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Full text of "Civic biology, a textbook of problems, local and national, that can be solved only by civic coƶperation"


PLATE I. A MAN-MADE PARADISE OR A MAN-MADE DESERT. WHICH? 



CIVIC BIOLOGY 

A TEXTBOOK OF PROBLEMS, LOCAL AND 

NATIONAL, THAT CAN BE SOLVED 

ONLY BY CIVIC COOPERATION 



BY 

CLIFTON F. HODGE, PH.D. 

PROFESSOR OF SOCIAL BIOLOGY IX THE UNIVERSITY OF OREGON 
AUTHOR OF "NATURE STUDY AND LIFE" 

AND 

JEAN DAWSON, PH.D. 

DEPARTMENT OF SANITATION, BOARD OF HEALTH, CLEVELAND 

FORMERLY OF MACDONALD COLLEGE, CANADA, AND CLEVELAND NORMAL 

SCHOOL; AUTHOR OF "THE BIOLOGY OF PHYSA " AND 

"BOYS AND GIRLS OF GARDEN CITY" 



It will teach only such uses of authority as 
are necessary to secure cooperation of several or 
many people to one end ; and the discipline it will 
advocate will be training in the development of 
cooperative good will. CHARLES W. ELIOT. 




GINN AND COMPANY 

BOSTON NEW YORK CHICAGO LONDON 
ATLANTA DALLAS - COLUMBUS SAN FRANCISCO 



COPYRIGHT, 1918, BY CLIFTON F. HODGE AND JEAN DAW8ON 

ENTERED AT STATIONERS' HALL 

-ALL RIGHTS RESERVED 

318.10 



gtftenaum 



GINN AND COMPANY PRO- 
PRIETORS BOSTON U.S.A. 



PREFACE 

Discovery is pushing forward in every direction as never 
before in the history of the world, and still it would seem 
that enough is already known to make living well-nigh ideal 
and the world almost a paradise, if only enough people knew. 
In how many of our civic units does every citizen know 
enough to conserve effectively the valuable bird life, the trees, 
the soil, and water on his own premises, to exterminate the 
rats and English sparrows, the flies, mosquitoes, and San Jose 
s-?ale, the hookworms, diphtheria, and tuberculosis germs ? If 
every individual citizen knows enough to do these things, 
iii how many communities do all the people know enough 
to cooperate, to work together with efforts so timed and 
planned that the good work of one, or of all but one, shall 
not be rendered vain by the failure of someone else to do 
his part? 

The tides and currents, storms and floods, of living nature 
are too vast and powerful to be held within any dikes less se- 
cure than those built by the common, united effort of the whole 
community. The measure of our present need is seen in the 
v/astage and loss that is streaming through our ineffectual 
ciefenses, the probably not less than five hundred thousand 
^ aluable lives sacrificed annually to the currents of prevent- 
able disease, along with the several billions of dollars' worth 
of foods and other property swept away by rats, insects, 
weeds, and fungi. How much higher must the cost of living 
soar before we begin to awake from the dream that we are 
a scientific and efficient people ? As we are now organized 



iv CIVIC BIOLOGY 

(or, rather, disorganized), who knows whether his next- 
door neighbors know what to do in solving common civic 
problems ? From the way they do and live he may conclude 
that they do not know, but they may all be passing the same 
judgment upon him. So, instead of each one doing his civic 
part, and knowing that the rest are doing theirs, we are 
caught at every turn in the do-less net of " what 's-the-use- 
ness." A would gladly protect his birds, but not to feed 
Mrs. B's cats. C could easily exterminate his own flies, but 
they continually swarm over from D's filthy premises. And 
so it goes for the thousand and one civic problems, at every 
turn the deadly question, " What 's the use ? " How can we 
extricate ourselves from this net? 

Cooperative good will is the essential idea in civic biology, 
as it is in the progress of civilization itself. This means that 
civic biology consists of all those problems whose solution 
requires cooperative effort. In the nature of the case we 
cannot control many of the forces of living nature by any 
amount of uncoordinated individual effort, any more than we 
can turn back the ocean tides by haphazard sweeping with 
brooms. The problem of civic biology, therefore, is to make 
it possible for everyone to know what these forces are, for 
good or for ill, and to understand how to do his part for his 
own good and for that of the community. Cooperative build- 
ing of the defenses offers our only hope of success, and our 
education needs to be so organized that every citizen shall 
know enough to stop a breach the instant he sees it. 

Acknowledgments in the text accompany pictures and 
other contributions, except in the following cases : The figures 
of ticks, in, Plate IV, are rearranged from those published 
by the United States Department of Agriculture and the 
United States Public Health Service. The upper view in the 
frontispiece is taken from a photograph looking northward 



PREFACE v 

down the Hood River valley, Oregon, across the gorge of the 
Columbia, with Mt. Adams in the background. It is used 
by the courtesy of the United States Reclamation Service. 
The lower view is from one of Bailey Willis's photographs of 
Shingkung, China, and shows desert conditions, man-made 
within the short space of about the last two centuries. With 
complete deforestation of the mountains, the once fertile 
valley has been buried under the wash of floods, which, 
alternating with burning droughts, have made the country 
uninhabitable. We are indebted for use of the print to 
the Carnegie and Smithsonian institutions. 

The idea of the book is expressed at a glance in the fron- 
tispiece, the question " Which ? " being applicable to every 
landscape and home in the world. 

C. F. H. 

J. D. 



CONTENTS 

CiAPTER 1AGE 

I. PLAN OF THE COURSE AS A WHOLE 1 

II. EQUIPMENT, APPARATUS, AND LIBRARY 10 

III. THE INSECT PROBLEM 18 

IV. BIRDS. 23 

V. METHODS OF BIRD STUDY AND SPECIAL PROBLEMS . '35 

VI. TREE STUDY AND Civic FORESTRY 55 

VII. PLANT PROBLEMS : PRESERVATION OF WILD FLOWERS, 
CONTROL OF WEEDS, MEDICINAL AND POISONOUS 

PLANTS 67 

VIII. HOME PLANTING AND LANDSCAPE GARDENING ... 77 
IX. PRACTICAL BIOLOGY OF AGRICULTURAL PRODUCTION 

AND Civic UTILIZATION OF LAND 91 

X. INSECT TYPE PROBLEMS : IMPORTANT FLIES .... 107 

XI. INSECT TYPE PROBLEMS : MOSQUITOES ...... 123 

XII. INSECT TYPE PROBLEMS : CABBAGE BUTTERFLY . . 136 

XIII. INSECT TYPE PROBLEMS : ANTS 141 

XIV. SPECIAL PROBLEMS OF INSECT CONTROL . . . . . 148 
XV. ARACHNIDS. PROBLEMS OF SPIDERS, MITES, AND TICKS 163 

XVI. AMERICAN MAMMAL PROBLEMS 169 

XVII. THE RAT PROBLEM 173 

XVIII. FUNGI : BACTERIA, YEASTS, MOLDS, MILDEWS, RUSTS, 

SMUTS, AND MUSHROOMS . 186 

XIX. FUNGI CONTINUED: MUSHROOMS, POISONOUS AND 

EDIBLE 200 

XX. FUNGOUS AND BACTERIAL DISEASES OF PLANTS . . 207 

XXI. BACTERIA 218 

XXII. BACTERIA CONTINUED : LABORATORY METHODS . . 224 



viii CIVIC BIOLOGY 

CHAPTER PAGE 

XXIII. CONTROL OF BACTERIAL DISEASES 231 

XXIV. CONTROL OF ANIMAL PARASITES 253 

XXV. Civic PROBLEMS RELATING TO MOLLUSKS . . . . 271 

XXVI. CRUSTACEA 285 

XXVII. PROBLEMS OF FISH AND FISHING 295 

XXVIII. AMPHIBIA : SIRENS, PROTEANS, SALAMANDERS, FROGS, 

TREE FROGS, AND TOADS, 313 

XXIX. REPTILES : CROCODILES, ALLIGATORS, TURTLES, TER- 
RAPINS, TORTOISES, LIZARDS^ SNAKES 321 

XXX. PRACTICAL LAWS OF LIFE 330 

XXXI. KNOWING How TO KNOW How 346 

XXXII. PROGRESS IN DISCOVERY . 355 

INDEX 363 



Working together will be one of its fundamental ideas, of men with 
God, of men with prophets, leaders, and teachers, of men with one another, 
of men's intelligence with the forces of nature. It will teach only such uses 
of authority as are necessary to secure cooperation of several or many peo- 
ple to one end ; and the discipline it will advocate will be training in the devel- 
opment of cooperative good will. ELIOT, ff Religion of the Future," p. 22 

Physical forces or the exhaustion of purely physical resources never have, 
and for at least five million years in the future, so the astronomers tell us, 
cannot extinguish human civilizations. Floods or volcanic eruptions may 
cause small and local effects ; while biological forces are oceanic, subtile, all- 
pervasive, continuously active, ever ready, whenever a break in the vital 
defenses of knowledge occurs, to surge in and obliterate individual, nation, 
civilization. Even the great movements of human races, conquests and wars, 
are not so all-annihilating in their effects as the ceaseless struggle of man- 
kind against other living species. Disease, pestilence, plague, and famine 
have taken their millions to war its scores. 

These forces are so powerful, so vast in their sweep, that for one individ- 
ual to attempt to cope with them is like Mrs. Partington trying to sweep 
back the ocean with her broom. Our education must be so organized that 
each may know and do his part. 

It is not labor, not capital, not land, that has created modern wealth or 
is creating it to-day. It is ideas that create wealth, and what is wanted is 
more ideas more uncovering of natural reservoirs, and less labor and 
capital and land per unit,of production. . . . 

Muscular effort can be stimulated by the lash intelligent supervision, 
intellectual production, never ! One single idea may have greater value than 
all the labor of all the men, animals, and engines for a century. The age of 
muscular human effort and of the lash is passing away, and the old morality 
with it : the age of supervision, of cooperative stimulus, is in full advance ; 
and with it comes a new morality, under which the Golden Rule can be ex- 
tended from the relations between individuals to those between classes, 
nationalities, and races. EMERSON, "Twelve Principles of Efficiency," 
pp. x and xi 



CIVIC BIOLOGY 

CHAPTER I 
PLAN OF THE COURSE AS A WHOLE 

Vfotto of the course : "That we may know enough to work together." 

United effort is the central idea in civic organization, and 
its extension underlies advance in civilization. Civic biology 
consists in that group of problems in the control of living 
nature to solve which requires that a community unite in 
working together intelligently. There is a large body of 
such problems which must be made a vital part in the edu- 
cation of every citizen, for in no other way can they ever 
be solved. 

We are suffering enormous losses, in destruction of nat- 
ural resources, in unfruitful labor, in damage to property, in 
preventable disease, due to lack of proper civic organiza- 
tion. One ignorant or careless member of a community may 
kindle a forest fire, or clear a watershed that will cause a 
water famine over an extensive territory. He may permit 
insects or vermin to breed, or allow fungi or bacteria to grow, 
that will cause great damage to property, and disease and even 
loss of life among his neighbors. 

It is a slight matter to extinguish a match or a camp fire ; 
it may require the strenuous efforts' of thousands to cope 
with a burning forest. So with every member of a commu- 
nity cooperating intelligently, slight effort may achieve great 
results, utterly impossible unless all work together. 

1 



2 CIVIC BIOLOGY 

As an illustration, take the case of the common rat. These 
animals are probably costing the country $500,000,000 annu- 
ally in spread of disease, in damage to buildings, merchandise, 
and produce, and in cost of traps, poisons, and labor; and 
since bubonic plague has gained a foothold in America, they 
positively must be exterminated. A single pair may breed 




FIG. 1. Rats, where they all belong 

1250 rats in a year. As we are now doing, Smith attempts to 
rid his premises of the pests in October, driving many of them 
over to Jones. Jones undertakes the work in November, driv- 
ing them back to Smith, and in December both are practically 
where they were before. The same amount of effort, properly 
coordinated, might have proved effective. This principle ap- 
plies with added force to larger groups, and it is quite possi- 
ble that with even less expense and labor than is now almost 



PLAN OF THE COUKSE AS A WHOLE 3 

wasted annually, the rat could be exterminated from the 
continent within a year or even within a single month. 

Civic organization applies not only to the control of injuri- 
ous forces, but equally to saving valuable species from exter- 
mination. Lacking such organization, a number of species of 
gieat value have already been exterminated from vast areas, 
arvd several more are in imminent danger. A few of these, 




FIG. 2. Virginia deer 
Photograph by George Shiras 

chiefly among our game birds and game and fur-bearing 
animals, will receive attention in the appropriate chapters. 

At best, among the great number of such problems, we shall 
b( able to study only a few typical ones that touch the life 
of the community most vitally. Three or four insect types 
are all we shall have time for, but thousands of others may 
b( studied by similar methods. The purpose of the course is 
tli us to cultivate habits of observation, insights into the work- 
ings of living nature, and, above all, civic ways of thinking and 
cine methods of studying and of attacking such problems ; and 



4 CIVIC BIOLOGY 

the highest product of the course will be citizens who know 
enough to work together. 

Select the problems that your community needs to have 
studied most. A single problem actually worked out to a 
definite civic advance will be worth more educationally than 
a hundred problems memorized from a book. 

With the school year arranged as it is, it will be neces- 
sary to start many different lines of work in the early fall. 
A store of material must be collected for use during the 
winter, and as far as possible this should be done by the 
class, to give practice in collecting, insight into problems, 
and at least glimpses of the various forms in their natural 
environment. 1 

In order to collect intelligently and plan and organize the 
work of the year, first run through the book rapidly and copy 
into a pocket notebook the names of all the birds, insects, 
fishes, trees, and so on, described in the text. Estimate im- 
portance of topics and leave required space for notes between 
the names ; page and make an alphabetical index at the back 
of the notebook. This gives a place where every observation 
made during the year may be recorded and referred to in- 
stantly when wanted. Indent margins, date and space so that 
each note shall stand out clearly. Records at the end of the 
year may read about as follows : 2 

White Pine (Pinus strobus) 

SEPT. 3. Noted on a trip into the country that the squirrels were 
cutting quantities of the cones from the tops of the pine 
trees and were feeding on the ripe seeds. The cones were 
closed and green, but the seeds were brown and ripe inside. 
Gathered nearly a bushel and spread on papers in the attic. 

1 This outdoor work is such a vital part of the course that careful record 
should be kept of all types collected, and this should be understood to form 
the basis for a definite percentage or part of the pupils' required standing. 

2 A field notebook with printed index and topics is being planned to 
accompany this course. 



PLA:N OF THE COUKSE AS A WHOLE 



JAN. 10. Found cones dry and wide open, with many of the seeds 
fallen out. Brought enough to laboratory to supply the class. 1 

FEB. 22. Planted in a flat, 10 by 15 inches, 3 inches deep, 200 seeds, 
with the wings intact. The flat was filled with leaf mold 
mixed with sand, and seeds were planted about \ inch deep. 

MARCH 15. Seeds beginning to germinate (Lab. Book, p. 77). 

APRIL 10. Made a seed bed according to directions in Forest 
Service Circular 67, and planted all the seed I had left. 
Transplanted seedlings not used in laboratory into this bed. 




FIG. 3. Type collection, white pine 

1 It is supposed that this pupil undertook to supply the class with speci- 
mens of the white pine, other members of the class doing the same for other 
tree ;. References to the laboratory book mean that on pages 77 and 78 will be 
four d drawings of the specimens, the leaf bundle, with possibly a sketch of 
a tn e, the cone, the cone scale with the seeds in place, the seedlings in two 
or three stages of germination, and finally the flowers. He will also be able 
to t( 11 the class about methods of collecting, storing, and planting the seeds. 



CIVIC BIOLOGY 

MAY 7. Buds beginning to shoot. Seedlings coming up thick. 

JUNE 8. Collected blossoms, staminate and pistillate, together 
with cones one year and two years old on same branches 
(Lab. Book, p. 78). 

Seedlings 3 inches high. Estimated that there are 5600 in my 
seed bed. 

The Humming Bird ( Trochilus colubris) 

SEPT. 6. Seen daily about cannas, nasturtiums, etc. 

SEPT. 12. Saw last birds, I think. One alighted for a moment 
on bare twig and flew south. 

OCT. 3. Found deserted nest while picking apples (Lab. Book, 
p. 14). 

MAY 14. First arrival seen this spring, and first reported in class. 

Grape (Delaware) 

SEPT. 9. Selected as specimen to study a Delaware planted by 
myself six years ago (Lab. Book, p. 42 ; sketch of vine, size 
of stock, area of trellis covered, drawing of cluster and leaf). 
Garnered grapes, 42 pounds in 12 minutes. 

Nov. 3. Pruned vine 15 minutes. Buried a bushel of bones about 
roots (Lab. Book, p. 43 ; diagram of vine after pruning). 

APRIL 27. Buds beginning to shoot. 

MAY 15. Placed a cane 6 feet long in trench 3 inches deep, for 
layers. 

JUNE 19. Blossoms open, new shoots about 2 feet long. 

Codling Moth ( Carpocapsa pomonella) 

SEPT. 21. Examined 100 apples and found 92 worm-eaten. 
Found 15 larvae in the apples ; the rest had completed their 
growth and gone. Where did they go ? 

SEPT. 22. In one hour's search, scraping apple bark, found 163 
larvae in their cocoons under the bark scales. They must 
have gone there when they left the apples. 

Nov. 28. Observed a downy woodpecker at work on apple tree. 
From 8 to 8:15. saw him drill into 5 bark scales and remove 



PLAN OF THE COURSE AS A WHOLE 7 

the larvae. Climbed up and secured the punctured scales for 
my collection. At this rate how many might a woodpecker 
eat in a year ? Wish I could follow him and discover how 
many he actually destroys in a day. Put marrow bones and 
suet in the apple trees to attract woodpeckers to the orchard. 

DKC. 6. Refer to Lab. Book, p. 41 (sketch of larva, etc.). 

APRIL 12. Hunted one hour again for larvae ; found only 8, but 
have observed the woodpeckers working on the trees all 
winter, and counted 179 punctured bark scales from which 
the larvae had been removed. Those found were still in the 
larval stage. 

MAY 15. Apple trees in bloom. Hunted one-half hour; found 
1 larva and 2 pupae (Lab. Book, p. 42). 

JUNE 11. Apples about the size of marbles. 8 P.M., hung a lan- 
tern in a tree where apples were thickest. Caught a moth 
in act of laying an egg on an apple. As I raised my net to 
catch another, a bat flitted by and snapped it. Tried to 
catch bat but he was too quick for me. 

The main laboratory for this course is the out-of-doors, 
the yard, garden and orchard, streets and roadsides, pastures, 
fields, woods, streams, lakes, hills, and swamps. Thousands 
of interesting things are happening out there all the while, and 
it is there the student must go if he would really learn his 
lessons. With definite assignments of what to seek or to study 
and observe, most of this field work should be done either 
singly or in small groups of two or three. In addition to 
this there should be individual problem-working and lesson- 
learning for discussion and demonstration of the more general 
'problems, such as the study of habitats ; the struggle for life 
as seen in a dense woods ; the distribution of a number of 
the types studied in the course ; migration of birds ; recog- 
nition of trees, birds, common plants. A number of special 
field trips also should be arranged. The success or failure of 
these will depend upon the teacher's knowledge of the locality 



8 CIVIC BIOLOGY 

and of the times and seasons for the appropriate lesson. 1 The 
course supposes at least seven field excursions : two in the 
fall, for general outlines ; one in dead winter, for recognition 
of trees, study of animal tracks and doings, winter birds, 
hiding places of insects ; and four in the early and late spring. 
In these excursions plan to take in a model dairy, vineyard, 
orchard, nursery, tuberculosis sanitarium, fish hatchery, bird 
sanctuary, or other local institutions of interest. 

Fall is the most favorable season of the school year in which 
to study insects and to begin the study of birds. The largest 
share of the time usually spent in " learning " lessons out of 
books or in the indoor laboratory will be devoted to collect- 
ing and studying specimens out of doors. Hunt particularly 
for the species required by the course. There are so many 
thousands of different insect species that you will soon find 
yourself bewildered and discouraged if you try to study 
them all. Any insect of special importance in your locality, 
however, may be substituted for those in the 'course, if de- 
sired. Collect, so far as possible, the complete story of the 
life and work of each species, eggs, larvse, pupae and adults 
(male and female), injured fruit, eaten leaves, stings, galls, 
and the like. 

While working over the ground for insects it will require 
but little additional time to collect the materials for several 
other lines of work to be done in the laboratory during the 
winter. Among the more important will be : 

Leaves and fruits of forest trees. 
Fruits and seeds of common plants. 
Weeds and their seeds. 

Common mushrooms and tree-destroying fungi. 

As many as possible of the parasitic fungi described in the text, 
mildews, blights, rusts, and smuts. 

1 It will often be necessary for the teacher to keep careful watch and go 
over the ground himself the day before a general field trip. 



FLAN OF THE COURSE AS A WHOLE 9 

Deserted birds' nests for study of nesting sites, and analysis of mate- 
rials. Attach a label to each nest, stating locality and position, kind of 
tref, distance from ground, etc. 

Fresh-water clams and snails, with duckweed, milfoil, stonewort, 
and other aquatic plants common to the locality, for use in stocking 
aquaria during the winter. 

Fronds of all the common ferns, fruiting and sterile. These should 
be pressed between sheets of paper and preserved dry. 

The ants' nests must be stocked as early as possible, and may be 
maintained through the winter. 

It is not advisable to try to keep frogs, salamanders, newts, turtles, 
snakes, or many fishes in the laboratory during the winter, since their 
noimal period of hibernation will be interfered with and they are not 
likrly to do well. These may all be collected and studied to better 
ad\antage in the spring. 

In general, the order of chapters follows that indicated 
above: insects and birds with beginning plant lessons in the 
fall; fungi, bacteria, and animal parasites for indoor work 
du i-ing the winter ; fishes and amphibia in early spring ; and 
the emphasis on plants with the completion of bird and insect 
studies in the latei* spring months. A natural conclusion of 
th( course is supplied by a brief statement of the principles 
and laws of life with an outlook toward the biological organ- 
ization of the nation. At best, with so many interests weav- 
ing a continuous pattern through the changing life of the year, 
the text will need to be used as a reference book rather than 
as a series of consecutive lessons. 




CHAPTER II 
EQUIPMENT, APPARATUS, AND LIBRARY 

Laboratory outfit. Equipment for the more special problems 
will be described in appropriate chapters, but there are a few 
general needs which should be understood at the outset. First 
of all, the course demands more than usual individual storage 
room for students' material. Each student should have not 
less than 6 square feet of shelf, closet, or locker space. This 
will be supplied by a simple wall case 1 foot wide, 18 inches 
deep, and 3 feet tall, with three shelves about 9 inches apart. 
The student must be given time to label and store his speci- 
mens neatly, since any appearance of "rubbish" about the 
laboratory is likely to prove fatal to the morale of the whole 
course". 

The laboratory should be provided with at least two good- 
sized aquaria and two vivaria. A convenient size for all of 
these is 24 inches long, 12 inches wide, and 15 or 18 inches 
deep. They may all be made according to directions given 
below for aquaria and then be used either as aquaria or viva- 
ria. Each student should have also a small aquarium, about 
12 inches deep, 10 inches long, and 6 inches wide, which 
may -be used nearly dry, for insect-rearing cases; moist, for 
salamanders, toads, frogs, and tree frogs ; or filled with water, 
for fishes and other aquatic animals and plants. By partially 
filling such aquaria with loam, sawdust, or sphagnum, covering 
the outside closely with black paper, tilting slightly, and plant- 
ing different seeds close against the glass, they may serve for 
interesting demonstrations in germination and the development 
of root systems. 

10 



EQUIPMENT, APPARATUS, AND LIBRARY 11 

Individual apparatus. In addition, the outfit of each stu- 
de it should contain the following: one insect net, one small 
sciim net for collecting in water, one cyanide bottle, one 
paper of assorted insect pins, one dozen insect-mounting cases 
(assorted sizes), and two notebooks (one pocket size for field 
noi;es and data of field collections, the other larger, unruled, 




FIG. 4. Making insect nets 

for laboratory notes and drawings). These should be paged 
and indexed for quick reference from one to the other. 

A vital feature of the course is the making of simple appa- 
ratus by the students themselves. Since time in the fall is so 
precious for outdoor work, the necessary apparatus should be 
provided to begin with, but after the first year it should be 
made by the previous class; that is, each class should take 
a tarn at making apparatus during the winter in order that 
the laboratory IE ly be well equipped for the work of the fol- 
lowing autumn. Since it is to be hoped that the students will 



12 CIVIC BIOLOGY 

continue the study after the course is completed, it would be 
well if each could be given the chance to make at least the 
two collecting nets and a small aquarium for himself. 

Materials for making the nets. Flat-drawn spring brass or tinned steel 
wire for the frames for the air and water nets respectively ; the strong- 
est cotton tape (mill tape, such as is used in wrapping electric wires, 




FIG. 5. Easy construction of insect net 
1, form of wire frame ; 2, slipping net on frame ; 3, net bound to handle with twine 

is good) ; then for the air nets, strong bobinet, light cheesecloth, or 
mosquito netting, according to preference. Mosquito netting, if the 
threads which cross run the long way of the net and care is observed 
to avoid water and briars, makes a fairly serviceable insect net. For 
the water nets use cotton scrim. There are several ways of making the 
nets, but for nets detachable from the handles the writer has found the 
method shown in Fig. 5 most serviceable. 

Materials for aquaria. The aquaria may be made for little more than 
cost of glass, the materials being : 



EQUIPMENT, APPARATUS, AND LIBRARY 13 

Glass. Double-thick window glass for sides and ends, and ribbed 
skylight glass for bottom for sizes above 20 x 10 x 12 inches. 
For smaller sizes, waste 10 x 12 in. negatives are good and 
cost little or nothing. 

Angle or valley tin, sizes indicated below. 

Aquarium cement. 

Solder. 

Green or black carriage paint and a little spar varnish. 




FIG. 6. Making aquaria 

From left to right, laying the cement; glass set in one, with bent green twigs 

to hold it in place ; painting frames, and frames of different sizes, 5x7x4 to 

24x15x10; cutting the angle tin to measure; soldering the frame held in a 

square fastened to table 

Tools. Every laboratory should be provided with a few simple tools, 
an ong which the following will be required in making aquaria : 

Carpenter's square, to hold the frame perfectly square at each 
an^'le while it is being soldered. A three-way square, made by nailing 
two 5-inch boards of convenient length at exact right angles and fasten- 
ing them to a work table, greatly facilitates getting each angle right at 
th< first trial. 



14 



CIVIC BIOLOGY 



Tinsmith's snips and square-nosed pincers, for cutting and bending 
the angle tin. 

A soldering outfit, soldering iron and fluid or resin, and some safe 
and convenient means of heating the iron. 

If the tools are not at hand, the frames may be made at the tinsmith's ; 
or often a handy janitor can make them in his shop, or a good-natured 
one may let the boys use his tools, if they are very careful to leave every 
tool in its place and the shop in better order than they find it. 

Dimensions for the frames are given in the table below. " Three- 
cross"" tin is heavy enough for all smaller sizes, and "four-cross" for 





FIG. 7. Showing relations of frames, cement, and glass in aquaria, 
of different sizes 

a, for the larger sizes; b, for smaller sizes; c, arrangement at top and cover. 
Black lines, metal ; flashed areas, glass ; dotted surface, cement 

aquaria between 15 arid 24 inches in length. The more slender the 
frame the trimmer and better the aquarium appears. For aquaria-dimen- 
sions in inches : 

5 x 7xlto8xlQx 5 : use f-inch angle tin. 
10 x 12 x 6 to 8 x 10 x 5 : use -inch angle tin. 
15 x 12 x 8 to 18 xlo x 9 : use f-inch angle tin. 
20 x 12 x 9 to 24 x 18 x 12 : use 1-inch angle tin (around base, 

and if the work is carefully done, f-inch, or even -|-inch, is 

strong enough for the rest). 

Fig. 7 gives the relation of cement to the angle tin and the glass for 
large and small sizes. In the larger sizes the strip of glass, with the 



EQUIPMENT, APPARATUS, AND LIBRARY 15 

orism of cement behind it, strengthens the angle and also protects the 
Abater from a large surface of cement, which might yield up enough of 
its lead to injure delicate animals. 

Lids may be made either of perforated tin, with the edges turned over 
to stiffen them, or of wire screen fastened to either wooden or tin frames. 
The lids will be needed when the aquaria are used as insect-breeding 
cages and for feeding tests with toads, frogs, or other insectivorous ani- 
mals. The hinges of brass or tin should be soldered to the frames when 
they are made. These points are sufficiently illustrated in Fig. 7. 

Aquarium cement. The formula used by the United States Fish Com- 
] nission is : by weight 6 parts whiting, 1 part red lead, 1 part litharge ; 
mix thoroughly while dry, and as required for use make into a stiff 
putty with pure linseed oil. The oil must be free from any trace of 
adulteration with fish oil, or the "cement is likely to remain soft and 
sticky. Do not expect the cement to "set" hard. If.it did this, the 
expansion and contraction, under changes of temperature of metal and 
glass with which it is associated, would be likely to crack either the 
glass or the cement. It should remain as a tough gum, solid enough to 
support the pressure of water and pliable enough to accommodate 
itself to changes of temperature. 

Lay the right amount of cement in all the angles of the frame with 
a putty or case knife, and press the glass for bottom, sides, and ends 
into place in the order named ; smooth all joints on the inside, removing 
h-ny extra cement ; spring pliable green twigs against the sides and ends 
1o hold them in place, and smooth up the outside joints. It is prefer- 
able to paint the frame, letting the paint dry well, before setting the 
^lass. A coat of spar varnish along the angles on the inside will protect 
the cement from contact with the water and also insure against leaks. 
Leaks seldom occur, but if they do, mark them, dry the aquarium 
thoroughly, press a little cement into the cracks, and give another 
coat of spar varnish to the inside corners. After drying for a week, the 
is ready to use. 



NOTE. It is easier to avoid daubs of cement than to clean them off the 
glass. The same applies to hands, clothes, tables, floors, and everything else. 
A class in aquarium-making can easily daub themselves and the laboratory 
s ) as to disgust all concerned with the work ; or, by the use of a few news- 
papers, can avoid all this to the satisfaction of everybody. Since the cement 
contains lead, it is better not to let it come into contact with the skin more 
than is necessary. Stir, mix, and lay it with proper tools. 



16 CIVIC BIOLOGY 

THE LABORATORY BOOKSHELF 
(The asterisk indicates books of special importance for this course) 

Nothing so inspires to good work on a subject as knowledge of what is already 
known about it ; hence this reference bookshelf is the vital basis of the whole 
course. The present list is intended to be merely suggestive, and should be freely 
modified to suit local problems and diligently kept up to date. On every subject 
you study obtain the latest word from the extension department of your state 
university, your agricultural experiment station, the United States Department of 
Agriculture, Bureau of Education, Bureau of Fisheries, Smithsonian Institution, 
and local, state, and national health departments. 

Insects, etc. 

DOANE. Insects and Disease. MITCHELL. Mosquito Life. 

EMERTON. Common Spiders. *SAUXI>EKS. Insects Injurious to 

HOLLAND. Butterfly Book. Fruits. 

HOLLAND. Moth Book. S< i DDER. Everyday Butterflies. 

HOWARD. The House Fly Disease *SMITII. Our Insect Friends and 

Carrier. Enemies. 

*KELLO(!(.J. American Insects. 

Biwfo 

*BAILEY. Handbook of Birds of the Western Bird Guide (for west of 

Western United States. the Rocky Mountains). 

CHAPMAN. Handbook of Birds of *TRAFTON. Methods of Attracting 

Eastern North America. Birds. 

*REED. Bird Guides. Parti, Water WEED and DEARBORN. Birds in their 

and Game. Part II, Land and Song. Relation to Man. 

Trees Forestry 
*AFUAR. Trees of the Northern SARGENT. Manual of the Trees of 

United States. North America. 

*GREEN. Principles of American 
Forestry. 

General Botany 

*BKKGEN and DAVIS. Principles of *OSTERHOLT. Experiments with 

Botany. Plants. 

HKITTON and BROWN. Illustrated *STEVENS. Illustrated Guide to 

Flora of Northern United States. Flowering Plants. 
*GRAY. New Manual of Botany. 

Fungi 

ATKINSON. Mushrooms. * JORDAN. General Bacteriology. 

*CONN. Bacteria, Yeasts, and Molds MC!LVAINE and MACADAM. One 

in the Home. Thousand American Fungi. 

*DCGGAR. Fungous Diseases of RUSSELL and HASTINGS. Experi- 

Plants. mental Dairy Bacteriology. 
GOKHAM. A Laboratory Course in 

Bacteriology. 



