles 
and  some  other  insects  live  over  winter,  and  the  same  is  true 
of  rotifers,  molluscs  and  other  fresh  water  forms  of  both 
plants  and  animals.  There  is  a  case  on  recoid  of  a  frog  re- 
viving even  after  being  frozen  in  a  solid  block  of  ice.  Sir 
John  Franklin  records  the  revival  of  frogs  and  fish  after 
freezing,  a  specimen  of  carp  recovering  sufficiently  to  "leap 
about  with  much  vigor  after  it  had  been  frozen  thirty-six 
hours."  An  Alaskan  fish  has  been  reported  by  one  observer 
to  survive  freezing  for  "weeks"  and  "when  thawed  out  they 
will  be  as  lively  as  ever.  The  pieces  (which  have  been 
chopped  out  of  a  frozen  mass  with  an  axe)  which  are  thrown 
to  the  ravenous  dogs  are  eagerly  swallowed,  the  animal  heat 
of  the  dog's  stomach  thaws  the  fish  out,  whereupon  its  move- 
ments cause  the  dog  to  vomit  it  up  alive. ' '  A  Jonah  among 
the  fishes !  '^ 

On  the  other  hand  some  algas  have  been  found  living  in 
hot  springs  with  a  temperature  of  about  17()°F.  and  some 

»  The  writer  would  hesitate  to  accept  this  story  without  corroborative 
evidence.  It  has  been  cited  however  by  Eigenmann  in  Ward  &  Whip- 
ple's "Fresh  Water  Biology." 


382  Biology  in  America 

bacteria  in  tlic  spore  stage  can  survive  boiling.  Some  fish 
even  may  witJistand  a  temporatuie  of  128°F.  Many  forms 
of  aquatic  life  however  can  api)arently  only  survive  the  win- 
ter as  eggs  or  other  resting  bwlies,  which  settle  to  the  bottom, 
there  remaining  quiescent  until  the  advent  of  the  spring. 
The  eggs  of  some  crustaceans  apparently  require  to  be  frozen, 
whiU;  others  apparently  inust  be  dried  as  well  as  frozen  in 
order  to  hatch.  Many  of  them  doubtless  can  survive  long 
periods  of  drouth  and  cold.  Those  of  Estheria  have  been 
hatclied  after  being  kept  dry  for  nine  years. 

Some  aquatic  animals  survive  unfavorable  conditions  by 
surrounding  themselves  with  a  shell  or  cyst  and  lying  dor- 
mant for  a  time.  The  deeper  waters  in  some  lakes  are  ap- 
parently entirely  free  from  oxygen  in  summer.  At  tliis  time 
Professors  Birge  and  Juday  have  found  in  certain  Wisconsin 
lakes  a  Cyclops,  which  surrounds  itself  with  a  gelatinous 
shell,  and  goes  to  sleep  until  the  cooler  weather  in  the  fall 
causes  the  surface  water  to  gradually  settle  to  the  bottom, 
carrying  with  it  the  oxygen  which  it  has  absorbed  from  the 
air;  whereupon,  the  Cyclops  wakes  up,  and  throwing  off  its 
sleeping  jacket,  resumes  the  ''strenuous  life"  once  more. 

Many  crustaceans,  rotifers  and  worms  lay  two  kinds  of 
eggs — a  thin-shelled  "summer"  c^^  which  develops  quickly 
without  fertilization,  and  a  thick-shelled  "winter"  egg,  which 
after  fertilization  passes  the  winter  at  the  bottom  of  pond 
or  pool  to  hatch  in  the  succeeding  spring.  Fresh  water 
sponges  and  Bryozoa  fonn  resting  bodies  known  as  "stato- 
blasts, "  which  over-winter  in  a  resting  condition,  resuming 
active  growth  in  the  spring.  Flowering  aquatic  plants  such 
as  the  ditch  grass,  the  crowfoot  or  the  water-cress,  may  like 
land  plants,  live  for  either  one  or  more  seasons.  In  the  for- 
mer case  the  life  of  the  species  is  continued  by  seeds  or  re- 
sistant buds,  which,  like  the  "winter  eggs"  of  various  spe- 
cies of  animals,  live  over  winter  at  the  bottom  of  pool  or  pond 
to  become  active  when  the  face  of  spring  smiles  again  upon 
the  waters.  In  plants  which  live  for  more  than  one  season 
much  of  the  plant  dies  in  the  fall,  leaving  mainly  the  under- 
ground parts  persisting  over  winter,  from  which  the  aquatic 
and  aerial  stems  and  leaves  are  renewed  the  succeeding  year. 
Some  plants  however  such  as  the  hornwort  (Ceratophyllum) 
and  the  water- weed  (Elodea)  may  retain  their  leaves  through- 
out the  winter  beneath  the  ice,  and  aid  in  furnishing  oxygen 
to  support  the  animal  inhabitants  of  the  water.  Plants  and 
animals  living  in  temporary'  pools  can  only  persist  through 
the  formation  of  resting  bodies  of  some  sort — seeds,  eggs, 
etc.,    which   can   withstand    a   prolonged   period   of    drying. 


Life  of  the  Waters  383 

Such  temporary  pools  may  be  restocked,  perhaps  chiefly  from 
the  outside  by  the  action  of  wind,  birds  or  other  agencies. 

But  not  only  do  inland  waters  show  an  annual  cycle  in 
their  life,  dependent  on  the  changing  seasons;  there  may  be 
several  cycles,  some  greater  and  some  less,  in  the  life  of  lake 
or  pond  or  river.  These  cycles  depend  in  large  measure 
upon  changes  in  amount  of  food-stuffs  in  the  water.  They 
are  initiated  by  the  plants  upon  which  the  animals  are  pri- 
marily dependent  for  their  food.  When  the  melting  snows 
and  rains  of  spring  are  washing  the  surface  of  the  land  and 
draining  through  the  soil  into  lakes  and  rivers,  they  carry 
with  them  large  quantities  of  mineral  and  organic  matters 
in  solution ;  which  substances,  especially  the  latter,  with  their 
high  nitrogen  content,  furnish  abundant  food  supply  for 
plants,  which  in  turn  serve  as  provender  for  animals.  Rainy 
periods  later  in  the  season  may  be  followed  by  temporary  in- 
crease of  life  in  inland  waters.  Even  the  phases  of  the  moon 
are  seemingly  reflected  in  the  abundance  of  the  plankton,  for 
Professor  Kofoid,  in  his  extensive  studies  on  the  plankton  of 
the  Illinois  River,  found  a  series  of  monthly  increases  or 
"pulses"  of  the  plankton,  corresponding  roughly  at  least 
with  the  periods  of  full  moon,  and  possibly  due  to  the  in- 
crease of  light  at  these  periods  resulting  in  increased  activity 
of  chlorophyl-bearing  plants  in  the  water. 

The  movements  of  fresh  water  animals,  to  which  reference 
has  already  been  made,  furnish  a  fascinating  field  for  study. 
They  display  vertical  and  horizontal  migrations  similar  to 
those  of  marine  animals.  The  surface  of  a  lake  which  may 
be  swarming  with  animals  by  night,  may  be  almost  depopu- 
lated by  day.  In  the  cool  days  of  spring  and  fall  the  shal- 
low shore  waters,  readily  heated  by  the  sun,  uiay  be  an  at- 
tractive haven  for  animals  of  many  sorts,  wliich  in  the^  hot 
days  of  midsummer  seek  the  cooler  waters  farther  out  from 
shore.  But  not  only  are  the  movements  of  auimals  coutroUed 
by  evident  physical  and  clu'mical  factors,  thei-e  appear  to  be 
biological  factors  also  which  determine  them,  which  is  prob- 
ably only  another  way  of  saying  physical  and  chemical  fac- 
tors in  a  less  evident  form.  But  however  that  may  be,  fresh 
water  animals  often  congregate  in  great  swarms,  just  as  do 
insects,  fishes,  birds  or  mammals.  One  region  of  a  pond  may 
be  almost  free  from  some  species  of  aninuil,  while  anotlier 
region  only  a  few  feet  distant  may  be  so  thickly  populated 
as  to  appear  "milky"  or  "soupy"  to  the  observer.  In  one 
such  swarm  of  the  crustacean  Moina  the  writer  has  estimated 
more  than  80,000  individuals  in  a  quart  of  water.  The  cause 
of  such  swarms  is  as  yet  unknown. 


384  Biolof/y  in  America 

Such  in  brief  are  a  few  of  the  methods,  discoveries  and 
j)robleins  of  the  acjiiatic  biologist.  Since  time  immemorial 
men  have  turned  to  the  water  as  tlie  source  of  life,  and  to- 
day the  study  of  its  life,  in  spite  of  difficullies  nnd  perplexi- 
ties, is  one  of  the  most  compelling  fields  of  human  interest. 


CHAPTER  XV 

Economic  biolufjtj.  Dependence  of  nuin  upon  nature.  Ig- 
norance of  7iature  the  cause  of  economic  loss.  Conservation 
and  increase  of  natural  resources. 

An  ardent  French  entomolog-ist  in  IMedford,  IMass.,  was 
one  day  eagerly  inspecting  some  caterpillars  which  he  had 
reared  from  eggs  brought  by  him  from  Europe,  when  some 
of  them,  growing  tired  of  his  society,  made  their  escape 
and  went  on  their  way  rejoicing.  This  was  in  1869.  From 
1890  to  1900  :\Iassachusetts  spent  about  $1,000,000  to  fight 
the  gypsy  moth.  At  this  time  the  pest  being  partly  under 
control  the  efforts  were  relaxed,  with  the  inevitable  increase 
of  the  pest,  and  its  further  spread  over  a  large  part  of  New- 
England  and  into  Canada.  At  the  present  time  large  sums 
are  spent  annually  by  national,  state  and  local  agencies  for 
its  repression,  but  in  spite  of  these  efforts  large  areas  of  for- 
est are  denuded  every  year  and  the  pest  is  still  spreading. 

In  1850  caterpillars  were  devouring  the  trees  of  the  eastern 
United  States.  But  in  England  there  was  a  merry,  if  not 
melodious  little  sparrow,  who  Avas  supposed  to  enjoy  nothing 
so  much  as  a  meal  of  luscious  juicy  caterpillars,  and  so  what 
was  more  natural  than  to  bring  sparrows  from  the  old  world 
to  enjoy  the  rich  feasts  of  caterpillars  provided  by  the  new? 
But  no  sooner  was  the  immigrant  comfortably  established 
in  his  new  home  than  he  proceeded  to  follow  the  injunction 
which  the  Creator  gave  to  primitive  man — "Be  fruitful  and 
multiply  and  replenish  the  earth,"  and  today  ho  has  spread 
over  virtually  all  of  the  United  States  and  nuich  of  Canada, 
and  is  emulating  the  example  of  his  fellow  countrymen  by 
driving  before  him  many  of  the  native  inhabitants  and  in- 
heriting their  patrimony;  so  that  today  the  English  sparrow 
is  one  of  the  few  recognized  pests  among  our  birds. 

Inliabiting  the  wheat  fields  of  the  greater  pai't  of  tlie 
United  States  is  a  little  fly  known  as  the  Hessian  ily,  about 
an  eighth  of  an  inch  long,  which  lays  its  eggs  on  the  leaves 
of  the  wheat,  and  whose  larvaj  as  they  hatch  crawl  down 
tlie  leaves  to  their  base,  where  they  burrow  into  the  stem 
and  kill  the  plant.  This  fly  is  supi)osed  to  have  come  to 
America  as  an  unintentional  ally  of  King  George  with  his 

385 


The  Gypsy  Moth 

(Rijjht) — Gypsy  moth  caterpillars  on  trunk  of  tree  below  band  of 
sticky  material.  From  Burjiress,  ' '  The  Gypsy  Moth  and  the  Brown-tail 
Moth  and  their  Control,"  Farmers'  Bulletin,  No.  845. 


Trees  Stripped  by  Gypsy  IMoth  Cateki'ii.i-aks 

Courtesy  u]  the  U.  S.  Bureau  oj  Entomuluyy. 

386 


Man  and  NaUire 


387 


Hessian  solcliors ;  henee  its  name.     Another  immigrant  which 
came  to  us  in  Revolutionary  days  was  the  brown  rat.^ 

This  rat  first  crossed  the  Russian  frontier  of  Asia  in  1727 
in  such  numbers  that  it  soon  overran  Kurope,  whence  it  came 
to  America.  With  the  rat  came  its  parasite,  tlie  deadly 
Trichina,  while  more  recently  the  j^et  more  deadly  Bacillus 
pestis  of  the  bubonic  playue  has  become  established  in  Cali- 
fornia, brought  in  by  rats  from  oriental  ports.  What  a  pity 
we  cannot  return  to  Europe  with  our  compliments  all  of  our 


Field  of  Alfalfa 

Ruined  by  meadow  mice  in  the  Humboldt  Valley,  Nevada,  1907. 

Courtesy  of  the  U.  ih'.  Buriuu  of  Biohujicdl  Sinn  ij. 


undesirables,  four-legged,  as  well  as  two-legged  and  winged 
ones  as  well ! 

An  old  Welsh  legend  tells  of  the  frantic  father,  wlio  upon 
returning  to  his  home  found  his  child  missing,  and  the  dog 
which  he  had  left  to  guard  her  dripping  with  blood ;  and 
thereupon  slew  the  faithful  creature,  only  to  find  his  child 
safe  and  the  body  of  a  great  wolf  which  the  ilog  luul  sla^in, 

'  There  are  two  other  si>ef'ies  of  naturalized  rats  in  the  United  States 
— the  black  and  tlie  roof  rats.  Both  are  too  few  and  restricted  in  dis- 
tribution to  be  of  tiuich  (Vdiiiiuiic  importance,  bciii",--  liehl  in  subjection 
by  the  stronger  and  lierccr  liroun   rat. 


388 


Biology  in  America 


lying  nearby.  Somewhat  akin  to  liis  feelings  may  have  been 
those  of  the  farmer  after  sliooting  the  hawk  which  he  thought 
liad  been  preying  upon  his  chickens,  only  to  find  in  its  talons 
a  rat,  which  was  the  real  culprit.  To  kill  a  hawk  is,  in  the 
minds  of  most  of  us,  a  laudable  act,  for  are  not  all  hawks 
"hen  hawks,"  the  inveterate  enemies  of  the  poultryman  and 
of  smaller  creatures  of  their  own  kind?  So  at  least  tliought 
the  farmers  in  the  Humboldt  Valley  in  Nevada,  which  in 
1907  was  visited  by  a  plague  of  mice,  which  ate  up  every- 


Eed-tailed  Hawks 
One  of  the  commoner  ' '  hen  hawks ' '  of  the  farmer,  from  an  ilhistra- 
tion  by  Louis  Agassi/.  Fuertes. 

Coiirttn!/  of  the  U.  S.  ISurciiu  of  Biological  Survcp. 

thing  in  sight,  gnawing  the  bark  from  fruit  trees,  burrowing 
in  the  alfalfa  fields  and  destroying  the  potatoes  and  other 
crops.  Out  of  20,000  acres  of  alfalfa,  15,000  were  so  badly 
damaged  that  they  had  to  be  ploughed  under.  At  the  heifdit 
of  the  plague  in  November,  1907,  it  was  estimated  that  there 
were  from  8,000  to  12,000  mice  to  every  acre,  while  the  total 
loss  to  the  valley  was  estimated  at  $300,000.  Such  mouse 
plagues  are  no  new  occurrence.  Numerous  outbreaks  of  these 
pests  have  occurred  in  Europe  at  various  times,  their  num- 
bers sometimes  becoming  so  great  that  the  simple-minded 
peasants  half  believed  that  they  had  been  rained  upon  them 
from  the  clouds. 


The  Barn  Owl 

I'liuto    hji    Elwin    li.    ^(nihorn. 
Courtesy   of   the   Seiv    York   Zooloijirnl    Sorieti/. 


A  Pile  of  Skulls  of  Mice  and  Rats 
Contained  in  the  pellets  disgoi-jjed  by  a  family  of  l)ani  owls.     Fruin 
Lantz,  Fanners'  Bulletin,  No.  (!70. 

Courtesy  of  the  U.  S.  J'.iireiiii  of  liioloyhal  Sum  i/. 


389 


390  i^iology  in  America 

The  abundance  of  the  mice  in  Humboldt  Valley  attracted 
hawks  iu  large  inimbers  to  feast  upon  the  good  things  which 
Nature  had  so  bountifully  provided  for  them.  But  failing 
to  recognize  in  the  hawks  their  best  ally  in  their  war  against 
the  mice,  the  ignorant  residents  seized  their  guns  and  pro- 
ceeded to  slay  their  best  friends;  so  that  a  traveler  through 
the  valley  observed  twenty-nine  of  these  birds  hanging  on 
the  fences. 

So  too  thought  the  legislature  of  Pennsylvania  when  in  1895 
they  passed  the  notorious  "scalp  act,"  providing  for  a  bounty 
of  fifty  cents  for  every  hawk  or  owl  killed  within  the  state, 
as  a  result  of  which  half-baked  legislation  more  than  100,000 
valuable  birds  were  killed,  at  an  expense  of  nearly  $100,000 
to  the  state  for  bounties  and  notary  fees,  and  an  estimated 
loss  of  more  than  $4,000,000  from  the  increase  of  harmful 
rodents  resulthig  from  the  destruction  of  their  enemies,  the 
hawks  and  owls.  And  yet  all  this  in  the  short  space  of  a 
year  and  a  half.  Fortunately  the  legislature  soon  recovered 
its  equilibrium  and  the  law  was  repealed. 

But  how  do  we  know  that  the  hawks  and  owls,  or  at 
least  most  of  them,  are  the  farmer's  friends  rather  than 
his  enemies?  A  few  specific  facts  will  best  answer  this 
query. 

Hawks  and  owls  have  a  habit  of  throwing  up  the  undi- 
gested parts  of  their  food  in  the  form  of  pellets  containing 
the  hair,  bones,  feathers,  etc.,  of  their  prey.  For  many  years 
a  pair  of  barn  owls  were  wont  to  nest  in  the  tower  of  the 
Smithsonian  Institution  in  Washington.  An  examination  of 
two  hundred  pellets  found  beneath  their  nesting  site  revealed 
451  skulls,  of  which  412  were  those  of  mice,  20  of  rats,  20 
of  shrews,  one  of  a  mole,  while  only  one  was  that  of  a  bird 
(sparrow). 

In  the  "Pacific  Eural  Press"  for  Oct.  23,  1897,  is  an  account 
of  a  pair  of  these  same  birds  nesting  in  a  pigeon  house,  whose 
owner,  supposing  that  they  were  feasting  on  his  pigeons,  shot 
the  male  and  trapped  the  female.  Upon  examining  the  nest 
he  found  ten  young  "gophers"  (ground  squirrels?)  in  it, 
whereupon  he  promptly  released  the  female. 

Of  146  stomachs  of  the  great-horned  owl  examined,  only 
31  contained  poultiy  and  8  other  birds,  the  remainder  con- 
taining various  mammals,  insects  and  miscellany. 

An  examination  of  562  stomachs  of  the  red-tailed  hawk 
showed  remains  of  poultry  or  game  birds  in  54,  other  birds 
in  51,  mice  in  278,  other  mammals  in  131,  insects  in  47,  mis- 
cellany in  59,  and  nothing  in  89. 

It  was  primarily  to  answer  questions  such  as  these  that 
the  U.  S.  Biological  Survey  was  organized  in  1885,  becoming 


Man  and  Nature  391 

a  bureau  of  the  Department  of  Agriculture  some  twenty  years 
later.  This  bureau  has  contributed  more  to  our  knowledge, 
both  scientific  and  economic,  of  tiie  birds  and  maimiials  of 
North  America  than  any  other  agency.  We  cannot  in  so 
brief  a  compass  do  justice  to  its  work,  but  a  bird's  eye  glance 
at  it  may  be  of  interest.  At  the  outset  it  nuist  be  admitted 
that,  like  a  lusty  youngster,  the  Bureau  has  fre(iuently  out- 
grown its  clothes,  and  frequently  also  has  it  wandered  far 
from  its  parental  home.  In  how  far  the  hair-splitting  re- 
finements in  the  classification  of  birds  and  mammals  in  wliich 
it  has  often  indulged  itself  may  be  of  value  either  to  science 
or  agriculture  is  open  to  question,  but  there  can  be  no  ques- 
tion of  the  value  l)oth  to  science  and  agriculture  of  the  great 
bulk  of  its  work.  The  vast  amount  of  data  which  it  has 
gathered  relative  to  the  classification  and  distribution  of 
North  American  birds  and  mammals  are  indispensable  to 
any  study  of  the  influence  of  environment  upon  their  evolu- 
tion and  spread,  wliile  its  studies  on  the  migration  of  birds 
have  furnished  invaluable  data  not  oidy  for  the  study  of  the 
causes  of  this  as  yet  inexplicable  phenomenon,  but  also  for 
the  formulation  of  laws  for  their  protection. 

Prior  to  the  establishment  of  the  Bureau  our  knowledge 
of  the  food  habits  of  birds  was  the  result  of  a  few  sporadi( 
investigations.  Since  its  inception  it  has  conducted  a  sys- 
tematic study  of  this  question,  including  the  examination  ot 
some  80,000  stomachs  of  many  species  of  birds,  as  a  result  of 
which  we  now  have  very  definite  information  regarding  the 
economic  value  of  most  of  our  wild  birds,  and  can  pursue  a 
rational  program  for  their  protection.  I\Tany  instances  of 
the  value  of  birds  to  the  farmer  which  have  been  sliown  by 
these  investigations  could  be  cited,  in  addition  to  those  al- 
ready given  of  the  food  habits  of  hawks  and  owls.  One  of 
the  worst  foes  of  the  horticulturist,  especially  the  fruit  grower 
of  California,  is  the  scale  insect.  This,  as  its  name  implies, 
is  a  tiny  scale-like  creature  of  no  resemblance  externally  to 
an  insect,  but  containing  evidence  of  its  relationshi]i  in  its 
internal  structure  and  its  development.  I  have  no  data  rela- 
tive to  losses  from  scale  insects,  but  an  estimate  of  a  cost  of 
10  to  25  cents  a  tree  as  a  protective  tax  against  the  San  Jose 
scale,  gives  some  idea  of  the  burden  they  put  upon  the  fruit 
grower.  We  shall  have  more  to  say  regarding  Ihese  insects 
later  on,  but  for  the  present  we  note  that  the  Bureau  has 
shown,  what  was  formerly  unknown,  that  many  species  of 
birds  prey  upon  them,  while  of  some  species  they  form  the 
favorite  food. 

The  habitue  of  field  and  fon^tst,  who  seeks  his  favorite  haunts 
after  the  first  snow  fall  of  the  winter,  is  likely  to  encounter 


392  Biology  in  America 

companies  of  little  birds,  who,  in  spite  of  winter  and  its  snow, 
are  busily  engaged  in  reaping  the  plentiful  harvest  of  the 
weeds.  Flitting  from  stem  to  stem,  they  pick  out  the  seeds 
from  their  siiells,  wliile  others  follow  in  their  wake  to  pick 
up  the  gleanings  from  the  snow.  The  late  Dr.  Judd  of  the 
Survey,  in  his  studies  of  the  food  liabits  of  sparrows,  exam- 
ined a  piece  of  ground  eighteen  inches  square  in  a  patch 
of  smartvveed  where  several  species  of  sparrows  had  been 
feeding.  On  this  patch  he  c(mnted  "113U  half  seeds  and 
only  2  whole  seeds.  During  the  ensuing  season  no  smart- 
weed  grew  where  the  sparrows  had  caused  this  extensive  de- 
struction."- It  has  been  estimated  that  in  Iowa  alone  a 
single  species,  the  tree  sparrow,  destroys  in  one  year  875  tons 
of  weed  seed,  and  tliat  in  tlie  United  States  as  a  whole 
the  clilferent  species  of  native  sparrows,  numbering  more 
tlum  one  hundred,  save  $35,000,000  for  tlie  farmers  every 
year. 

Heretofore  the  protection  of  our  birds  has  been  more  or 
less  of  a  hit  or  miss  undertaking,  principally  the  latter. 
"While  the  birds  might  be  fairly  well  protected  in  one  state, 
they  received  little  or  no  protection  in  another.  Realizing 
these  inequalities  and  injustices  in  our  local  laws,  the  Sur- 
vey, aided  by  bird  lovers  throughout  the  ccnntrv,  drew  up 
and  put  through  Congress  in  1913  the  m'grarory  bird  law, 
which  gives  the  nation  control  of  all  m'^rrating  birds  within 
its  domain.  \^y  this  aet  all  such  are  afforded  uniform  pro- 
tection throughout  the  United  States,  and  while  the  law  is 
imperfect  in  itself  and  as  yet  inade(}uately  enforced,  its  re- 
sults even  so  have  been  very  gratifying.  Especially  is  this 
true  of  game  birds.  Previous  to  the  passage  of  this  law  the 
shooting  of  game  birds  during  the  spring  migration,  when 
the  birds  were  en  route  to  their  breeding  grounds,  and  in 
many  instances  had  actually  begun  to  breed,  was  permitted 
by  some  states.  With  the  abolition  of  the  spring  shooting  has 
come  a  notable  increase  of  the  birds  in  the  fall,  which  is  the 
legitimate  time  for  hunting.  In  1916  a  treaty  was  drawn  up 
between  the  United  States  and  Canada,  providing  for  the 
protection  of  migrating  birds  between  the  two  countries.  This 
treaty  has  recently  been  made  effective  through  the  passage  of 
the  necessary  legislation  by  both  countries.  The  Lacey  Act, 
passed  in  1900,  which  controls  the  shipment  of  game  from 
one  state  to  anotlicr,  and  has  been  an  efficient  check  to  the 
pot  hunter  who  ships  his  game  to  large  cities  for  market,  is 
another  outcome  of  the  Survey  's  efforts  to  protect  our  wild 
birds  and  mammals. 

^'Judd,    "Tlie    Kelatinii    of    Sparrows    to    Agriculture,"    Biol.    Survey, 
Bull.   15. 


Man  and  Nature  393 

But  the  protection  of  the  farmer's  friends  is  only  one  of 
the  Bureau's  manifold  activities.  Many  a  wild  creature  is 
the  farmer's  inveterate  enemy  and  does  untold  damage  to 
his  cattle  or  his  crops.  Witli  the  drain  on  the  world's  re- 
sources caused  by  the  great  war  and  its  aftenuath  of  an- 
archy and  ruin,  and  the  ever-mounting  cost  of  existence,  it 
behooves  us  to  close  up  every  leak  where  natural  wealth  is 
wasted.  Within  the  borders  of  our  country  today,  we  are 
harboring  a  host  of  jiarasites,  who  are  "eating  us  ont  of  house 
and  home."  On  our  western  ranges  we  are  feeding  our 
wolves  and  coyotes  $20,(U1U,()()()  worth  of  stock  every  year; 
to  ground  squirrels,  mice  and  other  rodents  we  contribute 
i|>ir)U,0()(),0()0  worth  (;f  f(()d  crops,  vvliilc  the  brown  rat  levies 
an  additional  toll  of  $2()(),UUU,0U0.  These  figures  perchance 
sound  excessive.    Let  us  analyze  them  a  little  closer. 

"As  an  indication  of  the  losses  due  to  ])r,'(latory  animals 
it  may  be  stated  that  the  ehairman  of  the  State  Live  Stock 
Board  of  Utah  estimates  an  annual  loss  in  that  region  amount- 
ing to  500,000  sheep  and  4,000,000  pounds  of  wool.  Tlie  presi- 
dent of  the  New  Mexico  College  of  Agriculture,  as  a  result  of  a 
survey  of  conditions  in  tliat  state,  estimates  an  aiuiual  loss 
there  of  3  per  cent  of  the  cattle,  or  34,000  head,  and  105,000 
sheep.  A  single  wolf  killed  by  one  of  the  Bureau  hunters  in 
southern  New  Mexico  was  reported  by  stock  owners  of  that 
vicinity  to  have  killed  during  the  precediug  six  months  150 
head  of  cattle  valued  at  not  less  than  $5,000.  In  July,  1917, 
two  male  wolves  were  killed  in  Wyoming  which  in  May  had 
destroyed  150  sheep  and  7  colts.  Another  pair  of  wolves 
killed  near  Opal,  Wyoming,  were  reported  to  have  kiUed  about 
$4,000  worth  of  stock  a  year.  Another  Wyoming  wolf, 
trapped  in  June,  1918,  had  killed  30  cattle  during  the 
spring. ' '  ^ 

"In  the  Arnold  Arboretum,  Jamaica  Plains,  ^^.Tas-;.,  dnriiig 
the  winter  of  1903-4,  meadow  mice  destroyed  tl'  uisands  of 
trees  and  shrubs,  including  apple,  maple,  sumac,  barberry, 
buckthorn,  dwarf  cherry,  snowball,  busli  honeysuckle,  juniper, 
blueberry,  dogwood,  beech,  and  larch.  Plants  in  luirsery  beds 
and  acorns  and  cuttings  in  boxes  especially  were  harmed.  .  .  . 
During  the  winter  of  1905-0  a  small  orchard  of  apple  and 
pear  trees  near  Washington,  D.  C,  was  under  observation 
from  October  to  Ai)ril.  Attacks  by  meadow  mice  l)egan  in 
the  early  fall,  possibly  in  August.  They  were  contiiuied  dur- 
ing every  succeeding  montli,  being  greatest  during  two  short 
periods  of  snow.  .  .  .  Adjoining  the  orchard  was  a  tangUnl 
thicket  on  low,  moist  ground,  in  which  meadow  mice  were 
abundant. 

'Eeport  of  Chief  of  Bureau  of  Biological  Survey,  191S,  p.  :5. 


394 


Biology  in  America 


"On  IMarch  Ifi,  1906,  I  found  that  of  380  apple  trees, 
164,  or  over  43  ])(>r  cent,  were  ruined,  being  completely  gir- 
dled, some  to  a  height  of  8  to  ]()  inches  above  the  ground. 
Thirty-six  others,  nearly  10  per  cent,  were  less  badly  injured, 
while  180,  or  47  per  cent,  apparently,  were  uninjured.  Of 
200  pear  trees  in  the  orchard  50  were  more  or  less  seriously 
damaged.  The  injury  to  these  was  intlicted  early  in  the 
fall.  .  .  . 

"In  December,  1903,  I  examined  a  large  orchard  in  Marion 


Meadow  Mice 
A  great  pest  wliicli  sometimes  become  so  numerous  as  to  form  veritable 
plagues.     From  an   illustration  by  Morita. 

CotirtiHU  of  the  U.  ;S'.  liurcitii  of  Jiioloyicul  Purvey. 

County,  Kan.,  where  field  mice  were  causing  much  damage. 
.  .  .  The  orchard  comprised  480  acres  and  contained  about 
26,000  trees,  mostly  apple,  eight  to  ten  years  transplanted. 
The  trees  averaged  about  4  inches  in  diameter,  but  many 
measured  5  or  6  inches.  The  majority  were  headed  low,  their 
outer  drooping  branches  touching  the  ground.  In  the  spring 
of  1903  corn  had  been  planted  by  listing  it  in  the  open  spaces 
between  the  rows  of  trees ;  but  owing  to  an  unusually  wet  sum- 
mer, the  crop  had  been  abandoned,  and  sunflowers  and  other 
weeds  and  grasses  luid  made  a  luxuriant  growth  throughout 
the  orchard.     Over  much  of  the  area,  ai)parently,  no  attempt 


Man  and  Nature 


39; 


had  boon  made  to  cut  down  tlie  weeds;  and  where  tliey  liad 
been  mowed  they  liad  been  raked  into  piles  and  not  burned 
or  removed. 

"In  this  neglected  orchard  field  mice — the  prairie  vole — 
had  found  a  congenial  home.  Already  abundant  in  1002, 
they  bred  plentifully  in  the  open  fall  of  that  year  and  in  the 
early  warm  spring  of  19();i  The  ensuing  moist  sununer  also 
was  favorable  for  continued- reproduction,  and  by  llie  fall 
of  1903  they  were  present  in  hordes.  All  the  orchards  of 
the  neighboriiood — a  comparatively  level  upland  prairie — had 


Apple  Tree  Girdled  by  Meadow  Mice 
CoiirtcsD  of  the  I'.  S.  liurtitu   of  Blvlogivnl  Sum  if. 


been  neglect<'d  and  all  were  invaded  by  mice;  buf  the  one 
above  mentioned  was  the  largest  and  most  neglected,  and 
therefore  it  suffered  most  severely.  By  Decend)er  18,  the 
date  of  my  first  visit,  mice  had  wholly  or  partially  girdled 
at  the  surface  of  the  ground  fully  5, 000  apiile  ti'ces  and  had 
denudeil  of  bark  numy  of  the  low  branches.  The  owners  of 
the  orchard,  thinking  that  none  of  the  trees  could  survive  the 
injuries,  then  estimated  their  loss  at  fi-om  $'25,000  to  $30,000. 
"Examination  showed  that  the  ground  evi'rywhere  was 
honeycond)ed  by  mouse  burrows  and  tunnels  to  a  depth  of 
3  or  4  inches,  and  that  the  surface  was  almost  covered  by  a 


396  Biology  in  America 

network  of  rninvays  of  the  prairie  vole.  Upon  di<2:ging  into 
tlie  burrows  at  the  base  of  apple  trees,  I  found  many  twigs, 
4  to  H  inclu'S  long,  that  had  been  entirely  stripped  of  bark 
and  left  lying  in  little  piles.  I  had  no  difficulty  in  finding 
where  the  twigs  ha<l  been  severed  fi-om  low-growing  branches 
and  the  ti])s  of  sj)routs,  and  in  distinguishing,  by  the  smaller 
tooth  marks,  the  cutting  done  by  mice  from  that  done  by 
rabbits.  Whether  the  twigs  had  been  first  stored  and  after- 
wards fed  upon  in  cold  weather,  I  was  unable  to  determine, 
for  1  found  none  with  bark  remaining  upon  them.  Piobably 
they  were  carried  to  the  burrows  merely  for  leisurely  but 
innnediate  consumption, 

"Contrary  to  the  usual  habits  of  voles  in  our  Northern 
States,  this  injury  had  been  done  during  mild  weather.  Up 
to  December  18  the  season  had  been  very  warm  and  open.  No 
snow  lay  on  the  ground  for  more  than  twenty-four  hours. 
Ordinary  food,  such  as  grass,  seeds,  and  grain,  was  abun- 
dant, so  that  the  only  explanation  for  the  injury  to  trees 
seems  to  be  the  vast  numbers  of  voles  present  and  their  pref- 
erence for  a  partial  diet  of  bark. 

"Voles,  however,  were  not  the  only  animals  abundant  in 
the  orchard.  Rabbits,  both  cottontails  and  jacks,  were  there 
in  great  numbers,  and  already  had  begun  to  eat  the  bark  on 
the  trunks  of  some  of  the  trees  and  on  the  low  limbs,  and  to 
cut  the  tips  of  branches  and  sprouts  within  their  reach. 
Later,  when  cold  weather  set  in  and  snow  covered  the  ground, 
they  also  seriously  damaged  the  trees. "  * 

"Experiments  show  that  the  average  quantity  of  grain 
consumed  by  a  full-grown  rat  is  fully  2  ounces  daily.  A 
half-grown  rat  eats  about  as  much  as  an  adult.  Fed  on  grain, 
a  rat  eats  45  to  50  pounds  a  year,  worth  about  60  cents  if 
wheat,  or  $1.80  if  oatmeal.  Fed  on  beefsteaks  worth  25  cents 
a  pound,  or  on  young  chicks  or  squabs  with  a  much  higher 
prospective  value,  the  cost  of  maintaining  a  rat  is  propor- 
tionately increased.  Granted  that  more  than  half  the  food 
of  our  "rats  is  waste,  the  average  cost  of  keeping  one  rat  is 
still  upward  of  25  cents  a  year. 

"If  an  accurate  census  of  the  rats  of  the  United  States  were 
possible,  a  reasonably  correct  calculation  of  the  minimum 
cost  of  feeding  them  could  be  made  from  the  above  data. 
If  the  nund)er  of  rats  supported  by  the  people  throughout 
the  United  States  were  equal  to  the  number  of  domestic  ani- 
mals on  the  farms— horses,  cattle,  sheep,  and  hogs— the  mini- 
mum cost  of  feeding  them  on  grain  would  be  upward  of  $100,- 
000,000  a  year.     To  some  such  enormous  total  every  farmer, 

^Lantz,  "An  Economic  Study  of  Field  Mice."  Biol.  Survey,  Bull, 
31,  pp.  25-9. 


Man  and  Nature 


397 


and  indeed  every  householder  who  lias  rats  upon  liis  prem- 
ises, contributed  a  share.''' 

"(Corn)  sufit'ers  <ireater  injury  Iroiii  rats  than  any  other 
crop  in  the  TTnited  States.  Besides  depredations  on  newly  sown 
seed,  the  animals  attack  the  grrowino;  jyrain  when  in  the  milk 
stage.  They  cliinb  the  upright  stalks  and  often  strip  the 
cobs  clean  of  grain.  The  writer  has  seen  whole  fields  of  corn 
so  destroyed  and  in  many  cases  has  observed  parts  of  fields 
amounting  to  several  acres  practically  ruined.  A  writer  in 
the  "American  Agriculturist"  reported  an  instance  in  which 


>  ■•^^*  '^ 


The  Cottontail  EABurr   in   its   Form 

From  Lantz,  ' '  Cottontail  Rabbits  in  Eolation  to  Trees  and  Farm 
Crops,"  Farmers'  Bulletin,  No.  702. 

Courtesy  of  the  U.  S.  Burvmi  of  Biolof/icul  Kuririj. 

rats  destroyed  three-fourths  of  the  com  on  13  acres  of  land. 
In  1905  a  large  portion  of  the  crop  grown  on  the  I'otomac  flats 
near  Washington  was  destroyed  by  rats.  .  .  .  A  farmer  liv- 
ing near  Grand  River,  Iowa,  relates  the  following  experience: 

"  'We  had  about  2,000  bushels  of  corn  in  3  cribs  to  which 
rats  ran,  and  they  ate  and  destroyed  about  one-fourth  of  the 
corn.  IMuch  of  it  was  too  dirty  to  put  tliruugli  the  grinder 
until  it  had  been  cleaned  an  ear  at  a  time.  All  the  time  we 
were  poisoning  and  trapping  the  rats.  We  killed  as  high  as 
300  rats  in  two  days  and  could  liardly  miss  them.     They  de- 

^At  the  present  time  these  figures  would  be  considerably  greater. 


398  Biology  in  America 

stroyod  iiinro  llian  enough  corn  to  pay  taxes  on  400  acres 
of  land.' 

* '  The  destruction  of  feed  stuffe  by  rats  is  a  serious  loss  not 
only  on  the  farm  but  in  almost  every  city  and  village  in  the 
wliole  country.  Often  through  carelessness  or  the  indiffer- 
ence of  servants,  the  bin  or  barrel  in  which  feed  is  kept  is 
left  uncovered,  and  rats  fairly  swarm  to  the  nightly  feast. 
In  some  cases  investigated  in  Washington,  D.  C,  the  loss  was 
e<iua]  to  5  or  10  per  cent  of  the  grain  l)()ught.  A  grocer  was 
buying  feed  for  two  horses  and  several  hundred  rats;  the 
horses  were  fed  at  regular  intervals,  the  rats  nearly  all  the 
time.  In  the  cases  of  establishments  keeping  from  fifty  to 
a  hundred  horses,  the  loss  of  feed  in  the  course  of  a  year 
often  amounts  to  a  large  item. 

"Rats  destroy  also  many  eggs  both  on  farms  and  in  cities. 
Fresh  as  well  as  incubated  eggs  are  eaten  by  these  rodents. 
Commission  men  and  grocers  complain  much  of  depredations 
upon  packed  eggs.  Those  at  the  top  of  a  case  are  broken  by 
these  animals,  and  parts  of  the  yolks  run  down  and  stain  the 
unbroken  ones.  Often,  however,  rats  carry  away  eggs  with- 
out breaking  them,  and  display  much  ingenuity  in  getting 
them  over  obstacles,  as  up  or  down  a  stairway.  On  a  level 
surface  the  rat  rolls  the  egg  before  him,  but  he  can  easily 
carry  it  between  a  paw  and  his  neck  and  chin,  while  going 
upon  three  legs. 

''A  commission  merchant  in  "Washington  relates  that  he 
once  stored  in  his  warehouse  100  dozen  eggs  in  a  wooden  tub 
with  a  lid  of  boards  nailed  on.  Rats  gnawed  a  hole  through 
the  tub  at  the  top  and  carried  away  all  but  281/2  dozen,  leav- 
ing no  shells  or  stains  to  show  that  any  had  been  broken.  .  .  . 

"Rats  are  very  destructive  to  tame  pigeons,  attacking  es- 
pecially young  squabs,  but  destroying  eggs,  also.  They  often 
show  great  cunning  in  finding  entrances  to  the  cages.  A 
fancier  residing  in  Washington,  D.  C,  missed  many  of  his 
squabs  and  was  satisfied  that  the  only  opening  by  which  an 
animal  could  enter  was  the  exit  at  the  top  of  the  flying  cage. 
He  closed  the  opening  and  set  a  trap  there,  in  which  he  caught 
a  large  rat.  The  animal  had  climbed  the  wire  netting  on  the 
outside  and  descended  it  on  the  inside  to  reach  the  pigeons. ' '  ^ 

And  all  these  like  so  many  other  losses,  are  largely  the  re- 
sult of  ignorance  or  carelessness. 

Not  only  are  these  destroyers  living  at  our  expense,  but 
many  of  them  are  repaying  our  indulgence  by  spreading  dis- 
ease among  man  and  beast.  We  shall  see  elsewhere  how  the 
rat,  and  to  a  lesser  extent,  the  ground  squirrel  in  California 
are  a  constant  menace  to  our  health,  while  in  many  of  the 

"Lantz,  "The  Brown  Eat  in  the  United  States,"  pp.  18-23. 


Man  and  Nature 


3!).') 


western  states,  the  wolf  and  coyote  are  spreading  rabies  anions 
our  stock  and  thus  indirectly  endan{z:eriii<i:  human  life  itself. 
One  of  the  most  important  activities  of  the  l^ureau  at  the 
present  time  is  the  destruction  of  these  noxious  aniinals.  It 
keeps  a  force  of  about  thi-ee  hnn<li-ed  men  in  the  field  traj)- 
ping,    shooting    and    poisoning    ])redatory    animals,    mainly 


^^^^!'f*^'^ 


.Fi.  h'Ai-.'^'f:-  'CP  -ff 


The  Common  Eat 

Whose  board   bill   is  costing  us  i7i   the  neighborhootl   of  .^^OOjOOOjOOO 
annually.     Prom  a  drawing  by  E.  R.  Kalnibach. 

Courtesy  of  the  U.  H.  Ruremi.  of  Hioloyicdl  Hurvey. 


wolves,  coyotes,  wild  cats,  aiul  to  a  lesser  extent,  bears  and 
mountain  lions.  Definite  results  are  difficult  to  show  as  a 
result  of  this  campaign,  but  a  very  nuirked  reduction  in 
stock  losses  has  been  noted  in  those  regions  where  it  has  bern 
consistently  carried  on. 

Let  us  turn  aside  for  a  moment  and  follow  one  of  the  Sur- 
vey's hunters  on  his  lonely  way  as  he  pursues  the  big  gray 


400  Biology  in  America 

wolf  of  our  western  plains.  AVhetlicr  tliese  animals  are  in- 
telli<;eiit  or  not  we  shall  leave  to  the  psychologists  to  decide, 
if  they  can:  their  actions  in  any  event  certainly  appear  so. 
The  wolf  is  a  highly  picturesque  and  interesting  outlaw.  His 
teeth  arc  turned  ''against  every  man  and  every  man's  hand 
against  hiiu."  With  every  sense  rendered  keen  by  the  sharp- 
ness of  liis  struggU'  for  existence  lie  lias  become  on  the  one 
lunul  a  most  skillful  thief,  and  on  the  other  a  most  elusive 
criminal.  The  most  tempting  bait  will  not  decoy  him  into 
a  trap,  while  the  least  scent  of  man  is  a  warning  of  dan- 
ger. The  trapjier  as  he  goes  afield  soon  strikes  some  cattle 
path  or  trail,  winding  in  and  out  among  the  hills.  He  fol- 
lows this  until  he  finds  two  bushes  growing  a  few  inches  apart. 
Between  these  he  makes  a  little  hole  in  which  he  sets  his  trap 
and  firinly  fixes  it  to  a  sunken  stake  or  heavy  stone.  Upon 
the  trap  he  lays  a  sheet  of  paper  which  is  well  covered  with 
fine  earth  and  bits  of  sticks  or  leaves  or  straw,  causing  the 
surface  of  the  ground  over  the  trap  to  appear  as  natural  as 
possible.  Over  all  a  little  water  is  sprinkled  and  nearby  a 
few  drops  of  wolf  perfume  or  scent.  Xow^  a  wolf's  notions 
as  to  perfume  are  not  exactly  in  accordance  with  our  own.  A 
very  choice  preparation  for  a  wolf  is  prepared  by  allowing 
a  chuid<  of  raw  meat  to  rot  until  it  "smells  to  Heaven."  To 
this  is  addetl  some  animal  oil  such  as  sperm  or  lard  oil  and 
then  a  little  musk  or  beaver  castor.  In  preparing  the  trap 
great  care  must  be  taken  to  avoid  leaving  any  trace  of  hu- 
man scent.  This  is  prevented  by  wearing  old,  well  scented 
gloves  and  covering  the  shoes  with  scent. 

Or  the  trapper  finds  beneath  some  overhanging  ledge  of 
rock,  high  on  the  slope  of  a  barren  hill,  tracks  it  may  be 
leading  to  a  den,  or  the  bones  of  some  unfortunate  victim, 
and  digging  out  the  den  a  family  of  puppies  is  discovered 
and  their  earthly  career  is  quickly  ended.  Or  the  freshly 
killed  carcass  of  beef  or  sheep  is  found,  which  is  poisoned 
witli  strychnin  and  when  the  wolf  returns  for  a  second  meal, 
this  meal  becomes  his  last. 

The  war  on  prairie  dogs,  ground  squirrels,  pocket  gophers 
and  other  rodents  is  largely  conducted  with  poisoned  grain. 
A  few  kernels  of  grain  poisoned  with  strychnin  placed  in  a 
burrow  will  effectually  dispose  of  the  occupants  in  short 
order. 

"As  an  illustration  of  the  effectiveness  and  economy  of  the 
methods  of  destroying  these  pests,  a  badly  infested  plot  of 
320  acres  was  chosen  for  a  demonstration  in  northern  Ari- 
zona. One  man  spent  a  day  distributing  poison  over  this 
area,  at  a  total  cost  for  labor  and  material  of  $0.79.  The 
following  day  1,641  dead  prairie-dogs  were  picked  up  from 


Gray  Wolf  and  Pups 
Killed  by  one  of  the  government  hunters. 


«.                     -•» 

OxE  OF  THE  Many  Species  of  Ground  Squirrels 

Against   which  the  government  is  now  waging  an  active  campaign. 

Courtesy  of  the  U.  t>.  Bureau  of  Biological  Hurvcy. 


401 


402  Biolog]/  in   Awrrira 

tliis  trai't.  AVitli  tlie  imraber  which  must  have  (lied  in  their 
holes,  tlierc  can  he  litth'  question  that  more  than  2,000  prairie- 
dogs  were  destroyed  in  this  experiment. 

"More  than  3,5()(),()()0  acres  of  Government  land  have  been 
practically  freed  from  these  pests.  "^ 

One  of  the  worst  ])()achers  in  the  West  is  the  jack  rabldt, 
which  one  may  occasionally  see  from  the  railway,  loping  leis- 
urely across  the  prairie,  or  sitting  up  on  Ins  haunches  to  gaze 
w^ith  fearless  curiosity  at  the  passing  train.  Besides  helping 
himself  libei-ally  to  the  farmer's  grain  and  hay,  he  varies  his 
diet  now  and  then  by  nibbling  a  circular  strip  of  bark  from 
the  fruit  trees,  "girdling"  and  thereby  killing  them.  A  fa- 
vorite pastime  in  the  Southwest  has  been  the  rabbit  drive. 
On  a  given  day  a  troop  of  boys  and  men  with  dog.s  and 
horses  form  a  line  about  a  given  area  and  then  riding  to 


■5^ 


■^  ■      ■    ^---      J) 

The  Pocket  Gopher 
One  of  our  numerous  mammal  pests.     From  an  illustration  by  E.  T. 
Seton. 

CoiirtiKi/  of  the  f.  ,S'.  Hiircdu  of  liiol<)<jlc<il  t^urici/. 

and  fro,  with  the  aid  of  the  dogs,  proceed  to  "beat  up"  the 
doomed  rabbits,  and  gradually  converging,  drive  them  toward 
the  town  where  the  residents  are  waiting  to  receive  them,  not 
with  open  arms,  but  with  clubs  and  shot  guns.  In  this  way, 
not  only  is  the  neighborhood  rid  of  a  host  of  pests,  but  a  large 
supply  of  meat  is  provided. 

The  trap  is  also  an  effective  weapon  in  the  campaign  against 
the  furry  pests  of  field  and  orchard. 

Through  the  watchful  activity  of  the  Bureau  it  is  probable 
that  many  another  catastrophe  similar  to  the  introduction  of 
the  English  sparrow,  gypsy  moth,  and  Hessian  fly  has  been 
averted.  Some  years  ago  the  mongoose  applied  for  admis- 
sion to  the  United  States,  and  a  few  iiulividuals  did  in  fact 
gain  an  entrance.  The  mongoose  has  been  called  the  "cat 
of  I'haraoh"  and  strangely  enough  it  has  also  been  named 
"Pharaoh's  mouse."  It  is  a  traditional  enemy  of  serpents 
and  "according  to  Aristotle  and  Pliny  (it)  first  coats  its  body 

'  Keport  of  Chief  of  Bureau  of  Biological  Survey,  1918,  p.  4. 


Man  and  Nature 


403 


with  a  coating  of  mud,  in  wliich  it  wallows,  and  then  with 
this  armour  can  dci'y  the  s(>ri)('nt.  Topscll  icjls  the  tale  bet- 
ter. The  lehneuiiion  burrows  in  the  sand,  and  'when  the 
aspe  espyeth  her  threatening  rage,  presently  turning  about 


San  Sost  Scale 

a,  Adult  fenialo  sr-alo;  b,  male  scale;  e,  younjj  scales;  d,  larva  just 
liatdied ;  d',  same,  much  enlarged;  e,  scale  removed,  showing  body  of 
female  beneath;  f,  body  of  female  insect,  more  enlarged;  g,  adult  male 
of  the  San  Jose  scale.  From  Quaiutance,  "The  San  Jose  Scale  and  its 
Control,"  Farmers'  Bulletin,  No.  050. 

tUiurivsy  0}  the  U.  >S'.  ISiinnii  of  Kntnmnliiiiti. 

her  taile,  provoketh  the  ichneumon  to  combate,  and  willi  an 
open  mouth  and  lofty  head  doth  enter  the  list,  to  her  owne 
perdition.  For  the  iciineumon  being  nothing  afraid  of  this 
great  bravado,  reeeivetli  tlie  encounter,  antl  taking  the  head 
of  the  aspe  in  his  mouth  biteth  that  off  to  prevent  the  east- 


404 


Biology  in  America 


ing  out  of  her  poison.'  In  the  "West  Indies  the  animal  has 
been  described  as  fearlessly  attacking  the  deadly  Fer  de  Lance 
and  receiving  its  bites  with  inipnnity;  it  is  also  added  that  it 
will  eat  the  leaves  of  a  particular  plant  as  an  antidote !  The 
real  explanation  of  the  result  of  these  encounters  is  of  course 
the  agility  of  the  Ichneumon."  ^ 

The  mongoose  preys  on  mice  and  rats,  but  unfortunately 
attacks  poultry  and  wild  birds  as  well.  It  has  been  intro- 
duced into  Jamaica  where  it  has  proven  a  nuisance  through 


Mass  of  San  Jose  Scales  on  Tree  Trunk  x  30 

From  Quaintance,  ' '  The  San  Jose  Scale  and  its  Control, ' '  Farmers ' 
Bulletin,  No.  050. 

Cmtrtcsy  of  the  U.  .S.  Biircaii  of  Entomology. 

its  dei)redations.  By  the  passage  of  a  law  placing  the  im- 
portation of  foreign  animals  under  the  control  of  the  Sec- 
retary of  Agriculture,  the  Bureau  has  been  able  to  prevent  its 
establishment  in  the  United  States. 

Monstrous  as  is  the  tax  which  we  pay  to  our  four-footed 
foes,  it  is  small  in  comparison  with  the  tribute  levied  by  our 
winged  enemies.  Estimates  of  so  uncertain  a  sum  as  the  loss 
caused  by  insects  are  bound  to  vary,  but  even  accepting  the 

'"Cambridge  Natural  History,"  Mammalia,  p.  409.  By  permission 
of   the   Macnullau   Company. 


Man  and  Katur6 


405 


minimum  figure  of  $1,000,000,000  annually,  the  amount  is 
surely  ample.  Early  awake  to  the  danger  from  insect  posts 
Congress  in  1854  appointed  an  entomologist,  whose  work  was 
at  first  conducted  under  direction  of  the  Commissioner  of 
Patents,  but  upon  the  organization  of  the  Department  of 
Agriculture  in  1889  was  embodied  in  the  Division,  now  the 
Bureau  of  Entomology. 


Apples  Infested  with  San  Jose  Scale 

From  Quaintance,  "The  San  Jose  Scale  and  its  Control,"  Farmers' 
Bulletin,  No.  650. 

Courtisi/  of  tlin  T'.  ."?.  liiirrdit   of  lUitomology. 

In  the  eighties  the  orange  and  lemon  groves  of  California 
were  threatened  with  ruin  by, the  innocent  looking,  bnt  de- 
structive scale  insect,"  to  which  Ave  luive  already  referred. 
Soon  the  Bureau  of  Entomology  had  experts  on  tiie  ground 
learning  all  they  could  about  the  vicious  stranger.  In  tlie 
course  of  their  studies  they  h'arni'd  that  the  scale  insects  were 
natives  of  Australia,  whence  they  had  been  imjiorted  into 
California  on  young  orange  trees  in  18G8.     Now  it  occurred 

"The   lluted   scale. 


4(J() 


Biology  in  America 


to  them  tliat  in  tlio  native  liome  of  the  scale  might  perchance 
be  found  some  natural  enemy,  wliieh  if  introduced  into  Cal- 
ifornia migiit  drive  out,  or  at  least  hold  in  cheek  the  terrible 
scale.  And  so  one  of  them  journeyed  to  Australia  and  there 
he  found  the  ladybird  beetle,  Vedalia,  which  i)reyed  upon  the 
scale.     Ami   this  he   brought   back   with   him   to    California, 


The  Pitiful  Ladybird 
a,  Rootle ;  b,  larva  ;   e,  pupa ;   d,  blossom  end  of  pear,  showing  scales 
with  larvco  of  ladybird  feeding  on  them,  and  i)upic  of  ladybird  attacdied 
Avithin  the  calyx.     From  Quaintance,  ' '  The  San  Jose  Scale  and  its  Con- 
trol,"  Farmers'  Bulletin,  No.  650. 

CoHrtcsij  uf  the  U.  .S".  Biircait  uf  Entomoloffy. 


wher(^  it  throve;  and  making  war  upon  the  scale  it  has  ever 
since  heUl  it  in  check,  delivering  the  orange  and  the  lemon 
from  their  threatened  destruction. 

Similar  attempts  have  been  made  for  several  years  in  the 
war  on  the  l)rown-tail  and  gypsy  moths,  which  are  so  destruc- 
tive to  fruit  and  shade  trees  in  New  England,  and  while  the 
results  have  been  less  spectacular  than  in  the  ease  of  the 


Man  and  Nature  407 

scale  insects,  tlie  prospects  for  the  ultimate  control  of  these 
pests  in  this  way  are  promising. 

In  Hawaii  the  ravages  of  the  sugar-cane  weevil,  wliicli 
bores  its  destructive  way  into  the  sugar  canes,  have  been  ma- 
terially reduced  by  the  introduction  of  a  pai'asitic  fly  from 
British  New  Guinea.  Anotlier  dread  enemy  of  the  Hawaiian 
sugar  planter  is  a  little  bug  known  as  a  "leaf  hopper,"  which 
was  probably  introduced  from  Australia  about  1898.  Soon 
it  was  doing  so  much  damage  that  the  production  of  one  large 
plantation  fell  from  10,954  tons  in  19U4  to  82G  tons  in  1906. 
Meantime  however  the  expert  entomologists  were  on  the  trail 
of  the  leaf  hopper,  pursuing  it  with  jjarasites,  furnished  by 
Australia.  Their  first  attempts  were  failures,  but  these  were 
shortly  followed  by  success.  The  parasites  throve  and  soon 
had  the  pest  so  well  under  control  that  this  same  plantation 
yielded  in  1907  11,630  tons  of  sugar. 

But  the  path  of  the  experimental  entomologist  is  by  no 
means  always  strewn  with  roses.  There  is  in  P^urope  a  fly 
which  parasitizes  the  caterpillar  of  the  brown-tail  motli,  which 
is  covered  with  poisonous  hairs.  These  hairs  are  sufificiently 
poisonous  to  produce  a  serious  eruption  in  man  known  as  the 
"brown-tail  rash."  Now  there  is  in  this  country  a  variety 
of  the  same  species  of  parasite,  which  does  not  attack  the 
brown-tail's  larva  because  apparently  it  is  susceptible  to  the 
poison  of  the  latter 's  hairs.  Upon  the  discovery  of  these  facts, 
the  European  race  was  imported  into  the  United  States  in 
large  numbers,  and  in  the  following  year  was  found  to  be  at- 
tacking the  caterpillars  of  the  brown-tail  moth.  The  enthusi- 
asm of  the  entomologists  aroused  by  this  discovery  was  short 
lived  however,  for  the  next  year  none  of  the  caterpillars  was 
attacked.  The  explanation  of  this  unfortunate  state  of  af- 
fairs proved  to  be  that  the  foreigners  were  interbreeding  with 
the  natives,  and  their  offspring  had  lost  the  immunity  enjoyed 
by  their  European  cousins. 

In  1796  an  epidemic  broke  out  among  Pennsylvania  cattle, 
which  was  traced  to  a  herd  from  South  Carolina  which  al- 
though healthy  themselves  were  infectious  to  olher  animals. 
In  1868  Texas  cattle  shipped  into  Illinois  and  Indiana  brought 
disease  into  these  states  causing  such  extensive  ravages  that 
the  eastern  states  became  alarmed,  not  only  because  of  the 
loss  to  stockmen  themselves,  but  because  of  dreaded  injury 
to  human  health  from  the  consumption  of  tliseased  meat. 

The  cause  of  all  this  trouble  is  a  protozoan,  parasitic  in  the 
blood  of  cattle,  where  it  produces  a  disease  somewhat  sim- 
ilar to  malaria  in  man;  while  the  disseminator  of  infection  is 
the  cattle  tick,  tlie  life  history  of  which  is  briefly  as  follo\ys. 
After  gorging  itself  upon  the  blood  of  its  unfortunate  vie- 


408 


Biology  in  America 


tim,  the  fertilized  female  drops  to  the  ground,  and  deposits 
on  the  avoi-age  about  2,000  sliiny  brown  eggs  about  1/50 
inch  in  diameter.  These  hatcli  in  about  three  weeks  in 
summer,  while  in  winter  incubation  may  require  nearly  six 
months.  After  hatching  the  young  tick  becomes  ambitious, 
crawling  up  blades  of  grass,  stems,  or  posts  and  there  waiting 
like  Mr.  Micawber  "for  something  to  turn  up."  Meantime 
it  keeps  its  forelegs  waving  to  and  fro  ready  to  grasp  the 


"Screw  Worm"  and  Cattle  Tick 
A — A  "screw  worm,"  the  larva  of  a  fly,  so-called  from  the  rings  of 
spines  about  tlie  body. 

C  and  B — Cattle  ticks  before  and  after  feeding. 

donrtiKji  itj  the  V.  S.  liiiniiK  of  Kiitomolog}/. 


hair  of  the  first  animal  which  comes  its  way.  It  may  thus 
patiently  await  its  victim  for  more  than  five  months,  under 
favorable  conditions,  but  the  victim  failing  to  arrive  it  finally 
dies.  If  an  unlucky  steer  comes  its  way  it  grasps  its  hair 
and  crawling  up  attaches  itself  to  the  skin.  Here  it  molts 
twice,  is  fertilized,  gorged  with  blood,  and  drops  to  the  ground 
to  repeat  the  vicious  cycle. 


Man  and  Nature  409 

By  careful  quarantine  measures  and  the  treatment  of  tick- 
infected  cattle  with  an  arsenical  dip  the  Department  of  Ag- 
riculture has  freed  some  500,000  square  miles  of  the  quaran- 
tined area  in  tlie  southern  states  from  a  pest,  which  at  one 
time  was  estimated  to  cost  the  nation  from  $-10,1)00,000  to 
$100,000,000  annually.  For  the  cattle  tick  not  only  does  vast 
damage  by  transmission  of  disease,  but  as  a  blood-sucker 
levies  a  tremendous  toll  upon  the  cattleman.  It  has  been  es- 
timated that  as  much  as  200  pounds  of  blood  may  be  lost  by 
an  animal  in  a  single  season,  while  in  the  case  of  the  horse 
tick,  as  much  as  fourteen  pounds  of  ticks  have  been  dropped 
from  one  animal  in  three  days,  and  probably  as  much  more 
was  still  attached.  But  further,  the  tick  has  a  companion 
in  villainy,  for  in  the  sores  which  it  makes  the  screw-worm 
fly  deposits  its  eggs,  from  which  the  larvas  burrow  into  the 
body  of  the  unfortunate  victim. 

Our  knowledge  of  the  Hy  and  the  mosquito,  upon  which 
the  campaign  against  these  pests  has  been  based,  is  largely 
due  to  the  work  of  the  Bureau  of  Entomology. 

But  space  will  not  permit  further  discussion  of  our  prog- 
ress in  wealth,  health  and  happiness,  due  to  the  work  of  the 
economic  entomologist. 

The  work  of  ridding  the  South  of  the  cattle  tick  is  in 
charge  of  the  Bureau  of  Animal  Industry  in  the  Department 
of  Agriculture,  whose  duty  also  it  is  to  wage  increasing  war- 
fare upon  the  animal  diseases  which  are  a  constant  mciuice 
to  the  nation's  supply  of  meat,  leather  and  other  animal 
products.  Scab  mites,  which  in  years  past  levied  a  heavy 
toll  upon  the  cattle  grower,  have  been  nearly  exterminated ; 
the  foot  and  mouth  disease,  which  in  1914  was  epidemic  in 
twenty-two  states,  and  was  seriously  threatening  the  live  stock 
industry  of  the  country,  was  stamped  out  after  a  hard  fight ; 
hog  cholera,  ever  a  serious  drain  upon  the  hog  industry,  is 
gradually  being  brought  under  control  by  the  use  of  a  serum 
and  other  measures,  and  an  active  campaign  is  now  under 
way  for  the  suppression  of  tuberculosis  in  hogs  and  cattle, 
a  disease  serious  not  alone  to  the  animal  industry,  but,  wiien 
present  in  dairy  cattle,  a  very  probable  nuMuice  to  human 
life  itself.  The  work  of  the  Bureau  in  safeguarding  our 
meat  supply  is  mentioned  in  another  chapter. 

In  addition  to  its  campaign  against  diseases  both  animal 
and  hunum,  the  Bureau  is  also  actively  engaged  in  the  in- 
crease and  improvement  of  our  supi)lies  of  meat,  milk  and 
other  animal  products,  ])ut  details  concerning  this  work  would 
carry  us  too  far  afield. 

But  the  economic  biologist  is  concerned  not  alone  with 
holding  fast  that  which  he  hath.     1 1  is  duty  it  is  likewise  to 


410 


Biology  in  America 


seek  "fresli  fields  to  eonquor"  and  to  lay  new  tribntes  npon 
the  altar  of  coninierce.  Tlic  earliest  record  of  the  ini})orta- 
tion  of  animals  of  eoinmercial  importance  from  one  country 
to  anotlier  is  the  story  of  the  Chinese  princess,  who,  defyinf? 
imperial  edicts  for  love  of  her  betrothed,  bronji'ht  some  eggs 


The  Quarter-Acre  Bamboo  CIrove  at  the  C.  J.  Edwards  Place 
Near   Abbeville,   Louisiana.      Planted    in    1898,    in    1915    it   produced 
over  200  large  shoots. 

Coiirtcsir   of  Die    I'.   S.    Hiircdii    oj  I'Innt    Induntrii. 


of  the  silkworm  over  the  mountains  to  her  Indian  lover,  while 
in  the  days  of  Justinian  silkworms  were  brought  to  Con- 
stantinojjle  by  Persian  priests,  who  concealed  the  eggs  of  the 
moth  in  hollow  canes. 

America  is  a  great  experiment  station  for  the  breeding  of 
new   animals   and  plants,   where   the   "stranger   within   our 


Man  and  Nature 


411 


gates,"  whether  man  or  lieast  or  flower,  is  jriveii  tlie  best 
opportunity  for  niakiii<;-  the  most  of  himself.  When  we  tliink 
of  our  immigrants  solely  in  terms  of  pettieoats  and  pan- 
taloons we  should  not  overlook  the  fact  that  many  of  thciii 
are  clad  in  furs  or  feathers  or  in  the  raiment  of  the  lilies, 
and  among-  these  innnigrants  we  find  not  only  tlie  Knglish 
sparrow  and  the  rat,  the  pugilists  and  sneak  thieves  of  the 
lower  strata  of  animal  society,  hut  the  ring-necked  pheasant 


The  Udo 
Thrives  in  the  eastern  United  States  and  California.     The  bhuiched 
shoots  make  a  very  delit-ions  salad  vegetable.     Introduced  by  the  l^.  S. 
Department    of    Agriculture    from    Japan,    where    it    is   a    very    pojjular 
article  of  food. 

Courtesy   of  the   U.   S.   lUirrdu   of  Phnit   IniUtslfy. 


and  the  reindeer,  the  aristocrats  of  the  animal  world;  while 
if  Russia  has  contributed  her  thistles  as  well  as  her  anar- 
chists to  our  society,  no  less  has  she  given  us  her  alfalfa  and 
her  fruits,  as  well  as  her  musicians  and  her  scholars. 

With  the  inrush  of  the  eager  throngs  of  Europe  and  of 
Asia  to  our  shores,  with  our  rapidly  growing  population,  and 
occupation  of  our  public  donuiin ;  it  behooves  us  to  "take 
thought  for  the  morrow"  in  order  that  we  may  have  the 
wherewithal  to  feed  and  clothe  and  shelter  our  future  liordes. 
So  Uncle  Sam,  ever  mindful  of  the  welfare  of  his  children, 


412 


Biology  in  America 


has  establislicd  ainoiig  liis  many  agencies  for  this  purpose,  the 
Offi('(^  of  Forci*:!!  Seed  and  Plant  Introduction  of  the  Uureau 
of  IMant  industry  in  tlie  Department  of  Agriculture,  whose 
duty  it  is  to  go  into  the  "uttermost  parts  of  the  earth"  and 
bring  back  to  us  its  treasures.  From  the  Asian  steppes  to 
the  jungh's  of  the  tropics  its  exph)r(M-s  liave  gone,  and  from 
the  fertih'  ish^s  of  Japan  to  tlie  (k'serts  of  Arabia,  in  their 
search  for  the  useful  and  the  beautiful,  to  enrich  our  fields 
and  adorn  our  dwellings. 


A  Single  Crown  of  the  Udo  after  Blanching 
Cmirtcsy  of  the   I'.  S.  Bureau  of  Plant  Industry. 


To  even  name,  let  alone  describe  all  the  manifold  varieties 
of  plants  whose  introduction  the  Office  has  attempted,  would 
be  out  of  the  question  in  these  pages,  but  a  few  of  them  may 
be  mentioned. 

We  are  accustomed  to  think  of  the  bamboo  in  terms  of 
wicker  work  or  fishing  rods,  but  how  many  of  us  realize  that 
the  young  bamboo  shoots,  which  grow  at  the  rate  of  a  foot  a 
day,  are  succulent  and  may  be  eaten  like  asparagus  tips,  while 
the  seeds  of  some  species  may  be  used  as  grain,  and  the  fruits 
of  others  cooked  and  eaten?     How  often  do  we  think  of  the 


Man  and  Nature 


413 


bamboo  as  serving;  such  varied  uses  as  pulp  for  paper,  masts 
for  vessels,  pipes  for  \vat(M-  and  timber  for  buildinfrs?  Says 
JNIr.  David  Faiieliild,  in  eliarge  of  the  plant  introduction  woik 
for  the  Bureau  of  Plant  Industry:  "...  there  is  no  plant 
in  the  world  which  is  ])ut  to  so  many  uses  as  the  bamboo,  and 


Thk  Tung  Oil  Tree 
One    of    the    many    valuable    plant    ininiigrants    introduced    into    the 
United  States  by  the  U.  S.  Bureau  of  Plant  Industry. 

Courtesy  of  the  Bureau. 


in  the  regions  where  it  grows  it  is  apparently  the  most  in- 
dispensable of  all  plants."  Strange  as  it  may  seem,  the 
bamboo  is  not  a  ti-ee  in  the  ordinary  sense  of  the  word,  but' 
a  grass,  the  rings  on  the  stem  marking  the  points  of  inser- 
tion of  the  leaves. 

About  twenty  years  ago  Mr.  William  Tevis  of  San  Fran- 
cisco bought  a  specimen  of  the  giant  Japanese  bamboo  from 


414 


Biology  in  America 


a  Japanese  inu-seryinan,  which  he  planted  in  Bakersfield, 
and  from  whieh  in  a  few  years  sj)rang  a  heautit'ul  grove  of 
trees  over  fifty  feet  in  height.  Several  species  of  bamboo 
have  been  introduced  into  California,  while  in  Florida  and 
other  southei'n  states  are  bamboo  groves  planted  by  the 
Bureau  in  its  experimental  gardens. 

In  the  markets  of  Japan  are  for  sale  the  stalks  of  the  udo 
which  is  used  by  the  Ja})anese  and  foreign  residents  as  we 


Branch  of  the  Tung  Oil  Tree 
Tlie   large   kernels   inside   these   fruits    form    the   wood    oil    nuts   from 
which  one  of  the  most  valuable  drying  oils  known  is  extracted.     These 
trees  will  grow  in  the  Gulf  States. 

CourtiKii   of  tliv    r.   .S'.   liiinau   of  Plant   Itiduxtnj. 


use  asparagus,  but  the  udo  has  the  advantage  of  the  aspara- 
gus, in  that  its  stalks,  which  are  often  two  feet  long  and  over 
an  inch  in  diameter  at  the  base,  are  completely  edible,  in- 
stead of  the  tips  alone  as  is- the  case  with  the  asparagus.  It 
is  a  hardy  plant  and  can  probably  be  raised  throughout  the 
United  States,  though  at  i)resent  it  is  raised  chiefly  in  the 
Sacramento  Valley.  The  udo  was  introduced  into  the  United 
States  by  Fairchild  and  Barbour  Lathrop  of  Chicago  in 
1903. 

Those  of  us  who  have  enjoyed  the  delightful  hospitality  of 


Man  and  Nature 


415 


the  South,  may  liave  been  victims  of  a  little  practical  joke  on 
the  part  of  our  friends,  when  we  accepted  from  them  a  fruit 
somewhat  resembling  a  plum  or  large  cherry  of  a  yellowish 
or  pinkish  color,  which  made  our  mouths  water  in  anticipa- 
tion and  pucker  in  realization.  But  the  Japanese  long  ago 
learned  how  to  take  the  pucker  out  of  persimmon  by  packing 
it  in  barrels  saturated  with  sake  or  Japanese  "booze,"  and 
experts  of  the  Bureau  of  Chemistry  have  found  a  means  of 
similarly  de-puckering  the  persimmon  with  carbon  dioxide. 
But  this  process  is  unnecessary  with  a  new  variety  of  Chi- 


A  View  of  the  Avenue  of  Pistache  Trees 
At    the    Plant    Introduction    Station    at    Chico,    California.      In    the 
autumn  the  leaves  of  this  Chinese  pistache  turn  a  beautiful  scarlet. 
Uourtesi/  of  the   U.  iS'.  Bureau  of  PUint  Industry. 

nese  persimmon  found  in  the  valley  of  the  Ming  Tombs  west 
of  Pekin,  by  Mr.  Frank  Meyer,  one  of  the  plant  explorers  of 
the  Bureau,  who  has  traveled  extensively  in  China,  whence 
he  has  sent  us  some  2,500  new  varieties  of  plants.  The  Japa- 
nese persimmon  has  also  been  introduced,  and  is  thriving 
at  many  points  in  our  southern  states. 

The  tung  oil  tree  of  the  orient,  from  the  seeds  of  which  is 
obtained  one  of  the  best  drying  oils  known,  the  importation 
of  which  in  1911  amounted  to  $3,000,000,  has  been  introduced 
into  California  and  the  Gulf  States,  where  it  appears  to  bo 
thriving;  while  the  pistache  tree,  a  native  of  central  west- 
ern Asia,  is  doing  nicely  in  California,  so  that  in  the  near 


416 


Biology  in  America 


future  it  may  not  be  necessary  for  us  to  go  to  the  Asiatics 
for  flavoring  for  our  pistache  ice  cream.  Yet  another  find 
in  China  is  a  cliestnut  tree,  which  is  to  a  consi{leral)le  extent 
7-esistant  to  the  chestnut  bark  disease  which  has  been  playing 
sucli  liavoc  in  our  ciiestiuit  groves  in  recent  years,  and  which 
may  some  day  replace  our  vanishing  native  species. 


An  Indian  Mango  Growing  in  Florida 
Coiirtisi/  of  the   U.  ^'.   BiD-Kiu   of  I'laiit  Industry. 

Into  southern  Floi-ida,  California,  Porto  Rico,  Hawaii, 
and  the  West  Indies  has  come  the  p]ast  Indian  mango,  a  fruit 
long  held  sacred  by  the  people  of  this  teeming  land.  In 
India  it  is  very  prolific,  some  trees  bearing  between  $100 
and  $200  worth  of  fruit,  even  at  the  low  rate  for  which  the 
fruit  sells  in  that  country.^     The  mango  is  described  in  Bai- 

"$6.(50  a  hundred  for  the  best  varieties  in  1910.     At  the  same  time 
mangos  were  selling  in  Florida  for  $3.00  a  dozen. 


Man  and  Nature 


417 


ley's  "Cyclopwlia  of  Horticulture"  as  follows:  "In  size  and 
character  of  fruit  the  mango  is  extremely  variable ;  there  are 
varieties  which  are  scarcely  larger  than  a  plum  and  there 
are  others  whose  fruits  weigli  as  much  as  four  or  five  pounds. 
The  shape  varies  from  rountl  to  long  and  sU'iidcr,  some  of  tlie 
commonest  types  being  reniform,  obliquely  heart-shaped,  oval 
or  elliptical.  The  skin  is  smooth,  somewhat  thicker  than  that 
of  a  peach,  commonly  yellow  or  greenish-yellow  in  color,  but 
in  some  varieties  bright  yellow  overspread  with  scarlet  or 
crimson,  and  of  extremely  beautiful  appearance.  Other  types 
are   uniformly   pale   lemon-yellow.     The   aroma    is   often  de- 


<J»-.J^i»..v,<V 


A  Six-Year  Old  Date  Plantation  in  California 

Courtesy    of   the    U.    S.    linn  mi    of   Plant    I niliisl ri/. 

licious,  spicy  and  tempting,  and  this  added  to  the  brilliaid 
color,  makes  some  of  the  finer  varieties  of  the  mango  among 
the  most  attractive  of  all  fruits."  "> 

The  date  palm,  that  Avondeid'ul  tree  of  the  oasis  in  tlie 
scorching  deserts  of  Arabia  and  Africa,  is  now  domesticateil 
in  Arizona  and  Southern  California  and  lias  taken  kindly  to 
its  new  home.  In  the  countries  of  the  East  the  date  is  a  sta- 
ple food  for  the  dwellers  in  the  desert,  and  not  a  luxury  as 
it  is  with  us.  With  some  trees  bearing  more  than  100  pounds 
of  dates  an  average  profit  of  $100  to  $150  per  acre  is  a  fair 
estimate. 

^"Bailey,  "Cyclopedia  of  Horticulture,"  p.  1986.  By  pennissiou  of 
the  Macmillan  Company. 


418 


Biology  in  Amrrica 


And  so  we  iiii<:;lit  continue  ad  iuutsc<ii)i,  if  not  ad  infinitum, 
to  rehearse  the  aehievenieiits  of  Uncle  Sam  lu  levying  tribute 
on  the  flowers  and  fruits,  the  grain  and  timber  of  all  the 
\\(H'\d  to  ])eautify  and  enrieh  liis  country,  but  this  brief  sketch 


A  Bunch  of  Dates 

liilKMiiii^i  ill  the  (li'sert  reg'.ou  of  s'juthcrn  C.ilifornia. 

Courtesy   of  the   LI.  H.   Burcdii    of  finnt   Jndiistri/. 

must  suffice  as  a  suggestion  merely  of  the  past  accomplish- 
ments and  future  possibilities  of  the  economic  biologist  in 
the  discoveiy  and  cultivation  of  Nature's  wealth  of  plants 
throughout  the  world. 

The  finds  of  the  plant  explorer  must  be  carefully  packed 
to  ensure  their  safe  arrival  after  a  journey  halfway  around 
the  world  oi-  more.  Dry  seeds  such  as  grains  or  beans  can 
be  shipped  in  bags  or  boxes  without  any  special  precau- 
tions.    Some  nuts  however  which  are  liable  to  be  parched  or 


Man  and  Nature 


419 


frozen  in  transit,  must  be  protected  by  moist  material  such 
as  sphagnum  moss,  whieli  seems  to  have  an  antiseptic  func- 
tion, and  to  protect  the  plants  from  infection  and  decay ;  and 
packed  in  strong  boxes  to  protect  the  young  si)routs  in  case 
of  germination  en  route.  Entire  plants,  or  cuttings  from 
them,  are  covered  with  the  sphagnum  and  then  carefully 
packed  in  bales  or  boxes  for  shipment. 

Arrived  in  Washington  each  package  is  carefully  inspected 
by  an  entomologist  and  plant  pathologist  to  guard  against  tlie 
importation  of  insect  pests  or  plant  diseases,  and  if  any  im- 
migrants are  found  concerning  whose  health  the  inspectors 
are  in  doubt,  they  are  kept  in  quarantine  in  gardens  near 


Buffalo  on  National  Blson  Range,  Montana 
One  of  the  few   remnants  of  the   once   mighty   herds   wliich    lunnorly 
roamed  the  West. 

Courtesy  0/  the  I'.  S.  liiinnn  0/  Biuloiiicdl  l^urvcy. 

Washington  until  all  danger  of  infection  is  passed.  Those 
which  pass  inspection  are  entered  in  the  records  of  the  office 
which  include  data  giving  the  source  of  the  plant,  its  uses, 
inspection,  consignee,  etc.,  and  are  then  forwarded  to  tlie 
experimental  gardens  where  they  are  to  be  propagated,  or  to 
the  special  experimenters  in  various  parts  of  the  country  for 
whom  they  were  obtained. 

But  not  alone  in  foreign  lands  is  the  economic  biologist 
seeking  to  increase  the  nation's  wealth.  JMany  are  our  nat- 
ural resources  unused  as  yet,  while  many  anotlier  fast  dis- 
appearing can  be  restored  in  part  at  least  to  its  former  abun- 
dance, not  only  by  the  negative  measures  of  conservation,  liut 
by  the  active  ones  of  propagation  as  well. 


420 


Biology  in  America 


In  the  days  of  the  pioneer  the  United  States  was  teeming 
with  game.  Today  the  flocks  of  wild  pigeons,  the  herds  of 
buffah),  elk  and  anteh)pe  are  but  memories  of  the  past,  but 
a  few  wanderers  renuiining  among  the  graves  of  their  de- 
parted kin.  Of  the  wild  pigeon  not  one  wild  bird  remains 
toilay  to  boar  testimony  to  tlieir  departed  glory.  To  save 
the  others  from  a  like  fate  the  Biological  Survey  in  co-opera- 
tion with  our  National  Park  Service  and  the  Audubon  Soci- 
ety has  established  havens  of  refuge  throughout  the  country, 
where  the  remaining  herds  of  large  game  are  safe  from  the 


Ei.K  IN  Winter  in  Yellowstone  National  Park 

Photo  by  Haynes,  8t.  Paul. 

Courtesy  of  the  U.  S.  'National  Park  Service. 

depredations  of  man,  and  others  where  our  wild  fowl  may 
breed  in  safety  and  replenish  their  fast  thinning  ranks.  The 
best  known  of  these  is  the  Yellowstone  National  Park,  where 
the  bears  and  elk,  due  to  plentiful  food  and  lack  of  molesta- 
tion, have  become  almost  as  tame  as  domesticated  animals. 
All  of  our  national  parks  are  ''out  of  bounds"  for  the  sports- 
men, except  for  the  ever  increasing  number  of  those  who  hunt 
only  with  the  camera.  In  addition  to  the  national  parks 
there  are  five  other  big  game  reservations,  all  of  them  in 
charge  of  the  Bureau,  containing  herds  of  elk,  buffalo,  ante- 
lope, and  deer.  All  but  the  antelope  are  apparently  thriv- 
ing, thanks  to  adequate  prote(!tion  and  winter  feeding,  when 


Man  and  Nature 


421 


the  snow  lies  so  deep  on  the  ranges  that  the  animals  cannot 
forage  for  theinselves ;  and  llic  hulTalo,  which  fonncrly  ap- 
peared to  be  doomed,  liave  probably  been  saved,  altliongh 
they  are  today  more  like  domestic  cattle,  retaining  little  of 
the  picturesque  cliaracter  of  their  foi-i)cai-s.  which  ranged  in 
such  magnificence  over  our  wcslein  domain,  liut  the  ante- 
lope at  present  appears  to  be  doomed.  Even  with  the  most 
careful   protection  the  young  often  fall   victims  to  the  wily 


An   Egret  Culuny  in   8outh  Cakglixa 

The  aigrette  which  formerly  adorned  women's  bonnets  so  e.\timsiv(  ly 
was  obtained  from  tiiis  Vdni,  whicli  was  nearly  exterminatcil  as  a  result. 
Photograph  of  a  group  in  tlift  American  Museum  of  Natural  History  in 
New  York. 

Couitisy  uj  the  Miisium. 


wolf  and  coyote,  and  the  destruction  which  man  began,  Na- 
ture seems  determined  to  finish. 

Until  comparatively  recent  times  the  swamps  of  our  South 
Atlantic  and  Gulf  Coast  were  the  home  of  countless  thou- 
sands of  snowy  herons,  bearers  of  the  beautiful  "aigretti', " 
which  woman  in  innocent  l)ai'l)arity  was  at  one  time  pi-oud 
to  wear.  The  story  of  the  aigictte  ti-ade  with  all  its  wanton 
cruelty,  has  been  told  so  often  as  to  need  no  rejietition  here, 
but   a   word   nuiy    be   said    regarding   its   sn|)])i(ssion.      .\boli- 


422  Biology  in  America 

tion  of  the  feather  traffic  was  one  of  the  primary  factors  in 
the  organization  of  the  Audubon  Society;  and  since  the  in- 
ception of  the  latter  it  has  played  a  prominent  part  in  the 
salvation  of  the  few  herons  still  preserved  from  their  ruth- 
less pursuers.  Through  its  activity  the  Audubon  model  bird 
law  has  been  passed  by  every  state  (among  many  others) 
where  the  egret  colonies  were  found.  But  this  law  was 
inadequate  because,  like  many  another  law,  it  proved  in  many 
places  to  be  but  a  "scrap  of  paper."  Especially  was  this 
true  in  the  conservative  and  easy-going  South,  where  public 
opinion  was  not  yet  alive  to  the  necessity  for  bird  protec- 
tion, and  so  the  Society  turned  its  attention  to  the  source 
of  the  trade,  namely  the  millinery  interests  of  our  great  cit- 
ies, and  after  many  a  hard  fight  these  interests  were  defeated, 
and  laws  were  passed  by  many  states  prohibiting  the  sale  of 
wild  bird  plumage.  The  Society,  with  the  aid  of  other  or- 
ganizations interested  in  bird  life,  also  secured  a  provision  in 
the  tariff  act  of  1913  prohibting  the  importation  of  feathers 
into  the  United  States,  which  for  a  time  created  much  con- 
sternation among  certain  aigrette-bedecked  ladies  returniiig 
to  this  country  from  abroad. 

The  passage  of  this  provision  through  Congress  was  only 
effected  after  a  bitter  fight  against  the  forces  of  sordid  greed. 
A  fine  example  of  the  spirit  of  its  opponents  is  afforded  by 
the  speech  of  a  man  who  still  figures  in  our  legislature  as  a 
champion  of  reaction. 

"I  really  honestly  want  to  know  why  there  should  be  any 
sympathy  or  sentiment  about  a  long-legged,  long-beaked,  long- 
necked  bird  that  lives  in  swamps,  and  eats  tadpoles  and  fish 
and  crawfish  :and  things  of  that  kind ;  why  we  should  worry 
ourselves  into  a  frenzy  because  some  lady  adorns  her  hat  with 
one  of  its  feathers,  which  appears  to  be  the  only  use  it  has." 
...  If  the  young  are  then  left  to  starve,  it  would  seem  to  me 
the  proper  idea  would  be  to  establish  a  foundling  asylum  for 
the  young,  but  still  let  humanity  utilize  this  bird  for  the  only 
purpose  that  evidently  the  Lord  made  it  for,  namely,  so  that 
we  could  get  aigrettes  for  bonnets  of  our  beautiful  ladies."  " 

But  not  content  with  mere  repression  of  the  feather  trade, 
the  Society  has  devoted  itself  to  the  protection  of  the  herops 
on  their  breeding  grounds,  establishing  and  patrolling  many 
reserves  along  our  coast,  where  they  now  live  in  peace  and 
are  multiplying  rapidly. 

In  guarding  these  reserves  two  wardens  of  the  Society  have 
been  shot  by  plume  hunters  angered  at  the  interruption  of 
their  illegal  trade. 

"  From  remarks  of  Senator  James  A.  Eeed  of  Missouri.  Cong.  Eec, 
Vol.   50,  p.   3426. 


Man  and  Nature 


423 


While  the  Audubon  Society  has  been  the  foremost  agency 
in  egret  protection,  it  has  been  aided  by  the  U.  S.  Biological 
Survey,  which  now  has  in  charge  a  number  of  government 
reservations,  where  not  only  egrets  but  other  sea  fowl  breed 
in  large  numbers. 