THE LABORATORY BOOKSHELF 17 

Agriculture 

*BURKETT, STEVENS, and HILL. * HOPKINS. Soil Fertility and Pel-- 
Agriculture for Beginners. manent Agriculture. 

Cyclopedia of American Agriculture. *KING. Farmers of Forty Centuries. 

Vol. I, Farms. *PLUMB. Types and Breeds of Farm 

*Vol. II, Crops. Animals. 

* Vol. Ill, Animals. WILKINSON. Practical Agriculture. 
Vol. IV, Farms and the Commu- 
nity. 

Animals General Zoology 

*LINVILLE and KELLEY. General SHALER. Domesticated Animals. 
Zoology. 

Fishes 

* JORDAN and EVERMANN. American * United States Fish Commission. 
Food and Game Fishes. Manual of Fish Culture. 



Miscellaneous 

*ALLEN. Civics and Health. *HODGE. Nature Study and Life. 1 

DARWIN. Earthworms. *HORNADAY. American Natural 
<DARWIN. Naturalist's Voyage History. 

around the World. LUBBOCK. Ants, Bees, and Wasps. 
*DAVENPORT. Principles of Breed- f Shrubs. 

ing. XKWHALL. 4 Trees. 
DICKERSON. Frog Book. [ Vines. 

DITMARS. Reptile Book. WALLACE. Malay Archipelago. 

GIBSON. Sharp Eyes. . WHEELER. Ants. 



Journals 

Agricultural Department publica- * American Forestry. 

tions. * American Journal of Public Health. 

*Experiment Station Record. *Bird Lore. 

*Monthly List of Publications. *Journal of Economic Entomology. 

* Weekly News Letter. *Journal of Heredity. 

*,Tournal of Agricultural Research. *School Science and Mathematics. 



1 f ' Civic Biology " presupposes a knowledge of the problems stated in this 
took. 



CHAPTER III 
THE INSECT PROBLEM 

Work of insects in nature. Geologically the present is 
known as the age of man, but zoologically it is the age of 
insects. There is but one species of man, Homo sapiens, 
while over 300,000 species of insects have been described, and 
it is estimated that in all there are not fewer than 10,000,000 
species in the world. The number of individuals of any one 
species may cover the forests and fields or even darken the 
skies over large areas. 

Compared with other animals insects are small, having 
developed, instead of size, refinement of mechanism and organ- 
ization and great reproductive power. This latter often sur- 
passes belief, but since it shows us the importance of natural 
checks to the increase of insects, it must form one of the 
central features of our insect lessons. A pair of San Jose 
scales could produce progeny in a season to the number of 
3,216,080,400. A single female plant louse might give origin 
to 9,500,000,000,000 in a season (Forbes). The house flies of 
a city, if all the young survived and could find food, would 
bury it before the people could escape (Jordan). We are led 
from these facts to see the importance of insectivorous animals ; 
for example, it has been estimated that the birds of Nebraska 
consume daily 86,000 bushels of insects during the warm 
months (B runner). 

No insects are used for food by civilized man, and it is 
remarkable that in so great a number of species so few pro- 
duce anything of value to man. Silk, honey and beeswax, 
shellac and cochineal, and cantharides virtually complete the 

18 



THE INSECT PKOBLKM 19 

list of important products. Many insects are of great value to 
man indirectly, because they destroy other insects. The great- 
est service, however, which they perform in nature consists in 
effecting cross-pollination of flowers, and many of our most 
valuable fruits and flowers would be infertile without their 
aid. Fortunately the honeybee is the most valuable insect for 
this work. 

In contrast to the value of these few insects, however, is 
the great injury done by others in their attacks upon man and 
animals, causing annoyance, suffering, and often disease. The 
majority feed upon plants and thus compete with man, directly 
or indirectly, for the vegetable food supply of the world. Re- 
cent estimates of the Department of Agriculture divide this 
damage as follows : 

ANNUAL Loss OF AGRICULTURAL PRODUCTS CAUSED BY INSECTS 
IN UNITED STATES 

Cereals $23 7,800,000 

Hay .......... ..." 66,000,000 

Cotton ............ 67,500,000 

Tobacco 6,900,000 

Truck crops . 68,000,000 

Sugars 6,400,000 

Fruits ............ 66,000,000 

Farm Forests 15,000,000 

Miscellaneous crops 18,900,000 

Animal products 267,000,000 

Natural forest products 130,000,000 

Products in storage 100,000,000 

Total $1,049,500,000 

These estimates are conservative and relate to purely agri- 
cultural losses. They do not include the damage caused by 
common household insects, clothes moths, carpet beetles, 
roaches, ants, and several human parasites, which entail great 
labor and expense in fighting them. The annual cost of wire 



20 -CIVIC BIOLOGY 

screen to keep flies and mosquitoes out of houses amounts to 
at least $12,500,000 annually. Nor does the above estimate 
take account of the depreciation of property, loss of time, and 
cost of diseases like malaria or yellow fever, known to be car- 
ried by certain mosquitoes, infantile paralysis, carried by the 
stable fly, and typhoid, cholera inf an turn, dysentery, and many 
other filth infections which are transmitted by common house 
flies. With these additions it is safe to say that insects annu- 
ally levy a tax of not less than $1,500,000,000 on the people 
of this country, and this in addition to the annoyance and 
suffering which they cause to human and animal life. 

Work for control of insects. Since insects possess such power 
of rapid increase, and since this increase is limited mainly by 
food supply, natural enemies, and artificial means of destruc- 
tion, any relaxation of natural or artificial checks tends to 
permit insects to increase up to the limit of food supply. With 
these checks entirely removed, insects would take practically 
the entire agricultural product in an incredibly short time. 

The relative efficiency of natural and artificial checks is 
well exemplified by a number of cases in which an insect has 
been accidentally introduced from some other continent with- 
out bringing the natural enemies of the species. The cottony 
cushion scale of Australia swept over the orange groves of 
California like a consuming fire until its natural enemy, the 
Vedalia lady beetle, was imported. The gypsy and brown- 
tailed moths in Massachusetts show even more clearly how 
ineffectual human effort is when pitted against such forces of 
nature. After expenditure of several millions of dollars and 
twenty years of futile effort we are brought to realize that our 
best hope of permanent success lies in the importation of 
natural insect enemies. The San Jose scale, accidentally in- 
troduced from China, is now rapidly exterminating fruit 
orchards and ornamental trees over almost the entire country. 
In 1901, Dr. Marlatt succeeded in importing a Chinese lady 



THE INSECT PKOJBLEM. '21 

beetle (Chilochorus similis), which is efficient in keeping the 
scale in check in its native home. It has not as yet proved, 
however, an equal success in America. 

Other cases in point are the Hessian fly, cabbage butterfly, 
codling moth, elm-leaf beetle, imported currant fly, and many 
more ; and these illustrate the almost irresistible power of an 
insect species when supplied with abundant food and relieved 
from its natural enemies. They also emphasize the need of 
watching all ports of entry with extreme care to prevent such 
e xpensive importations. 

All work with insect enemies reveals the absolute necessity 
of the general dissemination of a knowledge of the problems 
involved. One ignorant or careless importation may cost the 
\t hole country irreparable loss. A neglected garden or orchard 
is often a menace to an entire neighborhood. For one indi- 
vidual to try to hold such natural forces in check is discour- 
aging and well-nigh hopeless. In the successful handling of 
such problems all members of a community must unite. Each 
must know and do his duty and his part. If one person can- 
not or will not prevent his trees from breeding insect pests 
that damage his neighbors, he should promptly cut them down 
and burn them up. This law of nature applies with special 
force to the intelligent protection of birds and other insec- 
tivorous animals, in which all members of the community 
should unite. 




FIG. 8, Orders of American birds, with habitats 

22 



CHAPTER IV 

BIRDS 

In the air swallows and swifts are coursing rapidly to and fro, ever in 
pursuit of insects, which constitute their sole food. When they retire, the 
nighthawks and whip-poor-wills will take up the chase, catching moths and 
other nocturnal insects which would escape day-flying birds. The flycatchers 
lie in wait, darting from ambush at passing prey, and with a suggestive 
cli< k of the bill, returning to their post. The warblers, light, active crea- 
tures, flutter about the terminal foliage, and with almost the skill of a hum- 
ming bird, pick insects from leaf or blossom. The vireos patiently explore 
the undersides of leaves and odd nooks and corners to see that no skulker 
escapes. The woodpeckers, nuthatches, and creepers attend to the tree 
trunks and limbs, examining carefully each inch of bark for insects' eggs 
and larvae, or excavating for the ants and borers they hear at work within. 
On the ground the hunt is continued by the thrushes, sparrows, and other 
bir Is, who feed upon the innumerable forms of terrestrial insects. Few 
places in which insects exist are neglected ; even some species which pass 
their earlier stages or entire lives in the water are preyed upon by aquatic 
bir Is. CHAPMAN, "Bird Life," p. 6 

As planned for this course, bird study begins with the open- 
ing of school in September and continues throughout the 
year. No subject better repays attention. On the esthetic side 
it presents infinite possibilities for the discovery of beauty in 
gnice of form and action, in harmony of color, and in variety 
of song. From the standpoint of science and pure natural 
history, no field is richer, variety in size and form, instincts 
and intelligence, protective and recognitional coloring, geo- 
graphical distribution, pathways of migration, and even the 
ge< >logical record showing the evolution of birds from reptiles. 

Birds and insect destruction. In order that universal and 
adequate protection may be extended to all valuable species, 
evory member of the nation should know what the birds are 



24 CIVIC BIOLOGY 

doing for the common good. From an earlier chapter we have 
learned of the enormous tax which insects impose. The chief 
economic service of birds consists in the destruction of insect 
pests, and our national bill of insect damage, $1,049,500,000, 
may be roughly taken as a measure of our deficiency in bird life. 

Reed estimates that with 5 birds to the acre and 100 
insects daily per bird, the birds of Massachusetts require for 
food each day during five months of the year, 2,560,000,000 
insects; or, allowing 120,000 insects per bushel, 21,000 bushels. 
The work of winter birds and migrants, he thinks, amounts to 
nearly half this number for the colder months, in destruction 
of hibernating insects and eggs, larvae and pupae. A chickadee 
has been known to eat from 500 to 4000 eggs in a single day. 

For Nebraska, Professor Lawrence Brunner's estimate is as 
follows : 

Taking as a basis for our estimations the figures given in my leaflet 
entitled A Plea for tlte Protection of Our Birds, we would have about 
75,000,000 birds, or approximately 35,000,000 to 40,000,000 pairs that 
nest here (Nebraska). Should each pair of this large number rear four 
young, there would be required a sufficient food supply for from 140,- 
000,000 to 160,000,000 young birds. If, as we suggested in that paper, 
a single bird requires on an average 25 insects per day, the enormous 
number of 4,000,000,000 insects, or 35,000 bushels of 120,000 insects, 
would be required each day to feed the young birds alone. But young 
birds need much more food than do old ones, and we should at least 
double this quantity for the young birds. Then to this must be added 
that required by the parent .birds themselves while taking care of the 
young, making a grand total of 86,000 bushels, or 107 carloads of 20 
tons each, provided we allow 50 pounds as the weight of a bushel. 

Feeding tests and the actual observation of birds from 
daylight to dark have given us our most valuable data with 
reference to the destruction of insects by birds. 

A female wood pewee from 4.30 A.M. to 6.52 P.M. was seen to catch 
568 insects. A brooding bird of the same species from 4.46 A.M. to 6 P.M. 
caught 208. The first was feeding her nest ; the second merely catch- 
ing for herself. 



BIRDS 



2o 



A pair of house wrens were observed to feed their nest of five young 
five days old 230 insects, most of them large cabbage caterpillars; 
ti-ne, 4.24 A.M. to 7.38 P.M. 

A pair of orchard orioles, from 4.30 A.M. to 6.10 P.M., were observed 
to feed the nest, containing two nearly full-fledged young, 01) times, 
probably several insects at a feeding. 

A pair of phoebes, from 4.20 A.M. to 7.12 P.M., fed two young 206 
times. A young phoebe just out of the nest required as high as 200 
gc od-sized grasshoppers per day. 1 

A young robin about three weeks old ate 70 large cutworms on one 
day, and two and a half ounces of earthworms the next. A young scar- 
ier tanager ate 150 cabbage caterpillars, besides other food, in a day. 
.V cuckoo on 
the tenth day 
at<^ 42 grass- 
hoppers, 00 
woolly cater- 
pillars, and 30 
cabbage cat- 
erpillars. On 
th<> twentieth 
day the same 
bird consumed 
62 woolly cat- 
erpillars, 123 
cal >bage cater- 
pi liars, and 4 3 
grasshoppers, 




FIG. 9. Bobwhite chick three weeks old. Usual occupation 
Photograph by the author 

amounting to three ounces of food. An adult cuckoo ate 225 cabbage 
caterpillars, or 150 large woolly caterpillars, amounting to about five 
ounces of food daily. (From feeding tests by Andrew J. Redinon.) 

From such actual data as these we learn that the estimates given 
alve are conservative. Much more accurate observation is required, 
however, before entirely reliable estimates can be made. 

Outdoor laboratory work. This should extend throughout 
the year, and also to combine problems requiring continuous 

1 All the above data are taken from reports of students of the Indiana 
Ui iversity Summer School, Winona Lake, Indiana, for 1905 and 1906 
(O P. Bellinger in charge of cl 



26 CIVIC BIOLOGY 

observations upon birds, insects, trees, fungi, weeds, native 
flowers, and common plants, elaborate the following plan as 
early in the year as possible. Let two students combine upon 
the same tract of land, in order to secure greater completeness 
of the practical work, but each should make his own field charts 
in as careful detail as if he were working the tract alone. 

Select some readily accessible piece of land of limited area. 
On a farm, the home lot with the dooryard, garden, orchard, 
and grove will be most suitable. The village lot of an acre or 
two is exactly adapted to this work. In an open city the home 
lot, if well planted, may prove the best selection we can make, 
but probably the residential block in which the home stands 
will provide necessary variety and scope. For the crowded 
city we must have recourse to public parks and gardens, and 
to accessible tracts in the suburbs, for the study of which defi- 
nite permission can be obtained. The tract should present, if 
possible, a variety of natural features, hill, meadow, ravine, 
brook or edge of pond, and especially variety in plant forms, 
- lawn, garden, orchard, field, meadow, woods. A variety of 
shrubbery and low-growing trees makes a tract preferable to 
one with very tall trees, which are difficult and unsatisfactory 
to work. By properly dividing the neighborhood among the 
class, however, all the important features of the locality may 
be covered, and this will add interest and completeness to the 
work as a whole. 

As a preliminary, draw an outline map to convenient scale, 
and with due regard to points of the compass. Within this, 
first sketch in standard contour lines and indicate location of 
water, marsh, swamp, rock outcrops, and all buildings and 
superficial subdivisions, lawns, gardens, orchards, fields, 
pastures, woods. 

We are now ready to plot the details. Count and locate all 
the trees, vines, and shrubs, and indicate clearly the areas cov- 
ered by different plants or crops. Locate all birds' nests and 




FIG. 10. An ideal bird-study tract 
27 



28 CIVIC BIOLOGY 

determine the species as far as possible, indicating them by 
some device, like the initial letter of the name, on the plat. 
This work should be completed as soon as possible after the 
leaves fall in November. By inquhy it may be possible to 
locate nests that have been " collected " or destroyed by storms 
during the summer. This will give a " census " of the bird 
population of the tract. 

The main question which this investigation is designed to 
answer is, Are there enough birds in the area to hold the 
insects in check ? To aid in answering this question examine 
the district minutely for evidences of insect depredations, and 
make a list of important insect pests found upon it. Examine 
at least 100 of each variety of apple, pear, quince, possibly 
peach and plum, and tabulate the percentage of the different 
fruits injured by insects. Gather similar data, if possible, for 
the earlier fruits, strawberries, gooseberries, currants, and 
also for the. various garden vegetables and other crops grown 
in the tract. Add to the bill of damage the cost of materials, 
apparatus, and labor expended in righting insects. On the 
other side of the balance sheet record with equal care any 
injury caused by birds. Note what kind of birds caused the 
damage. 

From all you know and can learn of bird life try to discover 
what special features attract the birds to nest on the tract, 
water, food, suitable nesting sites and materials. Suitable 
and accessible water for drinking and bathing will be found 
to be one of the main factors, and food supply and absence 
of enemies, other elements. Never lose an opportunity to see 
what a bird is doing, what it is searching and finding for food. 
Clear observation on this point seldom fails to answer the 
question, Why is the bird here ? 

Study with equal care all the elements which can account 
for a scarcity of birds or the absence of particular species. 
What necessities of bird life are lacking? What natural 



BIRDS 



29 



tnemies of the different 
species are present ? Much 
of this side of the prob- 
lem will be worked out 
i aturally in connection 
with nesting habits, the 
study of nest building, 
and the fate of the differ- 
ent nests in the spring. 

Pay particular attention 
to the bird-food plants of 
the area with reference to 
abundance of food at dif- 
ferent seasons. Note the 
condition in this respect 
for the different months. 
Is the area stripped of 
available food by the time 
robins and bluebirds have 
migrated in the fall ? May 
this help to explain bird 
migrations? 

Note in detail what pro- 
visions have been made in 
your district to supply the 
necessaries of bird life, 
bird houses, drinking and 
bathing fountains, plant- 
ing of food trees. What 
ii- done to protect the birds 

from enemies ? What in- 

,11,1 in cement with deep chinks filled with soil 

tiuence have these provi- and planted with ^ osse ^ fen ^ and wild 

sions exerted on the bird flowers 

population as compared Photograph by the author 




* Ri - 



fountain. Natural rocks laid 



30 



CIVIC BIOLOGY 



with neighboring districts in which no such provisions are 
made ? What is the practical value of such work as shown 
by your account of insect injury ? of losses caused by birds ? 
Other important lines of bird work relate to destruction of 
weed seeds and the control by owls, hawks, and shrikes of nox- 
ious mammals, mice, moles, rats, gophers, etc. Keep these 
matters in mind throughout the year while doing the field work. 




FIG. 12. Bird house for study of home life ; windowpane is back wall of house 
Photograph by the author 

The birds in your district will change during different sea- 
sons. During the fall migration the " summer residents " will 
leave for the south, and many species whose breeding range is 
farther north will migrate through the territory. These species 
may be designated as "transient visitants." They migrate by 
us to the northward in the spring and southward in the fall. 
After settled cold weather begins there will be left the " per- 
manent residents," about thirty-six species for the latitude 



BIRDS 31 

ol New York (Chapman), and " winter visitants," seventeen 
species of birds that come from the north and spend part or 
all the winter. 

Make provision for the winter birds. Suet and a piece of 
fat pork may be tied to a branch of a tree, with a tray also 
fastened to the trunk, in which seeds (millet, corn, sunflower, 
pumpkin, or squash) and cracked nuts (butternuts are espe- 
cially good) may be kept, and on the ground close by a pile 
oi chaff or loft sweepings. The purpose of this is to attract 
all the winter birds within range of easy observation. The 
tray may be attached to the living-room window sill, if on the 
south side of the house, an attractive branch may be fastened 
at the side of the window, and the heap of chaff may be put 
under it, close to the house. This latter must be kept free 
from snow through the winter. 

The work of the year is intended to yield a complete pic- 
ture of the life and work of the birds in your district. At 
stated intervals your observations should be carefully written 
up under various heads. We suggest the following : 

SEPTEMBER My Bird Study Tract (giving chart and descriptions 
oi natural features). 

OCTOBER To what Extent do Birds prevent Insect Depreda- 
tions? 

NOVEMBER The Fall Migration of Birds. 

DECEMBER Winter Provision for Birds, Permanent Residents 
a] id Winter Visitants. 

FEBRUARY The Work of our Winter Birds. 

MARCH My Plans for Bird Work this Spring. 

APRIL Birds' Nests ; Nest Building; Nesting Sites of Different 
Species; Materials. 

MAY Bird Songs and Notes, and what they mean. 

MAY Feeding Habits of Birds. 

MAY My Observations on Feeding of Young; Amount of Insect 
Food. 

JUNE Summary and Results of my Bird Study for the Year. 



32 CIVIC BIOLOGY 

Other more general topics, like the following, are suitable as 
assignments for different members of the class to work out and 
report upon toward the close of the year : 

The English Sparrow in the Locality may be subdivided into : 1V- 

lations to JSTative Birds ; Damage caused by; Methods of Extermination. 

The Life and Work of the Bluebird. (Substitute the name of any 
other common bird, if desired. It would be well if each member of tin- 
class could devote special attention to working up the life of some 
important species.) 

By a free interchange of notes these reports may be made 
more complete, and in this way each is made the summary of 
the work of the whole class upon the topic. We may vary and 
enliven the reports by casting them in the form of debates 
about bird problems that are in dispute in the neighborhood. 
For example : 

Resolved, that the robin merits protection. (Substitute other birds.) 

Resolved, that the crow should be exterminated. 

Resolved, that there should be a bounty on hawks and owls. 

Resolved, that the bobwhite should be placed on the protected list for 
a period of ten years. 

Resolved, that spring shooting of waterfowl ought to be prohibited 
by law in all states. 

Resolved, that active measures be taken to establish a preserve for 
the breeding of grouse and waterfowl in this township. 

Resolved, that it is better policy to preserve native species than t<> 
import grouse from other countries. 

Resolved, that the killing of song and insectivorous birds for milli- 
nery purposes is legitimate. 

Resolved, that a person who allows his cats to kill birds should be 
subject to the same fine as if he killed them himself. 

Resolved, that a law be passed making owners of cats responsible for 
the birds they kill. 

Resolved, that it is an unwarranted waste of bird life to make egg 
collections. 

This list might be extended indefinitely. 
Birds are divided popularly into " soft-billed," eating mainly 
worms, insects, and berries ; and " hard-billed," feeding upon 




33 



34 CIVIC BIOLOGY 

seeds. Both classes, however, feed the young mainly on in- 
sects. Our gardens, fields, and roadsides are weedy enough, 
but who can imagine what they would be, were not thousands 
of tons of weed seeds destroyed annually by the sparrows, 
bobwhites, doves, larks, blackbirds, and others. About fifty 
species of birds are efficient weed destroyers. Compare and 
draw a few typical hard and soft bills to fix this distinction. 
Beal has estimated that the tree sparrows alone in the state of 
Iowa destroy annually about 875 tons of weed seed. Are both 
weeds and seed-eating birds abundant in your bird tract ? 

Hawks, owls, and shrikes render service in destroying noxious 
mammals. Are the mice, rats, field-mice, or gophers numerous 
in your district, and what amount of damage do they cause 
by eating grain or girdling trees ? Dr. C. Hart Merriam has 
estimated that a bounty act on hawks and owls, during its 
operation in Pennsylvania for a year and a half, cost the state 
not less than $4,000,000. 

The accompanying food chart shows about all we know of 
the foods of many of our commonest species. The blank 
squares in the chart indicate generally deficiencies in observa- 
tion, and not that any particular bird does not eat any par- 
ticular insect ; hence they are in reality the most interesting 
part of the chart because they suggest further study. Observe 
the birds in your district, or, if you have a young or disabled 
bird, make definite feeding tests and record the results in your 
food chart. The chart will thus enable you to feed intelligently 
many birds that come to hand, and also to add to our knowl- 
edge of the subject. The probable diet of any bird not named 
on the chart may be judged from that of its near relatives. 1 

1 The authors would be grateful if those who make such feeding tests 
would send them any data secured. 



CHAPTER V 
METHODS OF BIRD STUDY AND SPECIAL PROBLEMS 

I have no doubt, therefore, that the wild pigeon is still with us, and that 
if protected we may yet see them in something like their numbers of thirty 
years ago. JOHN BURROUGHS, 1906 

In order to do the work outlined in the last chapter we 
must know the birds. It is supposed that practical acquaint- 
ance with the commoner species has been begun in the nature 
study of the grades. The present course is planned as an " ad- 
vanced," and, so far as school life is concerned, a final year of 
bird study, which shall organize and complete previous knowl- 
edge, work out more thoroughly as practical problems the 
values and uses of different species, and help to answer the 
question, "How may a community make the most of its bird 
lite ? " If we are to have intelligent progress, every one must 
know these things, because the ignorance of one may vitiate 
the best efforts of a community. 

After completing plans for individual bird-study tracts, dis- 
cuss in the class what species merit a place in the year's 
course. Each member may present a list including his choices, 
and from these the official list for the year may be selected. 
The lists should be changed somewhat from year to year, as 
c< editions change and emphasis is shifted from one to another 
group of problems. 

In this connection, as well as in the general problem of 
organizing our knowledge of birds, scientific classification is 
o:l: great assistance. Scientific books have described for the 
\Norld 12,500 species of birds, and of this number 768 belong 
to North America. This large number of species means that 

35 




II 

ill 



I I! 



I 



'5 t: 



METHODS OF BIRD STt'DY 



37 



birds have become differentiated to fit all sorts of environments, 
air, water, marsh, prairie, and forest. Those of similar activi- 
ties, like machines built and adjusted to their work, have come 
to have similar structures, of bod)', wing, foot, and bill. 
Discovery of these adjustments will add fresh interest at every 
turn and increase respect for scientific bird study. Fig. 8 is 
designed to fix in mind the fundamental relations of the dif- 
feient orders to environment. Common names often vary in 



Primary Covert 
Greater Coverti 




Middle Coverts 

Lesser Coverts < 

i ula or Spurious Wing^ 

Crown 
Median Lin 



Tail Coverts 

Rump 

Back 



Lore 

Superciliary Line 
Far Coverts or Auricular* 



Scapiilars 
Wing Bars 
Shoulder 
Tibia 
Tarsus 



Fi<;. 15. Topography of a bird 
C. A. Ree.l 

different parts of the same country. Scientific names are the 
same for all languages the world over, and this is the time to 
learn them, if they are ever to be remembered. 

/Vgain, in order to describe birds quickly and accurately - 
an-. I as a help to seeing them properly we must learn to 
naiiie the external parts, the so-called "topography " of a bird. 
Tl e terms in Fig. 1 5 are, in the main, self-explanatory. The 
" primaries," " secondaries," and " tertials " are attached respec 
tiv ely to the hand, fore-arm, and upper-arm bones of the wing. 

The following list, suited to central New England, is given 
im-rely by way of suggestion, as if the writer were a member 



38 CIVIC BIOLOGY 

of the class. Several species not now found in the territory 
are included because they are related to problems which every 
intelligent member of the nation ought to be helping to solve. 
Order Pygopodes ("rump-footed") diving birds. The birds 
of this group enliven our waters, and the loons give us some 
weird music. While anglers may object to sharing the fish 
with them, the main question is whether we prefer to see 
them on our ponds and lakes or on the ladies' hats. The two 
common species within our territory are : 

Pied-billed grebe Podilymbus podiceps. 
Loon ; great northern diver Gdcia imber. 

Order Longipennes ("long- winged") gulls, terns, etc. The 
gulls and terns have required active protection in recent 
years to prevent their extermination by the egglers and plume 
hunters. What would our seascapes be without them ? The 
protection which has been accorded these birds is one of the 
most encouraging signs that values other than mercenary are 
beginning to be appreciated. Aside from their beauty, these 
birds are much-needed scavengers of our harbors and coasts, 
and the inland species are most efficient destroyers of insects. 
Two common types are : 

Herring gull Ldrus argentdtus. 
Common tern Sterna hirundo. 

Order Anseres (anser, "a goose") ducks, geese, swans. The 
problem of our waterfowl is nearing its final stage. 1 The vast 
breeding grounds in the Northwest are now open to sports- 
men and settlers, and when the wild fowl have been extermi- 
nated from these-, as they have been from their more southern 
ranges, the work of destruction will be complete and final. 
It is high time this is appreciated as a national problem, and 
effective measures taken toward its solution. The first step, 

1 See H. K. Job, Country Life in America, April, 1906. 



METHODS OF BIRD STUDY 39 

it seems clear, should be total prohibition of spring shooting 
from Florida, the Gulf, and Mexico to the Arctic Ocean. 

Next, we should offer, for a period of years at least, com- 
plete protection and every inducement for all birds of this 
order to breed throughout the United States, wherever a pond, 
marsh, or lake can be guaranteed as a safe and permanent 
" preserve." All kinds of waterfowl quickly learn where they 
are safe, and if unmolested become tame and breed in great 
numbers even in small ponds. Is there a chance for a preserve 
in the neighborhood ? The wood duck is already on the verge 
of extinction and should be absolutely protected in every 
state. Nests discovered in the neighborhood should be guarded 
from disturbance. In New England, for a term of years, let the 
broods go unmolested even in open season on the chance that 
more may return to breed the following spring. On the mur- 
derous and stupid principle, " If I don't shoot it, some one 
eke will," the last wood duck will fall to the ground and the 
raee of our most exquisite waterfowl be extinct. Extermina- 
tion of a valuable species is not only a national calamity, but 
a national crime, a piece of monumental stupidity and folly 
as well. Let us change the above principle to read, "If I 
have the decency and sense to spare, some one else may." To 
the problem of increasing and protecting our waterfowl and 
reJ Establishing them throughout their native breeding ranges 
sh mid be brought the best energies of the class. All members 
of the order should be considered in the light gained from a 
sti idy of the following types : 

W< >od duck A ix sponsa. Mallard duck Anas platyrhynclios. 

Pintail Ddjila acuta. Whistling swan Olor columbidnus. 

Canada goose Brdnta canadensis. Trumpeter swan Olor buccinator. 

Order Herodiones (herodios, "a heron") herons, storks, etc. 
These birds of our marshes and swamps are mainly of aesthetic 
im erest and value, and although they eat a few fishes, frogs, and 



40 CIVIC BIOLOGY 

snakes, they are, on account of this value, accorded the protec- 
tion of the law in Massachusetts. As examples we may take : 

Night heron Nycticorax ndvius a generally common species. 

Snowy egret Egretta candidissima a Southern species, but one 
which ought to be known to every American North and South, in 
order to save it from extermination by the milliners. 

Order Limicote (limits, "mud"; colere, "to dwell") shore 
birds. Many of these birds of our marshes and muddy shores, 
wet brook beds, and upland pastures, merit protection on ac- 
count of their valuable service as insect destroyers, and also 
because of the imminent danger of extermination in which 
several of the best species stand. The argument given for the 
wood duck applies with more than double force to the wood- 
cock, because the former produces from eight to fourteen eggs 
to the woodcock's four. The same preserves would serve for 
the waterfowl and shore birds as well. Several of the plover are 
in great need of protection, but the five species that follow 
are possibly all we can, begin with, and will serve to illustrate 
the problems of the group: 

Woodcock Phildhela minor. Spotted sandpiper A c.tilis macttldrta. 

Wilson snipe Gallindgo delicdta. Eskimo curlew Numeniu* boreal!*. 

( I olden plover Charddrius dominicus. 

Order Gallirue (gallus, "a cock") grouse, pheasants. The 
problem in regard to all the birds of this order is again that of 
protecting those that remain, and of reestablishing in their 
original ranges such species as have already been exterminated 
from certain regions. Were it not for stray and uncontrolled 
cats we could make town and city parks in fact, the limits 
of all villages, towns, and even cities preserves for grouse 
and waterfowl. We could in this way place them where the 
greatest number might enjoy seeing and hearing them ; while 
a constant supply would overflow the preserve limits for our 
sportsmen. Special problems occur with each of the five follow- 
ing types suggested for study. 







FIG. 1(>. Ruffed grouse cock strutting 







FIG. 17. Bobwhite cock caring for brood of fifteen chicks which he 

incubated and hatched 

Photograph by the author 

41 



42 



CIVIC BIOLOGY 



Bobwhite Colinus virginidnus. This species, if sufficiently abun- 
dant, could probably become our most important insect- and weed-seed- 
destroying ground bird for garden and field. The crop of one bird 
contained 101 potato beetles, another two tablespoonfuls of chinch 
bugs, and another 15,000 weed seeds. Winter protection and feeding 
is another problem which should receive attention. 

Ruffed grouse Bondsa umbellus. Wherever at all scarce, this finest 

of our game birds should be provided 
.with safe covers which will insure 
~its increase in the locality. 

Heath hen Tympanuchus cupidn. 
This specie's presents the problem of 
a numerous and valuable game bird, 
once generally distributed over New 
England and now reduced to a few 
pair confined to the oak barrens of 
Marthas Vineyard. It is a slightly 
variant woods form of the Western 
prairie chicken, which is rapidly 
being exterminated from the Missis- 
sippi Valley. Every effort should be 
made to save this remnant, and with 
it restock the mainland under condi- 
tions which shall insure the heath 
hen's regaining its original range. 

Mongolian or ring-necked pheas- 
ant Phasidnus torqudtus. This is 
an introduced species, concerning the 
value of which there is much ques- 
tion at present. 

Wild turkey Meledgris gallopdvo. As far as New England is con- 
cerned we must write the word ** exterminated " after the name of this 
our largest game bird. By concerted action, and with a suitable game 
preserve, might the wild turkey not be reintroduced ? Would it not be 
worth while ? 

Order Columb& (columba, "a dove")- The pigeons and doves 
the world over are among our most valuable food and game 
birds. The dodo of Mauritius and the solitaire of Rodriguez 
were gigantic ground pigeons as large as swans, but with wings 




FIG. 18. Ruffed grouse cock 

drumming 
Photograph by the author 



METHODS OF BIRD STUDY 43 

too small for flight. The last record of the dodo was in 1681. 
Both of these remarkable species were unwittingly extermi- 
nated by the introduction into the islands of hogs, which de- 
stroyed their eggs and young. 

There are in North America ten genera and seventeen 
species and varieties of pigeons and doves. Most of these are 
Western and Southern. The two named below suggest most 
in portant problems for eastern North America. For the Rocky 




Fia. 19. Egg of passenger pigeon, on black velvet, in nest of mourning dove 

The pigeon laid only one egg, about \\ inches long; the dove, two eggs about 
1 inch long. This figure thus furnishes a decisive means of distinguishing the two 
species. Photograph from specimens in the American Museum of Natural History 

M ountain and Pacific States" the types studied should be the 
b^nd-tailed pigeon, Columba fascidta, from British Columbia 
to Mexico; Viosca's pigeon, C.f. vitiscce, southern Lower Cali- 
fornia; and the red-billed pigeon, C. flavirfotris. 

Passenger pigeon Ectopistes migratdrius. This most valuable of 
N'>rth American pigeons existed less than forty years ago in flocks 
which stretched from horizon to horizon. It is now a serious .question 
whether the last living specimen has not been seen. 



44 



CIVIC BIOLOGY 



(For three years past rewards aggregating over $8000 for discovery 
and report of undisturbed nesting pairs or colonies of passenger pigeons, 
anywhere in North America, have remained unclaimed, and no tangible 
evidence has been received of pigeons killed or even seen during this 
time. This is commonly accepted as proving the species extinct in the 
wild state. One old bird still survives in the Cincinnati Zoological Gar- 
den. If nesting pigeons are ever found, they should be most carefully 
safeguarded, and all protective agencies, private, state, and national, be 

focused on their preservation 
and increase.) 

Mourning dove Zenal- 
f/iira macroura caroiinensis, 
Every effort is now bt'ing 
made to save this species in 
New England. It is abun- 
dant in the South and Middle 
West. 




FIG. 20. Youno red-shouldered hawks 



Order Raptores (raptor, 
" a robber ") hawks, 
eagles, owls. The luiwks 
and owls furnish perhaps 
the most complicated and 
difficult problem con- 
nected with our bird life. 
By many of the best authorities the majority are accounted 
among outmost valuable birds, on account of the great num- 
bers of noxious mammals field mice, gophers, rats, etc. 
which they destroy. Most of the hawks, too, feed largely on 
insects when they are abundant, and take comparatively few 
birds, either tame or wild. In determining the value of birds 
in this class, however, it is always an open question whether 
the few insectivorous birds, which may form only 1 or 2 per 
cent of the hawk's total food, if allowed to live, might not 
have done much more valuable work than the sum total of the 
predacious species. We must leave questions of this kind to 
be worked out from practical experience and observation. 



METHODS OF BIRD STUDY 45 

When depredations 011 the poultry yard or disturbance 
among small birds is marked, it is all but certain that either a 
sharp-shinned or a Cooper's hawk is causing all the mischief. 
These two, of the commoner hawks, feed almost exclusively 
on other birds and bring practically all the popular ill-repute 
upon the rest of the family. In addition to these, the Amer- 
ican goshawk, a Canadian species which enters the Northern 
States in winter, feeds largely on game and poultry ; and the 
rarer duck hawk, seldom seen far from the coast or larger 
waterways, feeds chiefly on waterfowl. 

Some authorities are inclined to maintain that the smaller 
species, sparrow and pigeon hawks, may prove useful in towns 
and cities in destroying English sparrows. This is a good 
problem to assign, if some of these birds are known to nest 
in the neighborhood. In the only case known to the author a 
pair of sparrow hawks which nested on one of the buildings 
of the Worcester Polytechnic Institute had finally to be shot 
on account of serious inroads upon the valuable bird life of 
the campus. Common types are : 

Marsh hawk Ctrcns hudsonias. 

Sharp-shinned hawk Accipiter t'c'fo.r. 

Cooper's hawk Accipiter cooper i. 

American goshawk Astur <ifric<i/'/ln. 

Red-tailed hawk Buteo boredlis. 

Red-shouldered hawk Buteo linedtus. 

Bald eagle Haliceetus leucocephalus. 

Duck hawk Fdlco pereyrinus dnatiun. 

Pigeon hawk Fdlco columbarium. 

Sparrow hawk Fdlco sparveriu*. 

American osprev, or fish hawk P and ion halkeetus carolinensis. 

Screech owl Otus dsio. 

Great horned owl Bubo virginidnus. 

Order Coccyges (coccyx, "a cuckoo"). These are among our 
most valuable birds as destroyers of hairy caterpillars, and on 



46 



CIVIC BIOLOGY 



this account they should be universally protected. The order 
contains the cuckoos and kingfishers. Types are : 

Yellow-billed cuckoo Coccyzus americdnus. 

Black-billed cuckoo Coccyzus erylhroplithdlmus. 

Belted kingfisher Ce'ryle dlcyon. This is an interesting bird, and 

we need not generally be- 
grudge it the minnows which 
it takes. About fish hatcher- 
ies and trout streams, how- 
ever, it is in general disfavor. 

Order Pici (picus, " a 
woodpecker"). The wood- 
peckers are in general of 
great value as destroyers 
of orchard and forest in- 
sects. The sapsucker is 
generally considered an 
injurious bird, and should 
be clearly distinguished 
from the valuable spe- 
cies which it resembles, 




FIG. 21. Ruby-throat, nest and young 
Photograph by E. E. Evans 



and which may sometimes visit its sap holes. We should 
study the following common species: 

Hairy woodpecker Dryobates villdsus. 

Downy woodpecker Dryobates pubescens. 

Sapsucker Sphyrapicus vdrius. 

Red-headed woodpecker Melanerpes erythrocephalus. 

Flicker Coldptes aurdtus. 

Order Macrochires (makros, "long"; cheir, "hand"). The first 
three of the types given below are among our most valuable 
insectivorous birds, catching, as they do, both day- and night- 
flying insects. The humming bird feeds upon minute insects 
and spiders, and also largely upon the nectar of flowers and 
the sap of trees (from the holes of sapsuckers). It is most 



METHODS OF BIRD STUDY 



47 



easily tamed, and may be fed on honey and water, half and half, 
with plant lice and spiders. All should be familiar with the: 

Whippoorwill Antrostomus vociferus. 
Nighthawk Chordeiles virginidnus. 
Chimney swift Chcetura peldgica. 
Ruby-throated humming bird Archilochus colubris. 

Order Passeres (passer, " a sparrow ") perching birds. In this 
largest order, which contains more than half the species to be 
studied, the family names will be of assistance in distinguish- 
ing the various groups. 

Family Tyrannidcz flycatchers. Types>: 

Kingbird Tyrdnnus tyrdnnus. 
Crested flycatcher Myidrchus crimtus. 
Phoebe Sayornis pJuxbe. 
Wood pewee Myidchanes virens. 
Least flycatcher Empidonax minimus. 

Almost the entire food of this group, as the name indicates, is 
insects, and stomach examinations have proved that the insects taken 
are mainly injurious. From the common habit of watching from a 
conspicuous perch and flitting 
out to catch insects as they 
PC..SS, the flycatchers are most 
interesting birds to study, espe- 
cially in ascertaining exactly 
h< >w many insects a bird may 
catch within a given time. A 
laboratory period devoted to 
si ch work will instill a higher 
appreciation of the value of 
bird life than will any other 
lesson in the course. 

The only question as to 
the value of the group refers 
to the kingbird and its de- 
st-uction of the honeybees. While few bees have been found in its 
stomach, and it was therefore acquitted of serious injury, hundreds of 
crushed bees have since been discovered under its favorite perches, when 




FIG. 22. Chipping sparrow feeding young 
cowbird 



48 



CIVIC BIOLOGY 



these are near the hives. This is a good problem to have thoroughly 
worked up in any neighborhood in which bees are kept. 

Family Alaudida (alauda, "a lark ") larks. Horned larkOtoco- 
ris alp&tris. For open fields and prairies this is a valuable bird, as it 

eats great quantities of weed 
seeds and insects. 

Family Corvidcs. (corvus, "a 
crow") crows, jays, American 
magpie. Blue jay Cyanocitta 
cristdta. This bird has an odious 
reputation for robbing other 
birds of their eggs and young. 
Study the bird for yourself, and 
before inflicting capital punish- 
ment decide whether the jay is 
good or bad for the locality. 

American crow Cor run 
brachyrhynchos. The worst crime 
of the crow is also nest robbing. 
(I have known a pair to empty 
two robins' nests of seven young 
as a single, perhaps partial, 
breakfast.) 

Family Icteridce (icteros, "a yel- 
low bird ") blackbirds, orioles, 
etc. Cowbird Molothru* <!/>/. 
This bird is a parasite and com- 
pels other species, generally 
warblers, vireos, and sparrows, 
smaller than itself, to brood and 
rear its young at the expense 
of their own. Cowbirds' eggs 
should be removed from the nests of other birds whenever found. 

Bobolink Doliclionyx oryzivorus. In the North this bird is appre- 
ciated as one of our most fascinating meadow songsters, if it is not at 
the head of the list. In the South it is the destructive ricebird. 

Bronzed grackle Qniscalus quiscula dnem. 
Red-winged blackbird Ageldius phcem'ceus. 
Meadow lark Sturnella mdgna. 
Baltimore oriole icterus ydlbula. 




FIG. 23. Junco's nest in the aviary 

of Mr. Herbert Parker, Lancaster, 

Massachusetts 



METHODS OK BUM) STUDY 49 

Family Fringillidcz (fringilla, "a finch") sparrows, finches. Typos: 

Purple finch ( ."arpodacas purpiireus. 

American goldfinch Astragalinus tristi*. 

English sparrow Passer domesticus. 

White-throated sparrow Zonotrichia nllticnUis. 

Tree sparrow Spizella monticola. 

Chipping sparrow Spizella pan&rina. 

Junco Juneo hyemaMs, 

Song sparrow Melospiza melddia. 

Fox sparrow Passerellu II ><. 

Towhee, chewink Pipilo erythrophtkdlmus. 

Rose-breasted grosbeak Zametodia ludovicidna. 

Indigo bunting Passerina cyftnea. 

The problems in this group are the valuable service rendered by all 
the sparrows in weed-seed destruction; and, also, the damage caused 
by the English sparrow. A single observation of the killing of a tree 
swallow or a bluebird by sparrows, or their eating the eggs from a rob- 
in's nest, is usually enough to convince a person of the advisability of 
ridding the neighborhood of these pests. The year after all agree, the 
English sparrow may be banished from the continent into which it was 
so foolishly introduced in 1851. Until all agree, not much headway can 
be made against a species that has the power to increase from a single 
pair to 275,716,983,698 in ten years. 

Family Tanagridce. the tanagers. The scarlet tanager Pirdnga enj- 
thrdmf.lm. Why are not these beautiful birds more numerous in your 
locality? 

Family Hirundinidcs. swallows and martins. Few more efficient, and 
certainly no more agreeable, insect traps exist than the swallows. They 
should all be protected until they increase up to the limit of their insect 
food. The purple martin and tree swallow nest preferably in bird houses, 
and provision about barns should not be lacking for the cliff and barn 
sw allows. Differences in nesting habits in species so closely related are 
of general interest. Types : 

Purple martin Progne auhia. 

Cliff, or eaves, swallow Petrochelidon lunifrnnx. 

Barn swallow Hit-undo erythrogdstra. 

Tree swallow Iridoprocne IticoJor. 
Bank swallow Rtpdria r!/mr!a. 



50 



CIVIC BIOLOGY 



Family Ampelide (ampelus, "a vine") waxwings. The cedar wax- 
wing, Bombycilla cedrorum, known also as the cherry bird, is noted for 

destruction of cankerworms 

in our orchards. 

Family Laniidaz (lanius, 
" butcher ) shrikes. The 
loggerhead shrike, Lanius lu- 
dovicidnus, frequents hedge- 
rows and borders of fields, 
where it feeds upon insects, 
field mice, and small birds. 
In cities it is said to be of 
some use in destroying Eng- 
lish sparrows. Study the prob- 
lem in your own locality. The 
number of our most valuable 
small birds chickadees and 
wrens which the shrike 
kills places it decidedly on 
the questionable list. 

Family Vireonidce. (vireo, 
" a greenfinch ") the vireos 
or greenlets. These birds of 
the terminal foliage and pen- 
sile nests are among the best 
of our orchard and roadside insect police. We may certainly make the 
acquaintance of at least three of the seven common species. 

Red-eyed vireo Vireosylva olicdcea. 
Warbling vireo Vireosylva gilva. 
Yellow-throated vireo Lanivireo fldvifrons. 

Family Mniotiltide (mnion, "moss"; tiltos, "pulled out") warblers. 
To make the first acquaintance with this interesting and difficult family 
we may begin with four of Jhe common resident species. 

Black-and-white warbler Mniotilta vdria. 
Yellow warbler Dendroica cestiva. 
Ovenbird Scurus aurocapillus. 
American redstart Selophaga ruticilla. 

Family Troglodytide (troglodyte, "cave dweller ") thrashers, wrens, 
etc. Mocking bird Mimus polyglottos. This offers the problem of a rare 




FIG. 24. Remains of chickadee killed by 
a shrike 

Photograph by the author 



METHODS OF BIRD STUDY 51 

bird for our district, and one which is becoming rarer year by year. The 
reason is largely that specimens are desired for collections. Hence rec- 
ords commonly read : " Remarkable instance of a pair of mocking birds 
nesting in central Massachusetts. On June 8 both parents with nest and 
c Jitch of six eggs were collected and are now in . . ." etc. The mocking 
bird is often described as the most remarkable bird musician in the 
world, and we could certainly not do less than encourage it to breed as 
f;tr north as possible. 

Catbird Dumetella carolinensis. 

Brown thrasher Toxostoma rufum. Both of these birds are valuable 
to control insects of garden and orchard, and, besides, are among our best 
musicians. 

House wren Troglodytes aedon. Every garden should be well stocked 
\\ ith this tireless insect destroyer. 

Marsh wren, short-billed Cistoihorus stelldris. Compare with house 
^ren for habitat, foods, nests. 

Family CerthiidG creepers. Brown creeper Certhia familidris ameri- 
ctina. One of our winter birds that should be generally known and pro- 
tected. 

Family Paridce nuthatches and titmice. White-breasted nuthatch 
Sitta carolinensis. 

Chickadee Penthestes atricapillus. All are agreed that the chickadee 
is one of the most useful birds in freeing orchards of all sorts of insect 
]> i sts, from cankerworms to aphides. 

Family Sylviid& kinglets, gnat catchers, etc. The ruby-crowned king- 
1( t Regulus sdtrapa. 

Family Turdidot thrushes, bluebirds, etc. The thrushes are typical 
" soft-billed " birds, their food being largely insects, worms, spiders, etc. 
They also feed upon fruits in season, and this has complicated the prob- 
lem of their economic value up to within recent years. A closer analy- 
sis of their foods has demonstrated that the birds prefer native wild 
fruits to cultivated ; hence this problem may be solved humanely and 
s< ientifically by planting a succession of these. ^Esthetically the thrushes 
a'-e among our most highly valued songsters, and structurally they rank 
as the highest family of birds. 

Wood thrush Hylocichla mustelina. 
Wilson's thrush Hylocichla fuscescens. 
Hermit thrush Hylocichla guttata pdllasi. 
American robin Plane'sticus migratorius. 
Bluebird Sidlia sialis. 




FIG. 25. Carrying incubated eggs (ruffed grouse) and the result 
Photograph by the author 

52 



METHODS OF BIRD STUDY 



It should be repeated that the above list is suggested for 
central New England, and that it should be freely modified to 
fit the species and problems of other sections. 

One of the most interesting civic problems in this field re- 
lates to conservation of American game birds. To accomplish 
this we need three things: (1) national control of migratory 
species; (2) universal property right in all game reared by 
individuals; (3) study of methods of breeding and rearing 
under control all kinds of American game birds. 

The third factor will speedily follow from legal authoriza- 
tion of game breeding, (2), which is being accorded by re- 
cent state laws. Follow legislation in your own state and 
w >rk for this at every opportunity. As long as the State 
cLiims ownership in all game, people cannot afford to raise it, 
and often the lawless trespassing and annoyance of hunters 
on private land make the owners Avish that the game were 
exterminated. As soon as we can secure the proper freedom 
from laws which work against conservation, breeding of game 
birds will become one of the most profitable of occupations. 

Thousands of nests of wild ducks, geese, bobwhites, wild 
turkeys, ruffed grouse, and prairie chickens, are yearly broken 
up by various farming or logging operations. The eggs at any 
stuge of incubation may be saved by carrying in the hat, as 
shown in Fig. 25. If all these eggs could be saved, they would 
speedily yield birds enough to restock portions of the country 
from which the species have been exterminated. 





FIG. 26. Black Hills National Forest 
United States Bureau of Forestry 

54 



CHAPTER VI 

TREE STUDY AND CIVIC FORESTRY 

Why are there trees I never walk under but large and melodious thoughts 
dt scend upon me ? WALT WHITMAN 

How foolish does man appear to be in destroying the mountain forests, 
for thereby he deprives himself of wood and water at the same time. 
ALEXANDER VON HUMBOLDT 

It is undoubtedly true that more pine timber has been destroyed by fire 
than the lumbermen have ever cut. GREEN 

The problem. The annual growth of all the forests of the 
United States is 7,000,000,000 cubic feet of wood, while our 
yearly consumption amounts to more than 20,000,000,000 
cubic feet. In addition to this, since 1870 forest fires, for the 
most part preventable, have caused a yearly loss of fifty lives, 
$50,000,000 worth of lumber, and a destruction, even greater, 
of all young growth and of soil fertility by the burning of the 
vegetable mold of the forest floor. Floods in the lower Missis- 
sippi alone during 1912, due to unwise and uncivic deforesta- 
tion, jn the main, caused great loss of life, extreme privation, 
arid damage estimated at $82,187,670. While this torrential 
rn ii-off is flooding the lower river valleys, millions of woodland 
springs and even wells back in the foothills and mountains 
are going dry. From one to two thousand million tons of the 
finest and richest soil - enough to bury Rhode Island from 
01 1 e to two feet deep is being washed yearly from the farms, 
where it may be worth a dollar a ton, into our harbors, where 
it costs millions to dredge it out of the way. 

Increasing population and consumption of wood, decreasing 
forests, inadequate control of forest fires, increased washing 

55 



56 (I VIC BIOLOGY 

of soil, floods rising higher each year these are the main 
elements in the problem. Records of flood plane of the Missis- 
sippi at New Orleans are as follows : 

DATK FKET 

1882 . . . . 15.8 

1892 17. 

1903 20.3 

1912 22.0 




FIG. 27. Flood showing result of deforestation 

If the flood of 1912 had not broken the levees and poured 
over 17,605 square miles above the city, the flood might have 
risen to thirty feet at New Orleans. 

Vital civic cooperation must be developed in growing more 
wood, in holding the water and soil where they belong and 
can do the most good on every farm, and in prevention of 
forest fires. 

These are not matters of private individual right and con- 
trol: they are civic and touch the life of the whole people. 



TREE STUDY AXD CIVIC FORESTRY 57 

Every particle of soil that a farmer in Pennsylvania, Minnesota, 
or Montana allows to wash from his farm eventually raises 
tie mnd bed of the Mississippi, helps to cause floods, taxes 
the nation to build higher levees. The clearing of a watershed 
at the headwaters of the Ohio or Missouri is the business of 
every one whose spring or well runs dry below it or whose 




* FIG. 28. Deforested slope, North Carolina, showing erosion 
United States Bureau of Forestry 

home is flooded farther down the rivers, and also of every one 
u ho is taxed or who is called upon to contribute or to suffer 
ii: sympathy for the common loss. 

Solution of problem. By the adequate planting of trees on 
e-'ery hill and mountain side and along every. gully and ravine, 
the rootlets of which will bind the soil and filter the water as 
it falls, we should have the water leaving every farm clear as 
ciy.stal from perennial springs. Vast national projects are 



58 CIVIC BIOLOGY 

afoot for building dams and impounding the flood waters of 
our streams and rivers. Much of this will be necessary on 
account of past mistakes in clearing watersheds and also on 
account of the original configuration of certain regions ; but first, 
and in connection with these plans, we should unite as a whole 
people in planting trees to conserve both soil and water on the 
farms. Otherwise, under present ignorance and mismanage- 
ment, how long will it be before our reservoirs are filled to the 
tops of their dams with mud ? 

Observe and study typical springs and streams, and learn 
the history of them for a number of years. Have they shrunk 
or gone dry ? If so, is it because woods have been cut above 
their sources ? They may be restored by replanting the water- 
sheds. Has it been necessary to deepen wells during periods 
of drought ? Has a man the moral right to clear off a woods 
that will cause his neighbor's spring or well to go dry ? 

Study in a practical way what the local streams are carrying, 
if muddy. Temporary streams will serve, if permanent ones 
are not available. After a freshet, are some streams clear and 
others muddy ? How do their relations to woodlands explain 
the difference ? Follow up a muddy stream and find where 
the soil is being eroded. Can you sketch a plan of planting 
with trees or permanent grass to prevent this ? Make a list 
and map of all the places in the district that are washing 
badly, or survey typical farms with this feature in mind. 
Sketch a plan of planting which will improve conditions 
throughout the district. After this has been perfected and 
thoroughly discussed by the class and with parents most con- 
cerned, arrange for publication of the plan in local papers or 
make it the subject of consideration in a community meeting. 
All can then arrange for saving or procuring the necessary 
seeds or young trees and for doing the actual planting. If not 
too extensive, possibly all of this work can be done in outdoor 
laboratory periods by the class. At least the seeds might be 



TREE STUDY AND CIVIC FORESTRY 



59 



gathered and many of the young trees be reared for a year 
or two in a nursery in connection with the school garden. 

Suggestions for tree planting. The general plan should insure 
having the most valuable trees for each location as the per- 
manent stand. It will thus be necessary to study conditions 
under which the different species will grow to best advantage. 
Some species bear shade or sun better than others when they 
are young. Analyze and study how and where young trees 
are thriving best. Especially note which species grow best on 
the driest hillsides and along the banks of brooks and streams. 
ID is often necessary, and profitable as well, to plant quick- 
growing, sun-enduring species as " nurse trees " for a more 
valuable permanent stand. 

The following table suggests possibilities in handling the 
different species of Eastern conifers and hard woods with refer- 
ence to tolerance of shade or sun. 



SHADE BEARERS INTERMEDIATES 



LIGHT DEMANDERS 



C 'onifers : 








White cedar 


Loblolly pine 


Long-leaf pine. 


Sugar pine 


Spruces 


Virginia scrub pine 


Short-leaf pine 


Scrub pine 


Balsam 


White pine 


Bald cypress 


Cuban pine 


Arbor vitae 




Tamarack 


Yellow pine 


Hemlocks 




Jack pine 


Pitch pine 


Spruce pine 




Red pine 


Red cedar 


Rock pine 








Hard woods : 








Beech, Elm 


Chestnut 


Sourwood 


Cottonwoods 


Black gum 


Black walnut 


Locusts 


Red gum 


Maples, hard, 


Butternut 


Yellow poplar 


Hickory 


red, silver 


Sycamore 


Oaks 


Black cherry 


Basswood 




Birches 


White elm 


Ironwood 




Willows 


Mulberry 



NOTE TO TEACHER. As early as possible in the year discuss with 
the class a list of trees desirable to study, and apportion, either by 
c'iioice or lot, one or more species to each pupil, according to sugges- 
tions for the White Pine, p. 4. Each will then be responsible for seeds, 



60 



CIVIC BIOLOGY 



Nut trees. The rocky hillsides of Italy and Spain, planted 
to chestnuts, are said to produce without labor as valuable 
crops as our own best wheat lands. We are importing annu- 
ally over |14,000,000 worth of nuts. How many, even then, 

have all the nuts they 
want ? 

Make careful collec- 
tions of all the differ- 
ent nuts in the district 
and prepare them for 
exhibition in class, keep- 
ing records of trees that 
produce the best. Pre- 
serve as many as pos- 
sible of the best for 
planting, exchange with 
other schools, and ar- 
range, if possible, to buy 
seeds or young trees, or 
obtain scions from the 
best varieties of pecan, 
hickory, walnut, and 
chestnut that can be had 

from any part of the 
The nuts hang on a few days after the leaves 

have fallen country. Organize ex- 

hibits of nuts in connec- 
tion with local horticultural fairs. By these means we may 
improve quality and increase yield of nuts to any desired 
amount. At the same time the wood of our native nut trees, 
- hickory, black walnut, chestnut, for certain uses, is the 
best we can grow. 

flowers, seedlings, and other specimens of his tree or trees, when needed 
by the class. Have each pupil study and be prepared to describe the 
method each tree has developed for scattering and planting its own seeds. 




FIG. 29. Youncr black-walnut tree 



TREE STUDY AND CIVIC FORESTRY 



61 



State and national helps. The national Bureau of Forestry 
mid your state forester print a number of practical bulletins 
Mid forestry leaflets, which may be obtained gratis or at cost. 
These will give directions for gathering, storing, and planting 
different tree seeds, and advice as to best species to plant. Tree 
seeds and even young seedling trees may be obtained from 
state or (in Canada) from provincial departments of forestry. 




FIG. 30. Crop of tree shown in Fig. 29 

'We do not have to " wait " fifteen years for such a crop ; we just plant the nut 
and go about our business 

Since the planting of trees is an important public service, 
states are beginning to pass laws exempting land so planted 
i'rom taxation. Massachusetts and New York exempt for 
thirty-five years all lands on which not fewer than twelve 
1 lundred trees are planted to the acre. 

Forest fires. In a hot, dry wind a spark or carelessly dropped 
match may start a fire which one standing over it cannot stamp 
out; and it may run down the wind faster than wild horses 



62 



CIVIC BIOLOGY 



can gallop. A smoldering camp fire may be blown into flame 
by the wind and give us another story like that of the Hinck- 
ley fire, which licked up several towns and 500 people in them, 
left 2000 people homeless, and destroyed $25,000,000 worth 




FIG. 81. Forest fire in Washington 
Photograph by J. L. Bridge 

of buildings and timber. Let public and private forest-fire 
service organize lookouts and fire wardens and volunteers, at 
great expense ; all these measures will not be effective until 
everybody is educated to be intelligent and careful about the 
little sparks that start the big fires. 



TREE STUDY AND CIVIC FORESTRY 



63 



( )ne evening last September when the men had quit work and were all 
in camp or on the way, a patrolman blew the fire signal at a "donkey " 
about sixty rods from camp and within three minutes fifty men were at 
work. In half an hour there were a hundred, and in fifteen minutes 
moie, a hundred and fifty. Even with this prompt action it took all 
nigl it and all the next day to extinguish the fire. Now what I should 
like to know is how to keep 
a fire from working you 
forty hours even when you 
see it start and can get your 
crew on the ground at once. 
It was a dry slashing and a 
cigarette. How stop the 
cigarette ? Proceedings 
of Forest-Fire Conference, 
Seattle, 1912, p. 19 

This is the crucial, 
vital point in civic co- 
operation, to have every 
one, young or old, na- 
tivo or foreign-born, 
rich or poor, thoroughly 
careful about these lit- 
tle sparks that start the 
big fires. 

For outdoor labora- 
tory work organize the 
class so as to utilize all 
local brush burnings 
and actual forest fires. Make practical demonstrations of put- 
ting out camp fires by the use of water and earth. Teach the 
factors that go to make up a safe, model camp fire proximity 
to water or moist earth, use of stones and rocks to prevent 
spreading, and distance from dry stumps, logs, peat, or leaf 
mold. Finally organize a survey for danger spots and try 
to liave these attended to before the danger season. 




FIG. 32. Forest-fire lookout, Croydon Moun- 
tain, New Hampshire 
Photograph by Charles I. Rice 



64 



CIVIC BIOLOGY 



Causes. Natural causes, lightning and friction, account for 
few forest fires, and as these occur during rainstorms, there is 
almost no damage from them. Study local forest fires and 
tabulate under the following causes: 



FOREST FIRKS IN MASSACHUSETTS ix 1908 



CAUSE 


NUMBER 


REMARKS 


Railroad trains (Locomotives) 


490 (38%) 


Usually cause about 50% of all 






forest fires. Can be stopped by 






proper use of spark arresters. 






or by burning oil, by turning 






hose into ashes before dump- 






ing, and by clearing roadbed 






of inflammable rubbish. 


Sawmills 


12 (\/ r \ 


Should have men organized, and 




\ J -/cf 


be provided with adequate fire- 






fighting apparatus. 


Burning brush 


90(7',) 


Escape of these fires can be 






avoided by burning when snow 






is on the ground or during a 






wet spell. 


Smokers 


HI (8%) 


Those who must smoke in the 






woods in a dry time should be 






compelled by law to dive under 






water to light up and stay down 






as long as there is a spark in 






their pipes or cigarettes. 


Campers' tires ; . 


1 (0.1%) 




Boys (incendiary) .... 


150 (11%) 


Boy Scouts may stop such fires. 


Unknown 


314 (25%) 


Probably mostly set by smokers 






and careless or incendiary boys. 



In all, for Massachusetts 1378 forest fires were reported 
in 1908, which burned over 40,327 acres of woodland, nearly 
2 per cent of the wooded area of the state. In the whole of 
Prussia 1400 acres have been burned in the past twenty-five 
years, or less than 0.02 of 1 per cent a year. At this rate the 



TREE STUDY AND CIVIC FORESTRY 65 

whole forest area in Massachusetts would be burned over in 
about fifty years, and in Prussia in 5000 years. Why this 
difference ? 

The actual loss by forest fires, although great, is not the 
woist feature of the situation. Forest fires discourage tree 




Fro. 33. Safe burning of brush 
United States Bureau of Forestry 

planting everywhere. Reduce or banish entirely danger of fires 
and tree planting will become a safe and profitable investment. 

NOTE TO TEACHER. After working over the ground and with special 
reference to local problems ask the town fire warden to visit the class 
and explain the state laws and the apparatus, equipment, methods, and 
organization of the state and town for preventing forest fires and for 
quirk work with those that are started. 



66 



CIVIC BIOLOGY 



To sum up the whole matter have each member of the class write a 
brief outline of a plan by which he thinks forest fires can be effectively 
prevented in the district, town, or county. The best of these plans may 
be printed in local papers or used as the basis for discussion in a timely 
neighborhood meeting. With every township safe and protected by a 
well-organized community, the entire country will be equally safe. 

Forest-fire laws. Secure the latest forest-fire laws in your 
state or province and familiarize yourself with them. These 
laws represent the best thought of your community on the 
subject. What can you do to help in making them effective ? 




CHAPTER VII 

PLANT PROBLEMS: PRESERVATION OF WILD FLOWERS, 
CONTROL OF WEEDS, MEDICINAL AND POISONOUS PLANTS 

Groups of plants present civic problems of no less impor- 
tance than those of birds and insects. For beautiful landscapes 
the people of a locality must learn to cooperate in preserving 
and planting native trees, shrubs, and vines. Additional study 
of these is taken up from this point of view in chapters on 
Forestry and Landscape Gardening. 

Conservation of native plants. Many of our most beautiful 
native plants are in -danger of extermination. To educate 
against wanton destruction a society of national membership 
has been organized, 1 and if all can be induced to join in rea- 
sonable conservation of these common interests, we may have 
much more attractive and interesting woods, parks, and 
country roadsides. Do you have trailing arbutus, fringed gen- 
tian, cardinal flower, maidenhair fern, pink lady's-slipper grow- 
ing in abundance ? By inquiry from parents, grandparents, or 
older members of the community, can you make out a list of 
native plants that have become rare and need protection in 

1 Society for the Protection of Native Plants, Boston, Massachusetts. 
For leaflets, address the Boston Society of Natural History. 
"Phis society urges that we all use : 

1 . Moderation. Do not pick all that you find. Many flowers must be left to 
develop seeds for future plants. 

2. Care. Never pull up the plant, for the roots are of no use in a bunch of 
flo^ ers, and their destruction means the extinction of the plant. Cut when possible. 

c. Judgment. Many flowers, such as wild roses, asters, and goldenrod, may 
be r icked with impunity, but when flowers are few or rare do not pick them. -Do 
not pick flowers which must die before you reach home, nor great quantities of 
those flowers whose grace and beauty are better seen in a few than in many 
massed together. 