Private  individuals  also  early  came  to  the  rescue  of  the 
birds  and  have  aided  in  their  protection  both  by  contribu- 
tions of  money  and  by  protection  of  the  birds'  nesting  sites. 
One  of  the  largest  egret  heronries  existing  today  is  tlie  one  on 


Some  Valuable  Fur  Bearers 
A,  Mink;   B,  Arctic  fox;    C,  Silver  fox;   D,  Red  fox.     From  Jones, 
' '  Fur  Farming  in  Canadfi. ' ' 

Commission   of  Conservation,  Canada. 


Avery  Island,  Louisiana,  established  some  twenty  years  ago 
by  Mr.  John  Avery  Mcllhenny  and  Mr.  Charles  AV.  Ward  with 
a  few  birds,  and  where  there  are  now  reported  to  be  large 
numbers  of  these  l)eautiful   creatures. 

The  furry  denizen  of  the  north  was  the  charm  wliicli  lured 
the  French  adventurer  into  the  depths  of  the  Canadian  for- 
est, while  an  early  map  in  which  Newfoundland  is  described 
as  "the  land  of  the  codfish"  is  evidence  of  tlie  spell  wliieii 
the  wealth  of  the  waters  cast  about  the  early  mariner.     Tu- 


Utters  in  >.atioxal  Zouloukal  Pakk,  Washington 

The  otter  is  one  of  our  wild  auiraals  which  is  being  cultivated  for  it? 
fur. 


Mink  Eaised  on  a  Fur  Farm 

Fur  farming  is  being  developed  cxtonsiveh',  especially  in  Prince 
Edward  Island,  and  while  still  largely  in  the  experimental  stage  gives 
promise  of  becoming  a  great  and  lucrative  industry. 

Courtesy  oj  the  U.  kS.  Bureau  of  Bioloyieal  Purvey. 

424 


Man  and  Nature  425 

day  the  role  of  the  beaver  is  being  played  by  his  humble 
cousin  the  muskrat,  while  fox  and  fislici-,  mink  and  martin 
are  following'  in  the  l'o(jtsteps  of  liie  bulTah),  tlic  elk  and  the 
antelope.  The  codfish  still  manag'cs  to  hold  his  own,  hut 
many  of  his  congeners  are  less  fortunate. 

The  rapid  dimiinition  of  our  fur-bearing  hosts,  with  the 
consequent  lise  in  i)riee  of  furs,  has  led  to  experiments  in 
breeding  these  animals  for  market,  which,  while  scarcely 
beyond  the  experimental  stage  as  yet,  give  promise  of  future 
success.  The  prim  ijial  site  of  these  experiments  lias  been 
Prince  Edward  Islaiul,  where  the  golden  possibilities  of  fox 
farming  have  so  seized  upon  the  imagination  of  many  of  the 
local  farmers,  that  they  have  mortgaged  their  farms  to  ob- 
ta  n  the  necessary  capital  for  undertaking  this  venture.  In 
1911  the  value  of  the  captive  foxes  was  twice  that  of  all  other 
live  stock  on  the  island.  That  enormous  profits  are  possible 
in  successful  fox  farming  is  shown  by  the  value  of  the  best 
animals  for  breeding,  as  high  as  $25,000  having  been  i)aid 
for  a  single  pair  of  silver  foxes  for  this  purpose.  Not  alone 
foxes,  but  fisher,  martin,  mink,  skunk  and  other  animals  have 
been  cultivated  for  their  furs,  and  to  aid  this  industry  in 
the  United  States  the  Biological  Survey  maintains  an  experi- 
mental fur  farm  in  Essex  County,  N.  Y.,  where  several  spe- 
cies of  fur  bearers  are  being  raised. 

When  those  of  us  who  are  privileged  to  pay  a  surtax  on 
our  incomes  and  can  accordingly  indulge  our  appetites  with 
such  delicacies  as  blue  points  on  the  half-shell,  lobster  a  la 
Newburg,  or,  shades  of  hpicurus  defend  us!,  diamond-back 
terrapin  stew,  how  often  do  -we  think  of  the  part  played  by 
our  benevolent  Uncle  Sam  in  providing  us  with  such  de- 
lights'? Were  the  wealth  of  Nature  used,  but  not  abused  by 
man,  her  resources  would  be  never  failing.  But  man  is  as 
stupid  as  he  is  greedy  and  gluttonous,  and  ofttimes  destroys 
just  for  the  sake  of  seeing  the  smash.  Hence  Artifice  imist 
come  to  the  aid  of  Nature,  and  learning  skill  from  her  may 
soon  come  to  outdo  her  in  the  production  of  her  own  wealth. 

Nowhere  has  the  pro])agation  of  wild  aninuils  been  under- 
taken with  greater  effort  or  larger  success  than  in  the  Tnited 
States.  Our  waters,  both  iidand  and  marine,  form  a  vast 
aquatic  farm  wherein  fish  and  other  aquatic  animals  are  be- 
ing reared  by  the  billion  every  year.  Our  biggest  fish  farmer 
is  Uncle  Sam  himself,  but  a  nmjority  of  the  states  are  also 
engaged  in  the  busiiu'ss  on  a  more  or  less  extensive  scale. 

The  American  Fish  Cultural  Association  was  organized  in 
1870,  later  becoming  the  American  Fisheries  Society,  and 
several  states  had  already  established  fish  conunissions. 
Through  the  activity  of  these  agencies  the  Federal  Govern- 


426  Biology  in  America 

ment  was  induced  to  establish  the  U.  S.  Fish  Commission 
in  1871,  under  the  leadership  of  the  late  Professor  Baird, 
whose  name  occupies  so  prominent  a  place  among  the  makers 
of  American  biology.  In  1903  the  Commission  became  the 
Bureau  of  Fisheries  in  the  newly  organized  Department  of 
Commerce  and  Labor. 

To  describe  in  detail  the  work  of  the  Bureau  since  its  in- 
ception would  in  itself  require  a  small  library.  All  that  can 
be  done  here  is  to  touch  briefly  on  a  few  of  its  activities  il- 
lustrating the  achievements  of  biology  in  the  conservation 
and  creation  of  wealth.  Fish  propagation  was  not  one  of 
the  functions  included  in  the  original  program  of  the  Com- 
mission, but  was  undertaken  by  it  shortly  after  its  incep- 
tion, and  has  since  become  its  most  important  service.  The 
first  fishes  propagated  were  the  shad,  Atlantic  salmon  and 
the  whitefish  of  the  Great  Lakes.  The  success  of  these  early 
efforts  has  caused  the  extension  of  the  practise  to  most  of  our 
important  food  and  game  fishes.  In  1921  the  number  of  eggs, 
young  and  adults  of  some  fifty  species  of  fish  and  the  lob- 
ster distributed  by  the  Bureau  totalled  4,962,489,405.  At 
least  that  is  the  figure  given  in  its  annual  report.  To  at- 
tempt to  estimate  to  units  so  inconceivably  large  a  number  is 
in  the  nature  of  the  case  an  absurdity.  Five  billion  in  round 
numbers  would  probably  be  as  nearly  accurate  as  the  figure 
given.  We  cannot  here  describe  the  various  methods  em- 
ployed in  propagating  these  many  species.  To  illustrate  the 
methods  of  the  Bureau  however,  we  may  describe  its  work 
in  the  propagation  of  the  Pacific  salmon. 

There  are  five  species  of  salmon  found  on  our  Pacific  Coast, 
which  were  described  as  early  as  1768  by  the  naturalist-ex- 
plorer Steller,  and  a  Kussian  investigator  with  the  appalling 
name  of  Kraseheninikov.  Since  the  life  history  of  each 
differs  only  in  minor  details,  we  may  tell  the  story  of  all  in 
giving  that  of  the  principal  one,  which  passes  under  several 
aliases,  namely,  ''king,"  "quinnat, "  "chinook, "  "spring," 
"tyee,"  "Columbia  River,"  "Sacramento,"  "tchaviche"  and 
last  and  worst  of  all — Onchorhynchus  tschawytscha.  The 
"king"  salmon  occurs  on  both  coasts  of  the  Pacific  from 
California  and  China  north  to  Behriug  Straits.  The  aver- 
age weight  is  twenty-two  pounds,  but  one  giant  was  taken 
in  Alaska  in  1909  weighing  101  pounds  minus  the  head. 
During  the  winter  the  fish  sojourn  in  the  sea,  but  in  early 
spring  they  slowly  gather  in  tlie  rivers,  especially  the  large 
streams  like  the  Sacramento,  Columbia  and  Yukon,  and  begin 
the  k)ng  and  arduous  journey  to  their  breeding  grounds, 
which  in  the  Yukon  may  be  over  2,000  miles  from  the  sea. 
In  the  ascent  of  tlie  rivers  they  perforin  prodigious   feats, 


Man  and  Nature  427 

ascending  falls  10-15  feet  in  height.  Arrived  on  the  spawn- 
ing grounds  in  autumn  the  male  excavates  a  little  hollow  in 
the  gravel  of  the  stream  bed,  where  the  female  deposits  her 
eggs,  upon  which  the  male  sheds  the  "milt,"  after  which 
they  cover  them  with  gravel;  and  then  the  function  of  re- 
production performed,  which  is  the  crowning  act  in  the  life 
of  either  animal  or  plant,  they  float  downstream  to  die. 

Perhaps  nowhere  else  among  animals  is  there  shown  a  more 
striking  example  of  the  influence  of  the  sex  organs  upon 
body  form  and  general  metabolism  than  in  the  male 
salmon.  In  the  spring  he  is  a  perfectly  respectable  looking 
fish,  but  as  summer  advances  and  his  sex  glands  ripen,  the 
jaws  become  greatly  distorted,  so  much  so  in  fact  that  in 
some  cases,  it  becomes  impossible  for  the  fish  to  close  them. 
Some  of  the  teeth  may  disappear,  while  othere  grow  very 
long.  The  body  becomes  compressed  and  assumes  a  distinct 
hump  in  the  back. 

The  average  number  of  eggs  laid  by  a  female  salmon  is 
four  thousand.  If  one-half  of  these  developed  into  females 
and  reached  maturity  in  four  years,  and  if  their  progeny  in 
turn  were  all  to  reach  maturity,  one-half  being  females,  this 
rate  of  increase  remaining  constant  from  generation  to  gen- 
eration, there  would  result  in  32  years  256,000,000,000,000,- 
000,000,000,000  salmon  weighing  2,816,000,000,000,000,000,- 
000,000  tons  or  468  times  the  mass  of  the  earth. 

Why  is  it  that  such  increase  is  impossible?  Let  us  see 
what  are  some  of  the  dangers  which  the  salmon  encounters 
in  its  journey  to  its  spawning  grounds  far  distant  from  its 
ocean  home,  and  what  those  which  await  the  eggs  and  fry. 
Near  the  mouth  of  the  salmon  stream  lurk  the  trollers  seek- 
ing to  entice  them  with  shining  lure.  Here  too,  and  in  the 
broad  reaches  of  the  lower  river,  are  the  seiners,  sweeping 
the  waters  with  their  nets.  Where  the  river  begins  to  nar- 
row so  that  a  definite  channel  is  established,  the  fish  encounter 
traps  and  weirs  to  stop  them  in  their  course;  while  higher 
up,  where  the  river  narrows  still  more,  the  fish  wheel  bars 
their  progress.  This  is  an  ingenious  device  constructed  some- 
what on  the  principle  of  a  Ferris  wheel.  It  is  placed  where 
the  river  is  narrow  and  the  current  swift,  and  the  river  is 
usually  still  further  narrowed  by  means  of  a  net  or  barri- 
cade of  some  sort  to  oblige  all  ascending  fish  to  pass  through 
the  channel  where  the  wheel  is  placed.  Upon  its  rim  are  wire 
baskets  which  catch  the  fish  as  they  try  to  pass  through 
the  narrow  channel,  and  as  the  wheel  turns  empty  the  fish 
into  a  spillway  or  sluice  which  carries  them  to  a  po<il  where 
the  fisherman  is  waiting  to  receive  them.  Some  of  these  fish 
wheels  are  movable,  being  attached  to  the  tail  of  a  scow,  if 


428 


Biology  in  America 


a  scow  can  properly  be  said  to  possess  such  an  appendagie, 
and  can  be  taken  from  point  to  point,  at  the  will  of  the  fish- 
erman. And  if  any  luckless  fish  chance  to  pass  all  of  these 
devices  for  his  destruction,  he  must  yet  run  the  gauntlet  of 
the  Indian  waiting  with  his  s})ear  upon  some  platform  in 
the  i"iver,  or  foUowing  his  finny  prey  in  swift  canoe. 

i)Ut  the  wih's  of  man  are  not  the  only  danger  which  the 
salmon  must  overcome  in  his  struggle  for  existence.  There 
is  the  danger  of  the  fungus  which  takes  such  a  heavy  toll  of 
the  eggs,  and  there  is  many  a  lurking  enemy  of  the  finny 


Seining  Spawning  Salmon  for  an  Alaskan  Hatchery 

CourtvHij   of  the   U.  8.  Bureau   of  Finheries. 


tribe  to  whom  a  meal  of  young  salmon  or  of  salmon  spawn 
does  not  come  amiss.  INIany  an  enemy  too  is  there  in  feathers 
and  ill  fur,  waiting  by  the  salmon  streams  for  their  share  of 
the  fishing,  among  which  are  the  gulls  and  bears,  while  the 
seal  is  not  averse  to  a  meal  of  salmon ;  and  many  a  smaller 
member  of  tlie  furry  tribe  skulks  by  the  streams  to  prey  upon 
the  harried  fish. 

From  the  data  of  the  canning  industry  between  1866  and 
1915,  published  in  a  recent  report  of  the  Bureau  of  Fisheries, 
there  appears  to  have  been  no  material  decrease  in  the  number 
of  cans  of  salmon  packed  on  the  Pacific  Coast  during  that 
period.     Indeed  there  has  been  on  the  contrary  a  consistent 


Man  and  Nature 


429 


increase,  due  probably  to  increased  facilitiL's  for  taking  and 
preserving  the  catch. 

The  survival  of  the  salmon  in  the  face  of  so  great  difficulties 
is  undoubtedly  duo  in  large  measure  to  the  extensive  propa- 
gation carried  on  maiidy  by  the  government,  but  also  by  state 
and  private  concerns. 

From  California  to  Alaska  the  l>ui-eau  of  Fisheries  main- 
tains salmon  luiteliei'ies,  -which  annually  distribute  in  our 
waters  some  2(H ),()(>( ),()()()  eggs,  fry  ami  older  lish.  Since  tl)e 
start  of  propagation  work  in  1872  to  the  end  of  1921  a  total 
of  about  4, ()()(), ()()().()()()  salmon  eggs  have  been  hatched  aiul 
"planted''  in  Pacific  waters,  besid(>s  those  which  have  been 
sent  to  the  Atlantic  Coast  and  to  foreign  countries.  The 
hatcheries  are  located   on   some  salmon  stream,   where  there 


Tray  of  Salmon  Eggs 

Courlcsy   of   the   U.  S.  liitrcftit   of  Finlicrirs. 


is  an  abundant  supply  of  good  water  and  plenty  of  fish  from 
which  to  strip  the  eggs.  The  fish  are  caught  on  their  way 
to  the  spawning  grounds,  either  by  seining  them  from  the 
river,  or  in  a  trap,  and  if  not  "ripe'"  (i.  e.  ready  to  siied  their 
sperm  and  eggs)  they  are  i-etained  in  a  pound  or  enclosure 
until  the  proper  time.  In  obtaining  the  eggs  two  methods  are 
employed,  either  the  living  fish  is  "stripped"  of  her  eggs, 
or  she  is  killed,  opened  and  the  eggs  removed.  The  latter 
method  causes  no  loss  of  fish  as  might  appear  at  first  sight, 
since  the  fish  die  after  spawning  in  any  case;  and  is  more 
efficient  than  the  former,  since  all  of  the  eggs  are  obtained, 
which  is  not  the  case  in  "stripping."  In  "stripping"  the 
female,  she  is  held  in  the  hand  or  placed  in  a  si)ecial  frame 
for  this  purpose,  while  the  "stripper"  runs  his  thumb  down 
her  belly  and  squeezes  out  the  eggs  into  a  pail.  The  sperm 
or  "milt"  of  the  male  is  obtained  in  the  same  way.     After 


430 


Biology  in  America 


the  eggs  and  sperm  liave  been  taken  they  are  mixed  together 
either  in  their  natural  condition  or  in  a  little  water.  The 
eggs  are  then  allowed  to  harden  for  an  hour  or  so  before 
they  are  transferred  to  the  hatching  troughs.  In  tliis  mixing 
of  eggs  and  sperm  fertilization  occurs,  while  the  hardening 
process  renders  them  tougher  and  less  liable  to  injury  than 
if  they  were  transferred  to  the  troughs  directly  after  fer- 
tilization. These  latter  are  long  shallow  troughs  divided 
into  compartments  about  two  feet  long,  a  foot  wide  and  six 
inches  deep.     In  each  compartment  is  a  wire  basket  in  which 


Interior  of  a  Salmon  Hatchery 
Courtesy  of  the  U.  S.  Bureau  of  Fisheries, 

are  placed  about  30,000  eggs.  Any  eggs  which  become 
fungussed  or  otherwise  diseased  are  removed  daily  to  pre- 
vent communicating  the  infection  to  other  eggs. 

At  first  the  young  fish  is  a  sack  filled  with  yolk.  Soon 
the  body  appears  as  a  narrow  band  extending  a  third  or 
half  way  around  the  sack.  This  little  band  represents  mainly 
the  brain  and  spinal  cord,  back-bone  and  muscles  of  the  future 
fish.  Soon  the  brain  begins  to  enlarge  and  the  eyes  appear 
as  two  black  spots  on  either  side,  and  the  little  fish  is  now 
all  head  and  eyes.  Meantime  the  body  is  being  lifted  up  and 
constricted  off  from  the  yolk  sack,  which  becomes  covered 
with  a  network  of  delicate  blood  vessels,  connected  with  the 
heart  which  bulges  out  beneath  the  head,  for  the  young  fish 


Man  and  Nature 


431 


may  be  truly  said  to  liavc  "its  hoart  in  its  tlirnat."  The 
tail  meanwhile  is  forming  and  liead  and  tail  Ix'nd  toward^ 
each  other  until  they  almost  touch,  while  Die  yolk  sack  appears* 
like  a  great  tumor  upon  the  belly  of  the  young  fish,  which 
soon  begins  to  try  its  muscles  in  sjiasmodic  jerks  and 
twists.  Prior  to  hatching  the  little  cMuhryo  is  surrounded 
by  the  delicate  and  highly  extensible  membrane  which  sur- 
rounded the  egg.  At  time  of  hatching  this  membrane  is 
broken,  the  food  stored  in  the  yolk  sack  is  soon  absorbed, 
and  the  young  fish  begins  to  "rustle  for  a  living."  At  this 
stage  the  fry  may  be  set  free  in  the  river,  or  if  suitable  ponds 
are  available,  they  may  best  be  kept  at  home  and  fed  on 
chopped  liver,  meat,  milk  curds,  etc.,  for  several  months  until 
they  are  better  able  to  take  care  of  themselves.     For  the  whole 


Developing  Fish 
Showing  yolk    sack.     From  Kunz  &  Eadcliffe,  Bulletin  of  the  U.   S. 
Bureau  of  Fisheries,  Vol.  35, 


principle  of  fish  culture  is  that  a  greater  per  cent  of  egg^  will 
be  fertilized  artificially  than  in  nature,  and  a  larger  number 
of  them  will  develop  safely  in  the  care  of  the  hatchery  than 
if  exposed  to  their  hosts  of  natural  enemies. 

While  the  seal  and  whale  are  not  fishes,  the  Bureau  of 
Fisheries,  on  the  basis  of  the  old  scriptural  classification  of 
"beasts  that  swim,"  has  included  them  and  all  other  creatures 
aquatic  in  the  field  of  its  activity.  The  fur  seal  industry  is 
but  one  among  many  examples  of  the  influence  of  natural 
wealth  upon  human  history.  The  fur  seals  of  the  Pacific  are 
grouped  in  two  main  herds,  those  of  the  Pribilof,  and  those 
of  the  Commander  Islands.  The  former  are  part  of  Alaska 
and  the  latter  of  Siberia.  The  former  herd  was  discovered  in 
1786  by  the  Russian  navigator  Pribilof,  whose  name  is  borne 
by  the  islands  of  his  discovery,  and  the  latter  in  1741  by  the 
naturalist  Steller  who  accompanied  the  ill-fated  Beh)-ing  on 
his  second  and  final  voyage  in  1741.  A  few  years  ago  the 
seals  were  threatened  with  extinction,  the  Pribilof  herd  having 
suffered  reduction  from  its  original  number  of  four  or  five 


432  Biology  in  America 

million  animals  to  about  four  luuulred  thousand.  The  early 
abortive  efTorts  at  protection  of  the  seals  are  but  one  of  many 
striking;  illustrations  of  the  folly  of  so-called  "practical" 
economists  and  amateur  le<]^islatoi-s  to  control  natural  wealth 
without  any  adequate  knowledge  of  the  methods  of  its  pro- 
duction. 

The  fur  seal  leads  a  roving  and  picturesque  existence.  As 
a  pup  he  gains  ac(iuaintance  with  Nature  in  a  wild  and  savage 
mood.  Ilis  puppyhood  is  spent  amid  the  rocks  and  breakers 
of  the  bleak  and  barren  islands  of  the  north  Pacific.  When 
a  few  months  old  he  makes  a  long  sea  journey  with  his  mother 
to  the  south  and  spends  his  first  winter  fishing  off  the 
California  Coast.  Early  each  summer  he  returns  as  a  young 
"bachelor"  to  the  ancestral  home,  where  he  lives  with  fellow 
"bachelors,"  while  the  old  seals  are  rearing  a  new  lot  of 
puppies.  When  five  or  six  years  old  the  mating  instinct 
gi'ows  strong  within  him  and  on  his  arrival  at  the  breeding 
grounds  he  selects  for  himself  a  little  patch  of  rocks  in  which 
he  establishes  a  "harem,"  which  may  number  from  thirty 
to  one  hundred  females,  depending  on  his  success  in  "round- 
ing up"  the  "cows."  During  this  time,  like  a  jealous  lover, 
he  stands  guard  over  his  "harem,"  engaging  ofttimes  in 
combats  to  the  death  with  intruding  "bulls,"  not  leaving  his 
stand  for  about  two  months,  even  to  feed,  and  becoming 
greatly  emaciated  during  the  summer  as  a  result  of  his  long 
fast.  Soon  after  the  arrival  of  the  females  the  young  (usually 
but  one)  are  born,  shortly  after  which  mating  occurs,  gesta- 
tion lasting  a  year.  During  the  nursing  season  the  mother 
seals  frequently  leave  their  puppies  and  make  long  journeys 
to  sea  in  search  of  food,  and  it  is  at  this  time  that  the  destruc- 
tive effects  of  pelagic  sealing  are  most  apparent. 

Sealing  privileges  in  Behring  Sea  have  long  been  a  bone  of 
bitter  contention  between  Americans,  Russians,  Canadians 
and  more  recently  the  Japanese.  The  Pribilof  Islands,  the 
principal  sealing  grounds,  originally  belonged  to  Russia,  the 
sealing  rights  on  the  islands,  being  a  perquisite  of  the  govern- 
ment. With  the  sale  of  Alaska  to  the  United  States  in  1867, 
these  rights  passed  to  our  government,  and  for  forty  years 
were  leased  by  it,  as  had  been  previously  done  by  Russia, 
to  private  concerns.  For  this  lease  the  government  received 
$50,000  annually  besides  a  royalty  of  $2  a  head,  and  it  is 
an  interesting  commentary  on  the  foresight  of  the  opponents 
of  the  Alaska  purchase  proposition,  that  from  1870  to  1890 
our  government  received  in  leases,  royalties  and  duties  on 
furs  made  up  in  London,  but  most  of  which  came  originally 
from  Alaska,  some  $13,000,000,  or  nearly  double  the  price 
paid  for  the  entire  territory. 


Man  and  Nature 


433 


Sealing  on  tlie  islands  is  restricted  to  tlie  "Ijachelor"  herd, 


the  number  taken  each  year  being  determined  by  the  go 
ment.     The  seals  are  rounded  up  and  driven  by  a  nu 
of  native  drivers  to  the  killing  pens  whei'e  they  are  slangli 
by  a   blow   on   the   head   with   a  club.     Tiie   skins   are 
removed  and  packed  in  salt  for  shipment  to  market. 

Despite  the  restrictions  on  the  killing  of  the  seals,,  the 
rapidly   diminished   to   about   one-tentli    of   its   original 
It  was  simply  a  repetition  of  "watcliing  the  spigot" 
the   "bung-hole"   was  allowed  to  take   care  of  itself. 


vern- 
mber 

lere<l 
then 

herd 
size. 

while 
The 


A  Seal  Rookery  on  the  Pribilof  Islands,  Alaska 
Courtesy  o/  the  U.  8.  Bureau  of  FishcHes. 

seals  may  be  ever  so  well  protected  on  their  breeding  grounds; 
but  if  allowed  to  take  care  of  themselves  elsewhere  they  are 
doomed  to  destruction. 

Realizing  the  threatened  extinction  of  the  herd  by  pelagic < 
sealing^  our  government  decided  to  avail  itself  of  a  right 
claimed  by  Russia  in  1821,  but  never  tested,  of  seizing  all 
vessels  engaged  in  pelagic  sealing  in  Alaskan  Avaters,  whether 
within  the  three-mile  limit  or  not.  This  immediately  brought 
on  a  controversy  with  Great  Britain,  whose  Canadian  subjects 
were  the  ones  chiefly  affected.  The  result  of  this  controversy 
was  arbitration  before  the  well-known  Behring  Sea  Tribunal, 
which  sitting  in  Paris  in  1895  decided  adversely  to  the  United 


434  Biology  'in  America 

States,  and  then  proeeeded  to  fornmlate  regulations,  govern- 
ing both  parties  to  the  controversy,  and  designed  to  furnish 
adequate  future  protection  to  the  seals.     But,  like  most  third 
parties   to    any   controversy,    the    seals    were    inevitably    the 
sufiferers.     The  regulations  prohibited  pelagic  sealing  witliin 
sixty  miles  of  the  breeding  grounds,   but   since   the   female 
seals   wander   far   outside   this   limit,   their  destruction   con- 
tinued as  before.     Now  the  death  of  one  female  during  the 
summer  means  the  destruction  of  three  seals — the  mother, 
her  unborn  young  (for  most  females  are  gravid  at  this  time) 
and  the  young  of  the  year,  left  to  starve  in  its  rocky  home 
on  the  breeding  grounds.     The  matter  was  finally  adjusted 
by  Eussia  and  the  United  States,  the  owners  of  the  rookeries, 
granting  to  the  Canadians  and  the  Japanese,  who  had  entered 
the  field  in  1903,  fifteen  per  cent  each  of  the  profit  from  land 
sealing,  in  consideration  of  their  abandoning  pelagic  sealing 
altogether.     As  an  additional  protection  the  United   States 
declared  a  closed  season  on  the  Pribilofs  from  1912  to  1917, 
at  which  time  the  herd  had  shown  some  increase,  numbering 
over  450,000  individuals.     Sealing  was  resumed  in  the  latter 
year  and  is  being  prosecuted  at  present  under  the  direction 
of  the  Bureau  of  Fisheries. 

In  respect  to  the  whaling  industry,  which  formerly  played 
so  large  a  part  in  our  maritime  industries,  the  Bureau  has 
done  little  more  than  publish  annual  statistics  and  some  data 
relative  to  the  utilization  of  whale  products.  In  the  nature 
of  the  case  propagation  of  these  animals  is  impossible  and 
the  most  that  could  be  done  is  the  imposition  of  a  closed 
season,  which  would  be  exceedingly  difficult  owing  to  the 
cosmopolitan  character  of  the  whale.  Only  through  inter- 
national agreement  could  this  be  effected,  and  hitherto,  so 
far  as  the  writer  is  aware,  no  steps  have  been  taken  in  this 
direction. 

The  use  of  whales  thus  far  has  been  limited  mainly  to  the 
skin,  oil,  "whalebone,"  ambergris,  bone  meal,  tallow,  glue, 
etc.  The  use  of  the  meat  has  been  restricted  largely  to 
"pemmican"  for  the  Esquimaux  and  arctic  explorer,  although 
the  Japanese  have  used  it  as  food  for  some  time,  and_  it  is 
now  finding  a  place  on  the  tables  of  Europeans  and  Americans. 
One  of  the  recent  activities  of  the  Bureau  has  been,  as  one 
wag  expresses  it,  to  "knock  H.  out  of  the  High  Cost  of 
Living. "  In  so  doing  it  is  finding  new  food  supplies  among 
our  aquatic  animals  and  educating  a  highly  prejudiced  and 
fastidious  public  regarding  their  use.  "What's  in  a  name!'\ 
If  offered  "dogfish"  we  are  highly  incensed  at  the  indignity, 
but  "canned  grayfish"  sounds,  and  therefore  tastes,  much 
better.    Just  as  Milady  takes  greater  pride  in  a  beautiful  set 


Man  and  Nature 


435 


of  "black  marten"  than  in  the  same  set  of  skunk  fur.  In 
a  recent  pamphlet  issued  by  the  Bureau  we  find  tliirty-two 
recipes  for  the  preparation  of  whale  meat,  some  by  so  liij,'h 
an  authority  as  Delmonico  himself.  In  anotlier  we  are  given 
seventeen  methods  of  preparing  "grayfish"  alias  "dogfish" 
or  shark,  while  still  others  tell  us  of  the  gastronomic  pcjssi- 
bilities  of  "goosefish,"  "bow-fin,"  and  other  hitherto  neg- 
lected possibilities  of  human  aliment. 

"Acres  of  diamonds"  are  indeed  on  every  hand.  It  is 
not  many  years  since  dwellers  along  the  Mississippi  and  its 
tributaries  were  accustomed  to  cast  aside  as  "worthless"  the 
mussel  shells  which  they  found  on  the  banks  of  the  streams. 
But  in  189-4  two  button  makers  from  near  Hamburg  visited 


A  Glochidium 

The  larva  of  a  fresli  water  mussel.  By  nieans  of  tlie  valves  of  its 
shell  it  attaches  itself  to  the  gills  or  fins  of  a  fish  and  grows  there  as  a 
]/arasite  until  it  reaches  the  adult  form.  After  Lefevre  and  Curtis  in 
"Journal  of   Experimeivtal  Zoology,"   Vol.  9. 


the  Mississippi  and  today  more  than  $3,000,000  are  invested 
in  establishments  for  the  manufacture  of  buttons  from 
mussel  shells,  with  an  annual  output  of  over  $5,000,000  and 
employing  about  8,000  people  in  1918.  But  in  this  case, 
as  in  so  many  others,  the  greed  of  man  soon  bade  fair  to 
ruin  a  promising  industry.  So  closely  were  the  river  bottoms 
raked  for  shells,  that  in  a  few  yeai-s  there  were  not  enough 
mussels  left  to  keep  up  the  supply,  and  the  end,  or  at  least 
serious  curtailment  of  the  industry  appeared  probable  in 
the  near  future.  But  now  enters  Uncle  Sam  upon  the  scene, 
calling  upon  biology  to  aid  him  in  finding  a  remedy,  l^o 
prescribe  a  remedy  the  physician  must  fii*st  be  able  to  diag- 
nose, his  case.  And  so  the  first  thing  which  the  biologists 
did  was  lo  study  the  life  history  of  the  nnissels  in  order 
to.  learn  how  Nature  herself   maintained  the   supply. 

After  fertilization  the  eggs  are  lodged  in  special  chambers 


436  Biology  in  America 

in  the  gills  of  the  mussel  which  hang  in  sheets  between  either 
valve  of  the  shell,  and  the  internal  organs.  Here  they  grow 
until  they  attain  what  is  known  as  the  glochidium  stage, 
when  the  young  mussel  possesses  a  shell  of  its  own,  with 
paired  valves.  They  are  now  set  free  in  the  water,  and 
slionld  they  be  so  fortunate  as  to  come  in  contact  with  cer- 
tain speeies  of  fish,  chiefly  those  of  the  sunfish  family, 
they  attach  themselves  to  the  gills  or  tins  by  means  of 
their  valves  and  force  the  fish  to  become  their  foster 
parents.  The  food  of  the  young  mussel  at  this  stage  is 
obtained  from  the  tissues  of  the  fish  whi.-h  acts  as  foster 
parent,  in  which  they  become  embedded',  living  as  parasites 
upon  the  latter.  After  ten  to  forty  ^~  days  of  this  indolent 
existence,  during  which  time  the  glochidium  is  metamorphosed 
into  a  mussel,  it  drops  to  the  bottom  of  the  river  or  pond 
and  burrowing  into  the  mud  or  sand,  proceeds  thereafter 
to  find  a  living  for  itself.  This  it  does  by  means  of  a  tube 
or  siphon,  which  it  thrusts  up  to  the  surface  of  the  river  bed, 
from  the  bottom  of  its  burrow,  and  through  which  there 
circulates  a  stream  of  water  carrying  in  oxygen,  and  food 
in  the  form  of  minute  plants  and  animals  or  finely  divided 
bits  of  organic  matter  of  any  sort,  and  carrying  out  carbon 
dioxide  and  other  wastes. 

The  task  for  the  mussel  culturist  then  is  to  secure  the 
glochidia  from  the  gravid  mussels  ^nd  find  foster  parents 
for  them.  This  is  done  by  placing  the  young  glochidia 
obtained  from  the  mussels  in  tanks  containing  the  proper 
number  of  fish  of  the  right  species  to  carry  successfully  the 
number  of  glochidia  provided.  The  extent  of  infection  by 
glochidia  which  any  given  fish  can  stand  is  a  matter  of 
importance,  for  if  loaded  too  lightly,  there  is  a  waste  of  time 
and  effort  in  securing  more  fish  than  necessary,  while  if 
loaded  too  heavily  the  fish  may  not  survive  the  strain  put 
upon  it,  and  both  fish  and  glochidia  are  lost.  The  optimum 
number  of  glochidia  varies  for  different  species  of  fish.  A 
young  bass  or  sunfish,  three  to  four  inches  long,  will  carry 
successfully  as  many  as  1,000,  a  number  which  will  kill  many 
other  species. 

Our  knowledge  of  the  life  history  of  the  mussels  is  largely 
the  result  of  the  investigations  of  Curtis  and  Lefevre  at  the 
University  of  Missouri.  Their  studies  have  been  continued 
and  amplified  at  the  Bureau  of  Fisheries  station  at  Fairport, 
Iowa,  where  the  practical  propagation  of  mussels  has  been 
conducted  for  several  years.  In  1918  fish  carrying  more 
than  200,000,000  glochidia  were  set  free,  but  no  definite  facts 
of  mussel  increase  as  a  result  of  the  work  are  yet  available. 

"  In  one  case   a   period   of   six  months  has  been   recorded. 


Man  and  Nature 


437 


While  the  primary  function  of  this  station  is  mussel  propa- 
gation, it  interests  itself  also  in  saving  the  multitude  of  tish 
found  in  the  overflow  waters  of  the  INlississippi  bottoms,  and 
to  which  reference  has  already  been  made. 

Living  a  humble  life  in  the  salt  marshes  of  our  Atlantic 
and  Gulf  Coast  is  the  delight  of  the  epicure — the  diamond- 
back  terrapin.  So  precious  is  this  creature  in  the  eyes  of 
some  persons  of  elegant  and  expensive  tastes  that  the  best 
grade  of  Chesapeake  terrapins  were  bringing  about  $70 
per  dozen  in  1917.  Here  surely  was  an  opportunity  for 
the   economic   biologist.     The   Bureau   promptly   rose   to   the 


The  Diamond-kack  Tkkrapix,  ax  Expensive  TluiiiT 
Piwto   by  R.    ir.   Shujeldt. 


emergency  and  in  1902  established  a  station  at  Beaufort, 
N.  C,  for  the  study  of  various  economic  and  scientific  i)r()b- 
lems  relative  to  the  flsheries  of  the  region,  and  more  esi)ecially 
those  concerning  the  propagation  of  the  terrapin.  In  the 
pens  connected  with  the  station  are  more  than  two  thousand 
terrapin  including  some  ten  generations,  wliich  have  been 
raised  in  captivity.  Man}-  of  these  are  now  large  enough 
for  market,  and  some  have  in  their  turn  produced  young. 
The  experiments,  the  details  of  which  cannot  be  given  here, 
demonstrate  the  possibility  of  terrapin  farming  on  a  com-^ 
mercial  scale,  and  establishing  in  this  nuinner  a  lucrative 
industry.  A  terrapin  farm  on  a  commercial  basis  has  been 
conducted  for  many  years  near  Savannah,  Georgia,  by  Mr. 
A.  M.  Barbee,  where  terrapin  are  raised  for  market  by  tlie 
thousand,  so  that  terrapin  fanning  may  now  be  fairly  said 
to  have  passed  the  experimental  stage. 


438  Biology  in  America 

But  not  alone  in  commerce  has  biology  played  its  part. 
It  has  entered  tlie  courts  of  justice  and  aided  in  disentangling 
the  knotty  problems  of  the  law. 

In  murder  trials  the  guilt  or  innocence  of  the  accused 
may  hinge  upon  the  kind  of  blood  in  a  stain  upon  his  clothes, 
whether  human  or  not.  Until  recently  there  was  no  certain 
test.  But  through  the  discovery  of  the  blood  test,  made 
chiefly  by  the  English  physiologist  Nuttall,  we  now  know 
how  to  determine  this.  For  if  human  blood  be  injected  into 
a  rabbit,  there  develops  in  the  blood  of  the  latter  an  "anti- 
body" which  produces  a  white  precipitate  with  human  blood. 
All  that  is  necessary  then,  in  diagnosing  a  blood  stain,  is  to 
soak  the  piece  ^f  clothing  in  salt  solution  and  mix  a  little  of 
the  latter  with  the  "anti-human  serum"  from  the  rabbit, 
a  resultant  white  precipitate  indicating  the  presence  of  human 
blood.  An  interesting  corollary  of  this  discovery  is  the  fact 
that  "anti-human  serum"  will  produce  a  precipitate,  though 
not  so  marked,  with  an  ape's  blood,  and  that  the  amount  of 
precipitate  formed  decreases  progressively  the  less  close  the 
relationship  between  man  and  the  animal  tested. 

Not  many  years  since  the  U.  S.  Department  of  Justice 
found  itself  in  a  muddle  over  the  status  of  certain  lands  in 
the  Mississippi  "bottoms"  in  eastern  Arkansas.  These  lands 
were  covered  by  timber  of  great  value  and  were  furthermore 
very  valuable  for  agriculture  after  the  timber  was  removed. 
Now  it  so  happened  that  certain  lumber  "barons"  having 
exhausted  the  supply  on  neighboring  lands  began  casting 
covetous  eyes  upon  the  rich  "bottoms."  In  18-17  when  the 
original  survey  of  this  district  was  made  the  land  in  question 
was  entered  on  the  maps  as  "permanent  lake."  So  the 
barons  decided  to  gain  possession,  not  by  purchase  of  the 
lands,  but  by  purchase  of  "riparian  rights"  along  the  old 
' '  lake ' '  shore,  which  according  to  the  law  would  entitle  them 
to  possession  of  the  "lake"  bottom,  when  the  latter  receded 
or  dried  up.  But  Uncle  Sam  threw  a  clog  into  their  nicely 
oiled  machine  by  bringing  suit  against  them  on  the  grounds 
that  the  survey  was  wrong  and  that  lakes  had  existed  there 
in  the  imagination  of  the  surveyors  rather  than  upon  the  lands 
themselves.  Then  the  Department  of  Justice  turned  to  the 
biologist  for  assistance  and  asked  Professor  Cowles  of  the 
University  of  Chicago  to  appear  as  an  expert  witness. 

There  were  many  lines  of  evidence  which  Professor  Cowles 
found,  all  closely  related  and  corroborative  one  of  the  other. 
These 'were  in  part  botanical  and  in  part  physiographic.  He 
found  for  example  that  at  the  time  when  these  supposed  lakes 
existed  there  was  an  upland  forest  standing  there  of  great 
age.     The  lumber  interests  tried  to  show  that  many  trees 


Man  and  Nature  439 

such  as  the  cypress  and  tupelo  gum  may  grow  in  standing 
water,  but  Professor  Cowles  countered  by  siiowing  that  even 
these  hydrophytie  or  water-loving  types  are  killed  by  too 
deep  or  too  long  submergence,  and  that  further  the  timber 
occupying  the  disputed  ground  was  composed  of  oaks, 
hickories,  cottonwoods  and  other  upland  types,  rather  than 
by  the  swamp  dwellers  of  the  forest.  Physiographic  evidence 
likewise  supported  the  story  of  the  trees.  The  disappearance 
of  a  lake  is  due  to  one  of  three  causes,  evaporation,  draining 
and  filling.  The  rainfall  of  the  lower  Mississippi  Valley  is 
too  great  to  admit  of  the  first  explanation,  and  the  cliai-ai-ter 
of  the  land  is  such  as  to  preclude  the  second,  leaving  the  last 
as  the  only  one  of  the  three  explanations  possible.  Hut  in 
these  bottoms  there  lie  the  unburied  trunks  of  trees  over- 
thrown in  a  great  earthquake  of  a  century  ago.  Had  they 
fallen  in  lakes,  which  were  subsequently  filled  in  by  debris, 
they  must  surely  have  been  covered  during  the  disappearance 
of  these  lakes. 

Other  evidence  there  was,  the  details  of  which  need  not 
be  elaborated  here,  but  to  make  a  long  story  short  the  judge 
of  the  district  court  at  Little  Rock,  gave  a  verdict  against 
the  lumber  companies  in  spite  of  the  fact  that  some  of  tiie 
"oldest  inhabitants"  testified  at  the  trial  to  having  actually 
seen  the  lakes  in  question.  In  the  words  of  Professor  Cowles 
— ' '  It  is  safer  to  believe  a  tree  than  a  man. ' ' 

Why  were  the  "lakes"  originally  recorded  on  the  survey? 
The  old  surveyors  received  so  much  per  mile  for  their  sur- 
veys, and  "per"  meant  more  for  their  purse  when  lake 
shores  were  surveyed  because  of  the  greater  difficulties  in- 
volved in  such  surveying.  Hence  many  of  the  old  maps 
are  probably  more  or  less  "scraps  of  paper"  and  not  repre- 
sentations of  fact. 

In  the  preceding  pages  we  have  hastily  sketched  a  few  of 
the  achievements  and  opportunities  of  economic  biology  in 
America.  Much  has  of  necessity  been  passed  by,  but  enough 
has  been  given  to  illustrate  the  indispensable  place  wiiich 
biology  has  in  our  economic  structure. 


CHAPTER  XVI 

Biology  and  Dudicine.  Microscopic  life  and-  its  rclat'on  to 
human  health.  The  role  of  animals  in  spreadi^ig  disease. 
Animal  experimentation  and  its  contributions  to  human 
welfare.  The  new  medicine,  safeguarding  the  health  of 
the  nation. 

Nowhere  has  the  service  of  biology  to  man  been  so  con- 
spicuous as  in  the  field  of  preventive  medicine  and  public 
sanitation.  While  the  entire  field '  of  medicine  is  strictly 
speaking  a  biological  one,  yet  the  study  of  the  human  mech- 
anism in  health  and  disease  holds  a  special  place  in  science, 
peculiar  to  itself,  and  it  is  only  in  so  far  as  our  knowledge 
of  plants  and  lower  animals  contributes  to  human  health  that 
we  shall  consider  meilicine,  or  more  properly  speaking, 
sanitation,  a  province  of  biology. 

In  days  gone  by  the  doctor's  chief  duty  was  to  heal  the 
sick;  today  his  main  function  is  to  keep  men  well.  The 
greatest  medical  progress  of  all  time  has  been  in  the  pre- 
vention of  disease.  It  is  ^the  knowledge  of  microscopic  life 
that  has  rendered  this  progress  possible,  a  knowledge  for 
which  the  world  is  indebted  to  biology. 