67 



68 CIVIC BIOLOGY 

the locality ? Discuss together as a class plans for bringing 
them back to their native haunts. ^ 

Weeds. Fighting weeds is often the most laborious and ex- 
pensive part of gardening and of raising certain staple crops. 
It was formerly said that weeds were the gardener's friends, 
because they made necessary the frequent stirring of the soil, 
which was considered beneficial to plant growth. Recent ex- 
periments in raising corn have shown equal production with 
absolutely none of this laborious stirring of the soil. In fact, 
earlier experiments on the root system of the corn plant had 
proved that the farmer actually, and very materially, reduced 
his corn crop by deep cultivation. Other crops await similar 
investigation. The results so far have been to rate the damage 
caused by these " robber plants " at much higher figures than 
formerly. If we could prepare the ground and plant our gardens 
and fields and never see a weed, the labor and cost of produc- 
tion from the soil might be reduced nearly, or quite, one half. 

Damage caused by weeds. Weeds are defined as " plants 
which persist in growing where they are not wanted." No 
less than seven hundred such plants are listed for the entire 
United States. Make a list of weeds that are locally most 
noxious. Weeds reduce yield of crops by crowding, and by 
robbing the plants of water and food in the soil and of light 
in the air. They injure seeds and flour, cause objectionable 
flavors in milk, and poison stock. A recent estimate by the 
Division of Farm Management of the United States Depart- 
ment of Agriculture places the total annual damage of weeds 
at $500,000,000. What part of this yearly tax is imposed on 
your own home, garden, or farm ? What is the annual damage 
and cost of fighting weeds in your district, township, county, 
or state ? l Can you propose a plan of cooperative work by 
which this may be reduced ? 

1 Secure your state bulletins on weeds to assist in working out the prob- 
lems suggested. AVrite also for the Weed Laws of your state. 



PLANT PROBLEMS 69 

Control of weeds. Select the largest specimens to be found 
in roadsides and vacant lots, barnyards, and gardens, of per- 
haps ten of the worst local weeds; dry carefully, thresh out 
and count or estimate the number of seeds in each. No one 
who takes part in such a lesson can ever be indifferent to al- 
lowing such weeds to ripen their thousands or even millions 
of seeds, 1 when a stroke of scythe or hoe at the right time 
would stop them. 

Failure to study weeds. and get clear ideas of their powers 
of reproduction and of effective methods of exterminating 
them is responsible for the fact that more decisive headway 
has not been made in their control. Further topics in this 
connection are the following: 

Dispersal of weed seeds. Along with rats, English sparrows, 
the San Jose scale, and gypsy moth, many of our worst weeds 
are immigrants from tbe Old World. They come mixed with 
seeds and grains, in merchandise, and in all kinds of packing 
materials. Watching ports of entry has not succeeded in keep- 
ing out these unwelcome guests. Our only hope lies in knowl- 
edge sufficient to recognize and give the alarm and unite in 
eradicating vicious importations Jbefore they become widely 
established. 

The more widely a plant is able to scatter its seeds, the 
better the chance of growth. Naturally weeds lead the world 
of plants in effective devices for dispersing their seeds. They 
are aided by different elements in the environment winds, 
flowing waters, and animals. Make a collection of weed seeds 

1 This suggestion carried out in the Cleveland Normal School yielded the 
following results : 

Milkweed Ascl&pias syriacea 2,510 seeds 

Sticktights Bidens frondosa 7,040 seeds 

Pigweed Amaranthus hybridus , 305,760 seeds 

Purslane Portulaca oleracea 1,250,000 seeds 

Lamb's-quarters Chenopodium album . . . . 1,613,320 seeds 
Wormseed Chenopodium anthelmir>ticum . . 26,085,150 seeds 



70 CIVIC BIOLOGY 

and study with reference to means of dispersal. These collec- 
tions will also be useful in identifying impurities in garden 
and field seeds. 

Vitality of weed seeds. The great length of time weed 
seeds remain alive in the soil furnishes another strong reason 
for not permitting them to ripen. Dr. Beal has found that 
seeds of pigweed, black mustard, shepherd's-purse, pepper- 
grass, mayweed, evening primrose, smartweed, purslane, curled 
dock, foxtail, and chickweed are able to germinate after being 
buried for twenty-five years. How much longer they may 
survive remains to be determined. 

Adaptability. Weeds, like other plants, attain their best 
growth under favorable conditions of soil, but they are able to 
produce seed under conditions of greatest hardship. A search 
of clay banks, ash heaps, gravel or cinder walks will reveal 
minute dwarf specimens of common weeds. Weeds also show 
extreme tenacity of life in many other ways. Uproot them, 
and if a rootlet remains in the soil, it will continue to grow 
and mature seed as it lies on the ground. If trampled down, 
branches that retain a shred of connection with the stem re- 
main Afresh and produce se^d. Even when cut close to the 
ground, new branches quickly appear. An outdoor lesson 
devoted to this topic will prove valuable in many connections. 

Classes of weeds. Success in fighting weeds must depend 
upon knowledge of each species. The methods used will de- 
pend in a general way upon whether the particular weed is : 

An annual. Most garden weeds chickweed, purslane, 
lamb's-quarters, pigweed, ragweed, pigeon* grass complete 
their life cycle in a single season. To completely eradicate 
these from the soil' it is only necessary to prevent any from 
maturing seed until seeds already in the ground have germi- 
nated. Barnyard manure or loam may reseed a clean garden 
plot, if not applied with great care. If manure is spread upon 
the top after plowing, all weed seeds in it are more likely to 



PLANT PROBLEMS 71 

germinate the first year than if they are plowed under deeply. 
Some weeds of this class chickweed, peppergrass, shepherd's- 
purse germinate late in the summer or fall, live through 
the winter, and are known as " winter annuals " in latitudes 
where this occurs. 

A biennial. These plants complete their life cycle in two 
years and hence rapidly disappear if prevented from maturing 
seed. Burdock, bull thistle, mullein, teasel, and wild carrot, 
all immigrants from the Old World, are familiar examples. 

A perennial. Couch grass (a native American), Canada 
thistle, curled dock, plantain, wild onion, milkweed, bind- 
weed, most of them importations from the Old World, are 
examples. Most of the hard problems relate to weeds of this 
class. The plants, besides producing seeds, live from year to 
year in the ground by means of perennial crowns, tubers, and 
burrowing rootstocks. Cultivation which would eradicate an- 
nuals or biennials may serve merely to subdivide and increase 
these pests of the soil. 

The fact that certain weeds tend to thrive best with certain 
crops suggests rotation as a means of control. Land should 
have a radical change of treatment, if badly infested with 
weeds. Annual weeds of gardens and cultivated fields die 
out if the land is seeded to grass. This applies to grainfields 
which have become seeded to chess, cockle, or ragweed. Pas- 
ture lands "run out" to perennial weeds should be planted 
to annual crops. Thus a system of field rotation and general 
management may be adopted which shall give weeds the least 
possible chance to survive. 

Chemical weed killers, herbicides. Salt or strong brine, arse- 
nate of soda, coal oil, crude sulphuric acid, carbolic acid, and 
sulphates of copper or iron are the chemicals usually employed 
and suggest interesting experiments for the lawn or garden. 

Medicinal plants. Many crude drugs and aromatic herbs 
used as condiments are now imported, although they grow in 



rivir BIOLOGY 



the United States. The table 1 below gives the amounts brought 
in and the prices we pay for some of our most common weeds. 



WEEDS 


PARTS USED 


AMOUNT IM- 
PORTED IN POUNDS 


PRICE PAID 

IN CENTS 
PER POUND 


Docks Rumex species . . . 


Hoots 


125,000 


2-8 


Burdock Arctium lappa L. . 


Roots 


50,000 


3-8 




Seeds 




5-10 


Dandelion Taraxacum tarax- 








acum 


Hoots 


115,522 


4-(5 


Quack or couch grass Af/ro- 








pyron repens L 


Root stock 


250,000 


3-7 


Mullein Verlxjmcum iJuipxux L. 


Leaves 


5,000 


2^-5 


. 


Flowers 




25-75 


Tansy Tanacetum vulgare L. 


Leaves and 








tops 


30,000 


3-0 


Horehound Marrublum vul- 


Leaves and 






oar L ... 


tops 


125,000 


3-8 


Jimson weed Datura stramo- 


Leaves 


100,000-150,000 


2i-8 


nium L 


Seeds 


10,000 


3-7 


Poison hemlock Conium mac- 


Seeds 


20,000 





ulatum L 


Leaves 


10,000-20,000 


4 


Black and white mustard <$/- 








napis species 


Seeds 


5,302,876 


3-0 











While the demand for medicinal weeds is not great, market- 
ing those that have useful properties would tend to check their 
spread, and might, in turn, pay at least for their removal. 

Other native drug plants. Clearing of the forests and the 
work of the drug collector have resulted in almost extermi- 
nating many of our native drug plants. To save these the 
Bureau of Plant Industry has undertaken the work of domes- 
ticating them with the hope not only of supplying the home 
market but also of exporting them. 

In the gardens at Washington some success in an experi- 
mental way has been attained in raising goldenseal, cascara 

1 Compiled from Bulletin No. 188, United States Department of Agricul- 
ture, ''Weeds used in Medicine." This gives prices and methods of pre- 
paring for market. 



PLANT PKOBLEMS 73 

sagrada, Seneca snakeroot, and purple cornflower. Ginseng 
has already been domesticated, the total yield in states east of 
the Mississippi River being about one million dollars annually. 

A considerable portion of crude drugs used in the United 
States is of foreign origin. To supply the home market and 
save millions of dollars now spent on foreign drugs, the 
Bureau has interested itself in the experimental culture of 
these foreign plants in soil and climate similar to their own. 
Plots of Asiatic poppy, camphor trees, cinchona, belladonna, 
foxglove, and red peppers have been planted in suitable parts 
of our country. 

Poisonous plants. Certain plants are poisonous either when 
handled, or eaten. For lack of statistics, no estimate can be 
g iven as to the amount of damage done by them. 

Complaints have been so numerous against various plants 
v Inch poison man and animals, that the Government has 
investigated them and has issued a number of bulletins on 
poisonous plants of the United States. 1 (See Bulletin 80, 
" Thirty Poisonous Plants.") 

Of the thirty plants described, about one third are weeds ; 
the others are fungi, herbs, shrubs, and trees. The most 
poisonous plants are mushrooms (Amavtita muscaria and Ama- 
riita phalloides), the various species of water hemlock (Cfada) a 
and the loco weed (Astragalus). Damage to the live-stock 
business from loco weed is enormous. Colorado, in a vain 
attempt to exterminate it, spent $200,000 in bounties between 

tlie years 1881 and 1895. 



1 Bulletins from United States Department of Agriculture : 

28. Weeds and how to Kill them. 

86. Thirty Poisonous Plants. 
188. Weeds used in ^Medicine. 
279. Methods of eradicating Johnson Grass. 

Besides these, almost every state issues complete and fully illustrated bul- 
1 tins on its own weeds. Canada issues weed bulletins on an elaborate scale. 



74 



CIVIC BIOLOGY 



Much suffering is caused by poison ivy, the active poison 
being a nonvolatile oil found in all parts of the plant even 
the dried wood. The oil is soluble in alcohol and may be 
removed from the skin by thoroughly bathing exposed parts 
in alcohol and then washing off with water. An alcoholic 




FIG. 34. Purple or woolly loco weed Astragalus mollissimus 

Photograph by C. Dwight Marsh, United States Department of Agriculture, 

Bulletin 112 

solution of sugar of lead (lead acetate) destroys the oil. The 
same remedy applies to poison sumac and poison oak. 



ADDITIONAL STUDIES 

1. Prepare a list of common weeds found along the roadside, rail- 
roads, in grass, field, backyard, and garden. 

2. Compare number of seeds borne by a weed with those of a wheat, 
oat, or barley plant. 

3. What weeds do you know that are eaten as vegetables? 

4. How is the fact that weeds are not valuable food for domestic 
animals to their advantage ? 



PLANT PROBLEMS 75 

5. Discuss the advisability of having foreign seeds and grains in- 
spected before being allowed to enter this country. 

6. Discuss the advantage of smothering weeds with quick-growing, 
thickly seeded crops, like red clover and rye. 

7. Test the germinating power of a weed by placing its seeds on damp 
blotting paper between two plates. 

8. Record instances observed of weeds damaging food plants. What 
did Darwin mean by the "struggle for existence " and "survival of the 
fr test " ? (Ref . : Hodge, *' Nature Study and Life," chap, vii.) 

Copy the following list of poisonous plants into your notebook, and 
make the acquaintance of each one, if possible, during outdoor tramps. 
Increase the list by wider observation. 

Poison ivy Rhus radicans [poison oak, three-leaved ivy, mercury, 
black mercury, markweed, pikry (Maine)]. 

Poison sumac Rhus vernix [swamp sumac, dogwood (Massachu- 
s(tts), poison elder (Alabama), poison ash (Vermont), thunderwood 
(Georgia, Virginia)]. 

Poison oak Rhus diversiloba [poison ivy, yeara, California poison 
sumac]. 

Poison hemlock Conium maculatum [hemlock, wild hemlock, spotted 
p;irsley, stinkweed, poison root, poison snakeweed, cashes, wode-whistle]. 

Water hemlock Cicuta maculata [spotted parsley, snakeweed, beaver 
poison, musquash root, muskrat weed, cowbane, spotted cowbane, chil- 
dren's-bane, death-of-man]. 

Pokeweed Phytolacca decandra. 

Corn cockle Ayrostemma yithago. 

Black cherry Prunus serotina [wild cherry, rum cherry]. 

Red buckeye and common horse-chestnut JEsculw pavia and 
Jnppocastanum. 

Broad-leaf laurel Kalmia latifolia [laurel (north of Maryland), ivy 
(^outh of Maryland), mountain laurel, sheep laurel, poison laurel, wood 
laurel, small laurel, high laurel, American laurel, poison ivy, ivy bush, 
ivy wood, big ivy, calico bush, spoon wood, kalmia, wicky]. 

Narrow-leaf laurel Kalmia anyustifolia [sheep laurel, lambkill, sheep 
poison, lamb laurel, small laurel, low laurel, dwarf laurel, wicky]. 

Jimson weed Datura stramonium and D. tatula, the taller and 
purple-flowered species [Jamestown weed, common stramonium, thorn 
aj >ple, apple of Peru, devil's apple, stinkwort, stinkweed, Jamestown lily, 
waite man's plant (by the Indians)]. 



76 CIVIC BIOLOGY 

Caper spurge Euphorbia lath yr is [garden spurge, mole plant, gopher 
plant, wolf's-milk, spring wort]. 

Snow-on-the-mountain Euphorbia marginata. 

Other poisonous plants are : 

Death-cup mushrooms, of the genus Amanita. 

American false hellebore Veratrum virtue [white hellebore, swamp 
hellebore, Indian poke, pokeroot, Indian uncus, crow poison, devil's-bite, 
duck-retter, itchweed, bugbane, wolfsbane, bear corn]. 

Dwarf larkspur Delphinium tricorne [staggerweed (Ohio) and purple 
larkspur D. menziesii (also D. bicolor and D. trollifoliwn)]. 

Woolly loco weed Astragalus mollisaimus ; and stemless loco weed 
Aragallus Lanibert'd and A. lagopos. 

Rattlebox Crotalaria sagittalis. 

Oregon water hemlock Cicuta vagans (also C. occidentalis). 

Great laurel Rhododendron maximum. 

Staggerbush Pieris mariana. 

Branch ivy Leucothoe catesboei. 

Black nightshade Solan inn itiyrurn. 

Bittersweet Solatium, dulcamara. 

Sneezeweed Helenium autumnal* . 

Zygadenm venenosti*. 

Lupinus sericeus. 

A sclep ias sp ec iosa . 

Hyoscyamm niger. 



CHAPTER VIII 

HOME PLANTING AND LANDSCAPE GARDENING 

A good city can no more successfully be imposed from without, than a 
gx>d character can be imposed upon an individual. A beautiful city and a 
beautiful public life must be the manifestation of the right spirit within. 
'1 herefore it is primarily incumbent upon every one interested in what has 
s<> happily been called "the forward movement 1 ' to develop a character 
( .vholesome), a love for truth and righteousness, a Christian grace. As we 
grow in knowledge and grace, we will reflect it in our public life ; and recip- 
rocally, as our public life advances, it will be reflected in higher personal 
andards. 

A Carnegie may build a library, a Marshall Field construct a great 
museum, a Rockefeller found a great university, but our cities must be built 
I y the people themselves. There is no magic to be availed of ; no Pauline 
conversion to be expected. Our municipal salvation must be wrought out 
patiently, carefully, ofttimes in fear and trembling, and not by any one or 
two, but by the whole community. C. R. WOODRUFF 

Just as the State grew out of the family, so the beautiful city can only be 
tie outcome of the beautiful home. ALEXANDRA BLUMBERO 

Iii general the physical features of a landscape supply the 
skeleton which life clothes with beauty of form and color, and, 
like skeletons, lifeless deserts or mountains are gloomy and 
forbidding. Without plants the animation imparted by animal 
life is also lacking, and the silence and loneliness of such scenes 
become oppressive. Hence the living factors which add attrac- 
tiveness and charm to home and country are legitimate topics 
for study. 

" Beautiful America " is the watchword of a national move- 
ment represented in organized form by the American Civic 
Association. This organization stands for more beautiful homes 
<md country roads, more beautiful towns, cities, streets, and 

77 




I 



7H 



HOME PLANTING AND LANDSCAPE GARDENING 79 



public parks and buildings, the abatement of smoke and billboard 
nuisances, conservation of the natural beauties of forest, moun- 
tain, waterfall, woodland, spring, glen, gorge, and canyon for 
these real values to the whole people of a beautiful America. 

The appearance of a country, especially of its homes, affords 
1 he best index of the char- 
acter of a people. Some 
homes express taste, re- 
hnement, good sense, and 
morals which warm the 
] leart of the passer-by with 
; i friendly feeling for those 
who dwell within. Some 
express pride and repel 
with ostentatious display 
of wealth. Many are mere 
muddles, accidents, com- 
mercial affairs of the nur- 
seryman. With the advent 
of the modern landscape 
gardener perhaps the 
greatest present danger 
is the monotony of set 
] )lanting a bit of shrub- 
bery here, another there, 
*' just so," which is frankly 
more tiresome than nat- 
ural accidents. 

The practical biology of landscape gardening relates to 
effective planting of the home or street, park, town, or city. It 
consists in problems of forming pictures with actual trees, 
shrubs and vines, lawns and flowers ; and the first requisite 
for success must be a clear knowledge of the living things 
with which we build. We must also bear in mind that we are 




FIG. 36. Lancaster elm, after the storm 



80 



CIVIC BIOLOGY 



forming not only one picture but a series of pictures to be 
viewed from different directions, and that planting is most 
effective which yields the most pleasing vistas. Then the 




FIG. 37. Lancaster t-lni 
Results of neglect and vandalism (the cavity had been burned out) 

pictures will come and go, from the red maples, pussy willows, 
peach and apple blossoms of spring, through the procession of 
summer bloom, the fruits and foliage of autumn, to the crystal 
fairy lands of ice storms and snow scenes of winter. Then, too, 



HOME PLANTING AND LANDSCAPE GARDENING 81 

our best effects will lack animation and charm without the 
action and music of birds ; and to complete the whole, we must 
have fragrance apple blossoms, lilacs and syriiigas of May, 
r >ses and grapes of June, honeysuckle and moonflowers, 
cinnamon vine and mignonette of summer, and the spicy, 
health-giving aroma of pines, firs, and spruces all the year. 
And finally, our pictures will grow from year to year, so that 
when w r e plant trees we must imagine ahead ten, twenty, 
fifty, one hundred years. 

Trees. Given the ground, the first thing to plan is the posi- 
t on and grouping of the trees. In order to do this intelli- 
gently we must know the biology of the different species 
the soil in which each grows best, and, especially for our future 
pictures, the height and spread and general form and color 
of each. 

For outdoor laboratory work measure the height and spread 
to scale and sketch the general form of ten specimen trees of 
different kinds. These data will be needed in determining the 
distances apart at which different trees are to be planted in 
the following plans of residence lots, parks, and streets. Ar- 
range, by committee of the class or otherwise, to have all the 
trees of the district studied so that notes of the class may be 
combined into a table like that on page 82, which shall give 
the planting data for all the native and horticultural trees 
available for the locality. 

We need to develop clear ideas of these dimensions in order 
to avoid the common mistakes of planting trees too near the 
house and too close together. In the one case the trees cause 
dampness and decay about the home, and in the other they 
grow into crowded jumbles rather than into beautiful pictures. 

After learning the individual trees we may next study 
effective grouping as presented both in natural woodlands and 
in specimens of artificial planting in the neighborhood. Select 
some of the finest groups available and analyze into component 



82 



CIVIC BIOLOGY 





a 2 
$ 8 



S a i 

S ^ 



g > b 53 
^ *^ ^ "^ 

]l |lll 




s s 



^ i 

i 

I 



5 

li 

c e 



I 




HOME PLANTING AND LANDSCAPE GARDENING 83 

trees; measure distances apart and draw the ground plan to 
scale, and sketch or photograph the groups. 

Rules for grouping trees are sometimes given. The follow- 
ing are modified from different authorities as suggestive and 
practical. 

1. Specimen trees those which stand alone should be 
chosen for special beauty or character; oaks, chestnuts, black 




FIG. 38. A specimen of nature's planting 

walnuts, old pines, and cedars for massive strength and dig- 
nity; hemlock, elm, larch, and spruce and the birches for 
graceful tracery of form and outline ; Colorado blue spruce, 
purple beech, Schwedler, swamp and Japanese maples for rich 
coloring. 

2. Groups should not be too compact, and on estates of 
lii nited extent are generally more effective if made up of trees 
of different characters. They should be unsymmetrical, irreg- 
ular, "natural" in form. The taller trees should, of course, 
occupy the center, or form the background in boundary-line 



84 CIVIC BIOLOGY 

groups. There is opportunity here for fine contrasts in form, 
color, and character oak and weeping willow or American 
elm, birches against white pine, etc. 

3. Plant trees or groups to screen objectionable features of 
the landscape, and leave open spaces toward all pleasing views. 

4. Plant deciduous trees on the south and west of the house 
for summer shade and winter sunshine, and evergreens along 
the northerly side to serve as stormbreaks in winter. 

Shrubs. Given the bounds and main features in tastefully 
planted trees, the shrubbery lets the picture down naturally 
to the ground, and supplies much desired color and fragrance. 
Shrubs, too, more than anything else form the setting for the 
house, fit it to the earth, and make it a part of the landscape. 
The house being the center of the general scheme, we should 
place the choicest shrubs nearest to it. 

For outdoor laboratory work study throughout the fall and 
spring, at least, good specimens of all the different ornamental 
shrubs to be found in your local parks or neighborhood. 
Observe them in all possible relations to trees, buildings, and 
other shrubs, so that you will be able to choose the shrubbery 
of a park or the home grounds with intelligent taste. 

A local planting table like that suggested for the trees 
should be made, giving size, form, preferred exposure, and 
color and season of bloom. A selection of shrubs may be made 
which will furnish bloom for cutting and fine color effects in 
either flower or fruit for not only the growing season but the 
entire year. If it is desired to combine use and ornament, 
a tendency growing in favor, nothing in the way of shrubbery 
can be more effective, either in bloom or fruit, than the dwarf 
fruit trees, especially peach, apricot, nectarine, cherry, pear, 
and apple. Lists and descriptions of desirable shrubs for the 
locality can be obtained from any good nursery catalogue. 

" American trees and shrubs for American homes " is a rule 
with exceptions, but one that has much good sense in its favor. 




Fi<;. 39. Mission grape. Largest grapevine in the world 
Planted in 1842, in 1H95 bore over ten tons of grapes, Carpinteria, California 







FIG. 40. Delaware grape 
Living decoration for a dining porch 

86 



86 



CIVIC BIOLOGY 



What exotic is more beautiful than our mountain laurel or 
our rhodora, or more graceful than our sumacs and elder- 
berry, or sweeter than our pepper bush and wild rose? It 
is no slight matter that a plant has become adjusted to its 
environment on a large continent through the many centu- 
ries of its struggle for existence. 

Flowers. With shrubbery now as the background come 
naturally, in the finest landscape effects, the hardy perennials 




FIG. 41. The most beautiful back door 
in Worcester, Massachusetts 



FIG. 42. An ugly back door 
Compare with Fig. 41 



peonies, lilies, irises, hollyhocks and phloxes, goldenrods 
and asters, and a host of others; also the annual bedding 
plants, the cannas and dahlias, sunflowers, marigolds and 
zinnias, nasturtiums, sweet peas and flowering beans, and by 
all means, here and there, a few tuberoses and a bed of helio- 
trope and mignonette. These supply the finishing touches for 
both color and fragrance, and should be studied largely as a 
matter of individual preference and taste. Here is the test, 
however, for harmonious and pleasing effects in color, and, 
since we must live with our homes so much of the time, the 



1LOME PLANTING AND LANDSCAPE GARDENING 87 



whole effect should be restful and comfortable and as far 
removed from fussiness as possible. 

Vines. Especially on the house and buildings, vines add a 
touch of comfort, as well as wilclness and grace, without which 
few pieces of landscape gardening are complete. Vines of all 

plants are also the most . . 

plastic, convenient, and ac- 
commodating. With them 
v Q may have shade of any 
degree anywhere we wish, 
c< >ver anything, from a snag, 
post, or rock to a factory 
\\ all, and we may have fra- 
grance and flowers and even 
fruit thrown in for good 
measure. 

As suggested for the 
trees and shrubs, make a 
special study of all the 
vines adapted for home 
and park planting in your 
locality, and include meth- 
ods of propagating and cul- 
ture of each. 

The world over, the grape 
combines in highest degree 
al 1 the best qualities of both 
use and beauty. The way 
our American wild grapes climb the tallest forest trees shows 
tli at with proper support they may be carried to any reason- 
able height. A growth of sixty-three feet of vine from a 
single bud in a season proves how quickly any extent of 
wall can be shielded from the hot sun of summer by prop- 
erly trained grapevines. For covering surface no other vine, 




FIG. 43. California grapes 

Photograph hy George C. Husmann, United 
States Department of Agriculture 



88 



CIVIC BIOLOGY 



excepting possibly the Aetinidia, can compare w^th the grape, 
if well established. The fact that it climbs by tendrils makes it 
much easier to train, prune, and control than vines which twine 
around their supports. The grape thrives in poor soil, wet or 
dry, and can be depended upon to flower and fruit for centuries, 
renewing its youth often from the root. Varieties differ much 
in form and size of leaf and in vigor and rapidity of growth. 
Make a special study, with sketch to scale, of at least one 
good specimen vine before it is pruned back in the fall. Note 

variety, age, size, and height 
of main stem and length 
of several of the most vig- 
orous canes of the season's 
growth. Record, if possible, 
the amount of fruit pro- 
duced. By each member of 
the class selecting a differ- 
ent variety, the grapes best 
suited to the locality may 
be compared and learned. 
Houses, even in crowded 
cities, might be transformed 
into bowers of shade and 
beauty by the adequate use of the grape alone. 

Actinidia arguta is a close second of the grape. After be- 
coming well established it is a most rampant grower, speedily 
reaching the tops of the tallest trees, and about buildings is 
likely to require severe pruning. The leaves are clean and 
glossy, with red petioles. Fragrant and attractive flowers 
appear in June, and the fruit ripens in September and October. 
This is a dull green drupe the size of a small plum, with a 
flavor and quality quite unlike anything American. The Acti- 
nidia comes to us from Japan and is hardy and well adapted 
to our climate. Along with other valuable importations from 




Fie. 44. Flowers of Actinidia 



HOME PLANTING AND LANDSCAPE GARDENING 89 



the same source it has the advantage, of not being attacked 
by American insect pests. Rosa rugosa, the Japanese quince, 
and the Japanese snowball are other cases in point. 
Following are some problems in landscape gardening : 

1. Make a series of sketches, to scale, of your home grounds, 
ground plan and at least one view, naming and locating 

tll trees, shrubs, vines, 
iind bedding plots with 
their contents. 

2. Draw a ground 
plan and view of your 
home grounds as you 
Avould wish to have 
them. 

3. Can you suggest' 
tuiy improvements in 
the street tree planting 
of your town, city, or 
neighborhood? Draw 
plans and specifications 
lor special local prob- 
lems of this kind - 

1 he treatment of certain 
streets or roadsides. 

4. Let each member 
of the class sketch a 
ground plan and view 

of the school grounds, giving both specifications and cost. 

5. Taking a local public square, -park, common, or play- 
ground as a special problem for analysis and study, can you 
suggest improvements in its planting ? 

The simplest principles of landscape gardening are often 
Jilluded to as the "A, B, C" of the subject. They are based 
upon the pleasing arrangement of trees, vines, and shrubs and 




FIG. 45. Actinid'm arguta 

Two vines, three years from transplanting, 

afford dense shade for a porch 



90 



CIVIC BIOLOGY 



open glades as found in .beautiful bits of natural woodland. 
A. Leave open glades for air and sunshine. They make even 
modest grounds seem roomy. B. Plant in masses, like the 
forms of clouds, leaving open vistas toward sunrise and sun- 
set and all pleasing views, and covering unsightly features 

of the landscape. C. Avoid 
straight rows ; Nature never 
plants that way. 

Finally we may study home 
and city planting as an invest- 
ment. If well done, probably 
no equal expenditure will re- 
sult in larger returns. Figure 
out increased value of property 
along well-planted streets and 
in the vicinity of public parks. 
Let each member of the class 
study and analyze his own 
home with this point in view 
figuring into the account 
first cost, yearly expenditures, 
and upkeep against enhanced 
values. A shade tree in the 
wrong place may be a positive 
injury to a home, while the same tree in the right place might 
enhance its value a hundred, or even a thousand, dollars. And 
in these, as in all similar cases, it is not the money values we 
are studying so much as the human health and comfort which 
they represent. 

The planning and planting of a home or a country beauti- 
ful enough to inspire the love of a people is no unimportant 
matter. Compare Russia and Japan with this feature in view 
and in connection with the results of the recent war. 




FIG. 46. Actinidia arguta in fruit 



CHAPTER IX 

PRACTICAL BIOLOGY OF AGRICULTURAL PRODUCTION 
AND CIVIC UTILIZATION OF LAND 

Public prosperity is like a tree : agriculture is its roots ; industry and com- 
merce are its branches and leaves. If the root suffers, the leaves fall, the 
branches break, and the tree dies. Chinese saying, from HOPKINS, fr Soil 
Fertility and Permanent Agriculture " 

In final analysis civilizations rest mainly upon agricultural 
efficiency. At least, this must be increasingly true as civiliza- 
tion advances. In this vital matter it is high time to cast 
aside all pride and conceit and wake up to a sense of our 
low agricultural efficiency as a people. In 1907 a total of 
^0,000 square miles of agricultural land in Japan supported 
46,977,003 people, or 2349 people to the square mile, with 
less than one dollar per capita excess of agricultural imports 
over exports. Fertile regions of both China and Japan sup- 
port as high as 3840 people per square mile. Compare these 
figures with those for Belgium, the most densely populated 
country in Europe ; here less than 300 people per square 
mile are supported. The best farming districts of the United 
States support about 30 people per square mile. 

Further, in little more than a brief century we have swept 
over a continent rich in the accumulated fertility of many 
1 housands of years, and in ignorance have wasted and depleted 
('" mined " rather than " cultivated ") the soil. As land in one 
region has been mined out, we have abandoned it and moved 
to virgin fields, but now, with practically no more new land 
available, we are forced to turn toward the more civilizing 
and socially ethical task of permanent American agriculture. 

91 







THE EFFECT OF THOROUGH CULTIVATION UPON THE FARMER'S 
OWN MIND, AND IN REACTION THROUGH HIS MIND BACK UPON HIS BUSI- 
NESS, IS PERHAPS QUITE EQUAL TO ANY OTHER OF ITS EFFECTS. EVERY 
MAN IS PROUD OF WHAT HE DOES WELL, AND NO MAN IS PROUD OF THAT 
HE DOES NOT WELL. WITH THE FORMER HIS HEART IS IN HIS WORK, 
AND HEWILL DO TWICE AS MUCH OFIT WITH LESS FATIGUE; THE LAT- 
TER HE PERFORMS A LITTLE IMPERFECTLY. LOOKS AT IT IN DISGUST, 
TURNS FROM IT, AND IMAGINES HIMSELF EXCEEDINGLY TIRED - THE 
LITTLE HE HAS DONE COMES TO NOTHING FOR WANT OF FINISHING. 

I HAVE SO FAR STATED THE OPPOSITE THEORIES OF "MUD- 
SILL" AND "FREE LABOR," WITHOUT DECLARING ANY PREFER- 
ENCE OF MY OWN BETWEEN THEM. ON AN OCCASION LIKE THIS, I 
OUGHT NOT TO DECLARE ANY. I SUPPOSE, HOWEVER, I SHALL 
NOT BE MISTAKEN IN ASSUMING AS A FACT THAT THE PEOPLE 
OF WISCONSIN PREFER FREE LABOR, WITH ITS NATURAL COMPANION, EDUCATION. 

THIS LEADS TO THE FURTHER REFLECTION THAT NO OTHER HUMAN OCCUPATION OPENS SO WIDE 
A FIELD FOR THE PROFITABLE AND AGREEABLE COMBINATION OF LABOR WITH CULTIVATED THOUGHT, 
AS AGRICULTURE. I KNOW NOTHING SO PLEASANT TO THE MIND AS THE DISCOVERY OF ANYTHING 
THAT IS AT ONCE NEW AND VALUABLE - NOTHING THAT SO LIGHTENS AND SWEETENS TOIL AS THE 
HOPEFUL PURSUIT OF SUCH DISCOVERY. AND HOW VAST AND HOW VARIED A FIELD IS AGRICULTURE 
FOR SUCH DISCOVERY! THE MIND, ALREADY TRAINED TO THOUGHT IN THE COUNTRY SCHOOL, OR 
HIGHER SCHOOL, CANNOT FAIL TO FIND THERE AN EXHAUSTLESS SOURCE OF ENJOYMENT. EVERY 
BLADE OF GRASS IS A STUDY ; AND TO PRODUCE TWO WHERE THERE WAS BUT ONE IS BOTH A PROFIT 
AND A PLEASURE. AND NOT GRASS ALONE, BUT SOILS, SEEDS, AND SEASONS - HEDGES, DITCHES, 
AND FENCES- DRAINING, DROUGHTS, AND IRRIGATION - PLOWING, HOEING, AND HARROWING - 
REAPING, MOWING AND THRESHING - SAVING CROPS, PESTS OF CROPS, DISEASES OF CROPS, AND 
WHAT WILL PREVENT OR CURE THEM - IMPLEMENTS, UTENSILS, AND MACHINES, THEIR RELATIVE 
MERITS, AND HOWTO IMPROVETHEM - HOGS, HORSES, AND CATTLE - SHEEP, GOATS, AND POULTRY 
- TREES, SHRUBS, FRUITS, PLANTS, AND FLOWERS - THE THOUSAND THINGS OF WHICH THESE ARE 
SPECIMENS - EACH A WORLD OF STUDY IN ITSELF. 

IN ALL THIS, BOOK LEARNING IS AVAILABLE. A CAPACITY AND TASTE FOR READING GIVES ACCESS 
TO WHATEVER HAS ALREADY BEEN DISCOVERED BY OTHERS. IT IS THE KEY, OR ONE OF THE KEYS, TO 
THE ALREADY SOLVED PROBLEMS. AND NOT ONLY SO : IT GIVES A RELISH AND FACILITY FOR SUC- 
CESSFULLY PURSUING THE UNSOLVED ONES. THE RUDIMENTS OF SCIENCE ARE AVAILABLE, AND 
HIGHLY AVAILABLE. SOME KNOWLEDGE OF BOTANY ASSISTS IN DEALING WITH THE VEGETABLE WORLD 
-WITH ALL GROWING CROPS. CHEMISTRY ASSISTS IN THE ANALYSIS OF SOILS, SELECTION AND 
APPLICATION OF MANURES, AND IN NUMEROUS OTHER WAYS. THE MECHANICAL BRANCHES OF NATU- 
RAL PHILOSOPHY ARE READY TO HELP IN ALMOST EVERYTHING, BUT ESPECIALLY IN REFERENCE TO 
IMPLEMENTS AND MACHINERY. 

THETHOUGHT RECURS THAT EDUCATION -CULTIVATED THOUGHT- CAN BEST BE COMBINED WITH 
AGRICULTURAL LABOR, OR ANY LABOR, ON THE PRINCIPLE OF THOROUGH WORK ; THAT CARELESS, 
HALF PERFORMED, SLOVENLY WORK MAKES NO PLACE FOR SUCH COMBINATION; AND THOROUGH 
WORK, AGAIN, RENDERS SUFFICIENT THE SMALLEST QUANTITY OF GROUND TO EACH MAN; AND 
THIS, AGAIN, CONFORMS TO WHAT MUST OCCUR IN A WORLD LESS INCLINED TO WARS AND MORE 
DEVOTED TO THE ARTS OF PEACE THAN HERETOFORE. POPULATION MUST INCREASE RAPIDLY. MORE 
RAPIDLY TH'.N IN FORMER TIMES, AND ERE LONG THE MOST VALUABLE OF ALL ARTS WILL BE THE 
ART OF DERIVING A COMFORTABLE SUBSISTENCE FROM THE SMALLEST AREA OF SOIL. NO COM- 
MUNITY WHOSE EVERY MEMBER POSSESSES THIS ART, CAN EVER BE THE VICTIM OF OPPRESSION IN 
ANY OF ITS FORMS. SUCH A COMMUNITY WILL BE ALIKE INDEPENDENT OF CROWNED KINGS, MONEY 
KINGS, AND LAND KINGS. 

IT IS SAID AN EASTERN MONARCH ONCE CHARGED HIS WISE MEN TO INVENT HIM A SENTENCE TO EE 
EVER IN VIEW, AND WHICH SHOULD BE TRUE AND APPROPRIATE IN ALL TIMES AND SITUATIONS. 
THEY PRESENTED HIM THE WORDS, "AND THIS, TOO, SHALL PASS AWAY." HOW MUCH IT EX- 
PRESSES! HOW CHASTENING IN THE HOUR OF PRIDE! HOW CONSOLING IN THE DEPTHS OF AFFLIC- 
TION! "AND THIS, TOO, SHALL PASS AWAY." AND YET, LET US HOPE, IT IS NOT QUITE TRUE. LET 
US HOPE, RATHER, THAT BY THE BEST CULTIVATION OF THE PHYSICAL WORLD BENEATH AND AROUND 
US, AND THE INTELLECTUAL AND MORAL WORLD WITHIN US, WE SHALL SECURE AN INDIVIDUAL, SO- 
CIAL, AND POLITICAL PROSPERITY AND HAPPINESS, WHOSE COURSE SHALL BE ONWARD AND UPWARD. 
AND WHICH, WHILE THE EARTH ENDURES, SHALL NOT PASS AWAY. -ANNUAL ADDRESS BEFORE THE 
WISCONSIN STATE AGRICULTURAL SOCIETY, AT MILWAUKEE, WISCONSIN. SEPTEMBER 30, 1859. 
ABRAHAM LINCOLN, "COMPLETE WORKS," VOL.1, P. 579 FF. 



92 



BIOLOGY OF AGKICULTURAL PRODUCTION 93 



Agricultural efficiency. Wherever possible let each member 
of the class choose some local plant or animal industry and 
c ollect records, establish working standards, and figure out the 
local percentage of efficiency. This might well form the main 
thesis work of the year, and, in a community in which agricul- 
ture is important, by distributing theses to cover the different 
crops we may make this work contribute to civic advancement. 
A recent estimate by Emerson yields the following results : 

STANDARDS AND PERCENTAGE OF EFFICIENCY FOR 
FOLLOWING CROPS 





STANDARD YIELD 

PER ACIfE 


AVERAGE 
YIELD 


PER CENT OF 
EFFICIENCY 


ANNUAL Loss BY 
Low EFFICIENCY 


J 'otatoes 


500 bu. 


1)0 bu. 


19 


$900,000,000 


Wheat 


50 bu. 


14 bu. 


28 


1,000,000,000 


Cotton 


1 bale 


0.35 bale 


86 


1,000,000,000 


( ,'orn ! 


100 bu. (record 239 bu.) 


28 bu. 


28 


2,680,000,000 


( )ats i 


100 bu. (record 2094- bu.) 


32 bu. 


32 


585,413,000 



The standard of 500 bushels of potatoes per acre is ad- 
mittedly low. By the mere addition of brains (" cultivated 
thought ") to breeding and selection of variety, and scientific 
precision in fertilizers and culture methods, this standard 
] night be raised to 1000 bushels, possibly, without increasing 
per-acre cost of operation, except to pick up the additional 
-~>00 bushels. Probably Lord Rosebery holds the world's 
record : 2053 bushels of potatoes 1754 marketable and 299 
bushels of culls per acre. With the standard at 2000 bushels 
our scale of efficiency falls to 4| per cent. 

Hills of potatoes vary remarkably in the same field, and 
beginnings have been made in " hill selection " of seed on this 
account. Tubers planted from strong hills have thus been 
Jbund to yield as high as sixteen times as many pounds as 

1 Data obtained elsewhere. 



94 



CIVIC BIOLOGY 



tubers from weak hills of the same variety. Little, however, 
has been done by way of recording the yields of single hills. 
Gmbb gives 16 tubers, weighing 8 pounds, as the ideal hill 
in field culture. Perry Nathan Pickett, aged twelve years, in 

connection with his industrial 
project work in Salem, Ore- 
gon, in 1914, produced a rec- 
ord hill of Burbank potatoes, 
containing 1 3 large and 2 small 
tubers, weighing 16 pounds. 
A record hill from Lexington, 
Oregon, yielded 24 pounds, 
and Carl Gabriels on, aged 
eleven, Puyallup, Washing- 
ton, has reported a volunteer 
hill in his school garden 
that dug 103 potatoes, rang- 
ing from 12 ounces to the size 
of a lien's egg and weighing 
40 pounds 12 ounces. If we 
know how to raise one hill 
best, we may extend this 
knowledge to any number 
of hills. Hence, for an ele- 
mentary standard unit the 
single plant will be a more 
usable one than the plot or 
acre. Any boy can find a 
place to raise one or ten hills 
of potatoes; he may try a different experiment on each hill, 
and thus learn more from a single hill than he might from 
an acre. The same is true of a single plant of wheat, corn, 
tomato, cabbage, lettuce, strawberry, blackberry, raspberry, 
grape, peach, apple, pear, rose, lily, or anything else. 




FIG. 47. Growth race between potatoes 

Potatoes weighed 186.7 and 9.8 g. At end 
of fifty-eight days the roots had grown 
8640 ft. and 155 ft. respectively. Photo- 
graph by Frances W. Tufts 



BIOLOGY OF AGRICULTURAL PRODUCTION 95 

It is interesting that Lincoln should state the problem so 
clearly, more than fifty years ago. 1 

My first suggestion is an inquiry as to the effect of greater thorough- 
ness in all departments of agriculture than now prevails in the North- 
west perhaps I might say in America. To speak entirely within 
hounds, it is known that fifty bushels of wheat, or one hundred bushels 
of Indian corn, can be produced from an acre. Less than a year ago I 
saw it stated that a man, by extraordinary care and labor, had produced 
of wheat what was equal to two hundred bushels from an acre. But 
take fifty of wheat, and one hundred of corn, to be the possibility, and 
compare it with the actual crops of the country. Many 'years ago I saw 
it stated, in a patent-office report, that eighteen bushels was the average 
crop throughout the United States ; and this year an intelligent farmer 
of Illinois assured me that he did not believe that the land harvested 
in that State this season had yielded more than an average of eight 
bushels to the acre ; much was cut and then abandoned as not worth 
threshing, and much was abandoned as not worth cutting. As to Indian 
corn, and indeed, most other crops, the case has not been much better. 
For the last four years I do not believe the ground planted with corn 
in Illinois has produced an average of twenty bushels to the acre. 

Lincoln admits too much for the sake of argument, however, 
when he says : 

Unquestionably it will take more labor to produce fifty bushels from 
an acre than it will to produce ten bushels from the same acre ; but will 
it take more labor to produce fifty bushels from one acre than from 
five ? Unquestionably thorough cultivation will require more labor to 
the acre ; but will it require more to the bushel ? 

Recent experiments have proved that less labor, rather than 
more, may produce the larger crop. Goethe's proverb, Nichts 
1st schrecklicher als tdtige UnwissenJieit, "Nothing is more ter- 
rible than active ignorance," applies with unusual force to the 
delicate task of raising a plant best. 

The most laborious and expensive factor in growing a field 
of corn has been "thorough cultivation." After this had been 

i Abraham Lincoln, Complete Works, Vol. I, p. 577. 



96 CIVIC BIOLOGY 

tearing off half the roots of the corn plants for centuries, 
and laboriously reducing the yields from 30 to 50 or more 
bushels per acre, some one hit upon the idea of studying 
applying " cultivated thought " to the roots of the single corn 
plant. It was discovered that many of them spread out near 
the surface, five, six, or even seven feet in every direction. 
Next came the thought, May not too deep cultivating injure 
these roots ? The experiment has now been tried of shaving 
the weeds without stirring the soil at all, applying careful 




FIG. 48. Two plots of corn on peaty swamp land 

Left, fertilized with phosphorus (not needed) ; crop, 0. Right, fertilized with 

potassium ;. crop, 72 bushels per acre. Seed, cost of fertilizer, and labor on the 

two plots about equal. Photograph by Cyril G. Hopkins 

shallow tillage to comparable rows in the same fields. Results 
have shown, on the average, equal yields from the uncultivated 
rows. Figure out, for your farm, township, county, state, or 
for the United States, how many dollars' worth of labor this 
one discovery may save annually. 

Pure-bred selected strains. Again, we have learned that by 
breeding and selection of productive strains the crop may be 
increased without additional labor. This fact gives the added 
value to pure-bred stock in animals and plants. Half the plants 
in an ordinary field of potatoes or corn may be "loafers"; half 
the trees in an ordinary orchard may be " resters " ; half the 



BIOLOGY OF AGRICULTURAL PRODUCTION 97 



liens or cows in the ordinary barnyard may be fc boarders.'' A 
single specimen of plant or animal may produce a phenomenal 
}ield, but the progeny may revert to loafers and boarders. 
Pure-bred strains have been carefully selected for generations, 
until all bad heredity has been weeded out and the progeny 
(an be relied upon to be thoroughbreds, that is, to yield a 
uniform, standard result. Collect records of various pure-bred 
strains in the neighborhood and compare yields, as below : 

DIFFERENCES IN YIELD DUE TO VARIETY, EXPERIMENT STATION, 
ROSTERN, CANADA 





YIKLD 
PER ACRE 


WEIGHT 
PER BUSHEL 


TIME TO 
MATURE 


UNMARKET- 
ABLE 


Huron wheat 


73 bu. 


59 Ib. 


107 days 




Marquis wheat .... 
Kubanka wheat .... 


70 bu. 
37 bu. - 


(51 Ib. 
52 Ib. 


98 days 
107 days 




1 Jeeves' Rose potato . . 
American Wonder potato 


623 bu. 
371 bu. 






40 bu. 

58 bu. 



Diseases-resisting strains. Variation applies to immunity 
from disease as well as to any other character, and hence the 
world is being searched for strains of animals and plants which 
Lave developed resistance to prevailing diseases. Cattle from 
India are being introduced into the south, because they are 
immune to Texas fever. The ordinary Crimson Rambler rose 
is much infested with mildew, while Van Fleet's seedling is 
[ractically immune to it. Such immunity may extend even to 
freedom from insects, as shown by many foreign introductions, 
notably Rosa rugom and the flowering quince and snowball 
from Japan. Thus in all sorts of epidemics it is of great im- 
portance to note any immune individuals, and these should 
be carefully preserved with a view to development of resistant 
s rrains. Collect the data on any local work along this line. 

A good case in point occurred recently in the cabbage industry 
o' southeastern Wisconsin. A fungus suddenly appeared which took 



98 



CIVIC BIOLOGY 



practically the entire crop. The Agricultural Department at Madison 
was appealed to for help, and the experts, on visiting the infested terri- 
tory, found here and there a cabbage plant that had not been attacked. 
Seed was saved from these specimens and a resistant strain secured. 
Another example is the resistance of mazzard stock to cherry gummosis. 

Problem of soil fertility. Fifteen chemical elements com- 
monly enter into or constitute the plant body. They are natu- 
rally the most abundant elements of air, water, and earth. 
Take, for example, the composition of corn : 



Elements obtained in abundance from air 
and water. 

Elements that the corn plant must get from 
the soil, and that we must buy if they are 
deficient. 



Elements seldom lacking in the soil in the 
small amounts required, except calcium, 
which in regions free from limestone is 
often added to w sweeten," or correct acid- 
ity in, soils. 



An acre of soil 6J inches deep weighs 2,000,000 pounds, 
and if we analyze this and determine how many pounds of 
the necessary elements it contains, and if we know how many 
pounds of these elements are removed in a given crop, we can 
figure roughly how long the soil will " last," that is, be able 
to produce the crop. Hopkins has done this in the table on 
the following page. 2 





PER CENT 


Oxygen . . . 
Carbon . . . 


46.000 ^ 
45.000 


Hydrogen . . 
Nitrogen . . 
Phosphorus 
Potassium . . 


6.400 , 
1.7601 
.300 
.340 J 


Magnesium 
Calcium . . 


.125' 
.022 


Iron .... 


.008 


Sulfur . 


.004 


Silicon . 


.014 


Sodium . 


.013 


Chlorin . 


.013 


Aluminium 




Manganese 
Total . 


99.99 i 



1 Cf . Hopkins, Soil Fertility and Permanent Agriculture, p. 18. 

2 Ibid., p. 59. 



BIOLOGY OF AGRICULTURAL PRODUCTION 99 
RELATIVE ** SUPPLY AND DEMAND " OF SEVEN ELEMENTS 



ESSENTIAL PLANT-FOOD 
ELEMENTS 


POUNDS IN 2,000,000 
POUNDS OF AVER- 
AGE SOIL 


POUNDS IN 100 
BUSHELS OF 
CORN 


YEARS SUP- 
PLY WILL 
LAST 


Phosphorus 


2,200 


17 


130 


Potassium 


49,200 


19 


2,600 


Magnesium . . .... . . 


48,000 


7 


7,000 


Calcium 


68,800 


H 


55,000 


Jron 


88,600 


i 


200,000 


Sulfur 


2,200 


i 


10,000 


Nitrogen (virgin N.W. soil) 1 . 


6,936 




69 


Nitrogen (in air over acre) l . 


70,000,000 


100 


700,000 



Of course the problem is not as simple as this table would indicate, 
because these elements are being returned to the soil in various ways 
from the air and from the decay of plants and from animal wastes. The 
1 able does show what tends to happen in the ordinary process of deple- 
tion from continuous cropping, if care is not taken to thus return the 
needed elements to the soil. 

The three absolutely essential elements which are likely to 
limit productivity of a soil are nitrogen, phosphorus, and po- 
tassium. Nitrogen, the most vital of all, does not exist in 
combination as a mineral in the soil, but must be added from 
the decay and waste matters of animals and plants or by bac- 
i erial action. Of the other two, phosphorus is likely to be the 
limiting element, but potassium compounds, as well as those 
(f calcium, are so easily soluble that they are likly to be 
completely leached away, as was the case in the peaty loam 
soil (Fig. 48). No matter what the abundance of the others, 
1 ick of any essential element limits plant growth ; it is like a 
storehouse full of food, with the key lost. This is well shown 
in the Maryland Experiments with Lime. 2 



1 Added to table from p. 559. 

2 Cf . Hopkins, Soil Fertility and Permanent Agriculture, p. 167. 



100 CIVIC BIOLOGY 

PRODUCE IN ELEVEN YEARS, PER ACRE 





BUSHELS OF COKK 
IN FOUR CROPS 


BUSHELS OF WHEAT 
IN THREE CROPS 


TONS OF HA YIN 
FOUR CROPS 


No lime . . ,.-.' . 
Ground shells (2500 Ib.) 


98 
145 


32 
43 


2.60 
4.20 



Learn the results of local experiments in fertilizing land 
and collect all available records and data on local soil analyses 
and surveys. The possible value of such work is well demon- 
strated in the following from the Oswego Experiments with 
strawberries : 

RICH BOTTOM LAND, SEASON FAIRLY DRY (181)7) 

Plat 1 : 350 Ib. dissolved rock per acre ; yield, 13,507 qt. 
Plat 1 1 : 700 Ib. dissolved rock per acre ; yield, 20,006 qt. 
(An expense of $7.00 made, a gain of $353.55 over Plat I.) 

Value of land. Some land may be dear as a gift. Agricul- 
tural nitrogen is worth $0.15 a pound, potassium $0.06, ground 
limestone $0.005, and phosphorus $0.03. At these prices let us 
compare the values of two samples of land. 

POUNDS IN 2,000,000 POUNDS OF SOIL 



PLANT FOOD 


MANITOBA 


VALUE 


BAVARIAN BARRENS 


VALI-E 


Phosphorus . . . 
Potassium .... 
Nitrogen .... 
Calcium .... 


2,530 
17,100 
20,100 

27,000 


$75.90 
1,026.00 
3,015.00 
135.00 


Trace 
None 
Trace 
1380 


$0.00 
0.00 
0.00 
6.90 


Total values . . 


.... 


$4,241.90 




$6.90 



Of course, beyond a certain limit additional amounts of any 
plant food may not be of immediate value, but the above fig- 
ures indicate a fundamental reason for the rush of agricultural 
emigration to the northwest. Still, with all the experience of 



BIOLOGY OF AGRICULTURAL PRODUCTION 101 



the past with exhausted and abandoned soils, the people 011 
these rich lands are again talking of the " inexhaustible f er- 
lility" of the soil, and burning their straw and manure or 
hauling the latter onto the ice to befoul their streams. A 
comparison of virgin soil in the Canadian "Northwest with soil 
adjoining it which had been cultivated twenty-two years 
showed a loss of nitrogen per acre from 6936 to 4736 pounds, 
or 2200 pounds, a loss of $3-50.00 worth of nitrogen per acre. 

FERTILITY CONTAINED IN DIFFERENT FARM CROPS 
(Approximate maximum amounts removable per acre annually) 









POI'NDS 




TOTAL 






NlTROUKN 


PHOSPHOR i s 


POTASSIUM 


VALUE 


Corn, grain . . . 
Stalks, cobs . . . 


100 bu. 
ST. 


100 
50 


17 
i 


19 
54 


$16.65 
10.93 


Corn crop . . . 
Wheat, grain .. . 
Straw ...!.. 


50 bu. 
2i T. 


150 

71 
25 


2:!. I 
12 
4 


73 
13 
. 45 


27.58 
11.79 
6.57 


Wheat crop . . 
Alfalfa hay . . . 
Cotton lint . . . 
< 'otton seed . . . 
( !ot,ton stalks . . 


8 T. 
1,000 Ib. 
2,000 Ib. 
4,000 Ib. 


96 
400 ! 
3 
63 
102 


16 
36 
.4 

11 
18 


58 
192 
4 
19 
59 


18.36 
72.60 
.70 
10.92 
19.38 


Cotton crop . . 
Potatoes . . . . 
Apj)les 


300 bu. 
600 bu 


168 
63 

47 


29.4 
13 
5 


82 
90 
57 


31.00 
15.23 

10 62 


Leaves 
Wood growth . . 


4T. 

^Q of tree 


59 
6 


7 
2 


47 
5 


11.88 
1.26 


Apple crop . . 
1 'at cattle .... 
Fat hogs .... 
Milk 


l,0001b. 
l,0001b. 
lOOOOlb. 


112 
25 

18 
57 


14 

7 
8 

7 


109 
1 
1 
12 


23.76 
4.02 
2.85 
9 48 


] '.utter 


400 Ib. 


8 


2 


0.1 


.14 















1 Much of this nitrogen is taken from the air, and the roots go so deep that 
even the phosphorus and potassium may be largely supplied from layers of 
soil below the reach of other crops. 



102 CIVIC BIOLOGY 

Losses in plant food due to cropping. Too many have not 
counted the cost of a crop to Mother Earth, and hence have 
taken it as a free gift, with no thought of making any return. 
The table above, modified from Hopkins, 1 shows what a few 
typical crops actually take from the soil. 

Complexity of the problem. It remains to add that the prob- 
lem of soil fertility is much more complicated than the above 
brief statement would seem to indicate. Warren says : "The 
fertile surface soil may be carried away by erosion, by wind, 
or water. ProBably more soil fertility is lost in this way than 
by cropping." 2 So the humus may be exhausted, and with it 
the soil may lose its power to hold moisture, so that it becomes 
hard and dry, and plant food in any amounts is of no avail. Or 
soil may be too wet and require drainage, and too free drain- 
age may rapidly leach away nitrates, potash, and lime. Chem- 
ical changes are going on within the soil, and additions are 
being made to it from the air, which lead some authorities to 
claim that mineral plant foods are practically inexhaustible. 
Poisonous substances, it is claimed, are excreted by the roots 
of certain plants, so that proper rotation of crops is all that is 
needed to maintain fertility indefinitely. That is, the soil is 
" A bank account which requires for its maintenance only the 
rotation of the check book among the members of the family ! " 
Hopkins sums up the whole matter as follows : 

The possible enormous and irreparable damage of such teaching lies 
in the fact that even our remaining supply of good land will ultimately 
be depleted . . . beyond the point of self-redemption, thus repeating the 
history of our abandoned Eastern lands, where the rotation of crops was 
the common rule of practice for more than a hundred years. 

Problems in animal industry. Perhaps the most important 
dairy records are those of Professor Fraser of the University of 
Illinois. He tested 554 cows in 36 commercial dairy herds, each 

1 Soil Fertility and Permanent Agriculture, p. 154. 

2 Farm Management, p. 184. 



BIOLOGY OF AGEIOULTUEAL PRODUCTION 103 

for a full year. The best 25 per cent produced 301 pounds of 
butter fat per year ; the lowest 25 per cent only 133.5 pounds. 
He concludes from the experiment as follows : " If it costs $30 
a year to feed the poorer cows and $38 a year to feed the better 
ones, then at present prices a herd of 25 of the better will 
produce as much net profit as would 1000 of the poorer cows." 
The Holstein, Banostine Belle de Kol, held the world's 
record for butter fat in 1912 1058 pounds in one year. 




By courtesy of the Ohio Farmer 

FIG. 49. Banostine Belle de Kol 

According to above figures, five such cows would yield the 
net product of 25 of the better dairy cows, and their calves 
might be worth even more for breeding purposes. The highest 
dairy record for 1913 is 1073 pounds of butter fat, scored by 
May Rilma, a Guernsey. And so progress in every branch of 
agriculture becomes a game which, if well played, may ever 
' lighten and sweeten toil." 

Poultry offers perhaps the most practicable field for ele- 
mentary experiments in the breeding and care of animals, and 



104 



CIVIC BIOLOGY 



any branch of the industry, from pigeons and chickens to geese 
and turkeys and native game birds, is likely to yield a sub- 
stantial profit from the start. One of the chief problems of 
present interest is that of breeding for egg production, the 
accepted unit being the number of eggs laid in a year. Some 

recent American records are 
shown in the table below. 

Variations in growth of flesh 
or fat are similar to those in 
milk and egg production. This 
means that one animal may 
not digest or assimilate food 
as well as another, or one may 
use its energy in developing 
nervous activity (which is not 
edible) while the other is grow- 




FIG. 50. Hen C. 521 



Bred by Professor James Dryden, 
Corvallis, Oregon 



ing flesh and fat. Experiments 
have shown that one animal 
may thus require over 30 per cent more food to gain a pound 
of flesh than another. Here selection and thorough breeding 
are saving enormous losses and increasing productive efficiency. 

AMERICAN EGG RECORDS 



YEAR 


NUMBER OF EGGS 


DESCRIPTION OF HEX 


1910 
1911 
1912-1913 


282 . 
281 
303 


Barred Plymouth Rock, .Agricultural 

College, Guelph, Ontario 
White Plymouth Rock, Lady Showyou, 
Illinois 
Hen C. 521, cross between white Leg- 
horn and barred Plymouth Rock. 
Reared at the Oregon Agricultural 
College, Corvallis, Oregon 1 



1 This is held to be the world record up to date. In attempting to make 
a record of this kind it is necessary to have official control to guard against 
any possible mistakes or falsification, if the records are to stand. 



BIOLOGY OF AGKICULTUKAL PRODUCTION 105 



Special problems. Keep the record of a cow and figure profit or loss 
on basis of cost of feed and care. Trap-nest a flock of hens and study 
variation in egg production, making results the basis for future breeding 
and improvement of flock. 

Try different chemicals or fertilizers in strips across the rows in 
the garden, to discover special needs of soil or crop. 




FIG. 51. Growth and oppor- 
tunity 

One of the 8 carrots, thinned 
to 4 to the foot, which weighed 
11 pounds, and the smallest 
of 50 carrots, vinthinned and 
standing 25 to the foot, which 
weighed 1.7 pounds 




FIG. 52. Parsnips show- 
ing result of a hard spot 
in the row 



Experiment with different consistency of soil : trench a strip two or 
three feet deep, dynamite a strip, or even leave a hard strip across the 
garden, in order to study differences in production due to tillage (Fig. 52), 
and thin plants to different distances (Fig. 51). 

Test seeds of all kinds before planting in garden or field. By blow- 
ing off the light, small seeds and planting the 5 or 10 per cent of the 
heaviest and strongest seeds, crops of remarkable vigor and evenness are 



106 CIVIC BIOLOGY 

secured. Saving seed from strong, productive plants potato, wheat, corn, 
cotton, timothy has given rise to a large increase of production without 
other change or difference in method of cultivation. 

In order to unite the work of the school with the interests of the 
community, offer to test all kinds of seeds, especially corn, if in a corn- 
raising section. An increase of from 30 to 40 per cent in the corn crop 
of the district has resulted from such testing. 

A most remarkable fact has developed with reference to seed potatoes. 
Immature tubers, about half or two thirds grown or ripened, may pro- 
duce twice as many potatoes as dead or so-called overripe seed from the 
same field. Immature seed potatoes are specially raised and saved in 
Europe, and this one factor may account for the great difference in favor 
of European over American yields more than 2000 bushels per acre 
as compared with less than 1000 as the best American record. This 
must be a matter of activity, or vigor, of buds, or of availability of the 
starch food supply. For information on raising seed potatoes, write your 
state experiment station. 

Work for record production of thoroughly cultivated, pure-bred, pedi- 
gree single plants the world-record hill of potatoes, the best plant of 
corn, wheat, cotton, oats, sunflower, tomato, cabbage, currant, raspberry, 
blackberry, grape, peach, plum, cherry, apple, etc. More may be learned 
from intensive practical study of a few plants, each of which is a special 
experiment, than from any number of less intelligently cultivated acres. 

In all such problems, with both animals and plants, we need 
to learn all we can about the laws and forces of heredity, 
breeding, and breeds, and also all we can about favorable en- 
vironment, feeding, care, and treatment. The former topics are 
treated further in the appropriate chapters. The latter should 
be made subjects of special study whenever it is possible to 
have the care of either an animal or a plant, and to secure an 
authentic record. Any one, by applying " cultivated thought," 
may render a world service by winning a new world record. 



CHAPTER X 

INSECT TYPE PROBLEMS: IMPORTANT FLIES 

If each egg of the common house fly should develop, and each of the 
larvae should find the food and temperature it needed, with no loss and no 
destruction, the people of the city in which it happened would suffocate 
under the plague of flies. JORDAN and KELLOGG, "Evolution and Animal 
Life," p. 59 

And as for the typhoid fly, that a creature born in indescribable filth 
and absolutely swarming with disease germs should be practically invited 
to multiply unchecked, even in great centers of population, is surely nothing 
less than criminal. L. 0. HOWARD 

What flies do. During the Spanish-American war typhoid 
fever wounded 20,738 United States soldiers and killed 1580. 
The chief means of spreading this infection were the swarms 
of flies which infested the army encampments. To emphasize 
this menace to health, Dr. Howard has suggested that we 
change the name of the house fly to typhoid fly. This opened 
the way for thorough investigation of the insect, and its filthy 
habits were soon found to render it the possible distributor 
for many other filth-disease infections. Tuberculosis, cholera, 
enteritis (including epidemic dysentery and cholera infantum 
the fly-time "summer complaint" of infants), spinal menin- 
gitis, bubonic plague, smallpox, leprosy, syphilis, gonorrhea, 
ophthalmia, and the eggs of tapeworms, hookworm, and a num- 
ber of other parasitic worms for all these and many more the 
fly has been discovered to be a ready actual or potential carrier. 
Since the fly is proved to be such an active agent of transmis- 
sion between all manner of filth, on which it feeds and in which 
it breeds, and human foods, Dr. Stiles, of the Hookworm 
Commission, has proposed to call it the filth-disease fly. 