In  bacteriology  no  American  ranks  with  Pasteur,  Koch  or 
Jenner.  Yet  America  has  not  lacked  men  noted  in  bacteri- 
ological science,  and  in  its  practical  application  she  ranks 
second  to  none.  Nowhere  in  all  the  fields  of  human  endeavor 
has  a  greater  contribution  to  human  welfare  been  made  than 
in  the  discovery  of  the  world  of  unseen  things  about,  and 
within  us,  the  bacteria  and  the  Protozoa,  and  the  recognition 
of  the  part  they  play  in  causing  human  disease.  This  dis- 
covery has  revolutionized  medical  practice,  created  the  new 
science  of  sanitation,  reclaimed  vast  areas  formerly  uninhab- 
itable by  the  white  race,  virtually  wiped  out  of  existence 
some  of  the  worst  scourges  of  mankind  and  saved  countless 
human  beings  from  death  and  misery.  This  debt  we  owe 
to  biology.  The  story  of  this  revolution  would  in  itself  fill 
volumes,  and  is  in  its  general  outline  so  widely  known  that 
its  repetition  here  would  be  prosaic.  And  yet  of  common 
knowledge  how  little  there  is  that  each  of  us  can  call  his 

440 


Biology  and  Medicine  441 

own!  We  are  so  accustomed  to  things  as  they  are,  that  only 
the  historian  thinks  of  things  as  they  have  been,  while  tlie 
constructive  prophet  is  as  rare  among  us  as  the  proverbial 
hen's  teeth.  How  often  do  we  go  back  in  memory  to  the 
days  of  the  market  basket,  when  the  telephone  was  not  at 
hand  to  bring  our  dinners  to  our  doors,  or  the  coal  oil  lamp, 
and  the  gas  lamp  post;  while  the  days  of  the  horse  car  and 
horse  carriage,  will  soon  be  classified  as  the  "age  of  horses," 
not  clearly  distinguishable  in  our  minds  from  the  "age  of 
reptiles,"  "Amphibia"  or  "fishes."  It  may  not  then  be 
amiss  to  contrast  for  a  moment  some  pictures  of  the  past 
and  present  in  medicine  and  public  health. 

At  the  time  of  the  great  smallpox  epidemic  in  1752  Boston 
had  a  population  of  15,684,  of  whom  5,998  had  had  the  disease, 
leaving  9,686  persons  who  were  susceptible  to  it.  Of  these 
7,669  contracted  the  disease,  5,545  by  contact  and  2,124  by 
inoculation  (in  order  to  produce  a  mild  type  of  the  disease 
and  escape  its  danger)  and  1,843  persons  left  the  city,  leav- 
ing but  174  who,  without  the  immunity  furnished  by 
a  previous  attack,  faced  the  disease,  but  were  not  stricken. 
The  history  of  smallpox  in  the  cities  of  Europe  in  pre- 
vaccination  days  is  one  long'  record  of  despair  and  death. 
In  America  the  disease  introduced  by  the  early  explorers 
swept  like  wild-fire  among  the  natives  who  proved  pecu- 
liarly susceptible  to  it,  carrying  away,  according  to  early 
historians,  whole  tribes,  and  reducing  others  to  mere  rem- 
nants of  their  former  selves.  One  of  these  writers  (Catlin) 
gives  it  as  his  opinion  that  at  least  one-half  of  the  Indians 
of  North  America  were  taken  by  smallpox.  Quoting  from 
Parker  he  says  of  the  Indians  below  the  Falls  of  the  Columbia 
that  at  least  seven-eighths,  if  not  nine-tenths,  were  destroyed 
by  smallpox  between  1829  and  1836.  Prior  to  the  advent 
of  the  United  States  in  the  Philippines  there  were  more 
than  6,000  deaths  in  seven  provinces  annually  from  small- 
pox. 

Turning  now  to  the  other  side  of  the  picture  we  find  a 
conspicuous  decrease  in  snudlpox  after  the  introduction  of 
vaccination,  while  in  countries  where  vaccinafion  is  com- 
pulsory, the  disease  scarcely  exists.  In  1905  and  1906, 
3,094,635  vaccinations  were  performed  by  the  II.  S.  Bureau 
of  Health  in  the  Philippine  Islands.  In  the  report  of  the 
director  (Doctor  Victor  (i.  lleiser)  of  1907,  he  says:  "In  the 
provinces  of  Cavite,  Batangas,  Cebu,  Bataan,  La  Union.  Kizal 
and  La  Laguna,  where  heretofore  there  have  been  more  llum 
6,000  deaths  annually  from  smallpox,  it  is  satisfactory  to 
report,   since   the   completion    of   vaccination    in    the   afore- 


442  Biology  in  America 

mentioned  provinces  more  than  a  year  ago,  not  a  single  death 
from  smallpox  has  been  reported."^ 

From  1901  to  190-4  smallpox  was  epidemic  in  Philadelphia. 
During  that  time  the  Municipal  Hospital  received  3,500  cases, 
about  80%  of  all  eases  in  a  city  with  a  population  of  1,293,000 
and  of  these  not  one  had  been  recently  successfully  vaccinated. 
Compare  this  record  with  that  of  Boston  in  the  epidemic  of 
1752.  In  this  same  hospital  "during  a  period  of  thirty- 
four  years,  in  which  time  almost  10,000  cases  of  small- 
pox were  treated,  there  was  no  instance  of  a  physician, 
nurse  or  attendant,  who  had  been  successfully  vaccinated 
or  revaccinated  prior  to  going  on  dntv  contracting  the  dis- 
ease. "^ 

The  earlier  method  of  protection  against  smallpox  by  inocu- 
lation from  a  person  who  already  had  the  disease  met  with 
strenuous  opposition  in  many  quarters.  During  an  outbreak 
of  smallpox  in  Boston  in  1821-3  this  practise,  which  was 
advocated  by  Cotton  Mather  6nd  others,  aroused  such  intense 
feeling  that  an  attempt  was  made  to  assassinate  the  worthy 
divine  by  the  time-honored  method  of  throwing  a  bomb  into 
his  house,  which  fortunately  however  failed  to  explode.  It 
was  accompanied  by  a  message  couched  in  these  affectionate 
terms:  "Cotton  IMather,  yon  dog.  Damn  you:  I'll  inoculate 
you  with  this,  with  a  Pox  to  you." 

When  Jenner  introduced  his  method  of  vaccination  with 
eowpox,  it  was  supposed  by  the  ignorant  that  i-hildren  when 
vaccinated  "developed  horns,  hoofs  and  tails  and  bellowed 
like  cattle." 

Such  primitive  prejudices  may  be  pardoned,  but  what 
shall  we  say  of  those  who,  in  supposedly  educated  and  civilized 
connnunities,  oppose  a  remedy  which  has  done  so  much  in 
the  relief  of  human  misery  and  the  prevention  of  death. 

In  a  recent  examination  given  by  the  writer  to  a  class  in 
elementary  hygiene,  one  of  the  questions  was  "State  the 
most  important  information  gained  by  you  in  this  course." 
In  reply  to  which  he  was  surprised  to  receive  from  several 
students  answers  which  summarized  ran  about  as  follows: 
"The  most  important  information  I  gained  in  the  coui-se 
was  that  regarding  vaccination  and  similar  remedies.  I  had 
always  been  rather  afraid  of,  or  at  least  skeptical  about  it, 
but  now  that  I  have  learned  its  results,  and  the  care  taken 
in  its  use,  I  believe  in  it,  and  have  no  further  fear  of  it. ' ' 

A  mysterious  remedy  such  as  vaccination  might  be  expected 
to  frighten  or  repel  the  primitive  and  the  uneducated.     An 

^Schamberg,  "Vaccination  and  Its  Kelation  to  Animal  Experimenta- 
tion," Defense  of  Research  Pamphlet,  1,  p.  34. 
^  Locus  citatus,  pp.  35-9. 


liiology  and  Medicine  443 

amusing  instance  of  tliis  is  cited  by  Bennett  in  liis  "History 
of  the  Panama  Canal":  "When  it  was  announced  that  they 
had  to  be  vaccinated,  one  of  their  number,  a  voodoo  doctor, 
led  a  mutiny  against  inoculation,  in  which  a  hundred  and 
fifty  took  part.  He  pronounced  it  an  attempt  to  put  'the 
inextinguishable  mark'  upon  them,  so  that  they  could  never 
escape  from  the  isthmus.  They  declared  they  would  rather 
suffer  martyrdom  abroad  than  to  be  held  captive  ashore,  and 
it  was  only  after  three  days  of  unsuccessful  parleying  that 
the  mutiny  was  broken  up  by  their  being  driven  ashore  by 
the  police.  Still  protesting  they  were  rounded  up,  in  spite 
of  their  efforts  to  escape,  vaccinated,  and  the  next  day  sent 
to  work. "  ^ 

And  yet  more  astonishing  is  the  fact  that  much  of  the 
organized  opposition  to  vaccination  should  emanate  from  a 
city  which  prides  itself  upon  being  the  intellectual  center 
of  America.  Surely  extremes  have  met,  when  so-called 
"Science"  and  Voodooism  walk  hand  in  hand. 

Prior  to  the  days  of  Lister,  the  great  surgeon  of  Glasgow 
and  Edinburgh,  the  discoverer  of  antisepsis  and  the  creator 
of  modern  surgery,  the  work  of  the  surgeon  was  a  continual 
nightmare. 

The  condition  of  a  patient  after  operation  was  often  too 
horrible  for  description.  Erysipelas,  lockjaw,  blood  poison 
and  gangrene  were  frequent  consequences,  but  since  the  com- 
ing of  antiseptic  surgery  such  conditions  have  been  unknown. 
There  is  nothing  wonderful  or  difficult  about  the  modern 
antiseptic  treatment  of  wounds  and  operations,  nothing  but 
the  painstaking  observation  of  scrupulous  cleanliness  and  the 
careful  sterilization  -of  the  wound  or  skin  itself  and  of  every- 
thing coming  in  contact  with  it,  but  today,  blood-poisoning, 
tetanus  or  gangrene  following  an  operation  are  virtually 
unknown. 

In  the  pre-antiseptic  period  the  surgeon  dared  not  operate 
upon  the  brain,  or  upon  the  internal  organs  except  as  a 
desperate  "last  hope,"  for  death  was  almost  sure  to  follow.. 
Today  abdominal  operations  are  an  everyday  occurrence  and 
brain  surgery  is  a  common  practise.  In  the  olden  days 
ovarian  tumors  in  women  were  left  until  death  appeared 
inevitable  if  the  knife  were  not  used,  and  the  most  famous 
surgeon  in  America  lost  two  out  of  eveiy  three  of  sucli  cases, 
while  today  tumors,  weighing  in  some  cases  twice  as  much 
as  the  patients  themselves,  are  removed,  and  the  death  rate 
instead  of  being  over  sixty  is  about  one  per  cent. 

Prior  to  the  days  of  antiseptic  surgery  the  Caesarean  opera- 

'  Bennett,  ' '  History  of  the  Panama  Canal, ' '  p.  124.  Historical  Pub- 
lishing Company. 


444  Biology  in  A7ncrica 

tion,  or  opening  of  tlie  abdomen  of  the  mother  to  i-cinove  the 
child,  was  so  fatal  tliat  even  as  late  as  1887  Harris,  an  Amer- 
ican physician,  stated  that  the  operation  could  be  performed 
more  successfully  by  a  mad  bull  than  by  the  best  surjijeon  in 
the  best  hospital  in  America,  supporting  his  statement,  with 
evidence  from  nine  cases  in  which  the  abdomen  of  pregnant 
women  had  b(>en  gored  by  bulls,  in  five  of  which  the  victim 
recovered,  whereas  in  the  eleven  Cii'sarean  operations  pre- 
viously performed  in  New  York  there  were  but  two  recoveries. 
Today,  on  tlie  contrary,  Caesarean  operations  are  relatively 
common,  and  the  mortality  has  been  reduced  to  about  two 
per  cent. 

In  the  days  before  the  practice  of  antiseptic  methods, 
every  woman  who  entered  a  maternity  hospital  truly  went 
down  into  "the  valley  of  the  shadow  of  death."  Conditions 
in  the  lying-in  hospitals  of  Europe  were  horrible  in  the  ex- 
treme, while  in  America  we  were  but  little  better  off.  For 
thirty  years  prior  to  1833  in  the  Pennsylvania  Hospital  in 
Philadelphia  fifty-six  mothers  in  everj'  thousand  were  victims 
of  puerperal  or  'child-bed  fever,  while  in  the  Bellevue  Hos- 
pital in  New  York  in  1872  nine  out  of  every  fifty  mothers 
succumbed  to  the  disease,  and  similar  conditions  prevailed 
elsewhere.  It  M^as  this  awful  fatality  which  called  forth 
Dr.  Oliver  Wendell  Holmes'  famous  paper  on  the  "Conta- 
giousness of  Puerperal  Fever."  "With  the  coming  of  antiseptic 
methods  the  mortality  from  this  scourge  of  women  has  been 
reduced  in  good  hospitals  to  less  than  one-fourth  of  one  per 
cent,  wheieas  formerly  it  ranged  from  two  to  twenty  per  cent, 
or  even  more. 

But  it  was  not  alone  the  mother  who  suffered  from  this 
dread  scourge.  The  child  likewise  was  its  victim,  with  almost 
invariably  fatal  results.  Tetanus  or  lockjaw  also  levied  its 
toll  upon  the  new-born  babes.  Today  in  properly  conducted 
hospitals  puerperal  fever  in  infants  is  almost  never  seen, 
while  Professor  AVilliams  of  Johns  Hopkins  says  that  he  has 
never  seen  a  case  of  tetanus  in  more  than  10,000  new-born 
infants  under  his  care. 

One  of  the  most  wide-spread,  insidious,  and  appalling  dis- 
eases common  to  man  is  syphilis,  the  so-called  "red  plague." 
Exact  data  regarding  its  prevalence  in  the  United  States 
are  lacking,  but  the  best  available  estimates  place  the  figures 
at  from  2%  to  20%.  If  we  accept  5%  as  a  fair  average, 
this  means  that  over  250,000  in  New  York  City  are  victims 
of  the  disease. 

Two  and  twenty-three  hundredths  per  cent  of  the  recruits 
drafted  into  our  national  army  in  1917  were  found  on 
examination  to  be  infected  with  gonorrhea,  while  of  1,300,000 


Biology  and  Medicine  445 

(in  round  numbers)  iiu'ii  inducted  into  all  branches  of  the 
army  that  year  71,955  men  or  five  and  a  half  per  cent  were 
found  to  have  venereal  disease  of  some  sort,  most  of  which 
was  brougrht  with  them  on  their  entrance  into  camp.  After 
eidistment  the  rate  niat<'rially  decreased,  due  to  the  vij^onms 
methods  adopted  by  the  army,  both  for  repressing  vice  about 
the  army  camps,  and  for  educating  the  men  and  otherwise 
guarding  them  against  this  evil.  Perhaps  the  worst  fea- 
ture of  syphilis  from  the  standpoint  of  its  prevention  is  the 
difificulty  of  recognizing  it  in  its  latent  form.  Its  trans- 
missibility  from  husband  to  wife  and  vice  versa  and  from 
parent  to  child  is  well  known.  But  the  disease  is  curable 
and  marriage  of  a  former  syphilitic  is  permissible  when  such 
cure  is  definitely  established.  The  difificulty  is  to  determine 
when  such  cure  has  been  established.  An  individual  with 
no  apparent  symptoms  of  the  disease  may  yel  be  infected 
and  capable  of  infecting  consort  and  children.  Here  too  has 
lain  the  chief  medical  difficulty  in  the  control  of  prostitution. 
Another  very  serious  feature  of  the  disease  is  the  difficulty 
of  recognizing  it  in  its  incipient  stages.  The  earliest  symptom 
of  the  disease  is  the  chancre  or  sore,  which  appears  usually 
about  three  weeks  after  exposure,  and  then  often  cannot  be 
diagnosed  with  certainty.  If  treated  immediately  upon  its 
appearance  it  disappears,  a  positive  diagnosis  cannot  be  made, 
and  treatment  will  probably  be  relaxed  or  abandoned  alto- 
gether, leaving  the  disease  latent  in  the  body,  to  break  out 
anew  at  some  future  time.  On  the  other  hand,  if  treatment 
is  delayed  until  a  positive  diagnosis  is  established  valuable 
time  is  lost,  and  the  disease  may  obtain  so  firm  a  hold  upon 
the  system  that  its  eradication  becomes  extremely  difficult  if 
not  impossible.  Biology  has  largely  solved  these  difficulties 
by  providing  means  of  diagnosis,  even  in  the  absence  of  all 
external  symptoms. 

If  a  small  amount  of  sheep's  blood  be  injected  into  the 
body  of  a  rabbit  there  develops  in  the  blood  of  the  latter  the 
power  to  break  down  the  red  corpuscles  of  the  sheep,  liberat- 
ing the  coloring  matter  or  luemoglohin  wliidi  they  contain.  In 
this  rabbit's  blood  are  two  chemical  substances,  one  of  which 
destroys  the  sheep's  corpuscles  in  the  presence  of  the  second 
substance,  the  three  forming  a  chain  (according  to  modern 
bacteriological  theory)  a-b-c,  a  being  the  sheep's  corpuscles, 
b,  the  go-between  substance  or  ''amboceptor,"  and  c,  the 
destructive  substance,  or  "complement."  The  latter  is  prol)- 
ably  present  normally  in  the  blood  of  any  higher  animal, 
it  is  the  former  or  "amboceptor"  which  is  formed  by  the 
injection  of  the  sheep's  blood  into  the  rabbit.  This  rabbit's 
blood  is  now  heated  to  133°  F.  in  order  to  destroy  its  "com- 


446  Biology  in  America 

plement."  If  the  liver  of  an  unborn  or  newly  born  eliild 
infected  with  sypliilis  (such  bodies  may  frequently  be  obtained 
from  autopsies)  be  extracted  with  alcohol  a  substance 
"antigen"  is  obtained  which  has  been  secreted  by  the  germ 
of  the  disease,  the  Trepoiu'ma  pallidum.  This  substance  we 
may  designate  as  a'.'''*^  It  likewise  forms  a  chaiii  with  comple- 
ment c  in  the  presence  of  amboceptor  b,  which  we  may  repre- 
sent as  a'-b-c.  In  the  language  of  the  bacteriologist  it 
"fixes"  or  "anchors"  the  complement.  Tlie  blood  serum  of 
the  person  suspected  of  an  infection  with  syphilis  is  also 
heated  to  133°  F.  to  destroy  its  "complement."  The  "anti- 
gen" is  now  mixed  with  the  blood  serum  of  the  suspect  and 
a  definite  amount  of  guinea  pig  serum  containing  free 
"complement,"  which  has  not  been  heated,  is  added  and 
the  whole  placed  in  an  incubator  or  oven  for  an  hour  and 
a  half.  If  the  suspect  is  syphilitic,  his  blood  will  contain 
the  amboceptor  b,  which  has  been  developed  there  through 
the  presence  of  the  germs  of  the  disease.  In  this  case  the 
antigen  a'  will  combine  with  the  complement  c  of  the  guinea 
pig,  through  the  medium  of  the  amboceptor  b,  present  in  the 
suspect's  blood.  If,  on  the  contrary,  the  suspect  is  free 
from  infection  no  amboceptor  Avill  be  present  and  the  antigen 
will  not  be  able  to  fix  the  complement  in  the  guinea  pig's 
serum.  A  definite  amount  of  the  rabbit's  blood  mixed  with 
the  sheep's  blood  is  now  added  and  in  the  former  case 
(presence  of  syphilis)  no  reaction  will  occur,  the  complement 
being  fixed.  In  the  latter  case  however  (syphilis  absent) 
the  complement  will  be  free  to  combine  with  the  amboceptor 
in  the  rabbit's  blood,  the  first  reaction  (a-b-c)  will  occur  and 
the  red  corpuscles  of  the  sheep  will  be  broken  down  with 
liberation  of  their  hemoglobin. 

This  test,  known  from  its  discoverer  as  the  Wassermann 
test,  is  not  absolutely  certain,  but  it  is  efficient  in  probably 
90%  of  the  tests  made.  If  it  is  repeated  at  intervals  for 
two  years  after  the  disappearance  of  all  active  symptoms, 
and  a  negative  result  obtained  each  time,  the  patient  may 
with  reasonable  certainty  be  considered  cured. 

There  has  recently  died  in  Germany  a  man  whose  name 
is  destined  to  be  ever  bright  in  the  annals  of  science.  Paul 
Ehrlich,  famed  for  his  researches  on  cancer  and  immunity, 
the  latter  based  upon  his  theory  of  the  chemical  affinities  of 
living  cells,  was  the  discoverer  of  a  specific  remedy  for  syphilis 
— salvarsan  or  "606",  successful  after  605  substances  had 
been  tried  and  failed!  This  remedy,  a  compound  of  arsenic, 
is  now  widely  used  in  the  treatment  of  the  "red  plague." 

^  This  was  the  original  niethod.  It  is  now  known  that  "antigen"  a 
is  non-siiecific.  Hence  extracts  of  various  normal  organs  may  be  em- 
ployed. 


Biology  and  Medicine  447 

One  of  the  most  fatal  diseases  in  days  gone  by  was  menin- 
gitis, caused  by  the  bacterium  Diplococcus  intracellularis, 
which  develops  in  the  meninges  or  membranes  surrounding 
the  brain  and  spinal  cord,  setting  up  an  inflammation  result- 
ing in  death,  or,  if  the  victim  is  spared,  often  leaving  paraly- 
sis, imbecility  or  some  other  dread  condition  in  its  wake. 
With  the  discovery  of  the  causative  organism  some  thirty 
years  ago,  biology  set  itself  to  find  a  remedy. 

It  is  a  well-known  fact  that  both  among  men  and  lower 
animals  there  are  many  instances  of  natural  immunity  and 
susceptibility  to  disease.  The  native  cattle  of  Austria- 
Hungary  and  Japan  are  relatively  immune  to  tuberculosis, 
while  other  breeds  are  very  susceptible.  The  Algerian  sheep 
are  comparatively  immune  to  anthrax,  to  which  all  other 
sheep  are  extremely  susceptible.  Field  mice  are  immune  to 
glanders,  while  the  house  mouse  is  susceptible.  The  negro 
is  more  resistant  to  yellow  fever  and  susceptible  to  tubercu- 
losis than  the  white  race.  Malaysians  are  very  susceptible  to 
beriberi,  while  other  races  are  much  less  so. 

"While  some  immunity  to  disease  is  thus  "natural"  or  in- 
born, other  immunity  may  be  "acquired."  After  recovery 
from  typhoid  fever  the  subject  is  unlikely  to  have  a  recur- 
rence of  the  disease  for  several  years.  The  victim  who  has 
successfully  withstood  an  attack  of  smallpox  is  thereafter 
usually  protected  against  its  ravages,  while  we  are  all  familiar 
with  the  measles  and  whooping  cough  of  childhood,  which  once 
experienced,  give  us  comparative  protection  against  further 
attacks.  Modem  theories  and  practice  of  immunity  are  of 
very  recent  date,  and  yet  methods  of  immunity  have  been 
practised  from  an  early  date  and  by  primitive  people.  The 
Chinese  and  other  orientals  were  wont  to  protect  themselves 
against  smallpox  by  putting  the  scabs  of  patients  into  the 
nose  of  persons  who  had  not  yet  taken  the  disease.  In  1721 
a  similar  method  was  introduced  in  England  by  Lady  Mary 
Montague,  and  was  practised  there  until  the  discovery  of 
Jenner's  method  of  vaccination.  The  Moors  used  to  protect 
their  cattle  from  pleuropneumonia  by  sticking  a  knife,  which 
had  been  previously  inserted  in  the  lung  of  an  animal  which 
had  died  from  the  disease,  under  the  skin  of  healthy  animals. 
One  of  the  tribes  of  central  Africa,  the  Vatuas,  are  reported 
to  immunize  themselves  against  snake  venom. 

The  various  theories  of  immunity  are  too  complex  to  be 
discussed  in  detail  here,  but  the  brief  general  statement  may 
be  made  that  immunity  depends  upon  certain  cheiiiical  sub- 
stances in  the  blood  which  either  aid  in  the  destruction  o£ 
bacteria  or  counteract  the  poisons  which  they  produce  (or 
both).     The  former  process  occui-s  in  vaccination  either  with 


448  Biolorjy  in  America 

a  weakened  (smallpox)  or  dead  virus  (typhoid  fever)  ;  the 
efTicieiicy  of  anti-toxins  in  diplitheria,  and  tetanus  depends 
upon  the  latter,  while  meningitis  serum  acts  both  as  a  means 
of  destroying  the  meningitis  bacterium  and  of  neutralizing 
the  toxin  produced  by  it. 

But  to  return  to  the  discovery  of  a  cure  for  meningitis. 
For  several  years  experimenters  had  been  attempting  to 
render  animals  immune  to  the  disease,  and  then  by  injectiiig 
some  of  their  blood  serum  into  other  animals  to  make  these 
latter  immune  in  their  turn.  Various  species  of  animals 
were  employed  for  this  pui-pose,  but  the  horse  M'as  the  one 
finally  selected,  partly  because  normal  horse  serum,  when 
injected  into  human  beings  produces  no  ill  effects,  and,  partly 
for  the  reason  that  the  horse  is  readily  immunized  against 
meningitis,  and  partly  because  of  the  large  amount  of  serum 
obtainable  from  one  animal.  In  immunizing  a  horse  the  first 
step  is  to  secure  the  bacteria  from  some  victim  of  the  disease 
and  grow  them  on  some  culture  medium  such  as  agar  impreg- 
nated with  beef  bouillon  and  other  nutrient  materials.  After 
a  good  growth  has  been  obtained,  the  culture  is  scraped  off 
from  the  agar  and  heated  to  55°  or  60°  C.  in  physiological 
salt  solution,  to  destroy  the  bacteria.  A  drop  or  two  of  this 
solution,  containing  the  dead  bacteria  and  some  of  their  prod- 
ucts, is  then  injected  into  a  horse  which  has  been  kept  under 
observation  for  some  time  and  rigorously  examined  to  deter- 
mine its  healthfulness.  After  eight  days  a  second  and  larger 
dose  is  given  and  this  is  repeated  at  similar  intervals  for 
periods  of  from  four  months  to  a  year,  until  the  horse  can 
withstand  large  injections,  not  of  dead,  but  of  living  bacteria. 
The  horse  is  then  bled  under  aseptic  conditions  and  the 
serum  so  obtained  put  in  sterile  vials  and  sent  out  to 
physicians  for  use. 

The  treatment  with  this  serum  was  not  at  first  successful 
however.  The  world-wide  epidemic  of  cerebro-spinal  menin- 
gitis beginning  in  1904  stimulated  the  search  for  a  remedy 
and  these  experiments  were  soon  successful.  The  credit  for 
the  first  successful  use  of  anti-meningitis  serum  probably 
belongs  to  a  European — Jochmann,  but  the  principal  devel- 
opment of  the  method  is  due  to  Flexner,  working  at  the 
Kockefeller  Institute  in  New  York. 

Early  in  his  experiments  Flexner  employed  monkeys  as 
more  likely  than  the  lower  animals  to  react  to  human  disea'^es 
in  a  manner  similar  to  men.  By  injecting  cultures  of  the 
meningitis  bacterium  into  the  spinal  column  of  monkeys  Flex- 
ner infected  them  with  the  disease.  Following  these  experi- 
ments he  similarly  employed  intra-spinal  injections  of  the 
curative  serum,  at  first  on  monkeys  and  later  on  man,  with 


Biohf/!/  (Did  Medicine  449 

marked  success,  tlie  comparative  i'aiJure  of  the  earlier  experi- 
ments being  apparently  due  to  the  fact  that  the  injections 
were  not  made  directly  into  the  space  surrounding  the  H\miid 
cord,  so  that  the  anti-serum  did  not  gain  direct  access  to  the 
seat  of  infection. 

While  the  results  with  anti-meningitis  serum  are  not  per- 
fect, they  are  nevertheless  very  encouraging.     Whereas  the 
mortality  in  the  disease  previous  to  the  introduction  of  anti- 
serum treatment  was  about  75%,  mounting  in  very  young 
children  to  over  90%  ;  in  1294  cases  treated  with  the  anti- 
serum the  mortality  was  only  31%,  and  when  the  injection  was 
given  early  in  the  disease  this  was  reduced  to  18%.     Even 
more    striking    results    have    been    obtained    in    the    case    of 
diphtheria  anti-toxin,  while  in  the  use  of  vaccines  as  preven- 
tive agents  the  immunity  secured  is  virtually  perfect.     The 
practically  complete  elimination  of  typhoid  fever  from  our 
army  in  the  recent  war,  and  in  the  wild  goose  chase  after 
Villa  in  1917,  is  sufficient  testimony  to  the  effectiveness  of 
anti-typhoid  vaccination,  while  the  prevention  of  tetanus  in 
the  wounded,  when  injected  with  anti-tetanus  serum  in  time, 
tells  clearly  the  story  of  the  blessing  of  this  remedy  to  man. 
With  the  extent  to  which  trench  fighting  was  developed 
in  the  great  war,  men,   with  rats  and  like  rats,  buriowing 
and  living  undeiground  in  trench  and  "dug-out,"  came  new 
diseases  and  we  heard  for  the  first  time  of  "trench  foot"  and 
"trench  fever."     The  first  of  these  was  clearly  an  individual 
indiction  due  to  imperfect  circulation  caused  by  long  standing 
in   the  wet.     But   the   latter  was   apparently   communicable, 
caused  by  some  sort  of  micro-organism.     Here  was  a  new 
problem   for  biology  to  solve.     Suspicion  quickly   fell   upon 
the  "cootie,"  and  conviction  soon  followed.     Twenty-two  men 
allowed   themselves   to   be   bitten    ])y   lice  from   trench   fever 
patients,  as  a  result  of  which  twelve  of  them  acquired  the 
disease;   while  four  who   were   bitten   by  lice   from   healthy 
men  did  not  contract  it,  and  eight  others  living  in  the  same 
quarters  as  the  bitten  men,  but  kept  free  from   lice,   also 
remained  free  from  the  disease,  proving  conclusively  the  guilt 
of  the  "cootie"  as  the  carrier  of  infection. 

In  the  field  of  protozoiilogy,  medical  entomology  and  ])ara- 
sitology  America  has  rendered  conspicuous  service  both  in 
discovery  of  new  facts  and  in  their  application  to  human 
welfare.  AVhile  the  proof  of  the  role  of  the  mosquito  in  the 
spread  of  malaria  is  mainly  due  to  English.  French,  and 
Italians,  the  extension  of  that  proof  to  include  the  relation 
of  the  mosquito  to  the  yet  more  deadly  yellow  fever  is  duo 
to  the  devotion  and  courage  of  four  young  Americans  (one 
a  Cuban),  as  a  result  of  which  two  of  these  suffered  an  attack 


450  Biology  in  America 

of  the  deadly  scourge,  and  one  of  them   (Lazear)   hiid  down 
his  life  as  a  sacrifice  to  science  and  to  mankind/ 

The  Italian  Grassi  and  the  Englishmen  Low  and  Sambon 
had  shown  the  necessary  causative  relation  between  the  mos- 
quito and  malaria,  and  the  relation  between  the  distribution 
of  3'ellow  fever  and  the  mosquito  genus  Stegomyia,  led  to  a 
strong  suspicion  of  the  latter  as  the  villain  in  the  plot. 

The  demonstration  of  the  theory  was  simple  enough,  but 
one  requiring  heroic  self-sacrifice  on  the  part  of  the  demon- 
strators. The  story  has  been  so  often  retold  that  it  may 
be  passed  over  here  in  briefest  outline.  The  theory  of  a 
causative  relation  between  the  mosquito  and  disease  is  not 
a  new  one.  The  very  ancient  literature  of  India  contains 
suggestions  of  such  a  relation,  particularly  in  regard  to 
malaria.  Many  primitive  peoples  have  had  a  dim  idea  that 
mosquitoes  were  to  blame  for  the  fevers  prevalent  in  low- 
lying,  marehy  regions.  The  Mschamba  tribe  in  Africa  avoid 
such  regions  for  fear  of  fever.  In  their  language  the  same 
word  (mbu)  is  used  both  for  fever  and  mosquito.  "When 
Humboldt  visited  the  region  of  the  upper  Orinoco  he  found 
that  the  natives  attributed  their  fevers  to  mosquitoes. 

As  early  as  1848  Dr.  Nott  of  New  Orleans  suggested  the 
mosquito  as  the  transmitter  of  malaria  and  yellow  fever,  and 
in  1853  Beauperthuy  published  an  article  in  the  "Gaceta 
Oficial  de  Cumana"  (Venezuela)  in  Avhich  he  advanced  a 
similar  theory.  Beauperthuy  pointed  out  that  yellow  fever 
prevailed  when  there  was  a  good  mosquito  crop.  He  sug- 
gested that  the  mosquito  injected  into  the  blood  of  its  victims 
a  poison  which  broke  down  the  red  corpuscles,  mixing  their 
coloring  matter  with  the  blood  serum.  This  poison  was 
obtained  by  the  mosquitoes  from  decaying  matters  along  the 
seashore  or  in  swamps. 

In  1881  Dr.  Carlos  Finlay  of  Havana,  as  the  result  of  a 
careful  and  extended  study  of  the  life  history  and  habits 
of  the  Stegomyia  mosquitoes  and  their  relation  to  yellow 
fever  concluded  that  they  were  the  agents  in  the  spread  of 
the  disease,  and  in  3897  Dr.  A.  C.  Smith  of  the  U.  S.  Marine 
Hospital  Service,  tried  an  experiment  at  the  national  quaran- 
tine station  on  Ship  Island  in  the  Gulf  of  Mexico,  which  was 
a  forerunner  of  the  later  work  of  our  government  in  Cuba, 
and  which  strongly  supported  Finlay 's  conclusions.  Dr. 
Smith  comi)letely  screened  the  quarantine  station  where  he 
had  under  treatment  some  thirty  cases  of  yellow  fever,  taken 
from  incoming  vessels,  and  no  new  cases  developed  there. 

The  final  and  definite  proof  of  the  theory  however  was  made 

*SubsoqueTitly  both   Rccd   aud   Carroll   dictl,   probably  as  the   indi- 
rect result  of  their  work. 


Biology  and  Medicine 


451 


by  a  U.  S.  Army  Commission  appointed  by  Surgeon-General 
Sternberg  in  1 !)()(),  during  our  occupation  of  Cuba.  Tlie 
commission  consiste<l  of  three  Ainericans,  with  Walter  Kecd 
in  charge,  assisted  by  James  Can-oil  and  Jesse  I^azear  and 
a  Cuban,  Aristides  Agramonte.  Two  wel^  built  houses  were 
erected  in  the  same  situation,  and  fully  sei-eened.  In  one  of 
these  soiled  bedding,  brought  direct  from  yellow  fever  patients 
in  Havana,  was  placed,  and  here  a  number  of  men  lived  for 
several  weeks  without  a  single  case  of  yellow  fever  developing 
among  them.  In  the  other  house  were'  two  rooms  separated 
only  by  a  mosquito  proof  screen.  One  of  these  rooms  was 
kept  free  from  mosquitoes,  while  in  the  other  were  placed 


■mmW 

JB 

Carroll,  Lazear  and  Eeed 
Members  of  the  U.  S.  Yellow  Pcver  Gominission,  which  (ieiuoiistiateil 
I  he  role  of  mosquitoes  in  the  carriage  of  yellow  fever. 

Coui-tcsy  of  the  U.  8.  Bureau,  of  Entomology. 


mosquitoes  which  had  bitten  yellow  fever  patients.  Among 
the  men  occupying  the  former  no  case  of  the  disease  devel- 
oped, while  one-half  of  those  in  the  latter  room  developed  the 
disease.  In  another  experiment  seven  men  were  bitten  by  in- 
fected mosquitoes  contained  in  a  glass  jar,  and  five  of  them 
contracted  the  disease.  The  subjects  of  these  experiments 
were  volunteers,  meml)ers  of  the  ('(»ininissi(.n  t heniselves, 
U,  S.  soldiers  and  three  Spaniards.  Doctor  Lazear  died  of  the 
fever,  as  the  result  of  an  accidental  bite  by  an  infected 
mosquito.  Dr.  Carroll,  contracted  the  disease,  as  the  result 
of  his  experiments,  and  while  he  i-eeovered  from  the  fever, 
his  death,  four  years  later,  was  probably  indirectly  tlue  to 
this  attack.     The  first  soldier  who  volunteered  was  John  R. 


452  Biology  in  America 

Kissinger  of  Ohio,  concerning  whom  Doctor  Eeed  says  in  his 
report : 

"I  cannot  let  this  opportunity  pass  without  expressing  my 
admiration  of  the  conduct  of  this  young  Ohio  soldier  who 
volunteered  for  this  experiment  as  he  expressed  it  'solely  in 
the  interest  of  huitianity  and  the  cause  of  science'  and  with 
the  only  proviso  that  he  should  receive  no  pecuniary  reward. 
In  my  opinion,  this  exhibition  of  moral  courage  has  never 
been  surpassed  in  the  annals  of  the  Army  of  the  United 
States.""'  The  iSpaniaids  who  volunteered  did  so  for  tlie 
money  offered  them,  and  because  they  had  little  faitli  in  the 
theory.  After  three  had  contracted  the  disease  however  no 
more  of  tlieni  volunteered. 

Let  us  look  for  a  moment  at  a  few  of  the  results  of  these 
discoveries  and  sacrifices. 

The  failure  of  the  French  under  DeLesseps  to  dig  the 
Panama  Canal  was  due  to  many  factors,  chief  of  which  were 
dishonesty,  extravagance  and  fever.  With  no  knowledge  of 
the  causes  of  yellow  fever  and  malaria  it  was  naturally 
impossible  for  them  to  successfully  combat  these  plagues. 
The  exact  mortality  figures  for  the  period  of  the  French 
occupation  are  not  available,  but  the  rate  is  known  to  have 
been  very  high.  The  contractors  who  were  doing  the  work 
for  the  Canal  Company  were  charged  $1  a  day  for  each 
of  their  men  cared  for  in  the  company's  hospital.  Conse- 
quently when  a  laborer  was  taken  sick  his  employer  often 
discharged  him  in  order  to  save  hospital  expenses^  and  many 
of  these  unfortunate  men  were  left  to. die  upon  the  roads 
leading  into  Panama  and  Colon.  Of  thirty-six  Catholic  nuns 
brought  from  France  to  serve  as  nurses  twenty-four  died  of 
yellow  fever.  Seventeen  out  of  eighteen  young  French  engi- 
neers who  came  over  on  one  vessel  died  within  a  month  of 
their  arrival. 

"When  the  United  States  undertook  the  canal  work  in  1904 
Colonel  W.  C.  Gorgas  of  the  army  medical  corps  was  placed 
in  charge  of  sanitation.  The  drinking  water  in  the  canal 
zone  was  almost  entirely  obtained  from  cisterns  or  water 
barrels.  In  the  city  of  Panama  alone  there  were  four  thou- 
sand breeding  places  for  mosquitoes.  These  were  immediately 
covered  to  prevent  the  entrance  of  mosquitoes,  and  in  eight 
months'  time  there  were  less  than  four  hundred  receptacles 
containing  mosquito  larvpe.  In  addition  to  covering  the  rain 
barrels,  about  700,000  gallons  of  oil  were  used  for  oiling  pools, 
and  nearly  four  hundred  miles  of  drainage  ditches  cleaned 
out  every  year  in  order  to  destroy  the  breeding  grounds  and 

'Howard,    "Mosquitoes    of    North    nn<l    Central    America,"    Carnegie 
Institution,  Pub.  159,  p.  244. 


Biology  and  Medicine  453 

to  kill  the  larvae  in  those  remaining.  In  order  to  ferret  out 
every  possible  breeding  spot  more  than  4,000  acres  were 
cleared  of  grass  and  2,000  of  brush  annually.  And  as  a 
further  protection  against  the  remaining  mosquitoes,  and 
other  insects,  about  $1,000,000  were  spent  in  screening  resi- 
dences, hotels  and  hospitals.  As  a  result  of  this  work  "not 
a  single  case  of  yellow  fever  was  contracted  during  the  first 
two  years  under  Doctor  Gorgas,  although  there  were  con- 
stantly one  or  more  yellow-fever  cases  in  the  hospital,  and 
although  the  nurses  and  doctors  were  all  non-immunes.  The 
nurses  never  seemed  to  consider  that  they  were  running  any 
risk  in  attending  yellow-fever  cases  night  and  day  in  screened 
wards,  and  the  wives  and  families  of  officers  connected  with 
the  hospital  lived  about  the  grounds  knowing  that  yellow 
fever  was  constantly  being  brought  into  the  grounds  and 
treated  in  nearby  buildings.  Americans,  sick  from  any  cause, 
had  no  fear  of  being  treated  in  the  bed  immediately  adjoin- 
ing that  of  a  yellow-fever  patient.  Colonel  Gorgas  and  Doctor 
Carter  lived  in  the  old  ward  used  by  the  French  for  their 
officers,  and  Colonal  Gorgas  thinks  it  safe  to  say  that  more 
men  had  died  from  yellow  fever  in  tliat  building  tban  in  any 
other  building  of  the  same  capacity  at  ])i'esent  standing.  He 
and  Doctor  Carter  had  their  wives  and  children  with  them, 
which  would  formerly  have  been  considered  the  height  of 
recklessness,  but  they  looked  upon  themselves,  under  the  now 
recognized  precautions,  as  safe  almost  as  they  would  have 
been  in  Philadelphia."'^ 

Similar  results  were  obtained  in  Havana  during  the  occu- 
pation of  Cuba  by  the  United  States.  Two  "brigades"  of 
mosquito  fighters  were  oiganized,  one  to  make  war  on  tlie 
Stegomyia  or  yellow-fever  mosquito  in  the  city  itself,  and  one 
on  the  Anopheles  or  malaria  mosquito  in  the  suburban  dis- 
trict. The  city  was  divided  up  into  sections  to  each  of  which 
an  inspector  and  two  laborers  were  assigned,  whose  duty  it 
was  to  see  that  all  rain  barrels  were  protected  against  mos- 
quitoes, all  cesspools  oiled,  and  other  receptacles  of  fresh 
water  emptied.  In  tiie  suburbs  ditches  and  gutters  were 
cleared  of  debris,  new  ditches  dug  where  necessary,  and  the 
little  puddles  of  water  in  the  footprints  of  cattle  or  horses 
and  other  depressions  in  the  field  were  drained,  but  little 
oiling  being  necessary. 

Prior  to  the  United  States'  occupation  Havana  was  a  pest 
hole  and  a  serious  menace  to  the  health  of  our  country.  Tliis 
condition  indeed  was  one  of  the  factors  leading  up  to  the 
Spanish-American  War.  In  1!)00  it  was  visited  by  a  severe 
epidemic  of  yellow  fever,  deaths  from  wliieh  nuiiibere<l  '.Vlh; 
"  Howard,  locus  citatus,  pp.  431-2. 


454 


Biology  in  America 


in  1907  as  a  result  of  the  auti-mosquito  campaign  there  were 
but  28  deaths,  and  the  disease  is  now  virtually  unknown 
there,*'^ 

Within  the  United  States  anti-mosquito  work  has  been 
sporadic  and  local  in  character,  in  many  cases  being  under- 
taken privately  rather  than  under  national  or  state  direction. 
Wherever  it  has  been  consistently  pursued  however  it  has 
given  striking  success.  One  of  the  most  notable  instances  of 
this  local  work  is  that  undertaken  on  Staten  Island  in  1901 


War  on  the  Mosquito 

Filling  in  salt  marshes  with  the  contents  of  Brooklyn  ash  barrels. 