107 




FIG. 53. Flytraps for barnyard or stable window 

1, first model as found after being set one week ; 2, same, emptied by lifting off 
top frame ; trap lifted from bottom board to indicate construction ; 3 and 4, larger 
window trap, showing construction and in position. The small traps in 3 are 
merely to take off samples of the catch for analysis. These traps are made to fit 
the window about which flies naturally congregate, gunny sacks are hung over 
the other windows to darken them and to flap in the wind, and, when properly 
placed and managed, one trap will catch practically all the house, stable, horn, 
black, bot, and blow flies and even the mosquitoes that try to get in or out, or 
that either feed or breed about the stable 
108 



IMPORTANT FLIES 



109 



First necessary step in health conservation. The most sig- 
nificant fact in the situation is that only by eliminating the 
fly can we form any notion of how much present sickness it 
is causing. On this account health officers everywhere are 



The figure may be supposed to 
represent a model 12 inches wide, 
12 inches tall, and 10 inches thick 
a convenient size for ordinary 
use in a city yard. The specifi- 
cations Avill then be : two end 
boards \ inch or \ inch thick, 
12x10 inches ; four strips for the 
top frame, Ix \ inch, two 12 inches 
and two 9 inches long ; wire for 
top frame, 10 x 12 inches (raw 
edges folded* over \ inch); two 
top shoulder strips lx inch, 11 
inches long ; four bottom strips 
j inch thick and 12 inches long, 
two \ inch wide and two 1 inch 
wide ; screen wire for sides and 
bottom in one piece, 12 inches 
wide and 41 inches long (allow 
1 inch to fold over raw ends, 
I inch each) 



FIG. 54. Cross section and detail of stable-window or barnyard flytrap 

These traps may be of any convenient size, to suit conditions, and may be made 
of box boards, strips, and screen wire. It is well to plan to use wire of standard 
Avidths. If used on the ground, the traps may be made without the trap-folds in 
the sides, which do most of the catching when the trap is set in a stable window. 
Fold the wire squarely at the angles indicated in the figure. A, B, C, I), E, F, G, and 
at these points snip in 2 inch. Fold the s-inch flaps to a right angle, turning them 
in directions indicated by small hooks along the course of the wire (dotted line). 
This allows the bottom ridge and the trap-folds to drop smoothly inside the end 
boards, and the flaps are tacked to the end boards to help hold the wire in place 
and make the trap absolutely fly tight so far as any cracks along the corners are 
concerned. The holes in the wire are punched by pushing ten 40-penny wire spikes 
through the exact apex of the bottom ridge, about 1 inch apart. If good bait is 
used, the flies may become much crowded here. (This must be a sharp 90 angle, 
not a rounded dome, or the flies will not find the holes.) Three holes are suffi- 
cient for the side folds. Punch all these holes after the wire is tacked in place. 
The trap is really as simple as a box. With proper tools a boy ought to cut out the 
end boards, rip out the strips, nail up, fold, and tack the wire, all in about one 
hour. The main feature of the trap is the 5-inch crack opening upward to the bait 

saying, in effect, " Clear the air of this universal distributor 
of filth, in order that we may be able to trace other ways of dis- 
ease infection." Thus extermination of flies comes to be the 
necessary first step toward the effective prevention of disease. 



TOP FRAME 
remove, to empty trap 




110 CIVIC BIOLOGY 

The evidence we have indicates that almost all dysentery and 
summer complaint (millions of cases and 56,000 deaths annu- 
ally) are caused directly by the house fly. One third of the 
typhoid (about 300,000 cases and 30,000 deaths) is estimated 
to be caused by flies, and an unknown and unknowable pro- 
portion of tuberculosis, spinal meningitis, and other filth infec- 
tions. Thus it is quite possible that flies carry the infections 
which cause from 70,000 to 100,000 deaths annually. About 
2 people in the United States die yearly from bites of poisonous 
snakes ; rabid dogs bite about 100 with fatal effect. Can you 
think of a more deadly animal than the common typhoid, or 
filth-disease, fly ? 

Spread of animal diseases. An additional factor is the prob- 
able causation of disease among domestic animals. As they 
are not even partially protected by screens, and flies swarm 
about their foods, epidemics of such diseases as fowl and 
hog cholera, bovine and fowl tuberculosis, and foot-and-mouth 
disease are almost certainly spread by flies. This matter has 
not been investigated as it should be, but we are likely to 
see a remarkable clearing up of animal diseases as soon as we 
exterminate flies from our farms. 

Futility of fly screens. Finally, a minor consideration is the 
(estimated) $12,500,000 we pay annually for screen windows 
and doors, which are not only expensive but disagreeable at 
best. These do not solve the problem, even if they did keep 
the pests out of our homes. We must prevent flies from 
contaminating foods on the farms and in the stores and mar- 
kets of our cities. Thus the fight against the common enemy 
must be community- wide, and, since one careless or ignorant 
household can breed flies enough to infest all the houses within 
a quarter of a mile, positively every one must cooperate. 

Need of universal cooperation. The general situation, espe- 
cially the relations between country and city, is shown so 
clearly in the following case that we quote in full from the 



IMPORTANT FLIES 111 

Bulletin of the Indiana State Board of Health, July, 1910. 
The note is entitled 

THIS HAPPENED IN INDIANA 

A few days ago a physician in Martin County called on the state 
bacteriological laboratory for Flexner's antimeningitis serum. Dr. 
Simonds went to the case and found a seven-months-old baby suffering 
from a very severe gastro-enteritis with the not infrequently accom- 
panying meningism. The father of the child was a farmer living in a 
f )ur-room house with few or no modern conveniences. On the wall of 
t le largest room was a family-history chart done in brilliant colors, 
v ith three columns of lines for the record of marriages, births and 
deaths. The parents had been married ten years and six children had 
been born to them. In the death column were the names of four chil- 
dren, all under two years of age. Another name has since been added 
to this list. 

The cause of this sad story became evident on inspection. There 
was a shallow surface well in the back yard, a short distance from an 
open privy. A large pile of manure lay uncovered, almost against the 
side of the barn. If this farmer had attempted so unthinkable a thing 
as transforming his premises into a fly hatchery for commercial pur- 
poses, he could not possibly have achieved a more brilliant success. 

The family and several of the neighbors were eating dinner on the 
back porch. Flies were swarming all over the table, but showed a special 
liking for a particular dish. They were so thick 011 this that it was 
absolutely impossible to tell definitely what it contained until one of 
fc]ie neighbors swung her arm over the table and cleared them away long 
enough for one, by looking quickly, to see that the dish contained cot- 
tage cheese. The flies were so thick in the house that it was only with 
d ifficulty that they were fought away from the field of the spinal puncture 
and kept from lighting on the instruments. 

On the death certificate the cause of the death of this child was 
doubtless given as " Gastro-enteritis." It would have been more in keep- 
ing with the facts to have said "Poisoned by Flies." 

Different kinds of flies. About 43,000 different kinds of 
flies and related gnats and mosquitoes have been described, 
and Dr. Howard estimates that this group of insects contains 
no less than 350,000 species for the whole world. One large 



112 



CIVIC BIOLOGY 



family, the tachina flies, many of which look much like com- 
mon house flies, feed upon other insects and are among our 
most effective helpers in holding certain insects in check. 
Tachina flies are being imported from Europe to destroy gypsy 
and brown-tailed moths. Syrphus flies are another large family 
which feed upon other insects. Tachina and syrphus flies are 
found about rank vegetation in which other insects abound. 
Of flies caught in and about houses the typhoid fly gener- 
ally numbers over 90 per cent. It is distinguished by the 
" elbow '' on the fourth vein as it curves up to the third 
vein near the tip of the wing (Fig. 55). The proboscis is an 

extensible trunk adapted for 
lapping up liquids, and cannot 
be used for either biting or 
piercing. The foot is provided 
with claws for climbing over 
rough surfaces, and also with 
two pads (pulvilli) covered 
with sticky, tubular hairs, 
which enable the fly to walk 
on ceilings and windowpanes. 
No more effective mechanisms 
for collecting dust could be designed than a fly's feet and 
proboscis, a combination of six feather dusters and thirteen 
damp sponges. The constant " cleaning " movements of flies 
are clearly designed to rub off and scatter the adhering germs 
everywhere they go. 

The " little house fly " (Fannia canicidaris), smaller than the 
common fly, is often seen in swarms hovering under chandeliers. 
In breeding and feeding habits it resembles the house fly. 
Other flies found about houses are the following : 
Bluebottles, greenbottles, and flesh flies, or blowflies, which 
so frequently lay their eggs on meat. These flies are scav- 
engers, but we can dispose of dead animals in much more 




FIG. 55. Wings of (a) house fly, 
(6) stable fly, (c) little house fly, 

(d) horn fly 
Photograph by I. A. Field 



IMPORTANT FLIKS 



113 



sanitary ways than by leaving them to the blowflies. Related 
to these, and of importance in the southern states, is the screw- 
\vorm fly (Ckrysomyia macellaria), which oviposits on wounds, 
the maggots feeding upon living flesh. These are the flies that 
sometimes lay their eggs in nostrils or ears of children or of 
people if asleep out of doors in the daytime, the maggots 
< i using painful and even fatal wounds. 

The stable fly (StomoxyB ealcitransi), which has somewhat 
the appearance of the house fly, except that it is provided with 
a strong, piercing beak, sucks the blood 
of animals. This fly is" now convicted 
of inoculating the germs of infantile 
paralysis with its bite. It also causes 
great suffering to cattle. The smaller 
horn fly (Hcematolna serrate), imported 
from Europe about 1886, is another 
bloodthirsty pest of cattle, biting both 
by night and day. It may be recognized 
by its habit of clustering in masses 
around the bases of the horns of cattle, 




and may be trapped by the method FIG. 66 Stable flies that 

J J a boy, with an insect net, 

recommended for the stable fly. caught on a cow in one day 

The black flies, deer flies, sand flies, 

and the many botflies of horses, cattle, and sheep are all of 
civic importance to the districts where they abound. The 
black flies of the genus Simulium are now under suspicion 
as possible carriers of pellagra. They breed in running water. 

Life history of the typhoid fly. In order to discover best 
\A ays of attack, we must study natural enemies from every 
point of view. The ease with which mosquitoes have been 
.exterminated has suggested similar methods for dealing with 
flies. But mosquitoes breed only in stagnant water, which is 
easily drained, filled, stocked with fishes, or oiled. Flies breed 
ii i decaying filth, chiefly in horse manure, but can breed in any 



114 



CIVIC BIOLOGY 



wet, fermenting matter, animal or vegetable. The maggots are 
hard to kill ; they will live for an hour or more in pure kero- 
sene oil and for over half an hour in alcohol. Tobacco kills 
many insects, but house flies have been bred from the snuff 
on a druggist's counter. This means that as long as there are 
flies about, they will find something in which to breed, and 

that, with stables and barn- 
yards, gutters, roadsides, 
and acres of pastures, with 
accidental accumulations, 
lawn clippings, compost 
and rotting weeds and fer- 
menting garbage, preven- 
tion of breeding by doing 
away with breeding places 
and materials is beyond 
human possibility. It is 
easy in comparison to exter- 
minate the breeders them- 
selves. 

Still, proper disposal of all 
this waste matter comes to be 
a problem of greatly increased 
importance when we attempt to 
prevent flies from breeding in 
it. If material becomes infested 
with eggs or maggots, the best 
treatment of it is probably to turn it out in the hot sunshine and 
dry it as completely as possible. If this cannot be done, the maggots 
may be killed by saturating the material with a solution of iron sul- 
phate (copperas), two pounds to the gallon of water. Treatment of 
stables with chloride of lime has been recommended, but this is expen- 
sive and disagreeable, and the fumes (chlorin) are likely to injure the 
animals. Stiles has buried infested material six feet deep and found 
that the flies work their way out. For the farm home the cost of han- 
dling is doubled and fertilizer value reduced from 55 to 69 per cent by 




FIG. 57. Member of Junior Sanitary 

Police of Cleveland 
Photograph by Dr. Jean Dawson 




PLATE II. LIFE HISTORY OF THE GYPSY MOTH 

! , egg cluster ; 2, single egg (enlarged about four diameters) ; 3, caterpillar ; 
'i- and 5, female and male pupte ; (3 and 7, female and male moths ; 8. im- 
ported lion beetle devouring a caterpillar. (All except 2 about natural size.) 



IMPOETANT FLIES 



115 



antiquated methods of storing, piling, and rotting. All stable waste 
should be hauled and spread on the land daily. It will generally become 
too dry for flies to breed in. 

The most expensive and disastrous fallacy in this whole problem 
is the "fly-tight " pit or receptacle for stable waste. This has been and 
still is recommended under the plausible excuse, " Make them fly-tight, 
sc the flies cannot get in to lay their eggs." Eggs by the million are 

laid in the material before it ____ 

is put into the pit ; the tight 
construction makes it an artifi- 
cially perfected fly incubator, 
and when it is opened, as it 
must be daily, the flies swarm 
out. By this method we actu- 
ally go to great labor and ex- 
pense to breed more flies. 

In cities, instead of fly-tight 
stable pits, we should have, 
by city ordinance, readily ac- 
cessible elevated hoppers or 
concrete-floored bins, and the 
city should arrange to empty 
these clean to the concrete at 
least once a week from May 
to October. It would be much 
better, for purity of air and 
economy of fertilizer, to have 
this done daily. By proper or- 
ganization of routes the city 




FIG. 58. 



First model of outdoor fly ex- 
terminator 



This has heen set fifty-eight minutes and 
has caught 2000 flies. It caught 2 quarts 
(ahout 16,000) the first day, and mighf as 
easily have caught 20 quarts if they had 
been there to catch a vacuum cleaner of 
the air for flies. Designed by the author 



sh ould be able to gather and dis- 
pose of the material at greatly 
reduced expense over scattering 
aiid irregular private cleaning. It ought to be managed so as to pay 
stable keepers fertilizer value of material, less cost of handling, and 
still deliver it regularly to gardeners and farmers, as planned for, and 
fo much less than it costs to collect the material privately. If this is 
net feasible, then the proper officers can license farmers and truck 
gardeners to collect from specified stables, under contract to remove 
the material in the cleanly manner specified and at weekly intervals. 
B< sides stables, the city should maintain strict supervision over all 



116 CIVIC BIOLOGY 

stockyards and slaughter-houses, public dumps, aud all industries which 
handle materials likely to breed flies. It is utterly uncivilized and 
brutish that accumulations of filth, which allow flies to both feed and 
breed, should be permitted to vitiate the best efforts of thousands of 
good people, cover their foods and homes with filth, and cause not only 
annoyance but disease and even death. 1 

The eggs of flies hatch in about eight hours into maggots 
which feed actively and complete their growth in six or seven 
days. They then burrow into the ground under a manure pile 
(hence the need of concrete floors) and transform into brown 
puparia, from which they emerge as adult flies in three days. 

After coming out as adults they fly about over an area 
not generally more than one thousand yards in diameter, and 
feed or drink from two hundred to three hundred times a 
day for from ten to fourteen days before maturing their first 
batch of eggs. This actually delivers the enemy into our 
hands. It means that, with flytraps on every garbage can or 
swill barrel, and with everything most attractive to flies very 
carefully kept in these receptacles, not a single fly will succeed 

1 In a large city the writer found, opening on an alley, and within a block 
of a great open public market, a pile of horse manure, entirely unprotected, 
at least thirty feet in diameter at the base and fourteen feet high. The outer 
layer of this whole pile was a solid, moving mass of housefly maggots. 
A moderate estimate for that pile would be ten barrels of fly maggots, which 
would make, when they reached their growth and emerged, from twenty to 
thirty barrels of flies. These flies were swarming black over the meat blocks 
and meats, fruits, fish, candies, cakes. and pies of the whole market. The 
market people (some few had electric fans) were wearing themselves out shoo- 
ing those flies from one to the other and back again. The filth of that manure 
pile was being carried into thousands of homes with the market supplies. 
The flies were feeding in the market and in hundreds of kitchens in every 
direction and going back to the manure to lay their eggs. It is unfair to 
place on the market people the burden of trying to protect their foods from 
flies under such conditions. 

The horses in this large stable were kept on the second floor ; the manure 
could have been cleaned into a hopper opening downward into a dump cart 
in the alley, and every morning before daylight, by effective civic organiza- 
tion of the work, it might have been out in the country and at work in the 
land, a paying proposition instead of an insufferable nuisance. 



IMPORTANT PLIES 117 

in feeding for two weeks without getting caught. In this 
o.ise no more eggs will be laid, and the pests will vanish. 
Possible multiplication. Allowing ten days for eggs to 
become adults, and, for convenience, ten days of feeding 
between emergence and oviposition, figuring that a fly lays 
one hundred and fifty eggs at a batch and lives to lay six 
batches, compute the increase of a pair of flies beginning to 
Liy May first. Half the progeny are supposed to be females. 
Test the following figures : 

May 10 152 flies 

20 302 flies 

30 ' 11,702 flies 

June 10 34,302 flies 

20 911,952" flies 

30 6,484,700 flies 

July 10 .* 72,280,800 flies 

20 . . . 325,633,300 flies 

30 ! 5,746,670,500 flies 

The common-sense question is, Why not let this pair of 
flies catch themselves in May ? This rapid increase also means 
that anything short of extermination is hardly worth the effort. 
A fly is possessed of no more cunning than shot rolling down 
a board, and the last pair will run into a trap as easily as the 
first. Why not let them all catch themselves ? 

Hibernation. Very few house flies survive the winter in 
Canada and the northern states, and these hibernate as young 
adults in cracks about buildings. They come out of winter 
quarters ravenously hungry and feed for about a week, at 
l^ast, before beginning to lay. If at this critical time every 
household had some effective form of outdoor trap ready for 
them, every early spring breeder would be caught, and the 

1 This last figure would equal about 143,675 bushels of flies from one pair 
i;i three months. If we continue the breeding through August and Septem- 
ber, the figure is 1.096,181,249,310,720,000,000,000,000 flies. 



118 CIVIC BIOLOGY 

whole battle would be won for the season. The first commu- 
nity that does this with absolute thoroughness, and whose 
every member is intelligent enough to realize the 143,000 
bushels that one pair might propagate in three months, will 
first be free from the world-wide, time-old plague of the 
" house fly, disease carrier," and from the diseases it carries. 




1 23 

FIG. 59. Outdoor fly exterminator as adopted for manufacture 

1, attached to garbage can (make hole in cover as large as inside of ring, to let 

in plenty of light) ; 2, on ring with which attachment is effected ; 3, on its own 

good-sized bait pan. Designed by the author 

Sketch a plan which shall prevent all flies typhoid, stable, 
horn, and flesh flies from either feeding or breeding about 
your own home. If the fight is carried out of doors into the 
camps of the enemy, this becomes one of the easiest problems to 
solve in the whole range of insect life, and its solution com- 
pletely relieves us of the need of screen windows and doors, 
as far as flies are concerned; and, expense aside, screenless 
windows and doors in summer are a luxury. 



IMPORTANT FLIES 119 

Study and experiment with all the most likely devices on 
the market for outdoor fly extermination, and invent better 
ones yourself, if you can. With the traps already available, 
o itcloor fly extermination, as one man who tried it has said, 
" is so easy as to be almost humorous and so effective (the 
flies disappear so suddenly) as to be little short of the uncanny." 




FIG. 60. " Getthelastone " fly nets 

The handles are long enough to reach the ceiling without stretching and the floor 
without stooping, enabling one to catch any stragglers that may get by the traps 
aiid into the house. Make them of finer-mesh mosquito net according to directions 
(Fig. 5), cutting six nets to the yard. Long-handled swatters were tried, but they 
too often spotted the ceilings and did not prove as effective or easy to use as the 
IK ts. A larger insect net is most effective in exterminating stable and horn flies 
from a dairy. Designed by the author 

Civic fly campaigns. As the fly problem becomes generally 
understood by a community, the campaign comes naturally to 
a dollar-and-cent basis. People will not trade in fly-infested 
stores, markets, or milk depots, or patronize hotels or res- 
taurants that are not free from flies. For this reason store 
ai id restaurant keepers must see to it that no fly feeding or 
breeding is possible on their own premises, and they must 



120 CIVIC BIOLOGY 

insist that all their neighbors do likewise. Thus general civic 
cooperation tends to enforce itself along lines of financial 
necessity. Work out a plan of campaign good enough to in- 
sure enlisting every home. In order to give time for discus- 
sion and publication of plans for the active work the following 
spring, this should be done in connection with insect lessons 
in the early fall, when flies are abundant and troublesome. 
Killing the breeders in the fall is as good or better than kill- 
ing them in the early spring, and on one farm where this was 
done scarcely any flies appeared the next spring, while farms 
half a mile away were swarming with them. 

Nothing can take the place of bringing the actual speci- 
mens into the laboratory and of studying the flies and mag- 
gots as] they swarm in and about the filth of outhouses and 
stables, gutters and spittoons. If every one could be shown, 

could be made to see and study the flies as they live, 

the community would be in the fight to a man, and this 
is all we need for complete success. One teacher who tried 
this writes: 

Last week I had some maggots in horse manure. 1 It was an unusual 
thing to do in school, but I wished to emphasize the idea of filth. I 
think it was successful, for the disgust was great when they saw that 
they changed into flies. People are so irresponsible that they have to 
be shocked to awaken their fighting power. 

Things to avoid in civic fly campaigns. During any season when 
breeding is possible, avoid offering prizes or money enough to encourage 
raising flies. Also, never give more than ten days the time of a gen- 
eration in prize contests during the breeding season. A fortune 
might be made raising flies at ten cents a quart. 

Avoid delay. While spring is the ideal time to start a campaign, one 
begun in midsummer or even fall will result in much good and will help 
educate a community in plans and methods for effective work the 
following season. 

1 This can be done in a safe and cleanly manner by means of large bottles. 
They must be stoppered securely, as maggots are strong and can burrow and 
squeeze through minute cracks. 



IMPOKTANT tf 

It has been customary in many early spring campaigns to offer 
children ten cents a hundred for all house flies brought in before, say, 
the first of May, or before breeding begins in the locality. On this 
basis bills of five or six hundred dollars may be expected in good-si/ed 
cities, and it would probably be better to offer one cent a hundred, and 
be sure to avoid paying for bluebottles, greenbottles, or other large flesh 
flies. These will always be killed along with the rest, but they begin 
active breeding much earlier in the spring and, if not ruled out, might 
easily swamp any treasury. The four flies whose wings are shown in 
Fig. 55 may be included in the list to be paid for. 

Life history of the stable fly. During the summer of 1912 a serious 
outbreak of stable flies occurred in grain-raising sections of northern 
Texas, Oklahoma, Kansas, and Nebraska. Cows fell off in milk and 
even went dry, operations had to be suspended in the fields because the 
animals could not endure the torment of the swarms of flies, and many 
mules, horses, and cattle were killed outright. Investigation showed 
that the flies were breeding in the following substances, named in approx- 
imate order of importance : in the wet, fermenting straw of oats, rice, 
barley, and wheat, and in horse and cow manure, especially where mixed 
with straw. Thus most of the trouble arose from decaying strawstacks 
in the fields and from uncleaned barnyards. The minimal time required 
for the different stages of development was found to be : egg, one day ; 
larva, eleven days; pupa, six days; making eighteen days from egg to 
adult fly. Probably most of the stable flies pass the winter in the larval 
or the pupal stage and so are ready to emerge during warm spells in 
winter and with the first warm days of spring. Where stock can be 
stabled, these flies can be successfully caught in the stable window 
traps shown in Fig. 53. 

Life history of the horn fly. The horn fly breeds exclusively in freshly 
droj >ped cow manure. The flies leave the cows and swarm to fresh drop- 
pings to lay their eggs, often covering the material as thickly as they 
can stand. This occurs especially in the early morning hours, and by 
following the herd a few mornings with a hand sprayer loaded with 
kerosene or any good oil mixture used to keep the flies off from ani- 
mals practically all the horn flies can be killed. Covering the fresh 
droppings with lime also prevents the flies from breeding in them. 

Health statistics. Watch local health statistics and re- 
ports, especially as to typhoid and cases and deaths from 
summer complaint, tuberculosis, and pneumonia, and any 



122 CIVIC BIOLOGY 

other prevalent filth infections. If the stable fly has been 
successfully dealt with, compare the monthly reports on cases 
of infantile paralysis with corresponding reports of previ- 
ous years. 1 

Some people may object to fly campaigns on the ground 
that flies were created for a good purpose. Any such should 
refer to Exodus viii, 31 : 

And he [Moses] removed the swarms of flies from Pharaoh, from 
his servants, and from his people; there remained not one. 

All we ask is that " there remain not one." 

1 While the above is passing through the proof the discovery is announced 
that maggots of flies (species not determined) which develop in the bodies of 
chickens dying of limber neck infect animals to which they are fed with the 
germs of infantile paralysis, or poliomyelitis. All such fowls should be com- 
pletely burned up. If buried, the flies easily work their way to the surface 
and may spread the infection. (Latest evidence points to contact infection 
by human carriers, and excludes any influence of flies or other insects in 
spreading this disease.) 



CHAPTEE XI 
INSECT TYPE PROBLEMS: MOSQUITOES 

Mosquitoes and disease. The discovery that malaria and 
yellow fever are transmitted by certain mosquitoes shows how 







PIG. 61. Anopheles mosquitoes and malaria in a city 

A, Anopheles mosquitoes breeding; dots, houses where malaria occurs. There 
would be more dots in various parts if there were any houses 

mportant a role an insect may play in the affairs of human 
life. No obstacles have so seriously blocked the progress of 
civilization in the tropics as these two diseases. The Panama 

123 






Adults 



Pupoe 




FIG. 02. 

Left, Anophele* (malaria) ; center, Culex pipien.s (common nuisance) ; 
right, Aedes calnpits (yellow fever) 



124 



MOSQUITOES 



125 



Canal has been made possible mainly through the control of 
malarial and yellow-fever mosquitoes. 

Of the ten genera of mosquitoes of North America, Anopheles, 
Aedcs (il e' dez), and (Julex concern us chiefly. There are three 
s] >ecies of Arwph- 
</>*? distributed 
tl iroughout the 
country, and it 
i^ important to 
romember that it 
is through these 
mosquitoes only 
tliat malarial fe- 
ver is spread. 
This disease is 
not as fatal as 
some others, but 
is important be- 
cause so widely 
distributed and 
because in ma- 
larial countries 
from 25 to 60 
per cent of the 
] >eople are af- 
llicted. In the 
United States, 
jtccording to the 
estimate of Dr. 
L. O. Howard, there occur 3,000,000 cases, causing a loss of 
SlOO,000,000, annually. In India, where the fever assumes a 
fatal form, 5,000,000 people have succumbed to it in one year. 

Anopheles is particularly active during the early part of the 
night. It may be distinguished from other mosquitoes at a 




FIG. 63. Aedes calopus Yellow-fever mosquito 
Egg, larva, pupa, and adult 



126 



CIVIC BIOLOGY 



glance by its mottled wings and by its posture. It resembles 
somewhat a thorn in the wall, standing as it does at an angle 
of almost ninety degrees to the surface, with proboscis in line 
with the body, whether the surface is vertical or horizontal. 



Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec, 



1897 



1900 




1897- 



1898- 



5- 1900-1901- 



FIG. 64. Yellow fever in Havana 



Aedes calopus. This is the mosquito responsible for the 
transmission of yellow fever, which in the memory of man has 
left its dead unburied in some parts of our country. Indeed, in 
the early part of the summer of 1905 a mosquito infected with 



MOSQUITOES 127 

yellow-fever blood came on a cargo from Central America to 
New Orleans. The fever spread rapidly and by the middle of 
September 2462 people had been attacked by the disease and 
329 had died. Aedes is the common rain-barrel mosquito of 
the South; it is frequently referred to as the "calico mos- 
quito " because of conspicuous banding of its legs, thorax, 
and abdomen with black and white. This mosquito is unable 
to survive the winter of the Northern states (Fig. 63). 




FIG. 65. Outdoor laboratory work in a malarial district of the city 

Culex mosquitoes. To this genus belong our most common 
household forms. They are generally brown and may be dis- 
ti nguished from Anopheles by the fact that they rest with body 
parallel to the plane of support and head and proboscis bent, 
giving a humpbacked appearance. While these mosquitoes 
are not known to be injurious to health, the annoyance and 
distress they cause furnish ample reason for the general move- 
ment to exterminate them. Culex pipiens is the common 
household pest throughout the country. Howard says these 
mosquitoes will not fly far from their breeding places unless 



128 CIVIC BIOLOGY 

they are carried by light and continued winds. With the 
exception of two species of Oulex that breed in salt marshes 
and migrate for long distances, mosquitoes seldom go more 
than two hundred yards from where they are hatched. In a 
town or city away from these marshes the work of extermi- 
nating mosquitoes is simple and not expensive. Indeed, the 
class in civic biology can accomplish the task as an interesting 
and valuable turn at outdoor laboratory work. Before begin- 
ning the work, however, much more should be learned about 
the habits and life history of the mosquito. 

Habits and life history. Mosquitoes are nocturnal ; during 
the bright part of the day they hide under leaves, in grass, in 
cellars, wells, cisterns, in barns, and in the dark corners of the 
house. Even the " day mosquito," Aedes, does not fly about 
or bite in the bright sunlight of midday. As winter approaches, 
the female mosquitoes seek dark, damp places in cellars, caves, 
hollow trees, and loose bark in which to hibernate. Can you 
find them ? 

Mosquitoes may be distinguished from gnats and other 
mosquito-like insects by the presence of a fringe of scale-like 
hairs on the margins of the wings. 

Like many other insects, especially those that suck blood, 
they are strongly attracted or repelled by different people. It 
is a matter of common experience that some people are annoyed 
by this class of insects much more than others. Odors like a 
mixture of oil of tar, oil of pennyroyal, and olive oil are effec- 
tual repellents, as is also a mixture of cedar oil (one ounce), 
oil of citronella (two ounces), spirits of camphor (two ounces), 
If an odor could be discovered that is highly attractive to 
mosquitoes, it might be effective in ridding a neighborhood of 
the pests if used in connection with a trap or some form 
of sticky fly paper. 

Mosquitoes seem to possess other likes and dislikes. They 
are attracted to dark colors and are repelled by lighter shades ; 



MOSQUITOES 



129 



an I certain musical sounds seem to possess a charm. The song 
of the mosquito varies with the species and with the sex ; it is 
be iieved these insects find their mates by the pitch of their song. 
Mosquitoes are not without their natural enemies. Birds 
(especially nighthawks, swallows, and whippoorwills flying at 
dusk), also bats and dragon flies, feed upon adult mosquitoes. 
One observer reports having found six hundred mosquitoes 




FIG. 00. Collecting mosquitoes 
Equipment : insect nets and smaller scrim nets for use in water 

in the crop of a nighthawk. A minute red mite may often 
be found clinging to mosquitoes, and it is said to greatly 
reduce their numbers in some localities. 

Young mosquitoes are aquatic. Mosquitoes lay their eggs on 
the surface of water, usually about three days after they have 
taken a meal of blood. The eggs are laid in the early morning 
hours and hatch into larvae about two o'clock the same day. 
( nlex lays from two hundred to four hundred cigar-shaped 
eggs which float on end in boat-shaped masses. The larvae, 
hotter known as wrigglers, swim actively about in the water, 



130 



CIVIC BIOLOGY 



feeding upon minute forms of animal and vegetable life which 
are swept into their gullets by the constant motion of little 
brush-like mouth-parts. A long respiratory tube comes from 
the eighth segment of the body, through which the larva 
breathes by opening it to the air. After undergoing three 
different molts the larva reaches maturity and changes into a 
pupa in from ten to fourteen days. The pupa differs radically 




FIG. 67. Survey of mosquito breeding places by a normal-school class 
Equipment : bottles, tumblers, and saucers 

from the larva in appearance, and breathes from the ear-like 
organs on the thorax (Fig. 62). Except when disturbed the 
pupa remains at the surface of the water. After two days 
it splits down the back and the adult mosquito rises from 
the pupa skin. 

Anopheles and Aedes lay their eggs scattered singly, those 
of Anopheles floating while the eggs of Aedes sink to the 
bottom (Fig. 62). The larva of Aedes resembles that of Culex, 
while that of Anopheles lies horizontally, just under the surface. 



MOSQUITOES 



131 




Its respiratory tube is short, its body black and spotted with 
tufts of long bristles protruding from the sides (Fig. 62). The 
pupse of the different species are not readily distinguished. 
Under favorable conditions the time required for the eggs to 
hatch and grow to adult mosquitoes is ten days ; when the 
we Bather is cold it may be indefinitely 
extended. Three days after emergence 
the adult may lay eggs. Culex has pro- 
duced from seven to ten generations in 
a season and Anopheles four. Allowing 
1'0 eggs to a generation, the possible 
progeny of a pair of Anopheles in one 
season would be 31,000,000. The natu- 
ral enemies of immature mosquitoes are 
fishes, newts, salamanders, dragon-fly 
nymphs, the larvae of water beetles, and 
e\en young turtles. 