Cottrtcsy  of  the  U.  tS'.  Bureau  of  Entomology. 

by  the  New  York  Health  Department  under  the  direction 
of  Dr.  Doty,  health  officer  of  the  port  of  New  York.  Staten 
Island  is  a  long  narrow  island  on  the  opposite  side  of  New 
York  Bay  from  the  city,  and  between  it  and  the  Jersey  shore 
a  ridge  of  low  hills  forms  the  backbone  of  the  island,  with 
the  land  sloping  down  to  salt  marshes  along  the  shores. 
Malaria  has  been  epidemic  there  for  many  years,  and  its 
mosquitoes  have  been  almost  as  famous  as  the  New  Jersey 
brand.  The  details  of  the  work  are  similar  to  those  already 
described,  except  that  more  extensive  ditching  operations  were 
'"  Noguchi  has  recently  discovered  a  probable  cause  of  yellow  fever 
in  the  Leptospira  icteroides.  He  has  also  devised  a  successful  pro- 
tective vaccine  and  a  curative  serum,  which  latter  in  several  experiments 
reduced  the  mortality  from  50%  to  9%. 


Biology  and  Medicine  455 

required  in  the  drainage  of  the  extensive  marsli  areas.  The 
results  were  most  gratifying.  The  Anoplieles  mosquitoes  were 
virtually  exterminated,  with  a  consequent  reduction  in  the 
number  of  malaria  cases  from  thirty-three  in  1905  to  five  in 
1909/  while  other  mosquitoes  also  have  been  greatly  reduced 
in  number. 

But  insects  play  not  only  a  necessary  role  in  the  spread  of 
disease;  the  incidental  part  which  they  take  is  on  the  whole 
far  more  dangerous  than  the  other.  In  its  discovei-y  of  this 
part  biology  has  made  one  of  its  greatest  contributions  to 
human  welfare.  The  trail  of  the  fly  has  been  followed  so 
often  and  with  such  care  in  the  literature  of  recent  years 
that  it  seems  superfluous  to  repeat  what  is  so  well  known. 
And  yet  a  few  of  the  more  striking  facts  concerning  the 
relation  of  flies  and  other  insects  to  the  spread  of  disease,  and 
especially  the  results  of  preventive  measures  may  not  be 
amiss ;  the  more  so  since  we  still  find  in  some  quarters  among 
supposedly  educated  and  intelligent  people  an  almost  total 
disregard  of  the  most  common  and  fundamental  laws  of  self- 
defense  against  disease. 

While  we  are  all  sadly  familiar  with  the  reproductive 
capacity  of  the  fly,  probably  few  of  us  realize  the  theoretical 
possibilities  of  such  increase — theoretical,  because,  owing  to 
the  inevitable  loss  of  eggs  and  young,  the  possibilities  are 
never  realized.  They  are  interesting  and  instructive  liowever 
for  if  such  possibilities  exist  theoretically,  the  realization  must 
at  least  be  very  great.  A  fly  lays  on  the  average  120  eggs 
at  one  time,  which  come  to  maturity  in  ten  days,  and  in  the 
latitude  of  Washington,  D.  C„  there  may  be  as  many  as 
twelve  broods  in  a  season.  If  every  other  egg  of  every  brood 
gave  rise  to  a  fertile  female  (assuming  an  equality  in  the 
number  of  males  and  femaleis)  and  this  in  turn  produced 
broods  of  its  own  in  due  season,  one  mother  fly  would  produce 
2,568,034,296,513,029,664,000  «  flies,  which  if  strung  end  to  end 
on  a  thread  would  reach  some  400,000,000,000  times  around 
the  earth. 

The  fly's  body  is  clothed  with  fine  hairs  and  a  single 
fly  has  been  estimated  in  some  cases  to  carry  more  than 
6,000,000  bacteria. 

In  1898  there  were  concentrated  in  army  camps  in  the 
South  thousands  of  men  gathered  there  for  our  campaign 
against  the  Spaniards  in  Cuba.  These  men  ate  in  unscreened 
mess  halls  near  which  were  the  similarly  unprotected  latrines 
of  the  camp,  affording  free  passage  for, the  millions  of  flies 

'Prior  to  1905  there  are  no  satisfactory  data  on  the  number  of  cases. 
'Computed  by  E.  F.  Chandler,   Professor  of  Civil   Engineering,   Uni- 
versity of  North  Dakota. 


456 


Biology  in  America 


which  swarmed  from  latrine  to  mess  table.  Typhoid  fever 
developed  in  the  camp  and  the  resultant  roll  of  22,420  cases 
and  1,924  deaths  told  all  too  plainly  the  work  of  the  fly  as 
tile  agent  of  death.  Bacteriological  examination  of  the  bodies 
of  flies  confirmed  the  evidence  of  the  siek  list,  showing  beyond 
peradventure  the  responsibilitj^  of  the  fly.  Contrast  this  with 
our  record  in  the  recent  war.  In  the  army  camps  an  almost 
entire  absence  of  flies,  even  though  nearby  towns  and  villages 
were  furnished  with  an  ample  quota,  no  uncovered  garbage 
piles,  loose  refuse,  or  unscreened  mess  halls  and  kitchens ;  no 
poorly  built  and  unsanitary  toilets,  no  dirty  streets  and  ill- 
scrubbed  floors.  A  returned  soldier  put  the  situation  in  a 
nut-shell  when  he  said  that  he  wished  every  civilian  could 
have  a  dose  of  sanitary  training  in  the  army.  And  the  result  ? 
A  reduction  of  the  death  rate  from  all  diseases,  prior  to  the 
influenza  epidemic  in  1918,  to  less  than  one-half  that  of  the 
healthiest  part  of  the  United  States.  This  epidemic  levied 
a  terrible  toll  upon  the  crowded  army  camps,  serving  to  illus- 
trate man's  utter  helplessness  in  the  face  of  an  enemy  who 
fights  with  unknown  weapons. 

As  a  further  specific  example  of  the  results  of  the  "swat- 
the-fly"  campaign  in  America,  when  consistently  carried  out, 
let  us  take  the  experience  of  Wilmington,  N.  C,  in  1911. 
During  the  summer  of  this  year  all  manure  piles  and  other 
possible  breeding  places  for  flies  were  several  times  sprinkled 
with  pyroligneous  acid  to  destroy  the  developing  eggs  and 
larvifi.  The  result  of  this  work  is  shown  in  the  accompanying 
table  in  which  +  indicates  the  time  of  sprinkling.^ 


Typhoid  Cases 


Date   of   sprinkling  with 
pyroligneous  acid 


June     1-7 

11 

8-14 

22 

+ 

15-21 

50 

+ 

22-28 

42 

29- 
July          5 

10 

+ 

6-13 

11 

14-20 

3 

+ 

21- 

0 

In   1907   the  Merchants'   Association   f)f  New  York   City 
appointed  a  committee  to  study  among  other  things  the  work 

'From  Hlockljridge,  "How  to  Make  a  P'lyless  Town,"  World's  Work, 
vol.  24. 


Biology  and  Medicine  457 

of  t^je  fly  in  spreading  disease.  Tlieir  findings  showed  that 
where  the  sewage  was  tliickest  there  tlie  flies  were  most 
•ibundant  and  further  that  tlie  number  of  deaths  from  various 
intestinal  diseases  corresponded  very  closely  to  the  abundance 
of  flies  from  week  to  week. 

A  similarly  incidental  role  in  the  spread  of  the  dread 
bubonic  plague  has  been  traced  to  the  rat  and  its  boon 
companion,  the  flea.  While  the  plague  is  a  native  of  the 
East,  its  ravaging  march  has  often  extended  over  Europe  and 
it  has  even  crossed  the  Pacific  and  visited  our  shores. 

The  role  of  the  rat  in  the  spread  of  plague  was  suspected 
by  the  ancients  centuries  before  the  Christian  era.  Samuel 
tells  us  that  in  one  of  the  numerous  wars  Ix'tween  the  Philis- 
tines and  the  Israelites,  the  former  made  ofi'  with  tlie  national 
emblem  of  the  Hebrews,  the  Ark  of  the  Covenant;  whereupon 
as  a  sign  of  His  displeasure  the  Lord  visited  upon  the  thieves 
a  scourge  of  plague.  To  assuage  the  wrath  of  tlie  offended 
Deity  the  priests  of  the  Philistines  told  them  to  return  the 
stolen  goods  and  to  make  a  peace  offering  to  the  Lord  of 
"five  golden  images  of  the  emerods  (boils)  in  their  secret 
parts,  and  five  golden  images  of  the  mice  (rats?)  that  marred 
the  land."  1° 

The  early  Greeks  recognized  Apollo  as  the  sender  of  the 
plague  and  the  mice  (rats?)  as  his  messengers.  During  the 
reign  of  the  Roman  Emperor  Severus  a  great  epidemic  of  the 
plague  broke  out  in  Asia  ]Minor.  A  coin  made  at  Pergamos 
at  this  time  shows  on  one  side  an  image  of  the  god  of 
medicine  ^sculapius,  with  a  dead  rat  at  his  feet  and  by  his 
side  a  naked  human  figure  in  an  attitude  of  supplication. 

Since  the  days  of  Justinian  down  to  recent  times  the 
plague  or  "black  death"  of  the  Middle  Ages  has  swept  re- 
peatedly over  Europe  leaving  death  and  desolation  in  its 
trail.  "Truth  is  indeed  stranger  than  fiction"  and  neither 
the  "Rienzi"  of  a  Bulwer  nor  the  "Romola"  of  an  Eliot  has 
outdone,  in  their  wonderful  pictures  of  the  pestilence  which 
overwhelmed  Italy  in  the  fourteenth  century,  the  colorless 
facts  recorded  by  history.  From  time  immemorial  plague 
appears  to  have  been  of  frequent  occurrence  in  Asia  and 
Africa,  but  only  in  recent  years  has  it  invaded  the  western 
hemisphei-c.  The  outbreak  in  San  Francisco  in  1905  brought 
home  forcibly  to  Americans  the  truth  that  in  these  days  of 
rapid  and  easy  communication  between  our  own  shores  and 
those  of  Asia  we  are  living  not  to  ourselves  alone,  but  are  in 
truth  our  "brother's  keeper."  AVith  the  opening  of  tlie 
Panama  Canal  and  consc'quent  shortening  of  the  voyage 
between  the  orient  and  our  Gulf  and  Atlantic  ports,  llie 
"  1,  Samuel,  vi,  5. 


458  Biology  in  America 

danger  of  an  occasional  recurrence  of  the  disease  among  ns 
becomes  still  greater. 

"Without  the  aid  of  biology  we  should  still  be  living  in  the 
Dark  Ages  so  far  as  plague  is  concerned.  With  the  discovery 
of  the  bacillus  causing  the  disease  in  1894  it  was  shown  that 
mice,  rats,  guinea  pigs,  rabbits,  monkeys  and  many  otlicr 
animals  can  be  infected  by  inoculation  as  well  as  by  feeding 
with  infected  material.  But  how  was  the  disease  trans- 
ferred from  man  to  man?  Was  it  a  "miasma"  or  foul  air 
which  did  the  damage?  Was  it  by  "fomites"  or  infected 
clothing  and  other  articles  that  contagion  was  spread?  Or 
was  personal  contact  necessary  for  infection?  Here  enters 
the  ubiquitous  flea.  The  Indian  Plague  Commission  appointed 
by  the  British  Government  to  study  the  scourge  in  India 
found  that  it  was  only  in  the  presence  of  fleas  that  con- 
tagion was  spread  from  one  animal  to  another.  Young  rats 
may  even  be  suckled  by  plague-infected  mothers  witliout  con- 
tracting^ the  disease,  provided  fleas  are  absent  from  their 
cages.  Rats  and  guinea  pigs  may  be  kept  healthy  in  cages 
hung  in  rooms  where  animals  have  recently  died  of  plague. 
But  if  the  cages  be  hung  near  enough  to  the  floor  to  permit 
the  fleas  to  jump  in,  they  become  infected.  On  the  other 
hand  the  cages  may  be  placed  upon  the  floor  without  danger 
of  infection,  provided  only  they  be  surrounded  with  "tangle 
foot"  thereby  preventing  ingress  of  fleas.  Furthermore  con- 
tagion may  be  spread  through  the  transfer  of  fleas  from 
infected  to  healthy  animals  without  any  contact  between  the 
latter.  In  the  light  of  these  experiments  proof  appears  to 
be  conclusive  that  the  flea  is  the  most  important,  if  not  the 
only  direct  intermediary  in  the  spread  of  plague. ^"'^ 

But  the  flea  does  not  confine  his  attentions  to  rats  alone. 
He  believes  in  a  varied  diet,  and  an  occasional  meal  of  human 
blood  is  quite  to  his  taste.  Consequently  in  rat-infested  and 
dirty  dwellings,  where  fleas  abound,  if  plague  breaks  out 
among  the  rats,  their  human  co-habitants  are  almost  certain 
to  be  stricken  likewise. 

Previous  to  1900  plague  had  never  occurred  in  the  United 
States  although  it  had  visited  IMexico  and  South  America. 
In  this  year  there  was  an  outbreak  of  plague  in  ' '  Chinatown 
in  San  Francisco,  followed  in  1907-8,  a  year  after  the  great 
earthquake  and  fire,  by  a  second  outbreak,  in  both  of  which 
there  was  a  total  of  281  cases  and  85  deatlis.  When  the 
disease  was  discovered  the  city  authorities  at  first  adopted 
the  ostrich  policy  and  endeavored  to  suppress  all  information 
relative  to  it. 

"In  San  Francisco  plague  met  politics.  Instead  of  being 
confronted  by  a  united  authority  with  intelligent  plans  Jor 

"*  Pneumonic   plague   niay  be  transmitted   direct  by   the   breath. 


Biology  and  Medicine  459 

defense,  it  found  divided  forces  among  which  the  question 
of  its  presence  became  the  subject  of  factional  dispute.  Tliere 
was  open  popular  hostility  to  the  work  of  the  sanitarians, 
and  war  among  the  City,  State,  and  Federal  health  authorities. 

"A  federal  health  officer  was  arrested  for  trying  to  do  his 
duty  as  he  saw  it.  Eugene  Schniitz,  wliile  nuiyor,  refused  to 
approve  the  printing  of  health  reports  and  vital  statistics 
and  attempted  to  remove  from  office  four  members  of  the 
Board  of  Health  who  persisted  in  the  statement  that  plague 
existed  in  the  City.  The  State  bacteriologist,  Ryfkogel,  found 
plague  germs  and  lost  his  position  and  part  of  his  back  salary. 

"The  public  drew  its  inferences  from  the  voluminous  mis- 
information furnished  by  the  disputants.  Plague  was  said 
to  be  a  medieval  disease"  It  belonged  to  the  days  of  Charle- 
magne or  James  II  before  the  common  people  had  soap.  It 
was  an  Oriental  disease,  peculiar  to  rice-eaters.  It  was,  a 
Mongolian  or  Hindu  disease,  and  never  attacked  whites.  In 
San  Francisco  it  was  not  a  disease  at  all — it  was  graft. 
Landlords  of  Chinatown  rat  warrens  contended  fiercely  that 
their  premises  were  perfectly  sanitary  because  the  plumbing 
was  vented. 

"For  a  while  the  people  were  in  the  gravest  danger  and 
it  seemed  impossible  to  convey  any  adequate  warnings  to 
them.  Intimations  from  medical  conventions  of  Eastern 
State  boards  of  health  that  unless  San  Franciscans  got  to- 
gether and  stamped  out  the  plague,  it  would  be  necessary 
to  enforce  a  general  quarantine  against  the  City,  actually 
brought  forth  a  demand  from  certain  quarters  that  the 
Marine  Hospital  fellows  go  back  to  Washington  where  they 
belonged."  ^^ 

Without  the  necessary  power  to  act  in  the  case  the  local 
health  authorities  called  upon  the  U.  S.  Public  Health  Serv- 
ice, with  the  result  that  Doctor  Rupert  Blue  was  placed  in 
charge  with  full  authority  to  act.  Doctor  lilue  immediately 
instituted  a  relentless  war  upon  the  rats  which  infested  the 
city,  with  the  result  that  the  disease  was  soon  entirely  eradi- 
cated. As  illustrative  of  the  role  of  the  rat  in  the  spread  of 
plague  in  San  Francisco  the  following  data  are  quoted  from 
Doctor  Blue's  reports. 

"Two  small  boys  (October,  1907)  while  playing  in  an 
unused  cellar  found  the  body  of  a  dead  rat.  The  corpse 
was  buried  with  unusual  funeral  honors.  In  forty-eight 
hours  both  were  ill  with  bubonic  plague.  A  laborer  finding 
a  sick  rat  on  the  wharf  picked  it  up  with  the  nakiMl  luuid 
and  threw  it  into  the  bay.  He  was  seized  three  days  later 
with  plague.     Doctor  C.  and  family  lived  in  a  second-story 

""Eradicating  Plague  from  San  Francisco,"  Eoport  of  tho  Citizena' 
Health  Committee,  pp.  30-31. 


460  Biology  in  America 

fiat  over  a  grocery  store  in  the  residence  section.  Being 
annoyed  for  some  days  by  a  foul  odor  the  doctor  caused  the 
waniscoting  around  the  plumbing  to  be  removed.  One  or 
two  rat  cadavers  v^^ere  found  in  tne  hollow  wall.  In  two  or 
three  days  the  two  membeis  of  the  family  who  used  the  room 
hickened,  one  dying  on  the  fifth  day  of  cervical  bubonic 
plague.  It  is  probable  that  infected  rat  Heas  were  set  free 
by  the  removal  of  the  wainscoting.  Dead  rats  were  frequently 
touncl  in  or  near  houses  waere  plague  had  occurred."  "- 

An  outbreak  of  plague  in  rats  occurred  in  New  Orleans 
in  1914.  As  the  result  of  prompt  measures  for  the  destruction 
of  rats  and  the  fumigation  and  rat-proohug  of  the  infected 
premises  the  disease  was  suppressed  with  but  a  snigle  case 
occurring  in  man. 

An  eftective  piece  of  plague  control  work  is  that  conducted 
by  the  Bureau  of  Health  in  the  Philippines.  The  method  of 
plague  control  piactised  m  ivianila  is  (_t  interest  as  showing 
how  it  is  possible  practically  to  suppress  the  disease  even 
though  it  may  be  impossible  to  completely  exterminate  the  rat. 

"A  list  of  the  places  at  which  plague-infected  rats  were 
found  was  made.  Each  was  regarded  as  a  center  of  infec- 
tion. Radiating  lines,  usually  five  in  number,  were  pro- 
longed from  this  center,  evenly  spaced  like  the  spokes  of  a 
wheel.  Rats  were  caught  along  these  lines  and  examined. 
Plague  rats  were  seldom  found  more  than  a  few  blocks  away. 
The  furthermost  points  at  which  infected  rats  were  found 
were  then  connected  with  a  line  (and)  the  space  inclosed  by 
the  dotted  line  was  regarded  as  the  section  of  infection.  The 
entire  rat-catching  force,  which  had  heretofore  been  employed 
throughout  tlie  eity,  was  then  concentrated  along  the  border 
of  the  infected  section;  that  is,  along  the  dotted  line.  They 
then  commenced  to  move  toward  the  center,  catching  the  rats 
as  they  closed  in.  Behind  them  thorough  rat  proofing  was 
carried  out.  One  section  after  another  was  treated  in  this 
way  until  they  had  all  been  wiped  out.  Once  weekly  there- 
after rats  were  caught  in  the  previously  infected  sections  and 
at  other  places  which  were  insanitary  and  which  had  been  in- 
fected i!i  years  gone  by.     This  was  coutinned  for  one  year."  ^^ 

But  not  alone  is  the  rat  responsible  for  the  spread  of  plague. 
At  least  two  species  of  ground  squirrels  as  well  as  the  tree 
squirrel  have  been  shown  to  be  susceptible  to  the  plague  ba- 
cillus, and  the  occurrence  of  plague  in  the  first  of  these  has 
been  shown  in  nature,  as  well  as  its  probable  relation  to  the 

""The  Knt  :uul  Its  Relation  to  the  Public  Health,"  p.  147.    The  U.  S. 
Public  Health  Service. 
"Locus  citatus,  pp.  205-G. 


BioloQjj  and  Medicine  461 

occurrence  of  the  disease  in  man.  In  3904  a  case  of  human 
plague  occurred  a  slioi-t  distance  east  of  San  Francisco,  and 
in  lUOG  a  boy  near  Oaldand  was  attacked  by  the  disease  after 
handling  some  ground  squirrels  which  he  had  shot  a  few 
days  previously.  In  July,  1908,  two  cases  of  human  plague 
were  found  in  the  same  region  in  California,  and  an  ('xaiiiiua- 
tion  of  425  ground  squirrels  collected  in  tiie  vicinity  showed 
the  presence  of  the  disease  in  four.  In  August  of  the  same 
year  a  boy  was  stricken  with  plague  in  Los  Angeles  after 
being  bitten  by  a  sick  ground  squirrel,  and  a  dead  s(|uirrel 
taken  in  the  vicinity  was  found  to  be  infected  with  plague. 
The  woodchuck  has  been  suspected  as  a  plague  spreader,  but 
its  relation  to  the  disease  has  not  been  proven  as  yet. 

Not  only  are  ground  squirrels  a  source  of  danger  in  the 
spread  of  plague,  but  the  loss  they  cause  in  the  destruction 
of  grain  is  very  serious.  Their  destruction  therefore  is  of 
first  importance  for  both  sanitary  and  purely  economic  rea- 
sons. To  the  accomplishment  of  this  task  both  the  U.  S. 
Public  Health  Service  and  the  Biological  Survey  are  devot- 
ing their  energies.  Many  methods  are  employed  at  present 
for  the  extermination  of  both  rats  and  ground  squirrels, 
which  have  been  discussed  in  a  previous  chapter.  In  the  de- 
struction of  rats,  trapping,  poisoning,  inoculation  with 
viruses  or  bacterial  cultures,  shooting  and  rat-proofing  have 
all  been  employed  more  or  less  successfully.  Space  does  not 
permit  a  detailed  discussion  of  the  use  and  merits  of  these 
various  methods,  but  it  may  be  said  in  a  general  way  that  the 
rat-proofing  of  buildings  and  systematic  trapping  are  the 
most  effective  means  of  control. 

There  are  many  diseases  of  man  and  lower  animals,  some 
of  them  among  the  worst  scourges  of  the  human  race,  which 
are  caused,  not  by  microscopic  organisms,  either  plant  or  ani- 
mal, but  by  parasitic  worms.  One  of  the  most  terrible  of 
these  diseases  is  trichinosis,  caused  by  a  minute  worm,  about 
1/20  inch  in  length,  the  Trichina  spiralis.  The  devas- 
tations of  this  disease  have  been  greater  among  some  of  the 
poorer  classes  of  Europeans,  who  were  accustomed  to  eat- 
ing raw  pork,  than  among  Americans.  Nevertheless  the  dis- 
ease is  not  unknown  in  this  country,  and  the  occasional  oc- 
currence of  the  parasite  in  American  hogs  led  about  1880  to 
the  prohibition  of  their  import  into  several  European  coun- 
tries. The  woi-m  is  a  parasite  of  man,  the  hog  and  the  rat, 
its  life  histoiy  being  similar  in  each.  Let  us  trace  this,  start- 
ing with  a  pair  of  adult  worms  living  in  the  intestine  of  the 
hog.  Here  the  female  is  fertilized  and  gives  birth  to  some 
thousands  of  progeny,  which  promptly  bore  their  way  through 


462 


Biology  in  America 


the  wall  of  the  intestine,  and  then  migrate,  probably  through 
the  blood  vessels  to  the  muscles.  Here  they  encyst,  surround- 
ing themselves  with  a  capsule  which  is  partly  secreted  by 
themselves  and  partly  by  the  irritated  tissue  surrounding* 
them.  If  now,  the  improperly  cooked  flesh  of  a  hog,  infected 
with  these  trichina  is  eaten  by  man  or  the  rat,  the  sheaths  are 
dissolved  by  the  digestive  ferments  of  the  second  host  and  the 


^^.^ 


,.'"...  .v 


Trichina  Imbedded  in  Muscle 
Courtrnii  o}  the  U.  .V.  Bureau  of  Animal  Industry. 

worms  are  set  free  in  its  intestine  to  repeat  the  cycle  occurring 
in  the  hog.  It  is  during  the  course  of  their  migration  and  en- 
cystment  in  the  muscles  that  occurs  the  terrible  suffering 
caused  by  this  disease  which  is  usually  relieved  by  death 
alone.  If  however  the  infection  be  light,  the  patient  may 
recover,  the  worms  finally  dying,  and  being  absorbed,  leaving 
only  the  connective  tissue  scars  to  mark  their  place.  Since 
hogs  rarely  have  the  opportunity  of  eating  human  flesh  the 
rat  becomes  in  one  sense  a  necessary  agent  in  the  persistence 


Bwlogij  (iiul  Medicine 


4fi3 


and  spread  of  tlio  disease.  There  is  no  remedy  known,  save 
that  of  prevention,  and  it  is  here,  in  the  safeo;nardinfr  of  onr 
meat  supply  tliat  the  proteeting  liaiid  of  Uncle  Ham  is 
stretched  forth  to  save  both  tlie  lives  and  the  dollars  of  his 
children. 

Other  parasitic  worms  of  occasional  occurrence  in  tlie 
United  States  but  of  minor  importance  from  a  medical  stand- 
point, because  of  their  relative  benignity,  are  the  tapeworms 
transmitted  to  men  in  the  flesh  of  both  hogs  and  cattle. 

The  stoiy  of  the  tapeworm  brietiy  told  is  as  follows:  This 
is  as  its  name  implies,  a  tape  or  band-like  animal,  divided 
into  segments  which  become  progressively  larger  and  riper  in 


A  Tape  Worm  op  Man 
Courtesy  of  the  U.  S.  Bureau  of  Animal  Industry. 

passing  from  the  "anterior"  or  "head"  end  posteriorly.  The 
beef  tapeworm  lives  in  the  intestine  of  man,  and  its  ripe 
proglottids  are  passed  in  the  stools  of  the  patient.  Tiiese  east 
proglottids  are  virtually  nothing  but  a  sack  full  of  embryos, 
each  surrounded  by  a  horny  sliell.  If  one  of  these  embryos 
is  taken  by  the  beef  in  its  food  or  water,  it  loses  its  shell  in 
the  beef's  stomach  and  passes  into  the  intestine  as  a  tiny  em- 
bryo about  1/80  of  an  inch  in  diameter.  This  is  armeil  with 
three  paired  hooks  by  means  of  which  the  larva  rapidly  works 
its  way  through  the  intestinal  wall  and  into  the  blood  vessels, 
through  which  it  is  carried  to  the  muscles  or  "flesh"  of  the 
animal  where  it  grows  to  a  considerable  size,  acquiring  the 
"head"  or  attachment  organ  of  the  adult  worm.     The  larva 


1R4-  Biology  in  America 

now  consists  of  a  sack-like  bladder  filled  with  fluid,  which  has 
griven  this,  and  similar  larvfe  the  name  of  "bladder-worm," 
inside  of  which  is  the  head  in  an  inverted  position  like  the 
intunied  finger  of  a  glove.  In  the  muscles  the  larva  is  sur- 
rounded by  a  connective  tissue  sheath  similar  to  that  surround- 
ing the  Trichina  larva  already  described.  If  a  piece  of 
improperly  cooked  beef  containing  one  of  these  larva?  is  eaten 
by  man,  the  "bladder-worm"  loses  its  "bladder,"  turns  its 
"head"  inside  out,  thus  bringing  it  into  the  proper  position 
for  a  frontal  attack  on  the  intestine  of  its  host,  to  which  it 
attaches  itself  by  means  of  four  "suckers"  on  its  "head," 
and  now  proceeds  about  its  business  of  growing  and  produc- 
ing ripe  segments,  which  may  in  their  turn  infect  another 
beef. 

For  the  benefit  of  those  who  enjov  a  nice  juicy  piece  of 
rare  beefsteak  it  may  be  said,  that  with  the  very  efficient  in- 
spection service  of  the  U.  S.  Bureau  of  Animal  Industry  the 
occurrence  of  tapeworms  in  this  country  is  decreasing,  and 
m(>at  coming  from  an  inspected  slaughter  house  may  be  eaten 
with  impunity.  This  of  course  does  not  apply  to  meat 
slaughtered  by  country  butchers. 

Living  in  our  Southern  States  is  a  community  of  people 
cfdlrd  with  contempt  by  negroes  and  whites  alike  the  "po'- 
whites."  They  are  a  shiftless,  lazy  lot  of  "ne'er-do-wee's" 
living  in  utter  disregard  of  health  or  decency.  Many  of  them 
have  never  been  to  school,  and  those  children  who  do  go  to 
school  stand  from  forty  to  ninety  points  lower  on  a  scale  of 
one  hundred  in  their  ability  to  improve,  than  their  comrades. 
They  are  found  in  rural  communities  and  the  smaller  towns 
and  villages  wherever  unsanitai-y  living  conditions  occur.  In 
Porto  Rico  about  ninety  per  cent  of  the  poorer  inhabitants 
are  of  this  type.  "Slany  of  them  are  what  are  known  as  "dirt 
eaters,"  rivaling  even  the  traditional  goat  in  their  fondness 
for  paper,  old  rags,  earth,  lime,  etc.  For  generations  these 
people  have  presented  an  insoluble  problem  to  physician  and 
philanthropist  alike.  Was  the  cause  of  their  condition  hered- 
itary ?  Had  some  outcast  from  the  slums  of  Europe  escaped 
to  America  with  the  early  settlers  and  peopled  the  South  with 
his  degenerate  progeny?  Or  was  the  hard  environment  too 
heavy  a  handicap  for  them  to  overcome  ?  AVas  weak  mental- 
ity and  feebleness  of  purpose  to  blame,  or  yet  was  the  cause 
a  physical  one,  some  insidious  disease  which  inappreciably, 
yet  none  the  less  certainly  was  sapping  the  energy,  both  men- 
tal and  physical  of  its  victims  ? 

The  answer  to  these  questions  came  to  us  indirectly  from 
Europe.  In  cutting  the  St.  Gothard  tunnel  through  the 
Alps  it  was  observed  that  many  of  the  miners  who  were  bare- 


Biology  and  Medicine 


465 


footed  were 
and  the  Ital 
the  liookwor 
the  Geniian 
infected  soil 
of  biological 
years  an  in 
of  "gronnd 


anemic,  run  down  and  unable  to  do  good  work, 
ian  Perroncito  at  that  time  traced  the  disease  to 
■m  Ankylostomum  duodenale.  Some  years  later 
Looss,  traced  the  eouise  of  the  worm  from  the 
to  the  intestine  of  its  victim  by  a  very  clever  bit 
detective  work.  There  had  been  known  for  many 
itation  of  the  skin  of  the  feet  under  the  names 
itch,"  "foot  itch,"  "dew  itch,"  etc. 


(a)  Female,  (b)  Male,  and  (c)  Mouth  of  the  Hookworm 

An  animal  which  is  mainly  responsible  for  the  condition  of  the  "poor 
whites"  in  the  Soutii,  and  wliii-h  causes  an  economic  loss  of  perhaps 
$500,000,000  annually.  The  disease  can  be  effectively  and  easily  cured, 
while  its  prevention  is  merely  a  jnatter  of  a  few  simple  sanitary  pre- 
cautions.    (After  Stiles.) 

"AVhile  experimenting  with  hookworm  larvie  he  spilled 
some  of  them  on  his  liand ;  he  noticed  a  burning  sensation 
and  in  a  few  minutes  the  larvae  had  disappeared.  After  the 
proper  interval,  about  two  months,  he  found  himself  sutfcr- 
ing  with  the  hookworm  disease.  To  determine  what  had  be- 
come of  the  larvffi  that  were  spilled  on  his  hand  he  poure<l 
some  larvffi  on  the  leg  that  was  about  to  be  amputated  from 
a  boy;  on  sectioning  the  skin  of  this  leg,  after  amputation, 
he  found  the  larva3  had  worked  their  way  through  the  skin 


466  Biology  in  Avicrica 

by  way  of  the  liair  follicles,  sweat  duets,  etc.  To  follow  the 
further  course  of  the  larva;  he  placed  some  of  them  on  the 
skin  of  a  number  of  dogs  which  were  killed  and  examined  at 
various  intervals.  In  this  way  he  worked  out  the  entire 
course  of  the  larva;  from  the  skin  to  their  final  resting  place 
in  the  intestine."  ^* 

Where  a  number  of  poor  and  ignorant  miners  were  col- 
lected in  narrow  underground  quarters,  as  in  the  building  of 
a  tunnel,  with  no  proper  arrangements  for  the  disposal 
of  bodily  wastes,  it  is  plain  that  the  most  elementary  rules 
of  health  would  be  disregarded  and  that  tilth  would  abound. 

The  hookworm  derives  its  name  from  the  slightly  bent  or 
hooked  anterior  end.  In  the  mouth  are  four  hooks  and  two 
conical  teeth  by  means  of  which  it  attaches  itself  to  the  mu- 
cous membrane  of  the  intestinal  wall.  Here  it  is  said  to  live 
for  several  years,  during  which  time  it  produces  an  enor- 
mous number  of  eggs.  If  these  chance  to  be  deposited  in  a 
moist  place,  as  in  the  pools  of  water  in  a  mine  or  tunnel,  they 
hatch  into  larva;  which  live  in  the  water  or  moist  earth  until 
they  meet  the  bare  skin,  usually  of  the  feet,  of  another  vic- 
tim. They  then  bore  through  the  skin  into  the  blood  ves- 
sels where  they  are  carried  by  the  blood  stream  to  the  heart 
and  finally  to  the  lungs.  Here  they  leave  the  circulation, 
enter  the  iungs,  and  crawl  into  the  bronchial  tubes,  up  which 
they  crawl  to  the  throat  and  thus  reach  the  oesophagus.  From 
here  they  pass  through  the  stomach  to  the  intestine.  The 
hookworm  may  also  reach  the  intestine  directly  in  unwashed 
fruit  or  raw  vegetables. 

Knowledge  of  hookworm  disease  and  the  part  it  plays  in 
deteriorating  so  large  a  proportion  of  our  southern  popula- 
tion is  mainly  due  to  Dr.  Charles  W.  Stiles,  the  parasitolo- 
gist of  the  U.  S.  Public  Health  Service.  Stiles  has  studied 
the  disease  extensively  in.  the  South  and  found  the  cause  to 
be  the  same  as  in  Europe  although  the  American  wonn  is 
somewhat  different  from  its  European  cousin.  Stiles'  re- 
searches, aided  by  the  liberality  of  the  Rockefeller  Founda- 
tion, and  by  the  activity  of  state  boards  of  health  throughout 
the  South,  have  made  widely  known  the  cause,  and  means  of 
prevention  and  cure  of  the  disease.  The  abolition  of  the 
unsanitary  privy  on  the  one  hand,  and  thymol  and  epsom 
salts  on  the  other,  will  rid  the  world  of  a  scourge  infesting 
an  area  in  which  live  about  1,000,000,000  people,  or  more  than 
half  the  total  poulation  of  the  world,  with  an  infection  rate 
in  some  countries  as  high  as  ninety  per  cent  among  the  labc^r- 

•*' Reese,  "Economic  Zoology,"  p.  35.  By  permission  of  P.  Blakiston's 
Son  and  Company. 


Biology  and  Medicine  467 

ers,  and  causing  an  economic  loss  in  sickness  and  death  of 
untold  millions. 

The  announcement  by  Dr.  Stiles  of  the  part  which  the  hook- 
worm was  playing  in  undermining  the  mental  and  physical 
health  of  multitudes  of  people  in  the  South,  in  causing  in- 
calculable financial  loss  and  retarding  the  development  of 
the  country,  was  at  first  greeted  with  amusement  or  indiffer- 
ence, followed  by  active  hostility.  He  at  once  became  the 
subject  of  the  usual  campaign  of  the  newspaper  reporter  and 
cartoonist,  which  greets  every  innovator,  especially  in  an  un- 
progressive  and  conservative  community.  In  an  early  con- 
ference at  Raleigh,  N.  C,  "an  incredulous  physician  in  the 
audience  asked  him  if  the  disease  existed  there.  'I  see  sev- 
eral pronounced  cases  in  the  room  now,'  he  replied.  A  local 
newspaper  declared  that  the  Commission  was  slandering  the 
community ;  the  Governor  gave  out  an  interview  in  praise 
of  the  health  of  the  fair  land  that  he  ruled  over  and  de- 
nouncing its  slanderers.  Sketches  of  the  lives  of  aged  men 
of  the  neighborhood  were  published,  to  prove  the  healthful- 
ness  of  the  community,  and  much  other  such  nonsense  and 
ignorance  was  put  forth."  ^^ 

The  opportunity  for  service  in  the  fight  against  the  hook- 
worm was  early  brought  to  the  attention  of  Mr.  John  D. 
Rockefeller,  and  the  result  was  the  organization  of  the  Rocke- 
feller Hookworm  Commission  in  1909.  Brieflj^  the  work  of 
this  Commission,  in  co-operation  with  state  boards  of  health 
throughout  the  South,  has  been  the  establishment  of  travel- 
ing dispensaries  for  treating  the  sufferers  and  educating  the 
people  in  general  regarding  the  danger,  prevention  and  cure 
of  the  disease.  The  following  quotations  taken  from  the  Com- 
mission's report  for  1911  illustrate  better  than  mere  figures 
what  the  Commission  has  done  in  its  service  to  tlie  South. 

"AVhen  the  work  began  two  years  ago  the  people  did  not 
know  hookworm  disease  as  a  disease.  The  announcement  of 
its  prevalence  they  had  not  taken  seriously.  It  was  ex- 
tremely dif^cult  to  induce  them  to  be  examined,  and  even 
more  difficult  to  get  them  when  found  infected  to  consent  to 
treatment.  The  physician  could  not  treat  them  until  they 
had  been  shown  that  it  was  to  their  interest  to  seek  his  aid. 
For  two  years  systematic  effort  has  been  made  to  give  theni 
the  facts.  The  educational  activities  outlined  in  the  report 
for  last  year  have  been  persistently  pursued  in  each  State; 
the  people  have  been  taught  by  public  lectures  with  charts 
and  lantern  slides,  by  bulletins  and  folders,  by  the  public 
press,  by  exhibits  at  State  and  county  fairs,  by  the  examina- 

"  ' '  World 's  Work, ' '  Vol.  24,  p.  505. 


468 


Biology  in  Anierica 


tion  of  children  in  the  schools  and  students  in  the  colleges, 
by  examinations  made  at  the  State  laboratories,  by  the  cele- 
bration of  public-health  day ;  and  most  effective  of  all  has 
been  the  teaching  of  the  people  by  demonstration  through 
the  treatmwit  of  large  numbers  at  the  county  dispensaries. 
...  At  times  the  clinics  are  small  when  the  dispensaries  are 
new  or  in  communities  where  the  infection  is  light;  but  in 
communities  where  the  infection  is  heavy  and  after  the  dis- 
pensary has  had  a  few  days  within  which  to  demonstrate  its 
effectiveness,  the  people  come  in  throngs ;  they  come  by  boat, 
])y  ti'ain.  ])y  private  conveyance  for  20  and  30  miles.     Our 


A  Hookworm  Dispensary  in  Kentucky 

The  people  travel  for  miles  to  obtain  treatment. 

Courtcsij  0/  the  Rockefeller  Foundation. 

records  contain  stories  of  men,  women,  and  children  walking 
m  over  country  roads  10  and  12  miles,  the  more  anemic  at 
times  falling  by  the  way,  to  be  picked  up  and  brought  in  by 
neighbors  passing  with  wagons.  As  many  as  455  people  have 
been  treated  at  one  place  in  one  day.  Such  a  dispensary 
group  will  contain  men,  women,  and  children  from  town  and 
country,  representing  all  degrees  of  infection  and  all  sta- 
tions in  life.  A  friend  who  had  just  visited  some  of  the  dis- 
pensaries said  to  me  recently:  'It  looks  like  the  days  of 
Galilee.' 

"The  people  usually  begin  to  arrive  early.  I  visited  one 
dispensary  at  8  o'clock  in  the  morning  and  found  43  per- 
sons there  waiting  for  attention.     They  linger;  they  gather 


Biology  and  Medicine 


469 


in  groups  around  the  tables  of  exhibits;  they  listen  to  the 
stories  of  improvement  as  told  by  tliose  wlio  have  been  treated, 
and  return  to  their  homes  to  report  to  their  neiglibors  what 
they  have  seen  and  heard.  .  .  .  The  effect  of  these  edi^x-a- 
tional  activities  is  seen  nist  of  all  in  the  transformation  which 
has  been  wrought  in  public  sentiment.  This  change  of  senti- 
ment shows  itself  in  the  co-operation  of  the  press — which  is 
now  practically  universal  in  all  the  States — in  the  growing 
co-operation   of  the  physicians,   of  the  educational  agencies. 


The  Kesllt  of  lia  kworm  Treatment 
(Left) — A  victim  of  hookworm. 
(Eight) — The  same  girl  after  treatment. 
Courtesy  of  the  Rockefeller  Foundation. 

of  the  whole  people ;  it  shows  itself  in  an  increasing  support, 
not  only  of  this  particular  work,  but  of  all  public-health  in- 
terests.''^'^ 

Probably  in  no  field  of  medico-biological  research  have  ani- 
mals played  a  larger  part  than  in  the  investigation  of  can- 
cer. Rats  and  mice  have  been  the  principal  subjects  for 
these  experiments,  because  of  the  readiness  with  which  can- 
cerous and  other  growths  can  be  transplanted  in  them,  and 

""The  Rockefeller  Sanitary  Commission,"  Second  Annual  Report, 
pp.  17-22. 


470  Biology  in  America 

because  of  their  small  size,  fecundity  and  the  ease  with  which 
they  can  be  reared  in  captivity.  Many  other  animals  how- 
ever have  been  employed,  including  the  long-suffering  guinea 
pig,  dog,  cat  and  chicken. 

The  study  of  cancer  dates  back  into  far  antiquity.  The 
early  Greek  and  Roman  physicians,  Hippocrates,  Celsus  and 
Galen,  thought  of  diseases  as  due  to  a  disproportion  in  the 
amount  of  the  four  cardinal  "humors"  of  the  body — the 
blood,  mucus,  yellow  bile  and  black  bile.  Cancer  was  fan- 
cied as  caused  by  an  excess  of  the  latter,  while  even  as  late 
as  1874  the  noted  English  surgeon  and  pathologist,  Sir  James 
Paget,  ascribed  cancer  to  a  morbid  condition  of  the  blood. 
At  the  beginning  of  the  seventeenth  century  one  writer  put 
forth  the  view  that  cancer  was  caused  by  a  spirit  (the 
Areheus)  resident  in  the  stomach  and  spleen.  Unless  this 
spirit  was  purified  it  was  apt  to  intrude  itself  into  parts  of 
the  body  where  it  did  not  belong,  thereby  producing  cancer. 

Green  frogs  have  been  associated  with  cancer  in  the  minds 
of  the  credulous  for  hundreds  of  years,  and  Bonet  of  Geneva 
in  1682  gave  a  formula  for  a  cancer  ointment  made  of  green 
frogs,  while  in  a  book  published  recently  (1905)  in  South 
Africa  occurs  the  following  interesting  item  (as  translated)  : 
"An  example  of  a  woman  who  had  cancer  of  the  breast, 
which  was  already  so  severe  that  eight  holes  had  been  eaten 
into  it,  and  who  recovered  through  the  following  expedient: 
She  took  eight  frogs  applied  to  the  breast  in  a  muslin  bag, 
which  attached  themselves  instantly  thereto  as  firmly  as 
leeches.  When  they  had  sucked  to  repletion,  they  dropped 
off  in  violent  convulsions  without  the  sucking  causing  pain. 
This  was  repeated  until  20  frogs  were  used,  which  all  from 
time  to  time,  sucked  until  they  died.  And  the  breast  was  not 
only  cured,  but  returned  again  to  its  normal  size  absolutely. 
Another  remedy  of  the  same  author  is  tortoise  liver  "laid 
on  the  cancer  and  used  continually." 

About  the  beginning  of  the  seventeenth  century  one  healer 
put  forth  the  following  receipt  which  he  asserted  from  cer- 
tain experience  to  be  excellent  for  "ulcerous  cankers." 
"Take  suckling  Puppies,  put  them  in  Wine,  and  distill  it 
half  off  in  Balneo;  then  take  the  puppies  out,  and  boil  them 
in  a  sufficient  quantity  of  Golden-Rod  Water,  or  common 
Water  with  Golden-Rod  in  it;  when  the  Decoction  is  made, 
add  the  Water  that  was  distilled  off  the  young  Dogs  and  boil 
them  together  till  the  flesh  comes  from  the  Bones.  Then 
distill  them  all  in  Balneo.  Keep  the  Water  for  use.  Wet 
dry  clothes  or  rags  in  this,  and  apply  it  to  the  ulcerous  car- 
cinoma. For  from  certain  Experience  it  heals  the  sore  by 
cleansing  and  drying." 


Biology  and  Medicine  471 

"Since  the  beginning  of  recorded  medical  history,  and 
doubtless  before,  imagination  was  given  full  play  in  the 
treatment  of  cancer.  The  'witch  doctor'  combined  the  secrets 
of  the  'black  art'  with  the  brewing  of  the  'witch's  broth,' 
and  the  unfortunate  victim  of  cancer  was  given  doses  of  the 
mixture.  Throughout  the  centuries  the  sufferer  from  this 
disease  has  been  the  subject  of  almost  every  conceivable  form 
of  experimentation.  The  fields  and  forests,  the  apothecary 
shop  and  the  temple  have  been  ransacked  for  some  success- 
ful means  of  relief  from  this  intractable  malady.  Hardly 
any  animal  has  escaped  making  its  contribution,  in  hair  or 
hide,  tooth,  or  toe-nail,  thymus  or  tliyroid,  liver  or  spleen,  in 
the  vain  search  by  man  for  a  means  of  relief.  The  hand  on 
the  dial  has  turned  many  times  to  the  same  point  of  effort 
during  the  progress  of  the  centuries,  and  it  is  possible  to 
find  in  remote  districts  today  the  same  remedies  being  used 
that  were  employed  by  'cancer  eurers'  of  long  ago."^' 

Apart  from  these  early  fancies  what  we  may  call  the  mod- 
ern theories  of  cancer  have  been  many  and  varied.  We 
know  that  its  immediate  cause  is  an  unlimited  growth  of 
certain  epithelial  cells  which  run  riot  in  the  body,  encroach- 
ing upon  and  finally  destroying  the  other  tissues  and  pro- 
ducing death.  But  what  it  is  which  causes  this  growth  we 
do  not  know.  It  has  been  supposed  to  be  the  result  of  the 
growth  of  a  wandering  germ  cell  which  has  become  misplaced 
and  undergone  a  sort  of  parthenogenesis  within,  rather  than 
without  the  body.  In  this  connection  the  observations  of 
Professor  Allen  of  the  University  of  Kansas  on  the  germ  cells 
of  certain  fish,  Ampliibia,  reptiles  and  mammals  are  of  interest. 
Allen  found  that  the  primitive  sex  cells  in  these  animals  in- 
stead of  arising  in  the  sex  glands  appeared  first  in  the  wall  of 
the  gut,  whence  they  wandered  into  the  ovary,  where  they  ex- 
perienced their  final  development.  It  is  quite  conceivable 
that  such  a  wandering  germ  cell  might  "get  lost"  in  its  mi- 
grations, and  finding  itself  in  strange  surroundings,  develop 
abnormally,  producing  a  cancer. 

Closely  related  to  this  theory  is  that  which  explains  can- 
cer as  the  result  of  the  type  of  division  of  epithelial  cells 
which  characterizes  the  germ  cells  at  a  certain  stage  of  their 
development,  and  which  is  explained  in  Chapter  VII  deal- 
ing with  the  physical  basis  of  Mendelian  inheritance.  Yet 
another  theory  of  somewhat  similar  character,  proposed  by 
the  late  Professor  Boveri,  the  noted  Cerman  cytologist,  re- 
lates cancer  to  some  abnormal  type  of  cell  division  in  which 
the  chromosomes  become  misplaced  and  unevenly  distributed 

'■^ Above  quotations  from  Bainbridge,  "The  Cancer  Problem,"  pp. 
2-3.     By  permission  of  the  Macmillan  Company. 


472  Biology  in  America 

to  different  cells.  Respecting  this  theory,  it  may  be  said  that 
while  there  undoubtedly  is  abnormality  of  cell  division  in 
cancer,  it  may  more  likely  be  its  result  rather  than  its  cause. 
Still  another  hypothesis  attributes  cancer  to  some  parasitic 
organism  presumably  bacterial,  of  which  many  have  been  de- 
scribed   by    entliusiastic   investigators,    but    none   proven. 

Finally  we  have  the  explanation  of  cancer  as  due  to  chronic 
irritation  of  some  part  of  the  body,  stimulating  abnormal  cell 
growth  of  that  region.  There  is  much  more  evidence  for  this 
than  for  any  of  the  preceding  theories.  One  of  the  most  fre- 
quent locations  of  cancer  is  the  mid^  gland,  an  organ  which 
IS  apt  to  be  under  continual  irritation  from  an  ill-ntting  or 
tightly  laced  corset,  in  sniokeis  the  tongue  and  lip  are  fre- 
quent sites  of  cancer,  regions  apt  to  be  irritated  by  the  pipe 
stem  or  cigar.  Cancer  or  the  abdomen  is  prevalent  among  tlie 
natives  oi  i\ashniir  who  carry  snmll  earthen  jars,  surrounded 
by  basket  work  and  containing  a  charcoal  nre,  under  their 
robes  next  to  the  skin  as  a  means  of  warmth. 

That  cancer  is  ndierited  in  mice  has  been  recently  claimed 
by  ^liss  Slye  of  the  Otho  S.  A.  Sprague  Memorial  Institute 
of  Chicago,  as  the  result  of  an  extensive  series  of  breeding 
tests ;  and  her  results  have  been  apparently  accepted  by  some 
members  of  the  medi.'al  profession.  They  lack  substantia 
tion  liowever  and  it  would  be  well  to  travel  slowly  over  a  path 
so  newly  blazed  into  the  unknown,  lest  we  stumble  and  fall 
into  error  on  our  way. 

The  past  twenty  years  have  witnessed  remarkable  devel- 
opments in  the  study  of  cancer  in  both  xVmerica  and  Europe. 
This  study  has  been  conducted  both  in  the  clinic  and  the  lab- 
oratory. At  present  its  net  result  is  a  negative  one.  It  h.i ; 
.served  to  explode  many  promising  theories  of  cancer,  and  to 
reveal  our  ignorance,  but  as  yet  we  are  still  fighting  blind- 
fold one  of  the  most  terrible  enemies  of  man. 

In  America  this  work  was  instituted  in  1898  when  the 
State  of  New  York  made  a  small  appropriation  for  cancer  re- 
search at  the  University  of  Butfalo.  Since  1901  the  laboratory 
at  Buffalo  has  been  known  as  the  Cancer  Laboratory  of  the 
New  York  State  Board  of  Health.  The  following  year  saw 
the  inauguration  of  the  Cancer  Commission  of  Harvard  Uni- 
versity, whose  work  is  conducted  jointly  in  the  laboratories 
of  Harvard  University  and  in  the  CoUis  P.  Huntington  ]\Ie- 
morial  Hospital  of  the  same  institution. 

These  initial  undertakings  have  been  followed  by  many 
others,  such  as  the  Research  Department  of  the  New  York 
Skin  and  Cancer  Hospital,  the  George  Crocker  Special  Re- 
search Fund  of  Columbia  University,  the  Barnard  Free  Skin 
and  Cancer  Hospital  of  St.  Louis,  and  the  Research  Hos- 


Biology  and  Medjicine  473 

pital  of  the  New  York  State  Institute  for  the  Study  of  Malig- 
nant Disease. 

Cancer-like  growths  are  of  frequent  occurrence  in  animals 
other  than  man.  Rats  and  mice  are  especially  prone  to  have 
them,  but  they  are  also  known  in  dogs,  cats,  horses,  mules, 
asses,  cattle,  hogs  and  in  a  host  of  wild  mammals.  Among 
birds  they  occur  commonly  in  chickens  and  have  been  re- 
ported in  others,  both  wild  and  dom'^stic.  They  have  been 
noted  in  various  reptiles  and  amphibians,  while  artificially 
reared  fish  are  especially  susceptible. 

Great  as  is  our  ignorance  regarding  many  of  the  scourges 
of  mankind,  the  advances  in  our  knowledge  in  the  last  fifty 
years  have  been  phenomenal,  and  the  promise  of  the  future 
was  never  so  bright. 

By  what  means  have  these  revolutionary  advances  in  our 
knowledge  of  disease  been  made  possible?  Chietiy  by  experi- 
ments on  animals.  Bacteriology  has  developed  methods  pe- 
culiar to  itself  and  the  development  of  these  methods  has 
been  possible  only  through  animal  experimentation.  When 
the  bacteriologist  announces  the  discovery  of  a  "germ,"  as 
causing  some  disease,  it  is  only  after  putting  his  new  find 
through  a  long  series  of  experiments,  which  demonstrate  con- 
clusively its  relation  to  tne  disease  in  question.  First,  it 
nuist  be  found  consistently  in  the  bodies  of  patients  afflicted 
with  the  disease.  Second,  it  must  be  isolated  from  such  pa- 
tients and  a  "pure  culture"  in  some  culture  medium  (gela- 
tine, broth,  etc.)  obtained.  Third,  it  must  be  possible  to  in- 
fect some  animal  with  this  culture,  and  thereby  produce  the 
disease  in  it.  Fourth,  the  same  germs  must  be  found  in  the 
infected  animal.  Fifth,  from  this  animal  a  pure  culture 
must  be  obtained  witli  which  the  disease  can  be  reproduced 
in  another  animal,  and  this  cycle  must  be  repeated  with  suffi- 
cient frequency  to  prove  tiiat  the  relation  between  the  germ 
and  the  disease  is  a  necessary,  and  not  merely  accidental 
one.  Sixth,  no  other  germ  tested  in  the  same  way  must  give 
similar  results. 

AVithout  experiments  on  animals  most  of  these  results  would 
have  been  impossible,  and  yet  there  are  today  many  seem- 
ingly rational  people,  who  would  restrict  the  use  of  animals 
for  the  saving  of  human  life,  and  alleviation  of  human  mis- 
ery, under  the  specious  plea  of  preventing  sutfering — to 
animals ! 

In  whose  hands  is  the  administration  of  this  new  knowl- 
edge? Who  are  responsible  for  safeguarding  the  nation's 
health  ?  Many  are  the  agencies  involved  in  this  great  work 
and  many  the  objects  of  their  care.  International,  national, 
state  and   local   in   scope;   public   and   private   in   support; 


474  Biology  in,  America 

philanthropic  and  commercial  in  purpose,  the  character  of 
these  agencies  is  as  varied  as  are  the  objects  of  their  con- 
cern. Space  forbids  any  adequate  consideration  of  them  all, 
but  we  may  glance  for  a  moment  at  the  work  of  one  or  two, 
wliicli  are  broadest  in  scope  and  foremost  in  accomplishment. 

When  we  are  enjoying  our  roast  beef  or  leg  of  mutton,  how 
often  do  we  stop  to  consider  the  care  which  Uncle  Sam  takes 
to  insure  our  safety  in  partaking  thereof?  At  every  slaugh- 
ter-house and  packing  plant  engaged  in  interstate  trade  the 
U.  S.  Bureau  of  Animal  Industry  maintains  inspectors  whose 
duty  it  is  to  prevent  diseased  meat  from  entering  into  this 
commerce.  When  the  animal  arrives  at  the  slaughter-house 
it  is  examined  "on  the  hoof"  before  butchering,  and  if  passed 
separate  examinations  are  made  of  neck  glands  and  viscera, 
and  finally,  if  the  animal  passes  muster,  the  meat  itself  when 
cleaned  and  dressed  is  inspected,  and  the  government's  ap- 
proval is  stamped  upon  it,  before  it  enters  refrigerator  car 
or  room  preparatory  to  shipment  and  sale. 

In  the  preparation  of  the  many  biological  remedies  on  the 
market  today,  such  as  vaccines,  antitoxins  and  glandular 
extracts  of  various  sorts  (pituitrin,  thyroidin,  adrenalin, 
etc.),  yet  greater  care  is  exercised  to  guard  against  con- 
tamination of  any  sort.  All  establishments  preparing  such 
materials  for  interstate  commerce  must  obtain  a  U.  S.  license 
before  the  government  will  permit  them  to  do  business.  Be- 
fore gi'anting  such  a  license  an  inspection  is  made  of  the 
premises  where  the  work  will  be  done  by  an  agent  of  the 
U.  S.  Public  Health  Service.  Such  inspection  is  repeated  at 
intervals  to  see  that  the  plant  is  up  to  standard,  and  the 
products  themselves  are  tested  for  purity  (both  chemical  and 
biological)  to  determine  their  efficiency  and  safety. 

As  an  illustration  of  the  care  which  is  taken  to  safeguard 
the  user  of  these  products,  let  us  follow  for  a  moment  the 
method  of  preparing  one  of  them,  namely,  smallpox  vaccine. 
This  vaccine  is  the  pus  which  forms  in  little  pustules  on  cat- 
tle infected  with  cowpox.  The  animals  used  in  its  prepara- 
tion are  usually  young  bulls  or  heifers.  These  are  quaran- 
tined for  several  weeks,  during  which  time  they  are  care- 
fully inspected  for  any  possible  disease  and  tested  for  tu- 
berculosis. If  found  healthy  they  are  given  a  careful  scrub- 
bing with  soap  and  water,  and  some  weak  antiseptic  and 
then  taken  to  the  vaccine  laboratory.  The  operating  and 
propagating  rooms  are  constructed  with  a  view  to  the  utmost 
cleanliness,  the  floors  being  of  concrete  and  the  walls  and 
ceilings  enameled.  The  interiors  and  fittings  are  washed  at 
■frequent  intervals  with  disinfectants.  In  the  laboratory  the 
animal  is  placed  on  a  special  operating  table,  the  abdomen 


Biology  and  Medicine  475 

shaved,  washed  with  sterile  water,  and  cut  in  a  series  of  paral- 
lel lines  with  a  sterile  knife.  Into  these  cuts  the  virus,  taken 
from  another  animal  under  aseptic  conditions,  is  introduced 
with  a  sterile  instrument.  The  animal  is  now  placed  in  the 
propagating  room,  where  an  attendant  is  at  hand  night  and 
day  to  keep  the  room  in  the  cleanest  condition  possible.  After 
about  a  week,  when  the  characteristic  pox  pustules  have  de- 
veloped, the  animal  is  killed,  its  abdomen  washed  with  sterile 
water,  the  pus  removed  with  a  sterile  instrument  and  placed 
in  50%  glycerine  in  a  sterile  vessel  which  is  then  placed  in 
a  refrigerator. 

The  carcass  of  the  animal  is  examined  and  the  vaccine  is 
tested  for  any  possible  contamination  by  inoculation  of  guinea 
pigs  and  culture  media.  Its  efficiency  is  tested  by  trial  vac- 
cinations of  calves,  rabbits  or  guinea  pigs.  If  found  to  be 
both  pure  and  potent  it  is  placed  in  small,  sterile  glass  tubes, 
or  on  ivory  points,  which  are  sealed  in  sterile  glass  contain- 
ers, labeled,  dated  and  returned  to  the  refrigerator  until 
ready  for  the  market. 

The  activities  of  the  U.  S.  Public  Health  Service  cover 
practically  every  phase  of  the  nation's  health.  From  guard- 
ing our  ports  against  the  entrance  of  infection  with  its 
quarantine  service,  to  examination  of  rats  and  mice  for  plague 
bacilli  at  Seattle  and  New  Orleans,  or  ground  squirrels  in 
California,  the  Service  is  waging  a  nation-wide  and  relent- 
less warfare  against  every  enemy  of  human  health. 

A  gipsy  family  camped  on  the  outskirts  of  a  country  town 
is  taken  sick  with  what  is  suspected  to  be  typhus  fever.  The 
Service  details  an  officer  to  study  the  cases  and  endeavor  to 
discover  the  cause.  Intestinal  trouble  breaks  out  in  an  in- 
dustrial plant.  The  Service  makes  an  investigation  and  dis- 
covers typhoid  fever,  and  the  necessary  steps  follow  for  its 
extermination.  Trachoma  is  present  among  the  school  chil- 
dren in  some  locality ;  a  surgeon  is  sent  to  investigate  the 
disease  and  advise  measures  for  its  control.  Influenza  sweeps 
like  wildfire  across  the  country.  The  resources  of  the  Serv- 
ice are  mobilized  to  meet  the  scourge.  Lack  of  definite  knowl- 
edge regarding  the  cause  of  this  disease  has  as  yet  rendered 
inefficient  any  efforts  for  its  control.  The  Public  Health 
Service  was  aware  of  the  danger  before  it  came  but  was 
powerless  to  prevent  it,  as  influenza  is  not  a  quarantinable 
disease.  The  spread  of  the  disease  was  so  rapid  and  exten- 
sive that  doctors  and  nurses  in  every  community  were  over- 
taxed, most  places  finding  themselves  without  a  sufficient  num- 
ber, especially  as  so  many  were  enlisted  in  the  army.  To 
meet  this  difficulty  a  special  appropriation  of  $1,000,000  was 
passed  by  Congress,  and  the  Service,  together  with  the  Red 


476  Biology  in  America 

Cross  and  local  health  org^anizations  thronghont  the  country, 
organized,  as  best  they  could,  a  teuii)orary  corps  of  doctors 
and  mirses,  which  were  sent  to  points  of  greatest  need. 
IMeantime  data  were  being  gathered  by  means  of  a  house  to 
house  canvas  in  certain  chosen  localities,  in  the  effort  to  as- 
certain the  factors  involved  in  the  spread  of  the  disease. 
Laboratory 'studies  were  made  on  the  possibility  of  trans- 
ferring the  disease  from  man  to  lower  animals  and  from  man 
to  man,  but  no  definite  information  obtained  except  as  to 
the  dit^culty  of  the  artificial  transfer  of  the  disease.  Tests 
were  also  made  of  several  anti-influenza  and  pneumonia  vac- 
cines, but  with  no  very  satisfactory  results. 

These  few  instances,  which  could  be  multiplied  many  times, 
will  illustrate  the  work  which  is  being  done  by  the  Service  in 
the  study  and  control  of  disease  in  the  United  States. 

In  this  work  it  employs  not  only  fixed  laboratories,  but 
laboratories  on  wheels,  having  two  cars,  which  can  be  sent  to 
any  point  for  a  study  of  disease  in  the  field,  as  occasion  arises. 

The  determination  of  the  cause  of  pellagra,  a  disease  of 
faulty  nutrition,  of  which  mention  has  been  made  in  a  pre- 
vious chapter,  is  largely  due  to  the  work  of  Goldberger,  one 
of  the  Service  Staff. 

When  the  youth  of  our  nation  were  concentrated  by  the 
hundreds  of  thousands  in  army  camps,  the  Service  was  called 
upon  to  protect  them  from  disease  in  the  extra-cantonment 
areas.  Within  the  camps  themselves  the  army  was  responsi- 
ble for  their  protection,  but  in  the  regions  about  the  camps, 
especially  in  the  towns  and  amusement  centers  visited  by  the 
men  when  on  leave,  the  responsibility  fell  upon  the  Public 
Health  Service,  aided  in  many  cases  by  the  Red  Cross. 

Realizing  the  terrible  menace  of  venereal  diseases,  and  un- 
der the  stimulus  of  patriotic  enthusiasm,  Congress  in  1918 
established  a  Social  Hygiene  Board  for  the  study  and  con- 
trol of  these  diseases,  consisting  of  the  Secretaries  of  War, 
Navy,  and  Treasury  and  the  Surgeons-General  of  War,  Navy 
and  Public  Health  Service  or  their  representatives,  and  ap- 
propriating nearly  $2,000,000  annually  for  carrying  on  the 
work.  The  administration  of  this  act  has  been  largely  in 
the  hands  of  the  Public  Health  Service,  which  by  co-operation 
with  state  boards  of  health  in  the  establishment  of  clinics 
for  the  treatment  of  venereal  patients,  by  the  establishment 
of  an  interstate  quarantine  against  infected  persons,  restrict- 
ing their  privileges  of  travel  from  state  to  state,  and  by 
means  of  a  widespread  campaign  of  education  has  made  a 
splendid  start  in  the  battle  against  these  social  plagues. 

In  the  field  of  industrial  hygiene  the  Service  work  looms 
large.    When  we  realize  that  to  change  one  employee  in  a 


Biology  and  Medicine  417 

factory  or  stnro  costs  the  employer  from  $35  to  $70,  we 
api)reciate  the  iinportauce  of  tlie  worker's  health  from  the 
standpoint  of  dollars  and  cents  alone.  Add  to  this  the  dan- 
ger of  the  crowded  factory  as  a  center  of  contagion  and  con- 
^  ecpient  menace  to  an  entire  community,  and  we  can  realize 
tile  necessity  of  industrial  hygiene  as  a  public  measure. 
During  tlie  recent  war  this  work  became  even  more  than 
usually  imperative,  for  the  city  of  ordinarily  20,000  or 
30,000  was  suddenly  swelled  to  one  of  100,000  or  more.  The 
housing  problem  became  acute  and  with  it  arose  the  even 
more  serious  ones  of  water  supply,  sewage  disposal  and  of 
all  the  factors  which  make  for  health  or  disease  in  any 
connnunity.  Then  too  the  great  munition  factories,  ship- 
building plants,  and  all  the  other  war  activities  sprang  up 
like  mushrooms  over  night,  bringing  with  them  teeming  life 
in  new  locations  and  consequent  menace  to  the  public  health, 
and  increasing  the  opportunities  as  well  as  the  responsibilities 
of  the  men  of  the  service. 

If  we  drink  water,  and  most  of  us  do  nowadays  by  virtue 
cither  of  choice  or  necessity,  we  will  be  interested  to  know 
that  when  we  travel  on  a  train  from  one  state  to  another 
our  drinking  supply  is  safeguarded  by  the  watchful  care  of 
the  U.  S.  Public  Health  Service.  These  supplies  are  under 
constant  supervision  by  agents  of  the  Service,  and  if  they 
do  not  meet  the  standard  set  they  are  condemned  and  the 
carriers  obliged  to  improve  them  or  obtain  new  supplies 
elsewhere. 

In  addition  to  a  station  in  Hawaii  for  the  study  and  treat- 
ment of  lepers,  whose  investigations  in  the  treatment  with 
derivatives  of  chaulmoogra  oil,  are  meeting  with  a  consider- 
able degree  of  success,  the  Service  has  established  a  national 
home  for  lepers  in  the  United  States,  a  number  of  which  un- 
fortunate people  live  among  us. 

The  Service  also  maintains  a  tuberculosis  sanitarium  at 
Fort  Stanton,  N.  M.,  and  numerous  hospitals  for  the  care  of 
sick  or  disabled  soldiers,  sailors  and  other  government 
employees. 

One  might  continue  indefinitely  to  rehearse  the  activities 
of  the  U.  S.  Public  Health  Service,  not  to  mention  those  of 
the  many  other  agencies  for  protecting  public  health,  but  the 
foregoing  must  suffice  as  a  bird 's  eye  view  of  this  great  and 
ever-growing  field. 

In  all  the  great  work  which  biology  has  done  for  man 
there  is  none  more  splendid  than  its  service  in  the  field  of 
preventive  medicine. 


chaptp:r  XVII 

The  outlook.     Some  unsolved  prohlenis  of  biology.     Possibil- 
ities  of  larger  service. 

It  is  as  profitable  for  Science  as  for  the  individual  to  pause 
now  and  then  and  take  an  inventory ;  to  view  in  retrospect 
its  successes  as  well  as  its  failures,  and  in  prospect  its  possi- 
bilities and  its  problems — such  a  backward  glance  over  the 
pages  of  biology  in  America  has  been  taken  in  the  preceding 
chapters.  In  closing  let  us  draw  aside  the  veil  for  a  moment, 
and  view  the  opportunities  for  future  service  of  biology  to 
man. 

The  most  urgent  demand  upon  biology  today  is  for  a 
study  of  the  factors  of  evolution.  In  spite  of  Darwin,  Weis- 
mann  and  DeVries  and  the  host  of  splendid  workers  who  have 
devoted  their  lives  to  a  solution  of  this  problem  in  the  past, 
the  final  answer,  or  answers,  for  there  are  doubtless  many,  is 
still  shrouded  in  mystery.  The  ultimate  causes  of  vanation, 
the  creative  power  of  selection,  the  possibility  of  the  inherit- 
ance of  characters  acquired  during  the  lifetime  of  the  indi- 
vidual— these  and  many  others  are  still  unsolved  problems. 

Closely  allied  to,  nay,  inseparable  from  the  problem  of 
evolution  is  that  of  inheritance.  Is  the  "unit-character"  the 
Ultima  Thule  of  the  explorer  of  life's  mysteries?  Or  is  it 
in  itself  a  little  cosmos  of  characters  acting  and  reacting 
upon  one  another  to  produce  the  end  result?  Is  the  behavior 
of  "unit  characters"  fixed  and  immutable,  like  the  laws  of 
the  Medes  and  Persians,  or  is  it  subject  to  environmental 
influence,  yielding  different  results  according  to  the  condi- 
tions imposed  upon  it?  And  what  is  the  nature  of  the 
"determiners"  of  these  "unit  characters"?  Are  they  con- 
stant physical  or  chemical  entities,  pereistent  from  generation 
to  generation  of  the  cell,  or  are  they  variables,  which  pass 
through  a  complex  series  of  developmental  changes  beginning 
in  the  fertilized  egg  and  reaching  fruition  only  in  the  adult 
organism?  Are  these  determiners  restricted  to  the  chromo- 
somes or  ai'e  they  present  in  the  cytoplasm  as  well?  And  if 
restricted  to  the  former  does  the  latter  exercise  no  influence 
upon  them?  Is  the  entire  organism  a  complex  of  unit  char- 
acters, or  is  it  the  superficial  characters  alone,  such  as  color, 

478 


The  Outlook  479 

size,  hair  form,  etc.,  which  behave  as  units  in  inheritance? 
Is  sex  purely  an  inherited  character,  subject  to  Mendelian 
laws,  or  is  it  determined  by  conditions  of  metabolism  or  other- 
wise, and  if  so  is  it  subject  to  experimental  control?  And 
what  is  the  significance  of  the  curious  sex  intergrades  which 
have  recently  been  described,  and  which  are  "neither  fish, 
flesh,  nor  good  red  herring"?  How  and  why  did  sex  arise? 
There  are  some  animals,  such  as  Hydra,  which  reproduce  both 
sexually  and  asexually.  What  are  the  factors  inducing  sexual 
reproduction  in  such  forms  ?  And  what  is  its  function  ?  Does 
it  exercise  a  rejuvenating  influence  upon  the  race,  or  does  it 
serve  to  produce  variation  and  thereby  lead  to  evolution  and 
adaptation?  Or  do  both  of  these,  or  yet  other  explanations 
contain  the  truth? 

Why  do  some  animals  reproduce  by  parthenogenesis  at  one 
period  in  their  life  history  and  sexually  at  another?  And 
what  is  the  significance  of  parthenogenesis,  which  in  some 
cases  has  gone  so  far  that  males  are  extremely  rare,  and  may 
possibly  in  some  species  have  disappeared  entirely  ?  At  any 
rate  if  they  occur,  they  are  yet  to  be  discovered. 

Surrounded  as  we  are  by  speculation  and  uncertainty  in 
the  realm  of  evolution  and  inheritance,  we  enter  a  veritable 
terra  incognitoi  when  we  come  to  speculate  upon  the  essence 
of  life  itself.  Is  life  purely  a  physico-chemical  process,  and 
the  organism  a  mere  machine  controlled  by  forces  extraneous 
to  itself  ?  And  if  so,  what  are  the  physico-chemical  reactions 
which  constitute  life  ?  Or  is  life  a  process  outside  the  realm 
of  physics  and  chemistry?  Are  our  concepts  of  consciousness 
and  intelligence,  of  volition  and  of  soul,  realities,  or  mere 
figments  of  the  imagination?  Or  is  there  yet  some  middle 
course  which  we  may  steer  between  the  Scylla  of  "mechanism" 
on  the  one  hand  and  the  Charybdis  of  "vitalism"  on  the 
other  ? 

If  life  be  an  unsolved  problem,  equally  so  is  the  cessation 
of  life  or  death.  Is  death  inherent  in  life  or  was  life  pri- 
marily unending,  and  death  secondarily  derived  from  factors 
outside  of  life  itself?  And  what  of  the  origin  of  life?  Is 
Harvey's  dictum  ''Omne  vivum  ex  vivo"  necessarily  true? 
Or  may  lifeless  matter  to-day  be  generating  life  and  continue 
to  do  so  throughout  the  ages,  as  it  did  at  some  time  in  the 
past  ? 

If  we  are  some  day  to  solve  the  riddle  of  life,  we  shall  then 
be  able  to  create  life.  While  some  enthusiasts  have  from  tirne 
to  time  claimed  that  they  have  done  this,  their  claims  are  yet 
unsubstantiated,  but  the  possibility  of  such  an  achievement 
looks  less  remote  to  us  today,  than  would  have  seemed  the 
Rontgen  ray  or  the  wireless  telegraph  to  our  forefathers. 


480  Biology  in  America 

IMucli  as  we  liave  already  learned  i-ejifai'diiijj^  the  stnietui-e 
of  the  cell,  it  is  but  as  a  drop  in  the  biieket  compared  with 
our  ignorance  of  this  marvelous  mechanism  of  life.  What 
is  the  origin  of  the  nucleus?  Is  it  primary  and  the  cytoplasm 
formed  from  it,  or  vice  versa.  Or  yet  are  both  nucleus  and 
cytoplasm,  co-ordinate  parts  of  the  cell  in  time  as  well  as  in 
function?  Do  such  apparently  anucleate  cells  as  the  bacteria 
and  the  blue-green  algffi  contain  nuclear  material,  and  if  so 
what  is  its  condition  in  these  cells,  and  is  such  a  condition 
primary  or  derived?  If  primary,  how  has  a  definite  nucleus 
arisen  in  higher  cells?  Is  the  distributed  nucleus  as  we  find 
it  in  certain  Protozoa  a  stejp  in  this  direction,  or  is  this  in 
turn  a  specialized  condition  derived  from  the  more  generalized 
one  in  which  but  a  single  nucleus  occurs  within  the  cell? 
Similarly  how  has  the  green  coloring  matter  of  the  majority 
of  plants  and  a  few  animals  been  evolved,  what  is  its  chemical 
composition,  and  by  what  physico-chemical  processes  does  it 
utilize  the  sunlight  in  building  up  the  complex  starches  and 
sugars  from  carbon-dioxide  and   water? 

Our  existing  knowledge  of  the  cell  has  been  obtained  mainly 
from  fixed  and  stained  material.  Does  such  material  tell  us 
a  true  story?  AVhat  of  the  living  protoplasm— its  physical 
structure  and  chemical  composition?  And  what  of  the  won- 
derful cell  products  known  as  ferments,  which  play  so  large 
a  role  in  all  processes  of  life?  What  is  their  chemical  char- 
acter, and  in  what  way  do  they  do  their  remarkable  work  ? 

AVhat  are  the  factors  regulating  the  growth,  and  determin- 
ing the  size  of  organisms  ?  What  enables  them  to  regenerate 
lost  parts?  And  why  does  regeneration  in  some  cases  repro- 
duce the  part  lost,  and  in  others  a  wholly  different  one? 

In  medical  biology,  great  as  have  been  the  advances  of  the 
past,  yet  greater  still  may  be  the  progress  of  the  future. 
AVhe'n' Christ  said  to  his  disciples,  "Among  them  that  are 
born  of  women  there  hath  not  risen  a  greater  than  John  the 
Baptist:  notwithstanding  he  that  is  least  in  the  kingdom  of 
Heaven  is  greater  than  he,"'  he  clearly  referred  to  the 
blessings  conferred  upon  men  by  the  coming  of  that  kingdom. 
While  it  is  scarcely  possible  to  conceive  of  discoveries  of 
greater  value  to  mankind  than  those  made  by  Pasteur,  never- 
theless "lie  that  is  least  in  the  kingdom  (of  modern  sanita- 
tion) is  greater  than  he."  Py  the  application  of  the  dis- 
covei-ies  ()f  a  Pasteur,  Metsehnikoff  and  Koch  or  Flexner  is  it 
chimerical  to  dream  of  a  future  world  from  plague  set  free? 
There  is  much  remaining  to  be  done  however  and  none 
need  eomi)lain  that  the  Ciolden  Age  of  Discovery  has  vanished, 
and  that  the  frontier  in  biology  exists  no  more.  The  filter- 
*  Matthew  xi,  11, 


The  Outlook  481 

able  viruses,  tliose  dise;is(>-formino'  or.uaiiisins  so  niiuute 
that  they  can  pass  through  the  pores  of  the  finest  filters,  yet 
remain  to  be  isolated;  the  cause  of  cancer,  and  many  otlier 
diseases  to  be  discovered,  and  the  functions  of  the  ductless 
fjlands  more  clearly  determined  than  they  are  at  present. 
These  are  a  few  of  the  more  urgent  tasks  which  the  medical 
biologist  has  before  him  today. 

The  palaeontologist  still  has  awaiting  him  untouched  areas 
of  the  earth's  surface,  where  may  lie  concealed  the  key  to  many 
a  riddle  regarding  the  evolution  and  relationships  of  animals 
and  plants,  and  their  distribution  in  past  and  present  time. 

The  embryologist  may  aid  the  palteontologist  in  his  studies 
of  animal  phylogeny  by  describing  the  embryology  of  many 
of  the  rarer,  and  as  yet  unstudied  forms,  while  the  compara- 
tive anatomist  is  partner  to  them  both  in  solving  the  problems 
of  animal  descent. 

IManifold  are  the  unsolved  problems  relative  to  the  life 
histories,  distribution,  and  economic  relations  of  animals  and 
plants.  Which  are  our  friends,  and  which  our  foes,  how  best 
can  the  former  be  protected  and  propagated,  and  the  latter 
exterminated,  and  what  new  sources  of  wealth  can  biology 
discover  for  mankind? 

With  such  a  job  on  its  hands,  and  the  foregoing  outline 
is  but  a  glimpse  of  its  burden,  how  best  can  biology  "carry 
on"?  Helpful  and  encouraging  as  is  the  endowment  of  great 
institutions  such  as  those  founded  by  a  Rockefeller  or  a 
Carnegie,  the  establishment  of  research  chairs,  and  equipment 
of  laboratories  in  our  universities,  and  the  devotion  of  govern- 
ment bureaus  to  biological  research ;  nevertheless  the  hope  of 
biology  is  in  its  followers.  "God  give  us  men,"  is  now  as 
ever  the  prayer  of  progress.  The  spirit  of  Agassiz  must  still 
fill  our  laboratories,  or  their  equipment  will  represent  but  so 
nuicli  waste  of  money  and  of  effort. 

Hut  the  spirit  of  investigation  needs  both  encouragement 
and  guidance.  It  is  indeed  true  that  investigation  is  its  own 
reward,  but  in  the  keenness  of  the  social  struggle  for  existence 
the  young  man  or  young  woman  of  today  is  not  likely  to 
choose  a  calling  which  has  glory  for  its  sole  reward.  lie  is 
too  likely  to  recall  the  words  of  Gray  anent  "the  paths  of 
glory."  If  our  research  institutions  are  to  secure  the  best 
men  they  must  offer  sufficient  inducement  to  at  least  provide 
for  the  ordinar}'  needs  of  life  and  enable  the  research  woikers 
to  enjoy  some  of  its  pleasures.  Herein  lies  the  need  for  the 
liberality  of  wealth  toward  science.  Otherwise  science  is  bound 
to  become  connnercialized  and  turned  to  purely  economic  ends. 
Another  great  need  of  biology  is  unification  of  effort. 
Co-operation  in  biology  is  not  lacking  today,  but  co-ordina- 
tion of  effort  is  conspicuous  chiefly  by  its  absence,    A  dozen 


482  Biology  in  America 

men  in  as  many  places  may  each  be  working  on  the  same 
problem,  wholly  oblivious  of  the  work  of  the  others.  Our 
journals  and  societies  do  indeed  serve  as  channels  of  com- 
iiinnication  between  workers,  but  usually  not  until  their 
problems  are  well  under  way,  or  perhaps  completed.  INIight 
not  these  societies,  through  committees  appointetl  for  this  pur- 
pose, serve  to  at  least  put  workers  along  similar  lines  in 
closer  touch  with  one  another  than  they  are  at  present? 
Such  a  suggestion  is  not  new,  but  so  far  as  the  writer  knows, 
it  has  not  yet  received  sufficient  consideration:'-  To  attempt 
to  dii-ect  research  in  the  sense  of  limiting  individuals  in  their 
choice  of  problems,  would  have  a  deadening,  if  not  deadly 
effect  on  all  scientific  progress.  But  guidance  along  the  line 
of  co-ordination  of  effort  should  be  as  stimulating  as  the  other 
would  be  depressing. 

Might  not  institutions  also  combine  with  advantage  in  the 
prosecution  of  special  researches?  A  striking  and  salutary 
example  of  such  co-ordinated  effort  between  governments  was 
afforded  by  the  International  Council  for  Investigation  of 
the  Sea,  prior  to  the  great  war,  whose  work  has  been  men- 
tioned in  a  previous  chapter.  It  was  organized  in  1902  to 
eliminate  waste  of  effort  and  of  money  in  the  study  of  the 
physics,  chemistry  and  biology  of  the  ocean  and  its  economic 
resources.  While  each  government  prosecuted  its  own  re- 
searches in  its  own  territory,  all  of  the  results  were  turned 
in  to  the  central  office  at  Copenhagen  for  collaboration  and 
publication,  and  the  general  plan  of  the  investigations  was 
outlined  by  a  central  committee  chosen  from  representatives 
of  all  the  governments  concerned.  By  means  of  this  co-ordi- 
nation results  of  great  scientific  and  economic  importance 
were  achieved,  with  material  saving  of  time  and  effort. 

It  would  appear  both  feasible  and  desirable  to  effect  a 
similar  co-ordination  of  effort  in  our  own  country.  On  our 
western  coast  for  example  are  several  institutions  engaged 
primarily  in  a  study  of  the  biology  of  the  Pacific  Ocean. 
Why  might  not  these  institutions  combine;  and,  with  theaid 
of  tile  U.  S.  Bureau  of  Fisheries,  prosecute  this  research  in  a 
svstematic  and  comprehensive  way,  rather  than  in  the  present 
sporadic  and  disjointed  fashion  ?=^     Why  also  might  not  the 

^  The  establishment  of  the  National  Eesearch  Council  during  the  war 
was    a    stop   in    this    direction. 

^  Looking  toward  such  an  end,  a  conference  was  held  at  Honolulu  in 
August,  1920,  under  the  auspices  of  the  Bishop  Museum,  which  was 
founded  in  1889  by  the  late  Charles  Eeed  Bishop  of  New  York,  for  the 
study  of  the  natural  history  and  ethnology  of  the  Pacific  islands.^  The 
Museum  was  a  memorial  by  Mr.  Bishop  to  his  wife,  who  was  Princess 
Bernice  I'auahi,  great  grand-daughter  of  tlie  Moi  of  Hawaii  wlien  Cap- 
tain Cook  visited  the  islands.  The  Museum  is  now  co-operating  with 
Yale  University  in  the  exploration  of  the  Pacific  and  several  other 
institutions  are   also   interested  in  the  project. 


The  Outlook  483 

life  of  our  inland  waters  be  studied  in  a  similar  comprehen- 
sive and  connected  manner,  by  the  several  aquatic  biological 
stations  working  under  the  general  direction  of  the  Bureau  of 
Fisheries?  Or  is  our  American  science  so  sectarian  in  char- 
acter that  co-ordinated  effort  ia  impossible? 

Today  American  biology  is  preeminent.  Its  growth  and 
achievement  in  the  past  have  been  phenomenal.  But  yet 
greater  possibilities  lie  before  it,  in  the  coming  reconstruction 
of  the  world. 


•  1 


INDEX 


Abdominal    ribs,    133 
Absorption   in    intestine,   299 
Academy  of  Natural  Sciences,  40; 

beginnings,    52,    53 

collections,  54 

workers,   53,    54 

ill.   53 
Accessory,  see  Cliromosonies 
Achatinellidae,  see  Hawaiian  snails 
Acquired    characters,    see    Inherit- 
ance 
Adaptation,  non-life,  281-2 

organisms,    281 
Adrenal  gland,  321-3 
Adrenalin,    function,    321-3 

see   Biological   remedies 
^pyornis,  135 
Agassiz,    A.,    350 
Agassiz,  Louis,  349,  481 ;  life,  38-9 

opponent  of  Darwin,  45 

ill.  38 
Age,  see  Amphibia,  fossils;   Lyco- 

pods;  Reptiles;  Trilobites 
Agramonte,    451 
Aggressive   resemblance,   338 
Aigrette,    see    Egret 
Air  sacs,  see  Birds 
"Albatross,"  350-1,  365;  ill.  350, 

364 
Albatross,  see  Isolation 
Alcohol,    295;    influence    on   chick- 
ens,   251-2 

guinea-pigs,    251-2 

rats,  251 

see  Crustacea,  light  response 
Alfalfa,  destruction  by  mice,  388 

see  Nitrogen  fixation 
Algae,    alternation    of    generations, 
100 

blue-green,   95,   480 

fossil,  117 

liot   springs,   381 

reproduction,  96 

symbiotic,    92 

see      Chromatophorea,      Nucleus, 
Shells 
Allen,  B.   M.,   471 

4S. 