Location of breeding places. After 
members of the class have learned to 
distinguish the different mosquitoes and 
their larvae at a glance, they should 
div T ide themselves into groups corre- 
sponding to convenient divisions of the 
district to be studied. Each group should 
be responsible for a full report upon the 
breeding places and the kind of mosqui- 
toes found in its territory. Collect speci- 
mens and put the eggs, larvse, and pupae 
from each territory into separate glasses 
or into vivaria with screen tops (Fig. 69). Keep a dish of 
water and a bit of fruit (apple, grape, banana) in the vivaria 
for the adults and have green algae in the water with the 
larvse. Catch full-fed mosquitoes about animals or in bed- 
rooms and keep in glasses arranged as shown in Fig. 70. 




FIG. 68. Insect-catching 
bottle 

For handling delicate in- 
sects this is better than a 
net. The essential feature 
is a paper cone opening in- 
ward through the thin cork 



132 



CIVIC BIOLOGY 



Watch for eggs, and examine the water for larva*. How 
many eggs were laid and how long did they take to hatch? 
Wherever yon have found mosquitoes breeding, indicate 
it upon a map of the locality with letters, A denoting the 
presence of Anopheles ; (7, Culex\ and Y", Aedes. Fig. 61 
shows the relation between malaria and the Anopheles mos- 
quitoes as worked out in this way by a biology class. 




FIG. 09. Vivarium set up for studying mosquitoes 
Cheesecloth top with sleeved opening and glass dish of water in moss at one end 

Did you find that, in general, Anopheles breed by preference 
in spongy bogs and stagnant water, green with alga? ; Aedes in 
cisterns, tanks, buckets, tubs, rain barrels, flowerpots, saucers, 
flower vases, and water pitchers ; Culex pipiens in ditches, 
stagnant pools, catch basins, or in any water near homes, 
indoors or out ? But algae may quickly change any neg- 
lected water into a green bog hole for Anopheles to breed in. 



MOSQUITOES 



133 




Methods of extermination. It is fortunate for us in our work 
of exterminating mosquitoes that they pass the first three 
stages of life in water, and that the adults must come to water 
to lay their eggs, that is, mosquitoes are strictly dependent 
upon suitable breeding waters. In all 
successful campaigns undesirable pools 
in which mosquitoes may breed have 
been drained or filled. Streams and 
ponds have had their shores cleaned of 
weeds, brush, and stumps, and have 
been graded so that pools were not 
left in which mosquitoes could breed 
after freshets and storms. Then they 
have been stocked with fishes which 
feed upon the young of mosquitoes. All 
water which was too temporary to drain 
or too polluted for fishes has been cov- 
ered with crude petroleum (one ounce 
to fifteen square feet of surface). This 
t reatment has been repeated as often as 
wrigglers have appeared. A mosquito 
can walk on the surface of water but it 
cannot stand on oil ; hence, as all mos- 
quitoes come to the near-by water to lay 

t heir eggs, they soon perish. Precautions ^ 

have been taken not to allow water to FIG. 70. Jam bottle and 

stand in tubs, barrels, or cisterns with- * umbler arran s ed so f 

to secure eggs of a single 
out being covered insect-tight. mosquito 

Through systematic application of 

these methods, Panama, Cuba, New Orleans, and many cities 
in the north have effectually rid themselves of mosquitoes. 
The results of these campaigns prove that the extermination 
(f the mosquito from any locality is no longer a matter of 
(ioubt or experiment. Through drainage of salt marshes whole 





FIG. 71. Connecticut salt marsh before draining 




FIG. 72. Connecticut salt marsh after draining 
Photographs by W. E. Britton 



134 



INSECT TYPE PROBLEMS 135 

states are being freed from migrating mosquitoes (Figs. 71, 
711). Incidentally, the yield of marsh hay is increased on these 
swamps, so that it more than pays for the cost of drainage. 

Locating Anopheles and Aedes mosquitoes in a neighbor- 
hood does not necessarily mean that malaria and yellow fever 
are present. These mosquitoes are not dangerous to health 
unless they have first bitten people sick with malaria or 
yellow fever. 

Planning a campaign. You may carry on a campaign 
ag'ainst the mosquito in a single neighborhood or you may 
conduct it as a city-wide movement. In either case offer 
your services as a class to the board of health. If malaria 
is present, your map showing location of breeding places 
of Anopheles might be offered to the board and cooperation 
secured in wiping out the disease. Arrangements should be 
made to have a doctor examine, free of charge, any one who 
has even a slight suspicion that he has malaria. Quinine is a 
cure for this disease, and every malarial patient should make 
use of this remedy (under the direction of a physician) and 
should be screened from mosquitoes to prevent them from 
becoming infected. 

Allow the newspapers to publish the results of your work, 
together with the accounts of mosquitoes and the methods 
of exterminating them. It is of the utmost importance that 
every one enter the campaign with enthusiasm, as a few care- 
less and ignorant people may continue to breed mosquitoes 
by thousands in all sorts of rubbish that can hold a small 
amount of water. 



CHAPTER XII 

INSECT TYPE PROBLEMS: CABBAGE BUTTERFLY 
(PONTIA RAPJE) 

Pontia rap(. This white butterfly commonly seen flitting 
over garden and roadside, has long been a serious pest. It 
gains its familiar name cabbage butterfly from ravages of 
the larva upon the Crucifer family, especially the cabbage. In 
the northernmost portion of North America it is two-brooded, 
in the latitude of New England three-brooded, and farther 
south many-brooded. A butterfly has been known to contain 
over 500 eggs, and the progeny of a pair of cabbage butterflies 
in a season in the latitude of Boston is estimated as 31,375,500. 

The cabbage butterfly was accidentally introduced into 
America from Europe in 1860, and twenty-five years later it 
had spread over nearly the length and breadth of the land. 
This rapid invasion was due to the fact that its natural enemy, 
the ichneumon fly (Apanteles glomeratus), was not present to 
hold it in check. This insect, however, was introduced in 
1883 and is increasing rapidly. The cabbage butterfly may be 
collected in its different stages and the specimens kept in 
breeding cages (Fig. 73) for study. Larvae thrive well in the 
laboratory if they are supplied with fresh cabbage leaves. 

Eggs and larvae. The small yellow eggs are deposited singly 
on the undersurface of cabbage leaves. Keep in water in the 
laboratory leaves upon which eggs have been deposited, noting 
how long it takes the eggs to hatch. Measure the young larva 
and note the time it requires to double in length. Does its 
color match that of the leaf upon which it is feeding ? What 
is the advantage of this ? 

136 



CABBAGE BUTTERFLY 



187 



Pupa. 



Larva. 



Place some larvae in a cyanide bottle. Study and draw 
a specimen. Can yon find the six single eyes (ocelli) on 
the side of the head ? Note the small feelers (antennce), and 
the strong teeth (mandibles). How many pairs of jointed 
legs has the thorax ? How many unsegmeiited legs (prolegs) 
on the abdomen ? Note the number of segments on the 
abdomen, and locate, if possible, all the spiracles. 

Pupa. After a larva is 
full-grown it ceases to eat 
a] id becomes restless, leav- 
ii ig the cabbage and crawl- 
ing about. When these 
symptoms are seen, keep 
a larva under a glass for 
observation. Note that it 
spins a mat of silk into 
which the claws of the 
List pair of prolegs are 
f listened, and a girdle of 
s Ik over the middle of 
ils back. After it is thus 
securely fastened it draws 
ils head down. When it 
has remained in this posi- 
t on for some time, the 
skin splits over the head 




T 



Parasites. 



Female. 



FIG. 78. Insect case to show biology of cab- 
bage butterfly 



a rid thorax, and we find a chrysalis in place of the green larva. 
Draw the pupa as it is fastened by its girdle. Search for 
1 upas and make a list of places where they are found. Save 
as many as possible in order to- see the butterflies emerge. 

Adult or imago. The rapid distribution of cabbage butterflies 
is due to their flight across the country from garden to garden, 
nd to the conveyance of the chrysalis on carriages and trains. 
Follow the butterfly for fifteen minutes and keep a record of 



138 



CIVIC BIOLOGY 




all that it does. It sips. nectar from flowers, and does much to 
fertilize them. The female imago is distinguished by having 
two black spots upon its fore wing while the male has only one. 
From your specimens in the laboratory study the butterfly, 
noting its parts. Draw from the side and from above. Make 

drawings of the head from the 
side, one with the proboscis 
curled up, and another with it 
extended. (Place a little thin 
sirup near the head and watch 
the butterfly unroll its proboscis 
and sip it.) Compare the struc- 
ture of the body with that of 
the pupa. Mount, according to 
directions, the complete life his- 
tory of the butterfly (Fig. 73). 
Control of the pest. Artificial 
means of control are (1) Paris 
green, sprinkled over the leaves, 
killing the worms but not injur- 
ing the plant; (2) kerosene 
emulsion as a spray ; (3) water, 
heated to 130 F., may be used 
without injury to the plant; 
(4) systematic " netting " of 
adults. The most effective meas- 
ure, however, has been the in- 
troduction of its natural enemy, 
Apanteles glomeratm. 

This minute wasp-like insect deposits its eggs in the body 
of the cabbage caterpillar where they soon hatch and feed upon 
the tissues of the host. They grow until they are about to 
pupate, and then eat their way out and spin their silken 
cocoons on or near the body of their enfeebled host. The 



FIG. 74. Convenient arrangement 
for studying larvse 

Two tumblers with card between 



CABBAGE BUTTERFLY 



139 



cabbage larva that is parasitized by the ichneumon fly usually 
dies before it transforms into a chrysalis. The adult ichneumon 
lly emerges from its cocoon in a week or ten days. It is not 





FIG. 75. Imported parasite of the cabbage butterfly 
Apanteles glomeratus 

Open cocoon," adult insect, and mass of cocoons near parasitized larva. 
Highly magnified 

known how long it lives or how many generations occur in a 
year. The fact that it is holding the butterfly in check in some 
localities would lead to the belief that it multiplies more 
rapidly than its host. 



140 CIVIC BIOLOGY 

The larvae that are infested with the parasites are usually 
a paler green and are not so easily bent. Examine a number 
of larvae, keeping in a closed vivarium those suspected of be- 
ing parasitized. How many parasites are found in a single 
larva ? The parasitic larvae begin to spin their cocoons as soon 
as they emerge from their host. With the aid of a lens watch 
this interesting process and note the length of time it takes to 
complete the cocoons. 

Apanteles does not escape without its enemies. Two small 
chalcis flies prey upon it, but thus far have not been effective 
in checking its ravages upon the cabbage worm. 



CHAPTER XIII 
INSECT TYPE PROBLEMS: ANTS 

No other group of animals presents such a maze of fascinating problems 
to the biologist, psychologist, and sociologist. WHEELER, "Ants," p. 11 

If I had to choose the form in which I would prefer to live again, I am 
not sure that I should not like to be an ant. You see that little insect lives 
under the conditions of perfect political organization. Every ant is obliged 
to work, to lead a useful life ; every one is industrious. There is perfect 
subordination to the good of all, discipline and order. They are happy, for 
they work. BISMARCK 

Economic importance. Over a thousand species of ants have 
been described, of which about two hundred belong to North 
America. As a group they are generally considered distinctly 
beneficial insects, though among so many species it is not 
strange that a few are injurious. Forel counted 28 dead in- 
sects per minute brought in by the foragers of a large colony, 
and estimated that this colony collected 100,000 insects per 
day. In China live ants are an article of commerce and are 
regularly used to control injurious insects in gardens and 
orchards. The Department of Agriculture has recently tried 
the experiment of importing a Guatemalan ant, the kelep, in 
the hope of discovering an effective enemy of the cotton -boll 
weevil. Observations of ants attacking injurious insects should 
be carefully recorded and reported to the class. 

Many species burrow deep into the earth, opening up the 
soil to air and moisture and preparing it for easy penetration 
of roots, and bring quantities of fine subsoil to the surface. 
In this way ants supplement the work of earthworms in the 
formation of vegetable mold. 

HI 



142 CIVIC BIOLOGY 

Three species, the red ant, little black ant, and pavement 
ant, are common household pests which can easily be looked 
up in state or national bulletins if they are locally important. 1 
Serious damage is sometimes inflicted by the corn-root louse 
(Aphis maidi-radicis). The eggs of this aphid are cared for 
over winter by the common brown ant (Lasius brunneus). They 
hatch early in the spring and the ants carry the young aphids to 
various grasses and weeds in the field, and later transfer them 
to the roots of the corn. Concerted work of farmers over an 
infested area by early spring plowing and repeated disk har- 
rowing, so that no weeds are allowed to grow before the corn 
is planted, effectually controls both ants and aphids. This 
topic is well adapted to laboratory demonstration and experi- 
ment in infested districts and where education is needed to 
secure general cooperation. 

The chief interest, however, attaching to a study of ants 
is their seeming intelligence and wonderfully perfect civic 
organization of the colony. 

The colony. Ant colonies are composed of queens, males, and 
workers. Queen ants are usually larger, are wingless when 
mature, and sometimes live fifteen years ; the males are smaller, 
always winged, and never live more than one year. The workers 
may be distinguished readily from the queens and males by their 
small size and lack of wings. They do all the work of caring 
for the queen and her young, gathering food, building and de- 
fending the nest, caring for plant lice (aphids*), and waging war. 

Before mating, the queens have wings. In the summer and 
early fall clouds of young queens and males leave the differ- 
ent colonies, flying in thousands. The flight over, the queen 
is either adopted by an old colony or establishes a new one. 
When once established, she removes her wings and never 
leaves the colony. While there is usually but one queen in a 
colony, there may be as many as thirty. 

1 Hodge, Nature Study and Life, p. 86 ff. 




PLATE III. LIFE HISTORY OF THE BROWN-TAIL MOTH 

1, egg cluster ; 2, single egg (enlarged five diameters) ; 3, winter nests 

(reduced about one half) ; 4, caterpillar ; 5, pupre, male at right, ventral 

view ; female at left, dorsal view ; 6 and 7, female and male moths 



ANTS 143 

Food. Ants feed upon both animal and vegetable matter. 
Their foraging raids extend over a radius of forty yards from 
the nest. They often take food into the nest, and in cold 
climates they hibernate during the winter. Much of the food 
of the queen and larvse is eaten by the workers and regurgi- 
tated from the crop when they return to the nest. Ants have 
a preference for sweet food, such as juices of fruits, sugar, 
honey, and honey dew. Aphids secrete honey dew, and on that 
account are cared for by the ants, taken into the ant nests 
over winter, and in the spring carried back to the plants upon 
which they feed. But the aphids are among the insects most 
injurious to vegetation, and their protection by ants may be 
of great economic importance to us. Watch the problem in 
your own "locality. 

Special senses. The organs of sight and hearing are very 
slightly developed in the ant, but the sense of smell is espe- 
cially keen. This sense is situated in the antennae. The ant 
travels from its nest and finds the way back by the odor of 
its own tracks. If a portion of the path the length of its own 
body is disturbed, the ant is lost and wanders about until it 
picks up the trail again, but a path left dry and undisturbed 
can be followed by it five days later. Experiments show that 
its own nest is evidently detected at quite a distance by odor, 
bat the odor of other ants is supposed to be recognized only by 
touching with the antennae. Each species of ant has a distinct, 
characteristic odor. Different colonies also of the same species 
differ slightly. In general, the odor of one species of ants is 
offensive to those of another species, and causes aversion and 
hostility. This is shown by well-defined warfare and slavery. 

Slavery. While most ants will capture and carry away 
the young of another species whenever the opportunity is 
offered, there are three species in America (Formica sangui- 
n>>,a, Polyergus rufescens, and TomognatJius americanus) that 
plunder the nest of their enemy and rear the young as slaves. 



144 CIVIC BIOLOGY 

The slaves undertake the work of the new nest much as they 
would that of their own. Can you find ant colonies with slaves ? 
Warfare. Many comparisons have been made between ants 
and man because of the diversity of their activities. Ants are 
said to indulge in games and athletic sports and to carry on 
war. The following observations are recorded that they may 
incite some young Lubbock or McCook to find the cause and 
purpose of these wars. 

On the morning of June 26, 1883, 1 observed numbers of large black 
ants wandering excitedly over a back piazza of my house in Boxford, Mass- 
achusetts. More careful observation showed a dozen of their dead bodies 
scattered around, while two living insects were struggling in a desper- 
ate conflict. In some places dissevered legs and antennae were thickly 
strewn, while in retired nooks living ants were resting, either exhausted 
or skulking. I gathered over twenty corpses from the piazza and the 
ground. Some of these warriors, having mutually inflicted mortal 
wounds, had never relaxed their iron embrace, but lay dead in pairs. 

The conflict was not yet ended, and I watched one of these Homeric 
encounters. An ant had his antagonist's feeler in his jaws. The com- 
batant, thus held, twisted and turned to get his own mandibles upon 
feeler, leg, neck, or waist of his antagonist. He was, evidently, much 
unnerved by the other's hold, for these, antennae seem as sensitive as the 
eyeball, and he was dragged about, resisting and struggling in every 
way, but all in vain. Finally, the antenna came off near the base? and 
the two warriors parted. 

Single combats like this probably went on through the day, and a few 
occurred the following night, for in the morning I found more dead 
bodies. One wounded soldier died in my custody, and many, doubtless, 
in cracks and nooks, but the level floor seemed to be the main battle- 
field. Altogether T collected from the fight about seventy complete 
bodies or dissevered heads, which I preserved in a red pill box the 
rather gaudy tumulus of this Waterloo ! 

In the same place on the morning of July 7, following, T found traces 
of another battle which was not yet finished. Again, July 19, there had 
been a battle during the night on the bare floor of a chamber at the 
opposite end of the house and upstairs. One morning in August, of the 
same year, I found traces of a similar battle in the cellarway of a neigh- 
boring house. W. P. ALCOTT, Bulletin, Essex Institute, 1897, p. '65 



ANTS 145 

A STUDY OF ANTS ix THE LABORATORY 

The nest (formicary). Most species of ants readily adapt 
themselves to an artificial nest. After the first few weeks 
they become accustomed to their surroundings, and may live 
for years working and rearing their young, much as they do 
in their natural environment. 

Kellogg in his "American Insects" describes several of 
the more commonly used formicaries. The large-sized insect- 
mounting cases serve admirably in this capacity. The case 
should be partitioned off into two or three rooms, by glueing 
strips of wood that reach nearly across. On the top of the 
walls of the case glue strips of Turkish toweling, so that air 
may . pass to the rooms after the upper glass is in place. 
Choose two pieces of heavy glass of unequal size for the roof 
of the formicary, so that one piece will cover two rooms. 
Exclude the light from these rooms by placing blotting paper 
over the glass, and keep a wet sponge (finest texture) in each 
of the darkened rooms. All food should be kept in the light 
room, and should consist of small pieces of sponge cake, 
moistened with sirup or honey, apple, mashed nuts, dried 
fruit, and insects. Keep the sponges wet. In cool weather 
the food need not be changed oftener than once in two weeks. 

How to obtain an ant colony. Dig up an ants' nest and 
take larvae, pupre, and workers. If you cannot find the 
queen, release the captives and try other nests until success- 
ful. Carry the queen by herself in an envelope, and the 
young and workers with some earth in a cloth or paper bag. 
Upon reaching the laboratory, empty the earth and ants upon 
a board afloat in water; pick out the ants and young from 
the earth and place them with the queen in the nest. 1 

1 An easy way to manage this is to scrape a hollow in the center of the 
pile of earth, put the queen in this, and cover it with a chip. The ants will 
then collect all the eggs and larvae into a pile, and they may be lifted into 
the nest with a spoon. 



146 



CIVIC BIOLOGY 



The carpenter ant {Camponotus penmylvanicus) is one of 
the most satisfactory species to study. The colony lives in 
wood, and hibernating queens may be obtained under the bark 
of stumps or logs in the fall or during a winter thaw. 

In general the logs and stumps in which they are found 
are not badly decayed. Most frequently queens are hiding 
beneath bark that may without difficulty be removed with the 




FIG. 76. Ants' nest 

This is made of an insect-mounting strip, 5 by 7 inches, -J inch deep, glued, with the 
two partial partitions, to the bottom glass. The top glass is cut so that one piece 
covers one, and the other two, of the compartments. A braided cotton twine is 
glued along the top of the frame and partitions to insure ventilation. The sponge, in 
the middle compartment, is kept moist ; and the living chamber, to the left, is kept 
dark when not under observation. Designed and photographed by the author 

fingers. The queen is curled up in a cleared space under the 
bark and may be alone or accompanied by several eggs, larvae, 



pupae, 



or workers. 



Having secured a queen of Camponotus pennsylvanicus, place 
her, together with her young, in a nest and carefully observe 
the beginning of an ant colony. Observations should continue 
for the remainder of the year and careful notes made to reen- 
force those taken upon ants in the field. 

Eggs. The queen may not lay for a month or more after 



ANTS 147 

she lias been brought into the laboratory. Note the intervals 
during which eggs are laid. Describe the action of the queen 
and workers in regard to the eggs when the nest is disturbed. 
How soon do ants become accustomed to the careful interfer- 
ence of being observed ? Fill the sponges with water, one day 
hot, another day cold. What effect upon the apparent care of 
the eggs has a difference in moisture, temperature, and light ? 

Larva. The time taken for the eggs to hatch depends upon 
the warmth and humidity of the atmosphere. The time of in- 
cubation is about twenty days. The larvae are soft, footless 
grubs, the smaller end being the head. The presence of hooked 
hairs upon the bodies of the larvae explains how they are car- 
ried in bundles. Note that the larvae are helpless. They are 
not only fed by the queen and workers, but are carried about 
to places of proper temperature and humidity. With the aid 
of a lens observe how the workers and queen feed the larvae. 
The queen has food stored in her body, which enables her to 
live and feed her first brood without herself taking food. This 
fact probably accounts for the small size of the first brood, 
which is composed of workers, as compared with subsequent 
broods. The queen is relieved of all work when the workers 
appear. They feed her and the larvae and assume all work 
of the colony. 

Note that the larvee are of different ages, and that they 
spin cocoons as soon as they become full-grown. Are the lar- 
vae and pupae kept together ? Ants have no regular places 
for their young ; even in the natural nest they are carried to 
places which offer suitable conditions. The pupa stage like 
the larval lasts about twenty days when the temperature is 
about 80. Observe that the cocoon turns yellowish before 
the young ant (callow) appears. How long before the callows 
assume the duties of adult workers ? 



CHAPTER XIV 
SPECIAL PROBLEMS OF INSECT CONTROL 

The life histories of insects lie at the foundation of the whole subject of 
economic entomology, and constitute, in fact, the principal part of the sci- 
ence, for until these are clearly and completely made out for any injurious 
^species, we cannot possibly tell when, where, or how to strike it at its 
weakest point. S. A. FORBES 

Control of insects by a community or nation must depend 
upon each citizen knowing the important species and actually 
doing his part. Insects are so small, tough, and hard to kill, 
and, above all, possess such powers of rapid dissemination and 
increase, that the problems of insect control are probably the 
most difficult in the whole field of living forces. However, in 
the life history of a species from the egg, through the actively 
feeding larval stage, in the quiescent pupal condition, or in 
the adult, egg-laying period, it is generally possible to discover 
some ivaakest point at which it may be successfully attacked. 
To work out these life histories, discover these vulnerable 
points of attack, and devise best ways and means is the 
function of our scientific experts ; but, in order that these 
discoveries accomplish their purpose, the people must learn 
and use the results. 

Organization for both research and information is so perfect 
that if any one wishes to know about an insect he has only to 
inquire of his State Experiment Station or of the United 
States Department of Agriculture at Washington. If the 
answer to his question is known, it will be sent to him prac- 
tically by return mail. If not, a special research may be 
ordered to solve the problem. 

148 



SPECIAL PROBLEMS OF INSECT CONTROL 149 

As a nation we are paying about $25,000,000 annually for 
the discovery and dissemination of just this sort of informa- 
tion. If we are not " getting our money's worth," it is our 
own fault. One truth with regard to an insect which causes 
disease or levies a tax of often hundreds of millions of dollars 
on some staple crop may be worth the entire annual cost of 
the scientific departments of the government, as soon as the 
knowledge is put to use. 

With hundreds of experts working at these problems, knowl- 
edge is growing so fast that statements are likely to be super- 
seded before the ink of a book is dry. In order to keep up to 
date, every biological laboratory should have available for all 
students two important publications, the Monthly List of Pub- 
lications and the Experiment Station Record, both issued by 
the United States Department of Agriculture. These will 
keep the student informed of every advance in our knowledge 
of insects, as well as of a great many other matters of interest. 

Make a list of the most important insects of the neighbor- 
hood, or those about which you wish to learn, and follow them 
through the indexes of the Experiment Station Record. Send 
to your State Experiment Station or to Washington for the 
bulletins you need, and, after studying them and collecting 
and observing your specimens in -the field, mounting them so 
that they will tejl as complete a story as possible, be ready to 
report your results to the class. 

Working independently and without consultation, let each 
member of the class prepare a list of the insects which he thinks 
every member of the community ought to know in order to 
prevent annoyance, spread of disease, damage to household 
goods, stock or crops. This should be done after working 
through the laboratory types given in Chapters X-XIII, read- 
ing bulletins and books assigned, and studying the lists given 
below. After comparing and discussing individual lists, pre- 
pare 'a class list which shall include the most important local 



150 CIVIC BIOLOGY 

problems, and one which the class can reasonably cover dur- 
ing the year, and then write the names on slips and let each 
draw a certain number, or distribute by individual preference, 
as the class may elect. As these studies progress they should 
be reported and freely discussed. Thus the biology class may 
be the organizing center for a better understanding of local 
insect problems, and enlist cooperation of homes and of boys 
and girls in the lower grades for more effective effort and 
better local control. 

The problem of insect classification. It is recognized that for 
an elementary and practical course the complete classification 
of insects is too difficult and would take too much time. The 
vast number of species, more than three hundred thousand, are 
commonly grouped into nineteen orders, and any student who is 
specially interested can find the subject fully treated in manuals. 
For all elementary purposes it will be sufficient to learn the 
names and characters of the seven more important orders. Every 
one ought to know what we mean by a "fly," a "bee," a "bug," 
a " moth or butterfly," a " locust," a " beetle," a " lacewing." 

Since classification consists in gathering into groups forms 
with similar structures and parts, we need to learn something 
of the way an insect is constructed. To begin, take any large 
insect, a beetle or grasshopper, and work out all the apparent 
subdivisions of the body. Note the three main subdivisions 
head, thorax, and abdomen and locate the breathing pores 
{spiracles) as indicated in Fig. 77. Insects, spiders, and myria- 
pods, instead of having one pair of nostrils, a windpipe, and 
lungs to which the blood is brought to be oxygenated, circu- 
late the air dir.ectry to the tissues by means of fine, elastic, 
branching tubes. These are known as tracheae, and these ani- 
mals are known, since this is a character of great significance, 
as tracheates. Contact insecticides oil films on water for mos- 
quitoes, oil-emulsion or soapy sprays depend upon clogging 
these fine breathing pores and thus smothering the insect. 



SPECIAL PROBLEMS OF INSECT CONTROL 151 



Water will not do this, because the openings are protected 
against its. entrance by oily secretions. Compare the effect 
cf dipping an insect into water and into kerosene. 

Next, beginning at the head, study all organs and mov- 
able parts (appendages) : the eyes, feelers (antenna^, replacing 

Head Prothorax Mesothorax Metathorax Abdomen 
Compound Eye \ j 

Simpte Eye/ 



/ / . Hind Wing 

X">x" 




Ear 



Antennfi', 
Lal)rum .. 





Spiracles 
Trochanter 



Legs- 
Mandible 
Maxilla 



''Femur 
''--.Tibia 
'''^.Tarsus 



Labium 
Mouth-Parts 




vipositor 



EIG. 77. External anatomy of the grasshopper 



( ars and nose as sense organs, at least partly), mouth parts 
( very complicated, consisting typically of an upper and lower 
lip (labrum and labium) and two pairs of jaws (mandibles 
find maxillae), which move sidewise instead of up and down). 
Watch a caterpillar or grasshopper eat a leaf and see if you 
can discover why the jaws move sidewise. A study of mouth 
I >arts is again important with reference to methods of destroy- 
iag insects. Those that bite and chew can be killed by spraying 



152 CIVIC BIOLOGY 

poisons upon their food plants or by mixing poisons with foods 
which attract them. Those whose mouth parts have been 
modified into an apparatus for piercing and sucking can be 
reached only by insecticides which kill by contact. 

The thorax is divided by rather conspicuous sutures into 
three parts named prothorax, mesothorax, and metathorax. 
Each carries a pair of legs ; that is, all insects have three pairs 
of legs. Wings may be present or absent. If two pairs, they 
are attached to the meso- and meta-thorax, and a single pair 
is usually attached to the meso-thorax. The insect wing is the 
most perfect flying mechanism in existence, and until man can 
match its structure for lightness and strength, he can hardly 
hope to solve completely the problem of flight. 

Note that insect wings vary in texture from the hard, shell- 
like structures, as in the fore wings of beetles and the leathery 
or parchment-like wings of grasshoppers and many bugs, to 
the transparent membranous wings of bees and flies. 

The abdomen is made up of a series of similar rings termi- 
nated by various organs concerned with reproduction, ovipos- 
itors, etc., sometimes modified into sharp stings. 

The life history of an insect also gives characters for classi- 
fication. With many insects the egg hatches into a worm-like 
maggot, grub, or caterpillar wholly unlike the parent, and 
later passes through a quiet stage (pupa or chrysalis) before 
becoming like the parent. In these cases the insect is said 
to show a complete metamorphosis (ineta, " over " ; morphe, 
" form" " change of form"). Name insects that you know, 
of which this is true. 

In other insects the egg hatches into something like the 
parent. T.o study this point, watch a nest of grasshopper or 
squash-bug eggs hatch. These insects are said to have an 
incomplete metamorphosis. In the case of a few insects 
the San Jose scale, aphides, and some of the flies the eggs 
hatch within the body and the young are born alive. 



SPECIAL PROBLEMS OF INSECT CONTROL 153 

Of the nineteen orders the seven most important are : 

I. Diptera (di-, "two"; pteron, "wing"). Two membranous wings, 
mouth parts for piercing and sucking or for lapping ; metamor- 
phosis complete, larvse various in form and habit but always foot- 
less ; maggots, wrigglers, etc. Examples : flies, mosquitoes, gnats; 
40,000 known species ; estimated number, 350,000 (Howard). 
II. Coleoptera (koleos, "sheath"; pteron, "wing"). Four wings, the 
front pair horny cases which cover the membranous hind wings ; 
mouth parts for biting ; metamorphosis complete, the larva a 
grub, with usually six legs. Examples : beetles, potato beetle, 
June beetle, lady beetle; 100,000 known species (Galloway). 

III. Hemiptera ( hemi-, ' ' half ' ' ; pteron, ' ' wing " ) . Fore wings membra- 

nous, parchment-like or with horny bases and membranous tips ; 
hind wings membranous ; many wingless forms ; metamorphosis 
incomplete, the young resembling the adults, but wingless 
the true " bugs." Examples : plant lice, scale insects, cicadas, lice, 
water bugs; 20,000 known species; probably 80,000 in all 
(Howard). 

IV. Orthoptera (orthos, "straight"; pteron, "wing"). Fore wings parch- 

ment-like, net-veined, hind wings almost always membranous ; 
mouth parts for biting ; metamorphosis incomplete, the young 
resembling the adult, but wingless. Examples : grasshoppers, 
crickets, cockroaches, walking sticks; estimated more than 
10,000 species. 

V. Lepidoptera (lepis, "scale"; pteron, "wing"). Wings and body 
scale-clad ; mouth parts modified into a coiling, sucking tube, or 
absent ; metamorphosis complete, larva a caterpillar. Examples : 
butterflies and moths ; 25,000 known species (Galloway). 
VI. Hymenoptera (hymen, "membrane"; pteron, "wing"). Wings 
four, membranous, a few wingless forms ; mouth parts for 
biting and lapping ; metamorphosis complete, larva maggot- 
like. Examples : bees, ants, wasps, sawflies, ichneumons ; about 
30,000 known species ; estimated number, 300,000 (Howard). 
VII. Neuroptera ( neuron, " sinew "; pteron, " wing "). Wings four, mem- 
branous, usually net-veined ; mouth parts for biting ; metamor- 
phosis incomplete or complete ; larva usually unlike adult, 
sometimes aquatic. Examples : dragon flies, lacewings, etc. 1 

1 This group is now subdivided into eight orders, among them the caddis 
flies (Trichoptera), dragon flies (Odonata), and white ants (Isoptera). 