Allen,   J.   A.,  88,   163 
Alligator,  distribution,  180 
ill.  179 

see  Sexual   Selection 
Alluring  resemblance,   338 
Alternation  of  generations,  98 
significance,   103 

see  Algae;   Ferns,  reproduction; 
Liverworts;    Medusa;    Mos- 
ses;   Polychaeta;     Polyzoa; 
Protozoa ;    Tunicates 
Amblystoma,    metamorphosis,    con- 
trol, 223,  224;  ilh  225 
Amboceptor,   445-6 
American  Association  for  Advance- 
ment of  Science,  46 
American    Breeders'    Asaociation, 

269 
American    Fish    Cultural    Associa- 
tion,  425 
American  Fisheries  Society,  425 
American  lemur,  see  Tarsier 
American  Museum  of  Natural  His- 
tory,  collections,   44 
exhibits,    55-9 
founded,  support,  54 
work,  55-9 
ill.    54 
American   Naturalists'   and   Geolo- 
gists' Society,  46 
' '  American       Ornithology, ' '       see 

Wilson,  A. 
Amino-acids,  296 
Ammonia,    298 

Ammophila,   nesting  instincts,   319 
Amoeba,  95,  243;   reactions,  301-4 
complexity  of   structure,  304 
volition,   281 
ill.    94,    302 
Amphibia,   blood   vessels,   89 
foot  prints,  123 
fossils,  121-2 
regeneration,     193 
sex  determination,  209 
spread,  154 
see  Germ  cells,  origin 
Amphioxus,     indeterminate     devel- 
opment, 192 
larval    asymmetry,    110 


486 


Index 


Ampliioxus,  mouth,  110 

relation   to   vertebrates   and   in- 
vertebrates, 108 

structure,   107,   et  seq. 
Amphipod,  226 
Anabolism,  see  Metabolism 
Anadromus,   see   Fish 
Anaptomorphus,  see  Tarsier 
Ancestral,    see    Fish;    Troehophore 
Ancon   ram,    239 

Andalusian    fowl,    see    Inheritance 
Andrews,  88 

Anesthesia  of  non-life,   318 
Angler,    see   Gigantactus 
Animal,    color,    cause,   332-4 
functions,  334  et  seq. 
theories,  335  et  seq. 

heat,  283-4 

Industry,  see  U.  S.  Bureau 

migration,    143 

organs,   remedies  from,   320 

phosphorescence,   354-5 

reactions,    301    et   seq. 
Animals,    aquatic,     diurnal    move- 
ment, 363 
horizontal  migrations,  383 
survival,  381-2 
swarms,   383 

arctic,  color,  334 

cave,   color,   226-7 
sensitiveness,   227 

compared  with  plants,  297 

dependence  on  plants,  161 

dispersal,  152,  154-5 

interdependence,   161 

polygamous,  see  Sexual  selection 

tropical,  color,  334 

see  Distribution;  Pools,  tempor- 
ary 
Ankylostomum,  see  Hookworm 
Annelids,  fossils,   117 

organ-forming  substances,  191 

regeneration,    193 

structure,    106 

typical  invertebrates,  106 
Annulate,  see  Annelids 
Anoci-association,    325 
Anopheles,  453 
Ant  leaf -cutting,  see  Mimicry;  ill. 

341 
Antelope,  174,  425 

extinction,  421 

preservation,  420 

see  Eecognition  marks 
Anther,   see  Flowers,   reproduction 
Anthrax,  447 

Anti-bodies,  see  Syphilis,  Wasser- 
man  test 


Antisepsis,  results,  443-4 
Antigen,   446 
Anti-human  serum,  438 
Anti-toxin,    see    Biologiical    reme- 
dies;    Diphtheria;     Tetanus 
"Anton  Dohrn,"  82,  ill,  83 
Ants,  see  Instincts 
Aphids,  see  Instincts  of  ants 
Appalachian    Mountains,    see    Per- 
mian period 
Apparatus,    deep-sea,    see    Bottom- 
sampling  ;    Current    meters ; 
Projection;  Sounding; 

Thermometers ;     Trawling 
Apteryx,  133 
Aquarium,    N.    Y.,    see    Zoological 

Society 
Arachnid,   see   Sex   determination 
Arboretum,  see  Arnold 
Arehaeopteryx,      131-3;      135      ill. 

131 
Arctic  fox,  hare,  distribution,  172; 

tern,  ill.  142 
Aristotle,   192,   243,   257,   402 
Armored  "fishes,"  117 
Arnold,    Arboretum,    65,    67,    393 

ill.  6.5,  66 
Arthropods,   see   Isolation 
Ascaris,  giant  larvae,  192 

see  Germ  cells 
Ascidians,   see   Tunicates 
Aspen,  distribution,  174 
Asthma,  see  Adrenal 
Audubon,  J.  J.,  account  of  Indian 
swan  hunt,   27-8 
Mississippi  in  flood,  28 
birth,   26 

commercial  enterprises,  26 
death,  32 
education,  26 

emigrates    to    America,    26 
failure  and  poverty,   27 
journeys    to    Florida,    Labrador, 

Missouri  Eiver,  32 
marriage,  26 
meets  Rafinesque,   28-9;   Wilson, 

20-2 
publishes  "Birds  of  America," 

31 
plans    "Quadrupeds    of    Amer- 
ica," 32 
visits    England,    France,    Phila., 

31 
ill.   Frontis. 
Audubon   bird  law,   422 
Society,   32,   420,   422-3 
sons,  pursuits  and  travels,  32 
Axone,  see  Nerve  fibre 


Index 


487 


B 


Baartsch,  256 

Bacillus  pestis,  see  Eat,  parasites 

Bach,  inheritance,  273 

Bachman,  54 

Bacon,   74 

Bacteria,  95,   480;   nitrogen-fixing, 
298 
reactions,  305 
related  to  disease,  440 
resistance  to   boiling,  382 
water,   378,   381 

Bacterium,  volition,  281 

Badger,  distribution,  176 

Bailey,  quoted,  417 

Bainbridge,   quoted,   470-1 

Baird,  work,  44,  61,  426 
ill.  45 

"Bakewell's  Geology,"  45 

Balanoglossus,    structure,    relation 
to  vertebrates,  106,  107 
mouth,  110 

Baleen,  see  Whalebone 

Balsam   fir,   distribution,    174,   175 

Bamboo,  412,  413,  414;  ill.  410 

Banta,  232 

Bantam,  see  Sexual  selection 

Barn,  see  Owl 

Barnacles,  see  Movement 

Barnard    Free    Skin    and    Cancer 
Hospital,  86,  472 

Barren    ground    caribou,    distribu- 
tion, 172 

Barriers  to   migration,   152,    155-7 

Bartram,  John,  20,  63 

Bartram,  William,  20,  see  Wilson, 
A. 

Bat,  see  Adaptation;  Animals,  dis- 
persal of 

Bates,  330,  342 

Bateson,  88,  243,  263 

Bdellostoma,   108 

Beans,  see  Nitrogen  fixation;  Pure 
lines 

Bear,  see  Polar 

Beaufort  Biological  Station,  437 

Beauperthuy,    450 

Beaver,  425;  distribution,  176;  ill. 
175-6 

Bee,  see  Mimicry;  Sex  cycle 

Beebe,  63,  134 

Bees,  relation  to  flowers,  330;   ill. 
332 
worker,   structure,  function,   331 
see     Heliotropism ;      Swarming ; 
Color,  warning 
Beetle,  ladybird,  see  Vedalia 


Beetles,     chrysomelid,     see     Calli- 
grapha 
potato,    distribution,    245-6 
experimental      production      of 

variation,  246-8 
food,  245 
habits,  245 
ill.  247 
Behring,   431;    Isthmus,   148 

Sea    Tribunal,    see   Seal   contro- 
versy 
Strait,  barrier,   254 
Belknap,  364 
Bennett,   quoted,   443 
Beriberi,    447;    symptoms,    cause, 

292-3 
Bernard,  320 
Beroe,  190;  ill.  189 
Big  trees,  see  Sequoia 
Bile  pigment,  see  Pigment 
Biological  bureaus,  U.   S.,  87 

remedies,  320;  inspection  of,  474 
Biological  Station  defined,  68 
see  Beaufort,  Fairport,  Havana 
Stations,  locations,  71 
see  Marine 
Biological     Survey,     see     Survey, 

U.  S. 
Biology  inland  waters,  379  et  seq. 
needs,  481-2 
problems,  478  et  seq. 
Biometer,  318 

Bird    laws,    see    Migration,    Lacey 
lice,  see  Isolation 
of  Paradise,  see  Sexual  selection 
Birds,  air  sacs,  130 
bones,    130 
classification,     distribution,     see 

U.  S.  Biological  Survey 
feather,  development,  133 
origin,   134 

structure,   133-4;    ill.   133 
flight,  origin,   133-5 
food,    347-8;    see   Hawks,    Owls, 

U.  S.  Biological  Survey 
lungs,   130 
migration,   152,   360 ;    see  U.    S. 

Biological  Survey 
sex  determination,   210,   232 
sex-linked  inheritance,  214 
skull,  131 
sternum,  130 
temperature,  130 
wings,   132 

see  Adaptation;  Color,  warning; 
Instincts;   Isolation;   Sexual 
Selection 
Birge,  382 


488 


Index 


Bishop  Museum,  482 

Bison,    148,    420,    421,    425 
migration,  152-3,  245 
ill.  419 

Blagden,   349 

"Blake,"  350 

Blending,  sec   Inheritance 

Blood    serum,    refractive    index    in 
Bright 's      disease,      cancer, 
syphilis,  tul)ercnk)sis,  85 
test,  438;   see   Syphilis,   Wasser- 
man  test 

Blue,  459 

Blue-green,  see  Algae 

Blumenbach,  208 

Boa  constrictor,  transport,  155 

Bobolink,   spread,    182 
molt  control,  225-6 
ill.  226 

Bob-tailed  cat,  240 

Bonaparte,  19,  31,  53 

Bones,       see      Birds,       Crocodiles, 
Pterodactyls 

Bonneville,  see  Lake 

Boreal  zone,  174 

Bonellia,  see  Gephyrea 

Bonet,   470 

Boston,  see  Water-works 

Botanical   Gardens,    62;    see  Bart- 
ram,    Missouri,    N.    Y. 

Bottom-sampling   apparatus,   365 

Boveri,  88,  471 

Bow-fin   as   food,   435 

Boyle,    283 

Brachiopod,   see   Spirifer 

Bradbury,    34 

Breeders'    Association,    see    Amer- 
ican 

Brewer,   44 

Bridges,  see  Land 

Bright 's  disease,  see  Blood  serum 

Brittle  star,  see  Cross  fertilization 

Brontosaurus,    126;    ill.    127 

Brooke,    349 

Brooklyn,  see  Water-works 

Brooks,    88 

BroAvn-tail,   see   Moth 

Briinn,    Natural    History    Society, 
203 

Bryozoa,  statoblasts,  382 

Buljonic,    see    Plague 

Buffalo  University,  472 
see  Bison 

Burt'on,   235;    see   Jefferson 

Bugs,  see  Color,  warning 

Bunting,  see  Lark,  Snow 

Bureau    of    Animal     fndnstry,    see 
U.  S. 


Bureau  of   Entomology,  see  U.   S. 
Fisheries,   see  U.   S. 
riant  Industry,  see  U.  S. 
Public  Health,  see  U.  S. 
Burrowing    owl,    distribution,    182 

ill.    18(1 
Bursa,  see  Inheritance,  shepherd 's 

purso 
Bursaria,  ill.  00 
Bussey,   87 

Bussey  Institution,   74,   87 
Butler,    313 
Butterflies,   distribution,    172 

influence    of    environment,    222-3 
see  Color,  warning;   Isolation; 
Mimicry;   ^Monarch;   Sex  de- 
termination;  Viceroy 


Cabbage  butterfly,  see  Pieridae 

Caesarean    operation,    444 

Caffein,    see    Crustacea,    light    re-: 

sponse 
Caithness   flagstones,   118 
California,    climate,    fauna,    flora, 

184,    185;    see    Sequoia 
Calligrapha,      germ      cell      deter- 
minants,  191 
Calorimeter    of    Benedict    and    At- 

water,  Lavoisier,  284-5 
Cambrian  period,  life,  95,  117 
Camel,  extinct,  148 

migration,  149 
Camouflage,  see  Color,  protective 
Canada  lynx,  distribution,  176 
Canadian  zone,  174 

forest,  ill.   171 
Cancer,   481 ;    animal   experimenta- 
tion, 469-70 
chromosomes,  471-2 
Commission,   Harvard,  472 
effect.  X-ray,  radium  ray,  248 
in  animals,  473 
inheritance,  472 
institutes,  472-3 
Laboratory,   N.   Y.   State   Board 

of   Health,   472 
theories,  470-2 
see  Blood  serum 
Capelan,    destruction,    156 
Carbohydrate,    energy    production, 
296 
synthesis,  92-3 
see  Diet 
Carbon   dioxide,   end    product,   280, 
294.   296 


Index 


489 


Carbon  dioxide,  sign  of  life,  318 

sugar  synthesis,  93 

see  Crustacea,  light  response 
Carboniferous    jxiriod,    life,    121-5, 
ill.  124 

climate,  124-5 
Caribou,      see       Barren       ground, 

Woodland,  ill.  109 
Carinatae,  130 

Carnegie  Institution,  biological  la- 
boratories,   73-4 

Dejiartment    of    Embryology,    73 

Nutrition   Laboratory,   284 
Carnivores,  origin,   140,  142 
Carp,   survival  in  ice,   381 
Carrel,    196-7 
Carroll,  451,  452;  ill.  451 
Carter,  453 

Cassowary,   distribution,   139 
Cassin,   44,    54 
Cassiopea,   348 

Castle,    88,   238,   267;    quoted,   266 
Castration,    325;    see    Sterilization 
Cat,  see  Bob-tailed 
Catalyzer,  295,  318 
Caterpillars,  color,  334;   see  Mimi- 
cry 
Catlin,   441 

Cattle,    color,    horns;    see    Inherit- 
ance 
Cave,  Port  Kennedy,  42;   see  Ani- 
mals 
Cecropia  moth,  grafting,  196 
Cedar,  see  Eed 
Celsus,  470 
Cell,  growth,  198-99 

immortality,.  201 

problems,  480 

see   Germ 
Centipedes,    fossil,    124 
Centrifuge,  52,  376 
Cephalopods,  destruction,   156 

see  Octopus 
Ceratium,  92 ;  ill.  91 
Ceratophyllum,  see  Hornwort 
Cerebratulus,    development    experi- 
ments, 192 
Cerion,  influence  environment,  256 
Cestracion,  invariability,  ill.  120 
"Challenger,"  363,  366 
Chameleon,  color  changes,  333 
Characteristics  of  life,  see  Life 
Characters,    acquired,    see    Inherit- 
ance 
Chaulmoogra,  see  Lepers 
Chemical  treatment,  see  Seed 
Chestnut,     Chinese,     bark     disease, 
416 


Chiasmodus,  358;  ill.  356 
Chicken,   see    Web-footed 
Child-bed,    see    Puerperal 
Chipmunks,    distribution,    176 
Chittenden,    (luoted,    286-92 
Chlorophyl,  81,  93-4,  98,  297,  330, 
383 

composition,      function,      origin, 
480 
Cholera,   see    Hog 
Chorea,  271-2 

Chromatin,    see   Chromosomes,    Mi- 
tosis 
Chromatophores,  333 

algse,  94 
Chromogen,  333 
Chromosomes,    478 

accessory,  209 

homologous,  206 

in  development   and   inheritance, 
202  et  seq. 

sex,  206,  208 

ill.  204  et  seq. 

see  Cancer 
Chydorus  spha?ricus,  232 
Cilia,    specializations,    91-2 
Ciliates,  90;  ill.  90-1 
Circulation   in  plants,   299 
Circumcision,    244 
Citrange,   268 
Cladoselache,   structure,    120 

fins,   112 

ill.  112 
Clams,    353 
Cleft  palate,   272 
Clements,   158 

Climatic  factor,  see  Huntington 
Closing  nets,  371 
Coast  Survey,  see  U.  S. 
Cock,  see  Sexual  Selection 
Codfish,  423,  425 
Coleps,  shell,  92 

ill.    91 
Colleges,      see      Harvard,      Kings, 
Pennsylvania,  Princeton, 

William  &  Mary 's,  Yale 
Color,  adaptation,  330  et  seq. 

blindness,   214 

cause,  see  Animal 

flowers,      metabolic     by-product, 
330 

man, -see  Inheritance 

jjrotective,  335  et  seq. 

warning,  346,  348 
Columbia   University,   50,   202 
Commander   Islands,   see   Seal 
Commensalism,  see  Protozoa,  mode 
of   life 


490 


Index 


Compass  plant,  ill.  307 

Complement,    446 

Condor,  distribution,  135,  185 
see  Giant 

Conduction  in  plants,  299 

Conklin,   189,   191 

Cootie,  see  Trench  fever 

Cope,   38,   39,   54,   88 

rivalries,  reminiscences,  42 
work,   40 
ill.   41 

Copepods,  381;  see  Plankton 

Coral  reef,  see  Fish 

Corals,   fossil,   117 

Corbins,  inheritance,  273 

Corn,  influence   of  selection,  238 
see  Inheritance 

Correns,   203 

Coryphodont,  142;  ill.  141 

Cosmobia,  228 ;  ill.  229 

Cotton,   hybridization,   268 

Cotton    Mather,    442 

Cotton  rat,  distribution,  178 
ill.  178 

Cottonwood,  distribution,  182 

Coues,  20,  43 

Coulter,   43 

Cowles,   438-9 

Cowpox,  see  Vaccine,  preparation 

Coyotes,  421;  damage,  393;  see 
Rabies 

Crab,  see  King 

Craig,  314 

Crampton,  196,  255-6;  quoted,  255 

Cranial  rib,  see  Vertebrates,  head 

Creodonts,  140,  142;   ill.  141 

Crenothrix,  379 

Cretaceous,  period,  140 
sea,  127,  129,  132,  140 

Cretinism,  273;  see  Thyroid 

Crile,    321-2;     quoted,    323-5 

Crocker,  George,  Special  Eesearch 
fund  (for  cancer),  472 

Crocodile,  bones,  130;  transport, 
155 

Cross  fertilization,  327-8;  see  Sal- 
via 

Crossing  over,  215 

Crossopterygians,  distribution,  re- 
semblance to  Stegocephala, 
121,  123 

Crowfoot,    382 

Crustacea,   358;    eggs,   relation   to 
temperature    and    moisture, 
382 
fossil,  see  Trilobite 
light  response,  315-6 
sex  determination,  232-3 


Ctenophore,  104;  see  Beroe 

Cuenot,    88 

Cunningham,  333 

Current  meters,  365-6 

Curtis,  436 

Cuvier,  38,  223 

Cyclopean  monsters,  194;  see  Fish 

Cyclops,    relation    to    oxygen,    382 

Cyclostomes,    structure,    108,    111; 

skull,  114 
Cynodont,    136 
Cynthia,  191;  ill.  190 
Cytoplasm,    189,   202,   478;    origin, 

480 


D 


Dana,  38,  349 
Danaidae,  see  Mimicry 
Daphnid,  ill.  231;  see  Sex  cycle 
Daphnia,  light  response,   315,  361 
heliotropism,  314 
see  Sex  intergrades 
Darwin,  45,  46,  116,  202,  222,  239, 
240,  242,  330,  334,  478 
quoted,  155,  235-6,  343-6 
Date  palm,  417;   ill.  417,  418 
Davenport,  88;  quoted,  271-4 
Dead  leaf  butterfly,  see  Kallima 
Deaf-mutism,    272 
Dean,    88 
Deane,    125 
Death,  cause,  200-1 
origin,    479 
Valley,   climate,   184 
Deep-sea,   see   Fish,   Apparatus 
Deer,    distribution,    176 
preservation,  420 
see  Recognition  marks.  Wolves 
Defectives,   elimination,  276-7 
De  Lesseps,  452 
Dentalium,  191;  ill.  190 
Department      of      Botanical      Re- 
search, Carnegie  Institution 
see  Desert  Botanical  Labor- 
atory 
Embryology,   Carnegie   Inst.,   84 
equipment,    establishment,    loca- 
tion, work,  74 
Experimental      evolution,      Car- 
negie Institution 
Marine  Biology,  Carnegie  Insti- 
tution, location,  81-2 
work,    82,    83 
ill.  82 
Depth,  see  Ocean 


Index 


491 


Dermal  bones,  see  Stegocephala 
Desert  Botanical  Laboratory,  76 
location,   75 

work,   76-81,  220,   222,   245,   297 

ill.  75 

Desmids,  shells,  94 

Destruction,    see    Capelan;    Cepha- 

lopods;     Fish,    death;     Gar 

pike;  Jack  rabbit;  Octopus; 

Eodents;    Tile   fish;    Wolves 

Determiners  of   characters,  202   et 

seq.,    478 
Development,  determinate,  190-2 
indeterminate,    192 
see  Chromosomes 
Devils  Lake,  N.  D.,  380 

disappearance  of  pickerel,  119 
Devonian  period,  Amphibia,  112 

lungfish,  120 
DeVries,  203,  240-1,  243,  478 
Diabetes,  see  Pancreas 
Diatom  ooze,  353 
Diaptomus,  light  response,  316 
Diatoms,  shells,  94,  360 
Dialysis,   295 
Diastase,   279 
Dicksissel,  spread,  182 
Didinium,  93 
Diet,   experiments 
athletes,    289 
dogs,  289-92;  ill.  291 
hens,   294 

soldiers,  287-8 ;  ill.  288 
requirements,   287   et  seq. 
Digestion,  295-6,   299,  321 
Dinornis,  see  Moa 
Dinosaurs,   40 

distribution,  125-6 
extinction,    127 
food,    127 
intelligence,   127 
structure,    126 
tracks,    125-6 
ill.  126 
see   Mammals 
Diplococcus,    see    Meningitis 
Diphtheria,  448-9;  see  Serum,  Tox- 
in 
Disease,    see    Bright 's.    Chestnut, 
Foot    and    Mouth,    Venereal 
Dispersal,  see  Animals,  Plants 
Distribution,    animals    and    plants, 
factors,  177 
horizontal,  see  Animals,  aquatic; 
Cassowary;       Emu;       Moa; 
Ostrich ;    Khea 
Ditch-grass,  382 
Ditmars,  63 


Diurnal    movement,    see    Animals, 

aquatic 
Dog,  see  Diet,  Hairless 
Dogfish,  see  Sharks 
Dominance,    258;    imperfect,    258- 

261 
Doty,  454 
Douglas   spruce,   distribution,    174, 

175 
Dredge,  369-70 
Drelincourt,    208 

Drosera,  reactions,  308-9;    ill.   309 
Drosophila,    210    et    seq.,    ill.    209, 

212;  see  Inheritance 
Drummond,  37 
Duck,  see  Wood 
Ductless  glands,  function,  481 
Dust,  organic,  volcanic,  353 
Dwarfism,  273 


E 


Ear    bones,    relation    to    gills,    see 
Vertebrates,  structure 

Earth,   age,   116-7 

Earthworms,  see  Annelids 

Eating,  healthful,  293-4 

Echinoderm,    development    experi- 
ments, 192 

Echinoderms,  larva},  105;  sex  deter- 
mination, 209 

Eckman,    365,    368 

Edwards,  inheritance,  270,  273 

Eels,    migration,    spawning,    361, 
363 

Eggs,  fish,  distribution,  426,  429 
membrane  formation,  328-9 
union  with  sperm,  327 
see   Crustacea,   Estheria,   Organ- 
forming,   Eeproduction,   Eo- 
tifers.       Summer,       Winter, 
Worms 

Egret,  preservation,  421-3;  ill,  421 

Ehrlich,    446 

Eigenmann,  88,  381 

Eimer,    243 

Elephant,  146;  see  Imperial 

Elk,  425;   distribution,  174 
preservation,  420 
ill.  420 

Elodea,    see    Water-weed 

Embryos,  104;  see  Vertebrate 

Empedocles,   235 

Emu,  distribution,  139 

Enamel,    see    Teetli,    Mammalian, 
Placoid  scale 

Endosperm,  245 


492 


Index 


Kniielnian,   fi3 

English     siiiirrow,     411;     iiitroduc- 

tidti,  spread,  385 
Eiitolci-liy,    189,    234,   1383 
Entoniology,  see  U.  S.  Bureau 
Environment,  influence  on  develop- 
ment, 220;  ill.  221 
relation  to  variation,  244  ct  scq. 
Enzymes,   205,  480 
constructive,  296 
digestive,  299 
oxydizing,    296,    333 
see   Drosera 
Eocene    epoch,    climate,    140 
earth  changes,  140 
life,  138,  142-5 
Eohippus,   40,    144 
Epilepsy,   270-1 

Epoch,  sec  Eocene,   Miocene,   Plio- 
cene,   Pleistocene 
Equatorial  plate,  see  Mitosis 
Era,  see  Mesozoic,  Palaeozoic 
Estheria,   egg,  382 
Eucrangonyx     gracilis,     effect     of 

light,  226-7 
Eugenics,  268  et  seq. 
Laboratory,  269,  274 
Record  Office,  74-5,  274 
Eustachian    tube,    see    Vertebrates, 

structure 
Evening     primrose,     influence      of 

radium,  248 ;  see  Mutation 
Everglades,    see    Florida 
Evolution,  234  et  seq. 
blood  vessels,  89 
factors,  478 
invertebrates,   103-7 
land     from     water     vertebrates, 

124-5 
relation      of      morphology      and 

physiology  to,  89 
vertebrates,  106  ct  seq. 
see   Darwin 
Existence,  see  Struggle 
Extinction,    see    Reptiles 
Extra  fingers,  see  Man,  polydactyl- 

ism 
Eye,   control   of   color,   333;    devel- 
opment,  193 


F 


Factors,    see   Inheritance,    Mendel- 

ian 
Fairchild,   413 

Fairport  Biological   Station,  436-7 
Fat,  digestion,  295-6 


Fat,  energy  ])roduction,  294  6 

reserve,   29() 

see    Diet,    food    changes 
"Fauna    boreal!  Americana, "    sec 

Richardson 
Feather,    contour,    down    and    hair, 

srr  Birds 
Feathers,    iiHj>()rtation,    sec     Plum- 
age 
Feeblemindedness,    270-1 
Feeble-minded,  see  Training  School 
Fer  de  lance,  404 
Ferment,  see  Enzyme 
Ferns,    horsetail,    122 

reproduction,     99-100 

spermatozoa,      chemical      attrac- 
tion, 327 
Fertility,  see   Rat  inbreeding 
Fertilization,    artificial,    328-9 

mechanics  of,   328 

see     Cross,     Protozoa,     Salmon, 
Volvox,   \y inter   eggs 
Fever,  see  Puerperal 
Fins,  see  Fish 
Finlay,    450 
Fir,  see  Balsam 
Fish,    anadromus,    361 

ancestral.    111 

commissions,    state,        425 ;     see 
U.  S. 

coral  reef,  340,  348;  ill.  339 

culture,  425;   see  American 

cyclo}»ean,    production,    227 

death     in    overflow    ponds,     118, 
119,   437 

deep  sea,   354-7;    ill.  354-6 

development,  430-1 

gills.    111 

hatclieries,  see  Fish  culture 

migration,   360-3 

monsters,    production,    227;     ill. 
228 

j)aired  fins,  111-2 

resistance    to    temperature,    382 

scales,    120 

sex-linked    inheritance,    214 

spiracle,    111 

survival    in    ice,    381 

sec     Ada])tation,     Dean,     Eigen- 
mann,       Germ       cells,       In- 
stincts,       Jordan,        Origin, 
Plankton 
"Fish  Hawk,"  350 
Fisher,    distribution,    174 
Fisher,  287 

Fisheries,  see   U.   S.  Bureau 
Fitzhughs,  inheritance,  273 
Fixity    of    Species,   belief,   45 


Index 


493 


F1;i<;p11:i,    92 

Flagellates,     92-3,     95,     98;     liglit 

reactions,    30G 
Flagstones,  see  Caithness 
Flatfish,  358;  color  adaptation,  333 
Flatworni,  regeneration,  193 
Fleas,  sec  Plague 
Flexner,    -148,    480 
Flics,  and  disease,  455-7 
control,    456 
increase,  455 
see   Mimicry 
Flight,  see  Birds 
' '  Flora    boreali-Aniericana, ' '     see 

Miehaux 
Florida  Everglades,  178 
Flotation,    means,    358,    360 
Flowers,  reproduction,  98-9;  ill.,  99 

see    Color,    Insects 
Fluted  scale,  see  Scale 
Fly,  see  Hessian,  Mimicry 
Flying  lizards,  see  Pterodactyls 
Food  changes  in  body,  294-(5 
Foot  and  mouth  disease,  409 
Foot  binding,   244 
Foraminifera,    352 
fossil,    120 
shells,  92 
Forced  movements,  see  Tropism 
Forests,   hardwood,   swamp,   dis'.ri- 

})ution,  178 
Fortuitous,  see  Variation 
Fossil,    see    Algae,    Annelid,    Centi- 
pede, Coral,  Crustacea,  For- 
aminifera,   Insects,    Inverte- 
brates,   Land    plant.    Lung- 
fish,  Nautilids,  Ostracoderm, 
Kadiolaria,  Scorpion,  Shark, 
Snail,       Spider,       Trilobite, 
Vulture,  Worm 
Four  o  'clock,  see  Inheritance 
Fowl,   Andalusian,   see  Inheritance 

rumpless,  sec  Mutation 
Fowls,      sex      determination,      see 

Birds 
Fox     farming,     425;     sec     Arctic, 

Red 
Fox-tail  p!ne,  distribution,  172 
Franklin,  Benjamin,  349 

Sir  John,  36,  37,  381 
Frog,      artificial      parthenogenesis, 
329 
cleavage   cell   experiments,   192 
color  changes,  333 
grafting,  ill.  195-6 
regeneration,    193 
8ex   determination,   230 
survival  in  ice,  381 


Frog,  see  Intercrossing 
I'^rwit    files,    see    Drfisojdiila 
i'^undulus,  mating   reactions,  314 
Fungus  and    fish   eggs,   428,  430 
Fur  farming,  see  Fox 


G 

Galen,    470 

Galton,    269 

Game  and  Bird  reservations,  420, 
423 

Gametophyte,  see  Algae;  Alterna- 
tion of  generations ;  Ferns, 
reproduction ;     Reproduction 

Gammarus,  light  response,  315 

Gardens,  see  Zoological  and  Bo- 
tanical 

Gar  pike,  destruction,   119 

Genetics,  practical  value,  266  et 
seq. 

Geographical  distribution,  see  U. 
S.  Biological  Survey 

Geographic  race,  see  Species 

Geotropism,   plants,    308,   311 

Generations,  see  Alternation 

Gephyrea,  sex  determination,  232- 
233 

Germ  cells,  see  Sex  cells 

Germ    layers,   105 

Giant    club    mosses,    see    Lycopods 

Giant  condor,  148 

Giant  sloth,  146 

Giant    wolf,    148 

Gigantactus,    355 

Gilbert,    43 

Gill,   54 

Gills,  see  Amphioxus;  Balanoglos- 
sus ;  Cyclostomes ;  Fish  ; 
Lungfish ;  Man ;  Stegoce- 
phala,  larvae ;  Tunicates ; 
Vertebrates 

Girard,    39 

Glaciers,  influence,  see  Plants 

Glands,    mouth,    ferment,    295 
see  Adrenal;   Internal  secretion; 
Kidney;     Liver;     Pancreas; 
Sex;      Thyroid;      Tunicates, 
structure 

Glanders,  field  mice  immune,  447 

Glandular  extracts,  see  Biological 
remedies 

Globigerina,   invariability,  120 
ooze,  352 

Gk)chidium,  436;  ill.  435 

Glycogen,    storage,    296 

Goat,   sec   Rocky   Mountain 

Goddard,    quoted,    270-1 


494 


Index 


Goldberger,    476 
Goldfinch,  color,  343 
Goldfish,   see   Japanese 
Goklschmidt,  233 
Gonorrhea,  extent,   445 
Goosefish,  as  food,  435 
Gopher,  see  Ground  Squirrels,  Owls 
Gorgas,   452-3 

Grafting   experiments,   194-8 
Grampus,    351 
Grapple-dredge,   365,  370 
Grassi,  450 

tJray,  and  Darwin,  45,  46;  ill.  42 
Grayfish,  see  Shark 
Gray    snapper,    348;    wolf,    distri- 
bution,  174 
Great-horned,    see    Owl 
Great  Plains,  tension  line,  182 
Great  Salt  Lake,  76-8,  157 
Grosbeak,   see   Rose-breasted 
Ground,   sloth,   148 

squirrels,  damage,  393 
destruction,  400,  402 
distribution,   177,   182 
ill.,    401 

see  Owls,  Plague 
Growth,  279,  280,  361 ;  see  Rat 
Guano,  298 
Guinea  pigs,  sex  determination,  209 

see  Inheritance 
Gulf  stream,  349,  353 
Gulick,    255-6;     quoted,    255 
Gynandromorph,  210;  ill.  209 
Gypsy   moth,   control,    406 

introduction,  spread,  385 

ill.  386 

see  Sex  intergrades 


H 


Hemoglobin,  330,  334,  445 

Haemophilia,    214,    273 

Hagfish,    see   Bdellostoma,   Myxine 

Hairless   Dog,   240 

Haiselden,  277 

Hare    lip,    272 

Harris,   444 

Harrison,    195,   199 

Harvey,    479 

Harvard  College,  47,  49,  50 

University,    see   Bussey    Institu- 
tion 
Hatteria,  see  Tuatara 
Havana,    111.,    Biological    Station, 
71 

Cuba,  sanitation,  453-4 


Hayes,  54 

Hawaiian  Islands,  topography,  254 

snails,    isolation,    254-6 
Hawks,  161 

benefits  from,  388,  390 

ired-tailed,  390;  ill.  388 
Head,  see  Vertebrate 
Heat,  see  Animal 
Heiscr,   441 

Heliconidse,  see  Mimicry 
Heliotropism,  313  et  seq. 
Hemiptera,  see  Color,  warning 
Hens,  see  Selection,  Diet 
Hensen  net,  373-5;  ill.,  374 
Hermaphroditism,     98,     103,     210, 

231-2 
Heron,  R.,  346 
Heron,  see  Egret 
Hesperornis,  40,  131;   ill.  132 
Hessian  fly,  introduction,  damage, 

385 
Hibernation,  296 
Hippocrates,  320,   470 
' '  History  of  American  Birds, ' '  see 

Baird,  Brewer,  Ridgway 
Hitchcock,  125 
Hog   cholera,    409 
Holmes,   Oliver  Wendell,   268,   444 
Holmes,    S.    J.,    quoted,    304 
Holoptychius,    123 
Hopper,  see  Leaf,  Tree 
Hooded    rat,    selection,    ill.    238 
Hookworm,  abundance,  466 

control,    466,    469 

effect,    464 

experiments    on    infection,    465- 
466 

life  historv,  466 

ill.  465,  468-9 
Hooker,  44 
Hopkins,    C.    G.,    238 
Hopkins,  F.  G.,  292 
Hormones,  314,  320;   sex,  325 
Hornaday,    63 
Horned     toad,     distribution,     177, 

184;     ill.    183 
Hornless    cattle,    see    Inheritance, 

cattle;  Mutation 
Hornwort,   382 
Horse,  evolution,  40,  149 

extinct,  148 

extinction,   149 

migration,  149 
Horse-tail  ferns,  see  Ferns 
Hospital,    see    Barnard,    Hunting- 
ton 
Howard,  quoted,  453 
Hudsonian  zone,  174  _ 


Index 


495 


Human,  Jiiachiiie,  economy,  285 
use  of  fuel,  294 

nutrition,  285  et  scq. 
Hume,    235 

Humming-birds,   distribution,   185 
Humboldt,    38,    450 

Valley,  see  Mouse  plague 
Huntington,    77,    79,   81;    hospital, 

472 
Huronian  period,  life,  117 
Huxley,  40 
Hyatt,  69 

Hybrid  infertility,  252 
Hybridization,    see    Cotton,    Muta- 
tion, Orange 
Hydatina   senta,    232 
Hydra,  92;  grafting,  194-5 

regeneration,    192-3 

reproduction,  control,  233,  327 

structure,    103 
Hydrolysis  of  food,  295 
Hydromedusse,  indeterminate  devel- 
opment, 192 
Hygiene,  see  Industrial,  Social 
Hyoid,    see   Vertebrates,    structure 
Hypophysis,  see  Vertebrates 


Ice   age,   143 
Ichneumon,  see  Mongoose 
Ichthyornis,    40,    131 
Identical    twins,    228 
Illinois   Eiver,   plankton,   383 
Illinois   State  Laboratory   of  Nat- 
ural History,  377 
Images,  see  Memory 
Immorality,  sex,  270-2 
Immunity,  practices,  theories,  447- 

448 
Imperial  elephant,   148 
Impulse,    see    Nervous 
Inbreeding,  see  Rat 
Incas,  marriage  customs,  85 
Indian  Plague  Commission,  458 
Indiana,  see  Sterilization 
Industrial  Hygiene,  476-7 
Infertility,  see  Hybrid 
Influenza,  experiments,  476 

work    of    U.    S.    Public    Health 
Service,  475-6 
Inheritance,    478;     acquired    char- 
acters, 244-5 

Andalusian  fowl,  259-60;  ill.  259 

beans,  pure   lines,   236-7 

blending,  258-64 

cattle,  color,  260;  horns,  267-8; 
ill.   267 


Inlicritance,  corn,  261-3 
Drosophila,  260-1 
four  o'clock,  258-9;  ill.  258 
guinea  pigs,  261,   263,   267;    ill. 

261-2 
kinds,  257 
man,    color,   264-5 
examples,  270,  et  scq. 
Meudelian,    203,    et    scq.    257     et 
scq.,  479 
Motaphyta,  257 
Metazoa,   257 
oats,  263 

peas,  203-5,  263 ;  ill.  205 
Protista,  257 
rabbits,    265-6;     lop-eared,    261. 

263;  ill.  260 
ratios,    expected    and    realized, 

264-6 
segregation,  261,  264 
shepherd's   purse,    265 
see  Chromosomes,  Selection 
Inland  waters,  see  Biology 
Inoculation,  see  Smallpox 
Inscctivores,  138 
Insects,  fossil,  124 

larvffi,  oxygen  requirements,  380 
ireactions,   312,   et   seq. 
relation  to  flowers,  330-2 
sex  determination,   209,   230-1 
see    Hawks,    Instinct,    Isolation, 
Mimicry,    Scale,   Sexual    Se- 
lection 
Instincts,  ants,  316 
birds,  319-20 
fish,    314 
insects,    319 
mammals,  319 
pigeons,    sexual,   314-5 
see  Ammojjhila 
Institute,     see     Carnegie,     Phipps, 

Eockefeller,  Wistar 
Institution,    see    Bussey,     Scripps, 

Smithsonian 
Intercrossing,      salamander      and 
frog,    sea    urchin    and    star- 
fish, 253 
Internal   secretions,   320,   361;    see 
Glands,  Salmon,  life  history 
Internal  perfecting  principle,  234 
International    Council    for    Inves- 
tigation   of    the    Sea,    349, 
360,  482 
Intestine,    see    Absorption,    Diges- 
tion 
Introduction,   animals    and   plants, 

410   et  scq. 
Invertebrates,  ancestral,  104 


496 


Index 


I  ir  crlebnites,  dispersal,  155 

fossil,    117 

iiiifxration.    154 
Tr^fl'Ti,  srr   Thyroid 
IrritaVilitv,    characteristic    of    life, 

282 
Trvmsr.  rjuoterl,  153 
Ls:ilati()ii,     arthropods,     liird     lice, 
birds,  butterflies,  253 

frcofjraphic,  252-6 

habitudiual,   insects,   253 

kinds,    252 

structural,  temporal,  253 
Isthmus,  see  Behring,  Panama 


Kelvin,   Lord,  363-4 

"Kentucky    Warbler,"    quotation, 

24-5 
Kerona,  92 

K'dney,  excretion,  322 
Kimball,   quoted.   268-9 
Kinetic  drive,  321-5 
King,   85,  194 
King  crab,  ill.  1 17 
Kings  College,  50 
Kissinger,    452 
Kiwi,  see   Aptervx 
Koch,  440,  480 
Kofoid,  306,  383 
Krascheninikov,   426 


Jackass,   see  Hybrid 

Jack  rabbit,  see  Rabbit 

James,  34 

Japanese   goldfish,   fins,    112 

Jaws,  see  Vertebrates,  structure 

Javs,  distribution.  177 

Jefferson,     contributions     to     bio- 
logy, 34 
corresnondence       with       Buffon, 

with  W=star,  33 
interes's,  32 

L(>\vis   and   Clark   expedition,   32 
pioneer  plant  importer,  33-4 
+-•■'"' o    from    Bryant,   33 
ill.  35 

Jell>tish,  see  Medusa 

Jenner,    442 

Jennings,     88,     237,     242,     305-6; 
quoted,   301-3 

Jochmann,  448 

Johannsen,    236-7 

Johns  Hopkins  University,  see  De- 
partment of  Embryology 

Jordan,   43,   88,   252 

Juday,  380,  382 

Judd,  347,   392 

Jukes,    270 


K 


Kalacoon,    see    Tropical     Research 

.Station 
Kallikaks,  270 
Kullima,     camouflage,     337-8;     ill. 

337 
Kane,    54 

Kangaroo,  see  Marsupial 
Kant,    235 

Katabolism,   see   Metabolism 
Kellogg,  quoted,  317-8 


Laboratories,    biological,    see    Bus- 
sey,    Carnegie,    Marine   Bio- 
logical   Laboratory,    Rocke- 
feller,  Scripps,  Wistar 
Laboratory,    biological    equipment, 
52 
see   Eugenics 
Labyrinthodont    tooth,    see    Stego- 

cephala 
Lacey  Act,  392 
Ladybird  beetle,  see  Vedalla 
Lahontan,  see  Lake 
La  Jolla,  Calif.,  see  Scripps  Insti- 
tution 
Lake  beaches,  old,  78,  80 
Bonneville,  76,  77 
Lahontan,  76,  79 
Minnewaukon,    79,    119 
Mono,    79 
Owens,  79,  80 
Pyramid,  79 
Winnemucca,    79 
Lakes,  disappearance,  78-80,  160 
Lamarck,  244,  249 
Land  bridges,  143 
Lantz,  quoted,  154,  393-8 
Lapland      longspur,      distribution, 

168 
Lark  bunting,  distribution,  182 
Larva,   see   Echinoderms,   Molluscs, 
Trocophore,  Tunicates, 

Worms 
Larvas,  see  Mosquitoes 
Larynx,  see  Vertebrates,  structure 
Latency,   see  Recessiveness 
Lateral  fin  fold  theory,  111-2,  120 
Lateral  line,  see  Stegocephala 
Lathrop,   414 
Laurentian  period,  117 


Index 


497 


Lavoisier,   283-4 
Lawrence,    44 
Lazear,  450;  ill.  451 
Leaf -cutting  ant,  see  Ant 
Leaf   hopper,   407 
Lees,  inheritance,  273 
Lefevre,    436 

Leidy,    54,    petty    rivalries,    remi- 
niscences, 42 
work,  38,  39,  ill.  41 
Lemming,   distribution,   172 
color  control,  222 
see  Mice,  migration 
Lens,      regeneration      experiments, 

193-4 
Lepers,   care,   477 
Lesquereux,    43 
Le    Sueur,    31,    54 
Leucosticte,  distribution,  168 
Lewis  and  Clark  expedition,  32 
Lice,  see  Trench  fever 

bird,  see  Isolation 
Life,    characteristics,    278    et    seq. 
energy,   281 
explanation,   479 
origin,   117,   479 
oxidation,    280 

see  Metabolism,  Motility,  Proto- 
plasm,     Eeproduction,      Ee- 
sponses 
Life  zones.  North  America,  163  ct 
seq. 
see  TJ.  S.  Biological  Survey 
Light,   apparatus,   367 
in    sea,    354,    367-8 
machine,    312 

production;    see    Animals,    phos- 
phorescence 
response,  see  Daphnia 
Lillie,   191 

Limber  pine,  distribution,  175 
Limbs,  see  Vertebrates 
Linin,   see   Mitosis 
Linkage,  211,  et  seq. 
Lion,  see  Sexual  Selection 
Lister,    443 
Liver,    excretion,    322 
ferment,    295,    321 
Liverworts,     alternation     of     gen- 
erations,  99 
reproduction,   99 
Lizards,  distribution,  177 
flying,   see   Pterodactyls 
Lobster,  regeneration,   193 
LockjaAv,  see  Tetanus 
Loeb,  86,  88,  305,  309-10,  317,  327- 
328 
quoted,  311,  313-6,  319 


Longley,   348 

Jjongspur,    see    Lapland 

Looss,    465 

Lop-eared   rabbit,    see    Inheritance 

Low,   450 

Lull,    146;    quoted,    137 

Lungfish,    Australian,    120 

blood  vessels,  89 

distribution,     114 

fossils,    120 

habits,    114 

relation   to   fish   and   amphibian, 
114 

structure,  114 

ill.  112 
Lungs,  see  Lungfish,  Birds 
Luther,  quoted,  33 
Lycopods,  122 
Lyell,   44;    quoted,   154-5 
Lynx,   see   Canada 


M 


Macauley   family,  inheritance,   273 

MacDougal,  245 

MacDoAvell,  251 

Magpie,    distribution,    spread,    182 

Malaria,    organism,    life    cycle,    97 

see    Mosquitoes 
Mall,  83,   228 
Mammals,  development,  cause,  137 

Eocene,  138 

classification,     distribution,     see 
U.    S.    Biological    Survey 

extinction,  cause,  145 

grafting,    196-8 

hermaphroditic,    210 

Mesozoic,    136,   138 

origin,    135 

recent,   142 

regeneration,    193 

relation  to  Dinosaurs,  136-7;  ill. 
137 

sex  determination,  230 

sex  linked  inheritance,  214 

see    Chromosomes,     Hawks,     In- 
stinct,   Owls 
Man,   development,   105j   282 

monstrosities,     cause,     228 ;    .  ill. 
229-30 

polydactylism,   240,   242 

regeneration,  193 

sex  determination,  209,  230 

sex   linked   inheritance,   214 

syndactylism,    242 

see    Inheritance,    color 
Mango,  416,  417;  ill.  416 


498 


Index 


Mantis,  ser  Alluring  resemblance; 
ill.  338 

Mare,  sec  ITybrid 

Marine       Biological       Laboratory, 
buildings,     G9 
environiiiont,    71 
founded,    69 
Avork,  CO,  70 
ill.  68,  69 

Marine  Biological  Stations,  Eu- 
rope, 340;  U.  S.,  see  De- 
partment Marine  Biology, 
Marine  Biological  Labora- 
tory,   Scripps   Institution 

Marine  Hospital,  see  IT.  S. 

Marmot,  sec  Woodcliuck 

Marsh,    145;    discoveries,    40,    131 
expeditions,  39 
meeting   with   Huxley,    40 
reminiscences     by     Osborn,     42, 

145 
ill.  41 

Marsupials,  138;  distribution,  139, 
140,    186 

Martin,  425;  distribution,  174 

Massachusetts  State  Board  of 
Health  work,   377,   381 

Mast,  88 

Mastodon,  34,  84 

Mating  reactions,  sec  Fundulus, 
Pigeon 

Maturation,   203-6,   209-10 

Mayas,  civilization,  see  Hunting- 
ton 

Mayer,   88 

Mayow,  283 

Meadow  mice,  see  Mice 

Meadow  mouse,  see  Microtus 

Measles,  see  Immunity 

Mechanism,  explanation  of  life, 
278  et  seq.  479 

Medical  Eesearch,  see  Kockefellcr 
Institute 

Medusa,  348,  358;  alternation  of 
generations,  100 

Memory  images,  319-20 

Mendel,  202-3 

Mendelian        characters,        experi- 
mental control,   220 
see  Inheritance 

Mendelism,    see    Inheritance 

Menhaden,    food,    industry,    372 

Meningitis,  447-9 

Merino  sheep,  mutant,  239 

Merriam,  C.  Hart,  88,  163 

Merriam,    J.   C,   quoted,    147 

Mesozoic   era,   life,   125-7,   135,   et 
seq. 


Metabolism,    279-80,    294,    et    seq. 

fish,  301  ;   sec  Food  changes 
Metamerism,  105 
Motapliyta,  89 ;  see  Inheritance 
Metazoa,   89,   103 ;    compared  with 
Protozoa,   201;    sec  Inherit- 
ance 
Meters,  see  Current 
Motschnikoff,  200-1,  480 
Meyer,  415 
Miacidfc,   142 

Mice,  climate,  influence,   248 
damage,  393-6 

deer,   California   races,   distribu- 
tion, 176-7 
influence  of  environment,  ill.  250 
field,  house,  see  Glanders 
meadow,    distribution,    176;    ill. 

394-5 
migration,    154 
variation,   experimental,   249 
see  Hawks,  Mouse  plague.  Owls, 
Sumner,  Weismann 
Michaux,    32 
Michigan  University,  50 
Microtus,   see   Mice,  meadow 
Middle  ear,  see  Vertebrates,  struc- 
ture 
Miescher,  207,  208 
Miossner,  quoted,  312  , 
Migraine,    271-2 
Migration,  bird  laws,  392 

see  Animals,  aquatic;  Dispersal; 
Barriers;       Bison;       Birds; 
Eel;   Fish;   Mice;   Octopus; 
Plaice ;         Rat ;         Salmon ; 
Shad;   Whales 
Miller,  222 
Mimicry,  339,  et  seq. 
Mimosa,  reaction,  ill.   308 
Minnewaukon,  see  Lake 
Mink,    174,    425;    ill.    424 
Miocene    epoch,    254 
Mirabilis,     see     Inheritance,     four 

o  'clock 
Miscarriage,  see  Mulatto 
Missouri  Botanical  Garden, 

founded,  63-4;   work,  64 
Mite,  see  Scab 

Mitosis,    203,    206;    abnormal,    see 
('ancer 
radium,  influence,  248 
ill.    204 
Moa,  135;   distribution,  139 
Moina,  swarms,  383 
Moles,  see  Owls 

Molluscs,  352;    flotation,   358,  360 
hermaphroditic,  210 


Index 


499 


Molluscs,   larva,    105 
over -wintering,  381 
Monaco,  Prince,  373 
Monad,  90,  95,  98 
Monarch      butterfly,      sec      Color, 

warning ;    Mimicry 
Mongoose,    402-4 

Monkey,  transport,  155;  see  Adap- 
tation 
Mono,  see  Lake 
Monotremes,  140 
Monsters,  see  Cyclopean  Fish 
Montague,   447 
Moose,    distribution,    174 
Morgan,  88,  189,  202,  210;    Stylo- 

nichia,   95-6 
Morphin,  narcotic,  322,  324-5 
Morphology,  problems,  89 
Mosaic,  structure  of  egg,  190 
Mososaurs,  129 

Mosquitoes,     Anopheles,      malaria, 
97 
control,  454-5 
disease,    early    ideas,    450 
larvae,   378 
malaria,  449-50 
yellow    fever,    450-2 
Mosses,  alternation  of  generations, 
reproduction,  99 
spermatozoa,      chemical      attrac- 
tion, 327 
Moth,     brown-tail,     155 ;      control, 
4U6-7,  parasites,  407 
gypsy,   155;    control,   40G-7 

parasites,  407 
sex-determination,  210 
sex-linked  inheritance,   214 
silkworm,  China,  410 
color,     protective;      see     Gypsy, 
Mimicry 
Motility    of    life,    280-1;    non-life, 

281 
Mountain  lion,  see  Puma 
Mountain  beaver,  see  Sewellel 
Mountain        sheep,        distribution, 

174 
Mouse,   plague,   IGl,  388,  390 

see  Mice 
Movement,  see  Motility 
Mulatto,    hybrid;    see   Inheritance, 

man 
Mule,  see  Hybrid 
Muller,   330 

Multiple    factors,    263-4 
Murray,    quoted,    156 
Murtrie,    31 

Museum,  U.  S.  National;  see  U.  S. 
National 


Museum   of    Natural   History,   see 

American  Museum 
Musk    ox,    distribution,    172;    ill., 

170 
Muskrat,  425;  distribution,  176 
Mussel,  destruction,  435 

life    history,    propagation,    436 

shells,  use,  435 
Mutants,   see   Mutation 
Mutation,    239,    et    scq. 

ill.  239-40 
Myriapods,  sex  determination,  209 
Myxine,  hermaj)hrodilism,  210 


N 


Niigeli,  203,  243 

Nanno -plankton,      see      Plankton, 

counting 
Nansen,    366 
Natural    History    Surveys,    State, 

37 
Nautilids,   117 
National    Park    Service,    420;    see 

Yellowstone 
Natural    History    Laboratory,    see 

Illinois,  Wisconsin 
Natural,  see  Selection 
Negro,    susceptibility    to    disease; 
see   Tuberculosis 
yellow    fever    color,    see    Inheri- 
tance, man,  color 
Nematodes,      sex      determination, 

209;   see  Sex  cycle 
Neoceratodus,  invariability,  120 
"Nero,"   352 

Nerve,   facial,  relation   to   muscle; 
see    Vertebrates 
fibre  development,   195-9 
Nervous  impulse,  318,  322 
system,  312 
see  Eat 
Nets,  see  Tow,  Closing,  Hensen 
Nevill,   292 
New  Jersey  Pine  Barrens,  178 

Training  School,   85,   270 
New  Orleans,  see  Plague  control 
New  York,  Aquarium,  see  Zoologi- 
cal Society 
Botanical  Garden,  65;  ill.  64 
Skin   and   Cancer   Hospital,   472 
State     Board     of     Health,     see 

Cancer    Laboratory 
State     Institute    for    Study     of 
Maligant  Disease,  473 
Zoological    Garden,    see   Zoological 
Society 


500 


Index 


New  Zealand,  inhabitants,  120-1, 
133,    135,    139 

Night  hawk,  color,  33G 
ill.   335 

Nilssou-Ehle,    263 

Nissl  bodies,  318 

Nitrites,    298 

Nitrogen,    fixation,    alfalfa,   beans, 
peas,   298;    sources,   297-8 
in  water,  383 

Non-life,  see  Adaptation 

No])sca,  134 

North  America,  see  Michaux,  Sil- 
va 

Nortli  Dakota,  see  Devils  Lake; 
Public  Health  Laboratory 

Notochord,  see  Balanoglossus, 
Tunicates,  Amphioxus,  Ver- 
tebrates 

Nott,  450 

Nuclein,    see    Protoplasm 

Nucleus,   algffi,   94-5,    189,    202-3 
origin,    480 
see  Paramctcium 

Nutrition,    see    Human 

Nutrition  Laboratory,  see  Carne- 
gie Institution 

Nuttall,  T.,  34;   ill.  35 
G.    H.    v.,    438 

f 

O 

Oats,  see  Inheritance 
Ocean,  depth,  351-2 

environment,    353 

floor,  composition,  352-3 

life,  353 

light,   354 

pressure,    353-4 
Oceanography,    scope,     351 
Octopus,  destruction,   156,  358 

migration,  154 

ill.   356 
Odcjr,  see  Water 
CKnothera,  .see   Mutation 
Onchorhynchus,   see   Salmon 
Ooze,   see   Foraminifera,  Pteroi)od, 

Radiolaria 
Operations,    see    Antisepsis,    Ca;sa- 

rean 
Opossum,  see  Marsupial 
Orange,  hybridization,   268 
Orbulina,  invariability,  120 
Orchestia,    sex    determination,    233 
Ordovician   period,  life,   117-8,    120 
Organ-forming   substances,   189-91, 

202;     ill.     190 
Oragnic,  see  Dust 


Organism,  see  Adaptation 
Organisms,   destruction,  see  Pools, 
temporary 

growth,   480 

marine,    quantitative    determina- 
tion, 371  et  seq. 

size,  480 
Orientation,  see  Tropism 
Origin,  see  Life 
' '  Origin  of  82)ecies, ' '  44,  45,  235, 

343 
Ortliogenesis,  256;  see  Evolution 
Osborn,    42-3,    54,    88,    134,    145; 

quoted,  235 
Osmosis,  279-80,  295,  299 

influence  on  heliotropism,  316 

ill.  279 
Osterhout,  318 

Ostracoderms,    117-8;    ill.    118 
Ostrich,    distribution,    139 
Ovary,    see    Reproduction 
Ovists,  189 
Owen,   39 
Owens,    see    Lake 
Owl,    great -horned,    food,    390 

barn,  food,  390;    ill.   389 
Oxidation,  see  Life 
Oxydizing    ferment,    296 
Oxygen,  carriage  by  blood,  322 

content  of  water  in  summer,  382 

in  winter,  379-80 

discovery,    283 

phos])horescenee,   355 

relation  to  aquatic  animals,  380 
Oysters,  food,  353 


Pacific   R.   R.   Surveys,   37-8,   44 
Paget,    470 

Palaeozoic    era,   climate,    137 
Panama,    Canal,    sanitation,    452, 
453 

Isthmus,    barrier,    254 
Pancreas    activator,    321 

in  diabetes,  320 

ferment,   295,   299,   321 
Pangenesis,  202 

Paramecium,    93,    327;    life    cycle, 
200-1 

reactions,  305-6,  310-2 

reproduction,    96,    200 

structure,  305 

see  Pure  lines 
Parasynapsis,    215 
Parker,    312 

Parrakeet,  distribution,  25,  180 
Parrot,  see  Parrakeet 


Index 


501 


Parry,  36 

Parthenogenesis,    479 
artificial,    328-9 
see  Sex  cycle,  Summer  eggs 

Partula,  see  Tahiti 

Pasteur,   440,   480 

Pavlov,    88 

Peacock,  extinct,  148;  see  Sexual 
selection 

Pearl,    237,    251-2,    294 

I'eary,   54 

Peas,  see  Inheritance,  Nitrogen 
fixation 

Peck,    372 

Peebles,    194 

Pellagra,  cause,  293,  476;  symp- 
toms, 293 

Penikese,  see  Agassiz,  L. 

Pennsylvania    University,    50,    84 

Pennsylvanian  period,  reptiles,  125 

Peridinium,  shell,  ill.  92 

Period,  see  Cambrian,  Carbonifer- 
ous, Devonian,  Huronian, 
Laurentian,  Ordovieian, 

Pennsylvanian,  Permian, 

Silurian,   Trlasslc 

Permian  period,  climate,  earth 
changes,  125 

Peromyscus,  see   Mice,  deer 

Perroncito,  465 

Persimmon,  415 

Pheasant,   see   Ring-necked 

Philadelphia,    scientific   center,   50, 
53 
zoological  garden,  see  Zoological 

Philippines,  see  I'lague  Control 

Phipps,  Institute,  86 

Phororachis,  135 

Phosphorescence,  see  Animals, 
oxygen 

Photometer,  see  Light  apparatus 

Photosynthesis,   81 

Phytolacca,  see  Poke-weed 

"  Phytogeography  of  Nebraska," 
158 

Pickerel,  see  Devils  Lake 

Pierida;.,  see  Mimicry 

Pigeon,  mating  reactions,  314-5 

Pigment,   332-3;    bile,   334 

Pika,  distribution,  168,  174 

Pilobolus,   spore  discharge,  307 

Pine  Barrens,  see  New  Jersey 

Pine,  see  Fox-tail,  Limber,  Piiiou, 
Yellow 

Piuon  pine,  distribution,  176 

Pipit,  distribution,  168 

Pistache   tree,   ill.   415 

Pituitary,  influence  on  growth,  321 
see  Vertebrates,  hypophysis 


Pituitrin,    see    Biological   remedies 
Placoid  scale,  134 
Plaice,  migration,  360 
Plague,  bubonic,  bacillus,  458 
control,  460-1 
and  fleas,  457-8 
ground   squirrels,   460-1 
history,  457 
and   rats,   457-61 
and  woodchi'.cks,  461 
see  Mouse ;  Rat,  parasites 
Plankton,    collection,    370    ct    seq. 
counting,  375-7 
l)ulses,   383 
relation  to  other  organisms,  372- 

373 
see  Illinois  River 
Plantain  weed,  see  Sex  intergrades 
Plant  Industry,  see  U.  S.  Bureau 
Plants,  alternation  of  generations, 
100-1 
aquatic,  overwintering,  382 
compared  with  animals,  297 
dispersal,   157-8 
distribution,    164,    et   seq. 
interrelation  with   aninuUs,   161; 

With  plants,  160 
introduction,  412,  et  seq. 
reactions,  307-11 
regeneration,  193 
societies,    158,    160 
stems,  unequal  growth,  ill.  310-1 
succession,  158-60 
see      Circulation;       Conduction; 
Pools,  temporary 
Plastic  Surgery,  197;   ill.  198 
Plato,   269 
I'lelstocene     epoch,     climate     and 

mamnuils,    143,    174 
Pleuroi)neumonia,    cattle,    inocula- 
tion, 447 
Pliny,  192,  320,  402 
Pliocene  epoch,  migration  of  mam- 
mals, 174 
Plunmge  laws,  422 
Pocket    gopher,    destruction,    400, 
402 
ill.  402 
Poke-weed,    influence    of    environ- 
ment,  222 
Polar   bear,  color,  338 
distribution,    172 
1raiisj)ort,     155 
ill.  169 
Pollen,  331  ;  see  Flowers,  reproduc- 

t  ion 
i'olychu'ta,    alternation    of    genera- 
tions,   100-1 
Polydactylism,  see  Man 


502 


Index 


Polyphemus  moth,  grafting,  196 
Polyzoa,     alternation     of     genera- 
tions,  101 
Pomeroy   family,   inheritance,   273- 

274 
Pools,  temporary,  life   of,   381-3 
Porcupine,   distribution,   174-5 
Porthesia,    response    to   light,    313- 

314 
Portuguese  man   of   war,   358 ;    ill. 

357 
Potato  bug,  see  Beetles 
Pound,    158 
Powers,  223,  224 

Prairie  dog,  182;  destruction,  400, 
402 
ill.,  181 
Preformation,   189 
Pribilof,  431 
Priestley,   283 
Princeton  College,   49 
Principle,   see   Vital 
Promethea  moth,  grafting,  19G 
Protective  color,  see  Color 
Proteid,  digestion,   energy   produc- 
tion, 296 
see  Diet 
Prothallus,  see  Ferns,  reproduction 
Protoplasm,  296-7 
analysis,  278 
chemistry,  207 
composition,  480 
structure,  480 
Protophyta,  89;   specialization,  94, 
95 
reproduction,  95,  et  seq. 
Protococcaeeae,  95 
Protozoa,   89 ;    alternation  of  gen- 
erations,  101-3 
colonial,   95 

compared  with  Metazoa,  201 
conjugation,  96 
fertilization,    96 
immortality,  200 
interrelation,  93-4 
mode   of   life,   92-3 
primitive  type,  95 
nervous    system,    306-7 
nucleus,   480 
organs,    92 

oxygen  requirement,  380 
related  to  disease,  440 
reproduction,  95,   96,   103 
shells,  92 

specialization,  90-4 
ill.  90-1 

see  Amoeba,  Paramcecium,  etc. 
Ptarmigan,  distribution,  color,  168 
ill.  166-7 


Pteranodon,  130 

Pterodactyls,  resemblance  to  birds, 

130-1 
structure,  129-31 
Pteropod,  352;    ooze,  353 
Ptolemies,    marriage    customs,    85 
Puberty,   325 
Public   Health   Laboratory,   N.   D., 

381 
Puerperal  fever,  444 
Puma,   distribution,  176 

transport,   155 
Puunett,  88 
Pure    lines,    selection,    236-7,    242- 

243 
ill.  237 
Ptyalin,    279 
Pyramid,  see  Lake 

E 

Rabbit,    damage,    396 
cottontail,  ill.  397 
jack,    damage,    destruction,    402 
Porto   Santo,   222-3 
see      Inheritance,       Eecognition 
marks,  Snowshoe 
Rabies,  spread  by  wolf  and  coyote, 

399 
Raccoon,  distribution,  176 
Race,   see   Species 
Radiolaria,  360;  fossils,  117 
ooze,   shells,   92 
ill.  352 
Radium,  see  Cancer,  Evening  prim- 
rose 
Rafinesque,  meets  Audubon,  28 
career,  30-1 
description,    28-30 
evolution,    30 
fossil  jellyfish,  30 
ill.  29 
Rana,  see  Frog 
Rand,  194 

Ranunculus,  see  Crowfoot 
Rat,  colony,  see  Wistar 
damage,  396-8 
diet,  292 
growth,  84 
inbreeding,  85 
introduction,  387 
nervous   system,   84 
parasites,  387 
sex  determination,   209 
spread,  153-5,  387 
ill.  399 

see  Cotton,  Hawks,  Hooded, 
Kangaroo,  Owls,  Plague, 
Rice 


Index 


503 


Eeactions,  see  Amoeba,  Bacteria, 
Compass  plant,  Crustacea, 
Daphnia,  Diaptomus,  Dros- 
era,  Flagellates,  Fundulus, 
Geotropism,  Heliotropism, 
Insects,  Mimosa,  Paramoe- 
cium.  Pigeon,  Plants,  Por- 
thesia,  Rheotropism,  Sten- 
tor,  Tropism,  Unicellular 

Realms,  see  Zoogeographic 

Recapitulation,  105 

Recessiveness,   258 

Recognition    marks,    342 

Red  cedar,   distribution,   176 

Red    Cross,    work,    476 

Red-eyed  Vireo,  migration,  spread, 
182 

Red  fox,   distribution,   174 

Reducing  division,  205-6,  215,  216 

Redwood,  see  Sequoia 

Reed,  J.  A.,  Senator,  quoted,  422 
W.,  Dr.,  451 
quoted,  452 
ill.  451 

Reese,  88;    quoted,  466 

Refractive  index,  see  Blood  serum 

Regeneration,    192-4,   480 

Reighard,   348 

Rejuvenation,  see  Protozoa,  con- 
jugation 

Religion,  see  Science 

Repair,  living  matter,  see  Metab- 
olism 

Reproduction,  asexual,  98 

characteristic    of   life,   282,   325, 

327 
non-life,   282,   327 
sexual,   98 

see  Algae,  Ferns,  Flowers,  Liver- 
worts, Mosses,  Paramoecium, 
Protophyta,   Protozoa 

Reptiles,  extinct,  125  et  seq. 
extinction,  127,  136 
spread,    154 
see  Sex  cells,   origin 

"Research  Methods  in  Ecology," 
158 

Resemblance,  see  Aggressive,  Al- 
luring 

Reservations,  see  Game 

Responses  of  life,  of  non-life,  282 

Resting  bodies,  animals,  plants, 
382 

Resting,  see  Sex  cycle,  daphnids 

Reversion,  see  Inheritance,  kinds 

Rhamphorhynchus,     130;     ill.     129 

Rhea,  distribution,  139 

Rheotropism,   roots,   308 


Rhumbler,    88 

Rhyncocephalia,  invariability,   121, 
ill.  121 
see  Tuatara 
Ribot,  quoted,  257 
Ribs,    see    Abdominal    Vertebrate, 

head 
Rice,  polished,  see  Beriberi 

rat,  distribution,  178 
Richardson,    31,    37 
Riddle,  232 
Ridgway,   44 

Ring -necked  pheasant,  411 
Ritter,  88,  quoted,  72-3 
Rockefeller,  Foundation,  466 
Hookworm  Commission,  467 
Institute   for   Medical   Research, 

73,   86,   448 
see  Hookworm  control 
Rock  thrush,  see  Sexual  selection 
Rocky  Mountain  goat,  distribution, 

174 
Rodents,  damage,  393  et  seq. 

destruction,  400,  402 
Rose-breasted  grosbeak,  color,  343 
Rotifer,  105,  381;  eggs,  382 

see  Sex   cycle 
Rotation    of    crops,    see    Nitrogen 

fixation 
Ruppia,  see  Ditch-grass 


S 


Saber-toothed   tiger,    see    Smilodon 
Sahara,    barrier,    254 
Salamander,  light  influence,  227 

see  Amblystoma,  Intercrossing 
Salmon,  canning,  data,  428-9 

catching,  427-8 

fecundity,  427,  430 

life   history,   426-7 

migration,    156,    360-1 

propagation,    429-31 

spawning,  427 

see  Sexual  selection 
Salton  Sea,  76-7 
Salvarsan  447 

Salvia,  ill.   331;   see  Insects,  rela- 
tion  to   riowers 
Sambon,   450 

Sand  hopper,  see  Orchestia 
San     Francisco,     Mountains,     life 

zones,   163   et   seq. 

profile,    163 

see  Plague 
Sargasso  Sea,  353 
Sargassum  weed,  353 


504 


Index 


Sargent,    67 
Say,   34 

San  Jose,  see  Scale 
Scab  mites,  409 

Scale,   insects,   391;    control,   405-6 
fluted,   405 
San  Jose,  ill.  403-6 
Scales,  see  Fish,  Placoid 
"Scalp  Act,"  Pennsylvania,  390 
Scarlet  Tanager,  color,  343 
molt    control,    225-6 
ill.  226 
Schmidt,    363 
Science  and  Religion,  45 
Scripps   Institution,   351 ;   location, 
71 
support,  work,  71-2 
Scudder,  43 

Scurvy,  cause,  prevention,  293 
Scorpions,  fossil,   124 
Scott,  W.  E.  D.,  reminiscences,  44, 
88 
quoted,  138,  140,  145,  174-5 
Screw  worm,  409 ;  ill.  408 
Sea  anemone,  see  Motility 
Sea  cucumber,  regeneration,  193 
Sea    island    cotton,    hybridization, 

268 
Sea-squirt,  see  Tunicates 
Sea  urchin,  artificial  parthenogene- 
sis, 329 
cross  fertilization,  328 
union   of   egg  and   sjterm,  327 
see  Intercrossing 
Seal,  controversy,  432-4 
destruction,  433 
discovery,  431 
distribution,    172 
killing,   433 
life  history,  432 
profits,   432 
ill.  433 
Sebright    poultry,    secondary    sex- 
ual characters,  325;   ill.  326 
Secondary  sexual  characters,  325 
Secretion,  see  Internal,  Sex  glands 
Sedgwick-Rafter   method,   376 
Seed,     chemical    treatment,    struc- 
ture, 245 
Segregation,  see  Inheritance 
Selection,   266,   330,   334;    natural, 
235-9 
see    Sexual 
Sensitive  plant,  see  Mimosa 
Sequoia,    climate,    77 

gigantea,  sempervirens,  distribu- 
tion, 184-5 
ill.  185 


Serum,  meningitis,   448-9 
tetanus,  449 

see     Anti-human,     Blood,     Diph- 
theria 
Sewellel,  distribution;  ill.  186 
Sex,  89;   beginnings,  96 
cells,   203-0 
origin,    471 
union,    327-8 
chromosomes,  see  Sex  determina- 
tion 
control,    232 
cycle,   bee,   230-31 
daphnids,  231 
rotifers,  231 
determination,  208-10,  228,  230-3 
see    Birds,    Crustacea,    Gephy- 
rea,  Orchestia 
differentiation,    97,    103 
function,   479 

glands  of  fish,  secretion,  361 
inheritance,  479 

intergrades,       Daphnia,       gypsy 
moth,   plantain   weed,   Sinio- 
cephalus,  233 
linked,  see  Linkage 
nematodes,  231-2 
organs,  see  Hydra,  Vaucheria 
origin,     471,     479;     see     tancer 

theories 
Protozoa,  96-8 
ratio,  see  Rat,  inbreeding 
see        Hormones,        Immorality, 
Secondary  sexual  characters 
Sexual    characters,   see    Secondary, 

selection,  343-6 
Shad,   migration,   156,    361 

propagation,  426 
Shagreen     denticles,     see     Sharks, 

scales 
Sharks,  as  food,  435 
fossil,    120 
Port  Jackson,  133 
scales,    120 
Sheep,   see   Ancon,   Merino,   Moun- 
tain 
Shells,  see  Diatoms,  Desmids,  Pro- 
tozoa 
Shrews,  see  Owls 
Shull,    A.    P.,    232 

G.    H.,   265 
Siamese  twins,  228 ;  ill.  229 
Sigsbee,   see   Sounding 
Silkworm,  see  Moth 
Silliman,  45,  50 
Silurian    period,   lungfish,   120 
"Silva   of   North  America,"   67 
Simocephalus,  see  Sex  intergrades 


Index 


505 


Skein,    see    Mitosis 

Skull,      see      Birds,      Cyclostomes, 

Head,  Vertebrates 
Skunk,  435;  distribution,  17G 

fur,  425 

warning  color,  ill.  339 
Sloth,  see  Giant,  Ground 
Slye,    472 
Smallpox,   inoculation,  442,  447 

Indians,  441 

Philippines,    441 

Phila.,   442 

Boston,    441-2 

N.  D.,  442-3 

see  Immunity,  Vaccination 
Smilodon,     distribution,     145 

extinction,  146 

prey,   146-7 

remains,  148 

structure,  145-6 
Smith,   A.   C,   450 
Smith,  L.   H.,   238 
Smithsonian      Institution,      estab- 
lished, 60 
Snake  venom,   see  Immunity 
Snail,     organ-forming     substances, 
191 

fossil,  124 

regeneration,    193 

see  Hawaiian,  Tahiti,  Cerion 
Snow-bunting,  distribution,  168 
Snowshoe  rabbit,  distribution,  174 

ill.  173 
Social  Hygiene  Board,  see  U.  S. 
Society,   see   American  Naturalists 

and  Geologists 
Societies,  see  Plants 
Solenhofen    quarries,    131 
Sonoran  zone,   176,   178 
Sounding  apparatus,  363-5 
Sparrows,  weed  destruction,  392 

tree,   392 

see  English,  Tree 
Spawning,  see  Salmon 
Species,  defined,  327 

and   geographic    races,    248 

elementary,  see  Mutation 
Sperm,  union  with  egg,  327-8 

see  Reproduction,  Spermatists 
Spermatists,    189 
Sphaerechinus,  giant  larva;,  192 
Spiders,    fossil,    124 
Spinal  cord,  see  Vertebrates,  struc- 
ture 
Spiracle,  see  Fish 
Spirifer,  constancy,  95 
Sponges,  Statoblasts,  382 

see   Motility 


Spores,  function,  see  Reproduction 
Sporophyto,  see  Reproduction 
Sporozoa,  93 
Sports,  see  Mutation 
Spruce,    distribution,    172 

see  Douglas 
Squid,  see  Octopus 
Squirrel,  transport,  155 

see    Ground 
St.   Hilaire,   235,    239 
Stag,   see  Sexual  selection 
Stamen,  see  Flowers,  reproduction 
Starch,  synthesis,  81,  297 

digestion,  279 

storage  in  plants,  299 
Starfish,  regeneration,   193 

see     Cross     fertilization,     Inter- 
crossing 
State  Board  of  Health,  see  Massa- 
chusetts 
Stations,  see  Biological 
Statoblasts,   see   Sponges,   Bryozoa 
Stegocephala,  121;  larvae,  124; 
ill.  123 

structure,    123-4 
Stegomyia,  188;  see  Mosquitoes 
Stegosaurus,    brain,    113,    127 

ill.  128 
Steller,    426,    431 
Stentor,   structure,    306 

reactions,  306-11 
Stereoisomers,   207-8 
Stereotropism,    ants,   316-7 
Sterilization  laws,  275-6 
Sternberg,   451 

Sternum,  see  Birds,  Pterodactyls 
Stigma,  see  Flowers,  reproduction 
Stiles,  466-7 

Stockard,  194,  227,  251-2 
Stomach,  ferment,  295 
Stone,  88 
Stout,  233 
Streeter,    84 
Struggle    for    existence,    90,    281, 

353 
Strychnin,  see  Crustacea,  light  re- 
sponse 
Stump   Lake,   N.   D.,   79 
Styles,    see    Flowers,    reproduction 
Stylonichia,  see  Morgan 
Sub-neural    gland,    see    Tunicates, 

structure 
Sugar,    81,    299 

cane,  see  Weevil 

conduction    in    plants,    299,  ' 

formed   from   starch,   279 

metabolism,  see  Pancreas 

synthesis,  81,  297 


506 


Index 


Summer  eggs,  382 
Sumner,    249-50,    333 
Sun  dew,   see  Drosera 
Sunfish,  358;  ill.  359 
Suprarenal,  see  Adrenal 
Survey,     U.     S.     Biological,     87; 
geolographical    distribution, 
162 

life  zones  of  N.  A.,  163  c<  seq. 

U.  S.  Geological,  38 
Surveys,   state,   37;    territories,   38 
Survival,  see  Selection 
Swainson,  31,  37 

Swamping  effect  of  crossing,  252 
Swarming,  bees,  317 
Swarms,   see   Animals,   aquatic 
Symbiosis,   see   Algae 
Syndactylism,  see  Man 
Synura,   odors   in   water,   378;    ill. 

378 
Syphilis,    diagnosis,    445-7 

extent,  444-5 

prevention,  446-7 

Wassermann  test,   445-7 

see  Blood  serum 


T 


Tahiti,    snails,    isolation,    environ- 
ment, 255-6 
Tanager,  see  Scarlet 
Tanner,  quoted,  156;  see  Sounding 
Tapeworm,   control,   464;    life   his- 
tory, 463-4 
Tar    pools,    contents,    148;    origin, 

147;   ill.  148-9 
Tarsier,  144-5;  ill.  144 
Tashiro,    318 
Taste,   see   Water 
Teeth,   bird,   embryo,   132 
fossil,  131-2 
crossopterygian,  123 
mammalian,    134 
Stegocephala,  123 
Temperature,  deep  sea;   see  Birds, 

Thermometers 
Tension  line,  see  Great  Plains 
Tern,    homing    instinct,    320;     see 

Arctic 
Terrapin,      diamond-back,      value, 

culture,   437 
Tetanus,  444,   448;   see   Serum 
Tevis,  413 

Texas  fever,  see  Tick 
Thayer,    348 


Thermometers,  deep  sea,  366-8 

Thespesius,    127 

Thinopus,     see     Amphibia,      foot- 
prints 

Thompson,  see  Kelvin 

Thought,    319,    325 

Thyroid   gland,   internal   secretion, 
320-3 

Thyroidin,  see  Biological  remedies 

Tick,  cattle,  life  history,  407-8 
control,  damage,  409 
ill.  408 

Tigers    and    marsupials,    186;    see 
Smilodon 

Tilefish,  destruction,  119 

Timberland  lawsuit,  see  Cowles 

Timberline,  172;  ill.  168 

Tissue  growth,  200-1;  ill.  199 

Titmice,  distribution,  177 

Tooth   enamel,   pattern;    see  Teeth 

Torry,  63,  65;   Botanical  Club,  65 

Tower,   81,   245-6,   249 

Tow-nets,  370;  ill.  371 

Townsend,   C.   H.,   63 

Townsend,  J.  K.,  34,  54 

Toxin,  diphtheria,  effect  on  brain, 
324 

Trachoma,    475 

Tracks,   see  Dinosaur 

Training  school  for  feeble-minded, 
see  New  Jersey 

Transition  zone,  175-6;  ill.  174 

Transpiration,   299 

Transjjort  of  animals,  see  Boa  con- 
strictor. Crocodile,  Mon- 
keys, Polar  bear,  Puma, 
Squirrel,    Wolves 

Trawling  apparatus,  363-4,  369- 
70;  ill.  369 

Tree-hopper,  see  Mimicry;  ill,  341 

Tree  sparrow,  see  Sparrow 

Trembley,  192,  194 

Trench  foot,  449;   fever,  449 

Treponema,  see  Syphilis 

Trial  and  error,  305-6 

Triassic  period,  mammals,  136 

Triceratops,  184;  brain,  127;  ill. 
128 

Trichina,  cause  of  disease,  461 
life    history,    461-3 
ill.  462 
see  Eat,  parasite 

Trichocysts,  94 

Trichodina,   92 

Trilobites,  age  of,  ill.  117 

Trochosphffira,  105 

Trochophore  larva,  105;  ancestral, 
106 


Index 


507 


Tropical  Eesearch  Station,  Zoologi- 
cal Society,  N.  Y.,  63 
Zone,   180 
Tropisni  theory,  309  et  seq. 
Tschermak,   203 
Tuatara,   133 

Tuberculosis,  409,  447;  sanitarium, 
477 
see  Blood   serum 
Tung  oil  tree,  415;  ill.  413-4 
Tunicates,    alternation    of    genera- 
tions,  100-1 
development,  100 
larva,   105 
mouth,  relation  to  Balanoglossus 

and  Vertebrates,  107 
structure,  100-1,  377 
see  Organ-forming 
"Tuscarora,"   364 
Twins,  see  Siamese;   Identical 
Tympanum,  see  Vertebrates,  struc- 
ture 
Typhoid,  475,  448;   see  Flies,  Im- 
munity, Vaccination 


U.   S.   Fish  Commission,  see  U.   S. 

Bureau  of  Fisheries 
U.  S.  Geological,  sec  Survey 
U.  S.   National  Museum,  building, 

60,   ill.    61 
collections,  39,  61 
founded,   44 
Avork,  61-2 
TJ.   S.   Navy,  ships,  349-50 
U.  S.   Public  Health  Service,  459, 

461,  466 
work,  474-7 
U.   S.   Social   Hygiene   Board,   476 
Unit    character,    see    Inheritance, 

Mendelian 
Universities,  State,  50 
University,  see  Buffalo,  Columbia, 

Johns     Hopkins,     Michigan, 

Pennsylvania,   Yale 
Upland   cotton,   hybridization,   268 
Urea,   end  product  of  metabolism, 

296 
Use  and  disuse,  see  Inheritance,  ac- 
quired characters 


U 


Udo,  414;  ill.  411-2 
Uintatherium,  142 ;  ill.  141 
Unicellular,  animals,  352,  378 
see  Protozoa 
organisms,  see  Plankton 
reactions,  306,  309 
plants,  378 ;  see  Protophyta 
U.  S.  Biological  Survey,  87 
collections,    61,    248 
established,    390 
work,    162    et   seq.,   347,   391    et 
seq.,  420,  423,  461 
U.    S.    Bureau    of    Animal    Indus- 
try,  87;   collections,  61 
work,  409,  464,  474 
U.  S.  Bureau  of  Entomology,  87; 
established,  405 
work,  405-7,  409 
U.  S.  Bureau  of  Fisheries,  87;  col- 
lections, 61 
vessels,    156,    350-1,    365,    482-3 
work,  350-1,  377,  426  ct  seq. 
U.    S.   Bureau   of    Plant   Industry, 
87;  collections,  61 
work,  412   et  seq. 
U.    S.    Bureau   of   Health,   Philip- 
pines, 441 
U.  S.  Coast  Survey,  349-50 
U.    S.    Exploring    Expedition,    see 
Wilkes 


Vaccination,   results,   441-2 

opposition,  442-3 

smallpox,  448 

typhoid,  448-9 
Vaccine,  influenza,  pneumonia,  476 

preparation,  474-5;   see  Biologi- 
cal remedies.  Smallpox 
Van  Beneden,   203 
Variation,  cause,  243  et  seq.,  478 

curve,  ill.  241 

fortuitous,    234 

influence     environment,     244     et 
seq. 

kinds,  242-3 

see  Geographic  races.  Selection 
Vaucheria,      sexual      reproduction, 

control,   233 
Vedalia,   406 
Velella,  flotation,  ill.  358 
Venereal  disease,  control,  476;  ex- 
tent, 444-5 
Vermin,  damage,  393   et  seq. 
Vertebrates,  embryos,  ill.  104 

ferments,  295 

head,   origin,    113-4 

hermaphroditic,    210 

hypophysis,   101 

jaws,  origin,  110-1 

limbs,  112 

mouth,  107,  110 


508 


Index 


Vertebrates,  nerve -inusclc  relation, 
115 
segmentation,    110 
strncture,    108,    110 
see       Aniphi])ians,       Aniphioxus, 
Balanoglossus,   Cladosclache, 
Cyclostonics,  I'^volution,  .la])- 
anese      pjoldfish,      Lungfish, 
Tnnicates 

A^i^ceroj  Initterflj,  342;  ill.  340 

Vireo,  see  Red-eyed 

Virus,    filterable,    481 

Vitalism,  278  et  seq.,  479 

Vital  principle,  188,  278,  283 

A'itamines,    293 

Volvocaceae,  95 

Volvox,      structure,      reproduction, 
97-8 

Volcanic,  see  Dust 

Voles,    see    Mice 

Vulture,  fossil,  135 

W 

Wagner,  252 

Walking  st^ck  insect,  337;    ill.  336 
Wallace,    155,    235,    330,    340 
Warning,  see  Color 
Wasps,   see   Mimicry 
Wasp,    solitary,   see   Ammophila 
Wassermann,  see  Syphilis 
Waste  products,  elimination,  322 
Water,    tastes,    odors,    378 
Water     bottles,     construction,     ill. 

368 
Water-cress,  382;    influence  of   en- 
vironment,  222 
Water   supplies,   examination,   377, 

477 
Water-weed,  382 
Water-works,      Boston,      Brooklyn, 

377 
Waters,  inland,  cyclic  changes,  379 
et   seq. 
food  relation,  plants  and  ani- 
mals, 383 
Watson,    320 

Weasel,  distribution,   174;   ill.   173 
Web-footed   chicken,   240 
Weevil,  sugar  cane,  407 
Weismann,   200,   202,   478;    experi- 
ments on  mice,  244-5 
Werber,  194,  227 
Whales,   and   squids,   358 
migration,    360 
stomach  contents,  377 
use,    434-5 
see  Whalebone 
Whalebone,  372-3;  ill.  373 


Wheel  animalcule,  see  Rotifer 

Whipple,    378 

Whitefish,    426 

Whitman,   314 

Whitney,    232-3 

Whooping   cough,   see   Imnnmity 

Wilder,    228 

Wild  pigeon,  extinct,  420 

William    and    Mary 's    College,    49 

Williams,  444 

Wilkes  exploring  expedition,  38,  39, 

54,   60,   349 
Willey,  88 

Wilson,  Alexander,  account  of  pas- 
senger pigeon,   23-4 
acquaintance  with  Bartram   and 

Lawson,  22 
"American     Ornithology,"     22, 

25 
birthplace,   22 
death,  22-3 
early  life,  22 

emigration   to   America,   22 
lines    to    the    bluebird,    24 
meeting  with  Audubon,  19 
travels,    22 
ill.  21 

see   ' '  Kentucky   Warbler, ' ' 
Wilson,  E.  B.,  88 
Wilson   E.   H.,   68 
Winnemucca,  see  Lake 
Wings,  sec  Birds 
Winter  eggs,  382;  see  Sex  cycle 
Wisconsin     Natural     History     and 

Geological   Survey,   377 
Wistar,  33,   84 
Wistar   Institute,    74;    established, 

84;    work,  84-6 
Wolf,  see   Giant 
Wolff,  189 
Wolverine,    distribution,    174;    ill., 

170 
Wolves  and  antelope,  421 
deer,    161 
damage,  393 
destruction,   400 
marsupials,    186 
transport,  155 
ill.  401 

see  Gray,  Rabies 
Woodchuck,  distribution,  168,  174; 
ill.  172 
see  Plague 
Woodland,     caribou,     distribution, 

174 
Woodruff,    200 

Woods  Hole,  see  Marine  Biological 
Laboratory 


Index 


509 


Worms,  oxygen  rcciiiircMiciit,  380 

Cf^gs,    382 

fossils,  117 

heniiuphroditic,   210 

larva,   105 

see   Screw 
Wright,  quoted,  37 


'^'ellow    fever,    e])i(leniic,    Havana, 
454 
Negro,    ininiuiiity,    see    Mosqui- 
toes, 447 

Yellow  ])ine,  distribution,   176 

Yellowstone  National  Park,  420-1 

Yolk  lobe,  sec  Dentalium 


Z 


X-ray,  see  Cancer 


Yale  University,  49,  50 
Yeast,  enzyme,  295 
Yellow  fever.  Commission,  188,  451 
control,  452-4 


Zone,     see     Canadian,     Hudsonian, 
Life,     Sonoran,    Transition, 
Tropical 
Zoogeographic     realms,     ill.     161-2 
Zoological  Gardens,  62 
Park,  U.  S.,  62 
Philadelphia,   62 
Society,    N.   Y.,    62-3 
Zoologists,  American  Society,  51 


i