154 CIVIC BIOLOGY 

Most insects in the following lists belong to the above 
orders. Each represents a problem of interest to the com- 
munity and home, and the time will come when each citizen 
must realize that he has 110 moral right to breed pests which 
cause annoyance and damage to his neighbors. In reading 
the lists review what you have learned of each in previous 
years, especially running over the life history. 

It is convenient also to classify insects according to their 
point of attack or their food plants ; as, insects of the house- 
hold, garden, field, forest ; insects of the apple, grape, peach, 
etc. Many books for practical horticulturists and the agricul- 
tural bulletins treat them this way. 

INSECTS OF THE HOUSEHOLD 

FLIES: House fly, typhoid fly, or filth fly Musca domestica; small 
house fly Hontalomyia canicularia; stable fly Stomoxys calcitrans; 
cluster fly Pollenia rudis ; bluebottle fly or blowfly Calliphora ery- 
throcephala ; green-bottle fly Lucilia ccesar ; fruit fly Drosophila am- 
pelophUia] cheese or ham skipper PiopJiila casei. 

MOSQUITOES : Common domestic species, in rain barrels and stag- 
nant pools everywhere Culex pipiens; malarial mosquitoes Anopheles 
maculipennis, punctipennis, and crucians ; and the yellow-fever mosquito, 
throughout the- South and wherever it is found breeding Aedes calopus. 

CLOTHES MOTHS: Case-making clothes moth Tinea pellionella ; 
Southern clothes moth TineolabisselUella] tapestry moth Triclioplmga 
tapetzella; carpet beetle Anthrenus scrophularm ; black carpet beetle 
Attagenus piceus. 

HOUSE CRICKETS Gryllus domesticus and G. assimilis. 

ROACHES: American cockroach Periplaneta americana\ oriental 
cockroach Periplaneta orientalis ; German roach, Croton bug Ectobia 
germanica. 

BEDBUG : Common bedbug Acanthialectularia; blood-sucking cone- 
nose ConorJu'nus sanguisuga ; kissing bug Opsicoetus personatus 

LICE: Head louse Pediculus capitis\ body louse Pediculus 
vestimenti. 

FLEAS : Human flea Pulex irritutix ; cat and dog flea Ctenoceph- 
<ilnx c>iit\ rat fleas Ceratophillus fasciatus and Pulex cheopis; chigoe, 



SPECIAL PROBLEMS OF INSECT CONTKOL 1<55 

burrowing flea (chiefly tropical) Sarcnpsnllu in< trans', hen flea (bur- 
rows into the eyelids of fowls), Southern states Xestopxylla </<t//h/(i<-i. 

This group was formerly classed with the diptera but is 
now usually given as an order by itself, the Siphonaptera 
(siphon, " a sucking tube "; , " without"; pteron, "wing" 
"' wingless bloodsuckers"). 

WHITE ANTS : Termites Termes flavipe*. These are not ants, but 
belong to another order, the Isoptera (isos, "equal"; pteron, "wing"). 
Destructive to wood of buildings and furniture and even to living trees. 

HOUSE ANTS : Red ant Monomorium pharaonis ; little black ant 
Monomorium minutum; pavement ant Tetramorium caespitum. 

BEETLES : Larder beetle Dermest.es lardariiis ; drug-store beetle 
ftitrodrepa panicea ; meal worms Tenebrio molitor and T, obscurus ; 
Indian-meal moth Plodia interpunctef/n. 

The above are only a few of the more important household 
insect pests. Many others may be found by searching the 
house, and can be identified, if they present interesting local 
problems, by reference to the books mentioned at the end of 
this chapter. The fact that no headway is made in the fight 
with these enemies is due chiefly to lack of organized coopera- 
tion. One family exterminates them and is reinfested from a 
neighbor who does the work at some other time. 

INSECTS INJURIOUS TO VEGETATION 

ORCHARD PESTS: Codling moth Carpocapsa pomonella ; tent cater- 
pillars (apple-tree) Clisiocampa americana ; fall webworm Hyphantria 
cunea; cankerworms (spring Paleacrita vernata; fall Anisopteryx 
pometaria) ; yellow woolly bear Spilosoma virginica; curculio beetles, 
weevils (apple Anthonomus quadrigibbus ; plum Conotrachelus nenu- 
phar; quince Conotrachelus cratcegi; grape Craponius incequalis; 
borer beetles ; round-headed apple-tree Saperda Candida ; flatrheaded 
apple-tree Chrysobothris femorata (also attacks the plum) ; pear-blight 
beetle Xyleborus pyr'r, pear-tree borer JEgeria pyri ; cherry-tree borer 
Dicerca divaricata; peach-tree borer Sanninoidea exitiosa; apple-twig 
borer Amphicerus bicaudatus)', sphinx moths ("humming-bird" moth) 
(plum Sphinx drupiferarum; green grapevine Ampelophaf/a myrori); 



156 CIVIC BIOLOGY 

scale insects (oyster-shell scale Mytilaxpis pomorum ; scurfy scale 
Chionaspis furfurus ; San Jos scale, Chinese pernicious scale Aspidt- 
otus perniciosus, the worst fruit-tree pest on the American continent; 
cottony cushion scale Icerya ptirchasi) ; apple-tree enemies (yellow- 
necked apple-tree caterpillar Datana ministra; red-humped apple-tree 
caterpillar CEdemasia concinna ; apple sphinx, or hawk moth Sjthhuc 
gordiuSj apple maggot, " railroad worm" Rhagoletis pomonella'); enemies 
of small fruits (strawberry crown borer, weevil Tyloderma fragruria : 
strawberry root borer Anarsia lineatella ; currant borer, American 
Psenocerus supernotatus ; currant borer, imported JEgeria tipulifonnix ; 
grapevine root beetle Prionus laticollis ; grape-berry moth Polychrosis 
botrancij grape, gartered plume moth Oxyptilus periscelidactylus ; rose 
chafer Macrodactylus sulspinosus) \ plant lice (aphids, grape Phyl- 
loxera vastatrix; woolly apple louse Schizoneura lanigera: cherry louse 

Myzus cerasf). 

VEGETABLE, GRAIN, AND COTTON PESTS : Colorado potato beetle 
Doryphora 10-lineata; striped cucumber beetle Diabrotlca vittata; as- 
paragus beetle Crioceris asparagi ; June beetle (May bug in the South) 

Lacknostema fusca and others; flea beetles Ildlticini; blister or oil 
beetles Meloidw ; cutworms Noctuida (larvaB of a number of owlet 
moths or noctuids) ; sphinx moths (tobacco, South Phlegethonthis sextet] 
tomato Phlegetkontius quinquemaculatcf) ; cabbage worm, imported 
Pontia rapcK ; cabbage looper Autographer brass icce ; cabbage and rad- 
ish maggot Pegomyia brassiwe ; onion maggot Phorbia ceparum ; 
cotton worm Aletia argillacea; boll worm (corn-ear and tomato worm 
of the North) Heliothis armigera; army worm Leucania unipuncta; 
Hessian fly Merisus destructor ; corn-root aphis Aphis maidi-radicis \ 
grain aphis or "green bug " Toxoptem gramineum ; chinch bug Blissus 
leucopterm ; squash bug A nasa tristis ; grasshoppers (Rocky Mountain 
locust) Afelanoplus apretus; red-legged locust Melanoplus femur- 
rubrum 

FOREST AND SHADE-TREE ENEMIES: Gypsy moth Ocnerla dlxpar 
(one of our most difficult problems) ; brown-tail moth Euproctis chrys- 
orrhea (a national problem) ; elm-leaf beetle Galerucella luteola ; white- 
marked tussock moth Notolophus leucostigma; cottony maple scale 
Pulvinaria innumeralnlis. 

Most of the Hymenoptera are highly beneficial insects, but 
among them are a few so injurious and troublesome that 
every member of a community ought to know them. These 



SPECIAL PKOBLEMS OF IXSECT CONTROL 157 

are leaf : eating sawflies, and many others of less importance 
are borers and gall insects. 

Currant worm or slug' Nematus ventricosus ; pear slug Eriocuinpa 
cerattij rose slug Monosteyia rosce. 

INSECTS ATTACKING ANIMALS: Botfly (ox warble) Hypoderma 
Jiwata; sheep botfly (Esstrus ovi\ horse botfly GastropMlus equi; 
horn fly Hceinatobia serrata ; screw-worm fly Compsomyia macellarm. 

Beneficial insects. As it is said to "take a thief to catch a 
thief," so it often takes an insect to catch an insect. From the 
usual study of injurious forms the impression is likely to be 
given that almost all insects are injurious. Yet even species 
which cause considerable damage may perform good service in 
cross-pollination of plants. The honeybee, our most useful 
species for this purpose, has the distinct advantage of winter- 
ing a large force of workers ready to cover the fruit bloom 
early in the spring, before our native, solitary bees have begun 
to breed in numbers. 

The problem of the honeybee and fertilization of fruit trees 
about the home or in the neighborhood is one which may well 
repay study. The question is, Are there bees enough to do 
the work ? The stone fruits are said to depend entirely on 
insect cross-pollination in setting fruit, and if the cherry, plum, 
and peach trees are not humming at some time during the 
bloom, there will be little or no fruit. Apples of some varie- 
ties and most pears are greatly improved in quality when 
cross-pollinated. 

For at least one hour on a bright, warm day while the trees 
are in bloom, with watch in hand, time and count the number of 
blossoms visited by bees per minute. Do this for all the differ- 
ent kinds of fruit accessible. How many men would it take 
to do the work of one swarm of bees of fifty thousand workers? 

Are there enough bees to pollinate the flowers and gather 
the nectar in the neighborhood ? 

Can you find any honeybees working on red clover ? 



158 CIVIC BIOLOGY 

Test the practical value of insect cross-pollination by cover- 
ing a twig of cherry, plum, or peach with wire gauze or mos- 
quito netting during bloom. Compare the fruit of this twig 
with a similar one on the same tree which was not covered. 

Is there any evidence that orchards near apiaries bear better 
than others ? 

What can you learn of the comparative merits of different 
races of bees in your locality ? 

National problems. In the above list three insects merit 
special emphasis as presenting civic problems of national im- 
portance. All are species of almost unthinkable destructive 
power imported from the Eurasian continent, and until re- 
cently, at least, without their natural enemies. 

The San Jose scale was imported into the San Jose valley, 
California, in 1868, and has since spread over almost the entire 
United States. During this time it has probably killed more 
fruit trees than all other insect pests combined, and is now the 
most serious menace to the home fruit garden. Minute as is 
the insect, one pair may produce in a season 3,216,080,400. 
This at once shows how little chance a tree can have and how 
futile any treatment is which leaves even a few pairs alive. 
After ten years of experimenting with the various spraying 
mixtures recommended, the writer is obliged to state as his 
opinion that nothing has yet been discovered which will ex- 
terminate the San Jose scale from a tree. Hence it is of the 
utmost importance for the class to follow all announcements of 
discoveries as to effective methods of dealing with this insect. 

Make a thorough examination of your home premises and 
learn the history of the San Jose scale on the place. How 
much damage has it done from year to year? How much 
has been expended in fighting it? What and how many 
trees have been killed by it? In connection with the field 
and laboratory work search for natural enemies, fungus or 
insect. Make a list of food plants upon which the scale is 



SPECIAL PROBLEMS OF INSECT CONTKOL 159 



found in your neighborhood. Compare results of different 
methods of combating it. From the data obtainable can you 
foretell the probable result? Will the home fruit trees be 
killed and the fruit industry confined to commercial orchard- 
ists who will care for their trees ? 

Gypsy moth. This pest is a European species. It was in- 
troduced into this country in 1869 by a Frenchman who was 




FIG. 78. Outdoor laboratory work 
Class inspecting a local nursery for San Jose' scale 

attempting to improve our native silkworms. Through acci- 
dent the insects escaped, but although the fact was reported, 
the grave danger was not realized until twenty years later. 
From a single nest in Medford, Massachusetts, the pest spread, 
slowly at first, and then like wild fire, over the towns and for- 
ests of New England. Millions of dollars have been expended 
in its control, yet hundreds of acres of forest have been de- 
stroyed. A report of 1897 says, "At the present time there 
can be little doubt that the extermination of the insect is 



160 CIVIC BIOLOGY 

possible and that it will be only a question of a few years " ; 
but now, nearly fifteen years later, it is still gaining ground. 

Since a large portion of the year is passed in the egg stage, 
this is the natural time for extermination. The egg masses 
are conspicuous dark yellow splotches, and in a badly infested 
region may be found anywhere, on fence or stone wall, 
under porches, among dead leaves, although the first and 
most common position is the trunk and branches of trees. The 
rapid fire which is sometimes sent through woods and under- 
brush to destroy other pests has no marked effect on these 
eggs. Attempts to remove the egg masses by scraping have 
proved equally ineffective, for eggs become scattered in the 
process and hatch as readily as ever. 

Saturating the egg clusters with the following mixture : 
creosote oil 50 per cent, carbolic acid 20 per cent, spirits of 
turpentine 20 per cent, coal tar 10 per cent, is the method of 
extermination recommended by state authorities. It is applied 
with a small brush. This treatment must find every egg mass, 
and therefore must be begun the instant the presence of the 
insect is known. The insatiable appetite of caterpillars makes 
so omnivorous a creature as the gypsy moth even more dreaded, 
for when one feeding ground is exhausted, a fresh one over the 
fence or across the road is quickly attacked. Thus the pest 
moves on, leaving every twig stripped behind it. 

Every effort must be made to keep the pest within its pres- 
ent limits. The female imago does not fly ; therefore distri- 
bution is effected by the caterpillars which frequently spin 
down from the trees and fall upon passing conveyances, or by 
egg masses which are overlooked on lumber or are carried in 
various ways. 

Brown-tail moth. The problem of the brown-tail moth is 
one of even greater importance to the country at large be- 
cause of the greater rapidity of distribution. Both male and 
female are strong, swift flyers, and eggs may be deposited at 



SPECIAL PROBLEMS OF INSECT CONTROL 161 



great distances from the original colony. Windstorms also 
aid in furthering the flight, and steam cars and trolleys trans- 
port these pests. Besides the injury to orchard, shade tree, 
and forest, the brown-tail caterpillar inflicts serious pain upon 
many persons. This is caused by fine hairs which pierce the 
skin, the irritation becoming severe enough in some cases to 
cause illness. A free use of 
vaseline will give relief. 

The brown tail cannot be 
controlled by an attack upon 
the eggs, since they are usually 
on the leaves and for a short 
time only. Spraying is em- 
ployed to destroy the swarm- 
ing caterpillars, but the most 
effective method is destruc- 
tion of the winter nests. These 
are conspicuous on the tips of 
branches between August and 
April. They may then be cut 
with pole shears, and must be 
carefully collected and burned. 

Parasites. The great aim 
in the attempt at control of 
any pest is to discover its nat- 
ural enemy. In the case of 

insects like the gypsy and brown-tail moths, a series of para- 
sites is necessary, for the parasitic insects restrict themselves 
to one stage only in the development of their host. The insect 
which attacks the egg takes no notice of the caterpillar, and 
the insect which attacks the caterpillar is never found upon 
pupas. Several native parasitic insects are known to attack 
these pests, and many have been imported ; but as yet the 
series is not complete and has failed of effective control. 




FIG. 79. Brown-Tail Moths 

Four egg masses and two moths laying, 

July 10. Photograph by Katharine E. 

Dolbear 



1(32 



CIVIC BIOLOGY 



COMPARISON OF GYPSY AND BROWN-TAIL MOTHS 



GYPSY MOTH 

Eggs. August to May. On the 
trunks and branches and every- 
where, especially on undersides 
and inner surfaces of objects. 

Masses. Light brown, long, broad, 
about the size of a silver quarter. 
300-1400 eggs. 

Caterpillar. May to August. On 
underside of leaves. Night feed- 
ers. Cluster in shelter during 
the day. 

Winter form. Egg. 



Full-grown. Two and one-half to 
three inches long. Rows of con- 
spicuous spots on the back 
blue near the head, red on posterior 
part of the body. Hairy tufts 
on the sides. 

Pupa. Late July. Found in some 
places as egg masses. Dark 
brown female larger than the 
male. 

Moth. Female, white with brown 
markings. Spread of wing, from 
two to three inches. Never goes 
far from pupa case. Male smaller, 
brown. 



BROWN-TAIL MOTH 

Eggs. July. Seldom on trunk or 
branch. Generally on underside 
of leaf. 

Masses. Smaller than the gypsy, 
more elongated, brighter, red- 
dish brown color. About 300 
eggs. 

Caterpillar. Hatched in August. 
On upper side of leaves in clus- 
ters. Day feeders. 

Winter form. Caterpillar in nest. 
Nest four to six inches long, 
composed of leaves and silk, 
contains about 250 caterpillars. 
Emerge in April, attack bud, 
blossom, and foliage of fruit 
trees, and then move to others. 

Full-grown. One and one-half to 
two inches long. Broken white 
stripe on each side of back, two 
red spots near posterior end. 
Hairy tufts on the sides. 

PHJKI. Late June. Five eighths of 
an inch long. Dark brown, with 
yellowish hairs. 

Moth. Pure white. Female- slightly 
larger, with conspicuous bunch 
of brown hairs at tip of abdo- 
men. Spread of wing, one and 
one-half inches. Night flyer, 
attracted by light. 




* 



Iff 





iver, del. 



PLATE IV. ADl'LT FEMALES OF FIVE IMPORTANT TICKS* 



CHAPTER XV 
ARACHNIDS. PROBLEMS OF SPIDERS, MITES, AND TICKS 

Prices would be higher, the demand greater, and the odium attached to 
ticky cattle at the .stockyards removed. Pure-bred Northern cattle could then 
be brought into the South to improve the native breed, without danger of 
(,eath from Texas fever ; Southern cattle could enter the show rings of the 
North without restriction ; and the total cost of tick extermination would 
be far less than the amount saved in the first year after it had been accom- 
plished. JOHN R. MOHLER, 1914 

Closely allied to insect problems are those of the arachnids. 
This group includes scorpions, spiders, mites, and some of the 
ticks. Interesting as they are, scorpions and spiders are far sur- 
passed in economic importance by the insignificant mites and 
ticks. Among the latter are the cattle tick (carrying the germ 
of Texas fever), the sheep scab mite, mites which attack poultry, 
and the red spiders and harvest mites which infest vegetation. 

Since arachnids are often mistaken for insects, compare any 
common insect and spider, noting their similarities, and dif- 
ferences. Make a diagrammatic sketch of each. 

Similarities. Both insects and arachnids are ringed or jointed 
animals. Both are tracheates, though a few of the arachnids, 
particularly spiders, have also pulmonary sacs. 

Differences. These will be found in the relation of head 
and body, the number of legs, presence of antennae, com- 
parison of palpi. 

* Five species are shown, enlarged and natural size. 1 and 1 a, adult 
i emale cattle (Texas-fever) tick ; 2, growth stages and variations in color 
c f this tick; 3 and 3 a, Rocky Mountain spotted-fever tick, adult female ; 
4 and 4 a, female dog, or wood, tick ; 5 and 5 a, female European dog tick ; 
( and 6 a, female chicken tick. (Reproduced from plates issued by the 
United States Department of Agriculture and the United States Public 
Health Service.) 

163 



1(34 



CIVIC BIOLOGY 



The larger arachnids, in spite of their bad reputation and 
terrifying appearance, are comparatively harmless. Even those 
of the poisonous varieties, tarantulas and scorpions, make no 

attack upon man un- 
less frightened or mo- 
lested. Their economic 
importance is not con- 
sidered great, though 
since they are insectiv- 
orous, they may be dis- 
tinctly beneficial. 

The smaller arach- 
nids, mites and ticks, 
cause great destruction 
of vegetable and animal 
life. They are charac- 
terized by an unseg- 
mented body, the abdo- 
men as well as the head 
being joined to the tho- 
rax. While we must 
not overlook the service 
of some species as scav- 
engers, we are con- 
cerned much more with 
them as parasites upon 

FIG. 80. Harvestiiien clearing the plant lice livin g animals and 

from a grapevine plants. 

Photograph by the author Red spider Tetra- 

nychidcR, " four-clawed." 

This greenhouse pest is found both indoors and out, and on 
various plants and trees. It is one of the commonest families, 
containing sixty species. The red spiders are most trouble- 
some in times of drought and are found chiefly on the underside 




PROBLEMS OF SPIDERS, MITES, AND TICKS 

>f leaves. So minute are they that a single one is scarcely 
visible to the naked eye, and they are often not noticed until 
he plant is badly infested. 

They pierce the surface of the leaf and suck its juices, and 

very soon the plant begins to appear yellow and sickly. When 

t is practicable the garden hose will exterminate these pests. 

I T nder other conditions spraying with fish oils or soap solution 

is effective. 

Clover mite Bryobia pratehsis. As the name indicates, these 
mites are found chiefly upon clover, but also on apple and 
peach trees, cotton woods and arbor vitee, and even on boards, 
stones, and fences. During the fall and winter they appear 
ulso on plum, almond, poplar, and elm trees, and frequently 
eave vegetation entirely and become very troublesome in 
houses. 

Of species found upon animals, there are some which can- 
not be considered a real menace to health, yet they are ex- 
; remely irritating and troublesome. The most common of these 
are harvest mites and wood ticks, the former being one of 
i he smallest of 'mites, a mere pin point of red, and the latter 
one of the largest of ticks, reddish brown, a quarter of an 
inch in length and swelling, as it feeds, to the size of an olive. 

Harvest mite Trombidium holosericeum. When in the larval 
stage, these are the "chiggers" of the Middle States. During 
oarly summer harvest mites will be found on grasslands and 
sandy slopes, or in the woods. They can be seen most easily 
in July, when the eggs are being laid, and that is the time 
also when they begin to attach themselves to any passing 
animal. The creatures of the woods, especially moles and 
hares, are sometimes literally infested with them, and dogs, 
jats, horses, and cows often show signs of intense itching 
from them. In some localities there are few people who have 
not felt their presence. Sulphur ointment or friction with a 
cloth dipped in benzine or strong alcohol will give speedy 



166 



CIVIC BIOLOGY 



relief, if applied soon after exposure and before the mites 
have become embedded in the skin. 

Itch mites Sarcoptes scabiei (scabere, "to scratch "). These 
mites have long been a terror to man. They multiply at the 
rate of 15,000,000 from a single pair during the season, are 
easily passed from one animal to another, and are extremely 
difficult to control. There are many varieties of itch mites, 

differing in size ac- 
cording to the thick- 
ness of skin of the 
animal they attack. 
The pig, horse, wolf, 
goat, camel, sheep, 
dog each has its 
own variety (de- 
creasing in size in the 
order here given) 
and the human mite 
is the smallest of all. 
The punctures made 
in the skin by mites 
are soon covered 
with a crust, the eggs 
being found beneath 
it. The human mite 

is best held in check by warm baths with free use of soap 
followed by an application of sulphur ointment. The same 
treatment is equally good for dogs. 

Sheep-scab mite. Psoroptes communis (var. ovis). This para- 
site is distributed over the entire world and has proved so 
destructive that most countries have passed laws to prevent 
its importation or spread. With intelligent cooperation in the 
use of precautions and methods of treatment now understood, 
sheep scab could soon be eradicated. 




FIG. 81. Egg cocoons of spiders on burdock 
Photograph by Dr. J. P. Porter 



PKOBLEMS OF SPIDERS, MITES, AND TICKS 167 

The poultry mite Der many ssus galling. This is a vicious- 
looking creature when seen under a microscope. In color it 
varies from yellowish white to blood red when fully gorged. 

Its presence is sometimes not suspected, for it is a night 
worker, and during the day it disappears into cracks, especially 
in the ceilings. If extremely numerous, adults may be found 
on the fowl, but generally not even the indications of their 
punctures are visible and only the condition of the poultry 
shows their existence. There is danger of this mite being 
carried to the stable, if near by, and the effect upon horses is 
sometimes serious. Absolute cleanliness in the henhouse is 
the price of freedom from this pest. 

The Rocky Mountain spotted-fever tick. Dermacentor ve- 
nustus. The germs of spotted fever are carried from native 
wild animals to man by the bite of this tick. The life history 
of the tick consists of four stages the egg, " seed " or larva, 
nymph, and adult and occupies from one to three years. 
Failure to find a host during any of the three active stages 
results in death of the tick by starvation, and the discovery 
that earlier stages are largely dependent on the rodents of 
the region has resulted in a plan of cooperative effort to ex- 
terminate rodents and ticks together. Since most of the host 
species are destructive to agriculture, the work is doubly 
worth doing. " Cooperation by all landowners in a district 
is essential to success of any extensive campaign of rodent 
destruction." 1 It has also been observed that sheep rid land 
of this tick, and this suggests that they might prove useful 
against chiggers and other ticks. 

Cattle tick Margaropus annulatus. The germ of Texas 
rever is now known to be carried by this tick. The loss to 
uhe South as a result of this disease has been estimated by the 

1 Clarence Birdseye, ff Some Common Mammals of Western Montana in 
Delation to Agriculture and Spotted Fever." Farmer's Bulletin No. 484, 
Washington, 1912. 



168 CIVIC BIOLOGY 

government to be $63,250,000 annually. Texas fever does 
not become established in the North, because the tick cannot 
survive the winter; nevertheless it frequently appears there. 
Northern cattle have been attacked by it as early as thirteen 
days and as late as ninety days after the tick -bearing cattle 
have passed through the locality. 1 Eight species of ticks have 
been found on cattle in this country, but only Margaropm 
annulatus carries the germ of Texas fever. It may be distin- 
guished readily from the other seven by its tiny reddish-brown 
head, contrasting with its dull yellow or even olive-brown 
body, and by its shape and size. The body is broadly oblong, 
sometimes reaching fifteen millimeters in length, and shows 
irregular markings of yellow. , Notice differences between 
Margaropus annulatus and comparatively harmless ticks com- 
mon on cattle (Plate IV). 

Dog tick or wood tick Dermacentor electus. Aristotle calls 
the wood tick, dog tormentor. Whoever has experienced one 
on himself knows well the firm grip which it takes, and 
appreciates the name. Force in removing the tick results 
either in pulling away the body and leaving the head still 
attached, or in carrying away a bit of flesh with the head. 
The better way is to touch the tick with a drop of kerosene 
or turpentine. It then loosens its hold and is easily removed. 

These are only a few of the mites and ticks. Frequently 
one comparatively unknown is discovered to be the cause of 
some baffling disease or a possible check to some pest. Your 
observations now may assist in the future. Keep a record of 
each new parasite you find insect or arachnid ; note name 
of specimen, date, locality, host (plant or animal upon which 
it is found), and any facts likely to be useful. 

1 This necessitated drawing the quarantine line of 1891 across the conti- 
nent from southern California to southern Virginia. This line has been 
pushed southward since active tick eradication was begun in 1906, and coop- 
eration of stockmen must eventually relieve the entire South. The problem 
is one for serious study in all schools within or near tick-infested territory. 



CHAPTER XVI 
AMERICAN MAMMAL PROBLEMS 

Each form of animal or plant .should be looked upon as an experiment in 
making a machine which shall best lit its environment and most effectively 
do the work required of it. The fit live ; the unfit are relegated to the bio- 
logical scrap heap, that is, become extinct. Care of offspring and protection 
from the elements are prime factors in fitness to survive. Mammals excel in 
both of these functions and characters, and while the feather is as light and 
perhaps more beautiful, hair is tougher and stands harder wear, and milk 
carried by the mother is a safer provision for the young than food packed 
in the shell of an egg. Above all, the intelligence which fashions adaptable 
protection from the elements, clothes and houses, caps the climax of purely 
biological fitness. 

Mammals. This group, to which man himself belongs, 
ranks highest in the scale of animal life. Its various forms 
dominate easily sea and land and yield only to birds domin- 
ion of the air. Every one knows a bird at sight, but, unlike 
this compact group, mammals differ extremely in structure 
from fishlike porpoises and whales to birdlike bats. In gen- 
eral, hair is as characteristic of mammals as feathers of birds ; 
and aside from a few freak forms, like the Australian duck- 
bill ( Ornithorynchm paradoxus, " bird -nosed paradox "), which 
lays eggs and incubates them like a bird, mammals agree in 
nourishing the young with milk. 

Among the more important problems relating to American 
mammals are the following: 

1. Extermination of predacious forms as the continent has 
been opened up to settlement panthers, bears, lynxes and 
wild cats, wolverines, wolves, minks, skunks, and weasels. 

2. Utilization of native wild animals bison, elk, moose, 
deer, antelope, mountain sheep and goats, hares and rabbits. 

160 




FIG. 82. Orders of mammals, with habitats 
170 



AMEKICAN MAMMAL PROBLEMS 171 

These have been an important source of food during the early 
settlement of the country. 

3. Trapping fur-bearing mammals beaver, otter, marten, 
sable, badger, muskrat, moles, and others. 

5. Efforts to prevent the total extinction .of valuable species. 

This last feature of the American problem has been late in 
developing. 

Our destruction of animal game resources is commonly 
spoken of as wanton, and in many instances this is undoubtedly 
true. Still the problems are not so simple as they often appear ; 
for example, thousands of bison were shot for the mere sport 
of shooting, and the species is now practically extinct in the 
wild state. This seems a great waste, but it is impossible to 
use the same range for both bison and domestic cattle, and 
cattle are much more valuable. The bison herds swept the 
range cattle with them in their migrations and strewed settlers' 
fences over the plains. When full-grown they are not amen- 
able to ordinary means of control and probably could not be 
profitably domesticated. Even tame buck deer and bull elk 
are dangerous animals. Rearing the bison in specially fenced 
preserves is quite a different matter, and has proved at 
present fancy prices for robes and heads a profitable indus- 
try. Both the United States and Canada have undertaken to 
thus safeguard the species from extinction, and the American 
Bison Society has been recently organized to make sure that 
the largest, and in many ways most picturesque, American 
mammal shall never entirely disappear from the earth. 

Those in charge of zoological parks and private forest 
preserves, as well as of the extensive national forest reserva- 
tions, are all making preservation of native animals a strong 
feature of their work. Many states are also beginning to 
legislate to prevent extermination of valuable animals. Sev- 
eral states derive considerable revenue from hunting licenses, 
and, in order to attract sportsmen, must maintain the supply 



172 CIVIC BIOLOGY 

of game. Wild deer are beginning to be seen in eastern Mas- 
sachusetts, the state allowing but a single week for hunting 
them and paying all damage which they cause to crops. These 
damages are increasing, however, so fast that it is a serious 
question whether such an animal should be allowed to range 
at large in a state not possessing extensive tracts of waste land. 
State forest reservations, private hunting preserves, and spe- 
cial parks will probably solve the problem in such a manner 
that the species will be preserved and the people permitted to 
see and enjoy them in their native haunts, Avhile promiscuous 
damage is prevented. 

The preservation of the fur seal has come to be an inter- 
national problem which is engaging in its solution the best ex- 
perts of England, Russia, Japan, and the United States. There 
is thus a good chance of saving a great industry to the inter- 
ested nations and a number of fine species of seals to the world. 

As the animals have been trapped off, the price of furs has 
steadily advanced, until the rearing of fur-bearing animals 
notably the silver fox is becoming a paying industry. At 
present prices it ought to be possible to rear many of our fur- 
bearing animals at enormous profit. " The beaver," says Pro- 
fessor Shaler, " particularly the North American form, offers 
a most attractive opportunity for a great and far-reaching 
experiment in domestication. On this continent, at least, the 
creature exhibits a range of attractive qualities which is ex- 
ceeded by none other in the whole range of the lower mam- 
malian life." Here is a new field of biological interest, 
experiment, and human advance in control of animal life which 
ought to appeal to boys who live on farms affording opportu- 
nities for such work. Methods of caring for the animals in 
confinement or under control may be learned to advantage 
from zoological gardens ; and anything in the way of local 
" deer farming " or " fur farming " should be studied and 
reported on by interested members of the class. 



CHAPTER XVII 
THE RAT PROBLEM 

The rat is the worst mammalian pest known to man. Its depredations 
throughout the world result in losses amounting to hundreds of millions of 
dollars annually. But these losses, great as they are, are of less importance 
than the fact that rats carry from house to house and from seaport to sea- 
port the germs of the dreaded plague. DAVID LANTZ, "The Brown Rat 
in the United States," p. i). Bulletin No. 33, Biological Survey, United States 
Department of Agriculture 

The smell of mice shall be in their nostrils and they shall die. Old saying 

To pay $1,000,000 for the last pair of rats on the North 
American continent, after the Panama Canal is cut through, 
and every harbor is properly sea-walled, might be money well 
expended. The warfare which has been going on for thou- 
sands of years might then be terminated in at least one conti- 
nent and may not all good Americans unite in the hope 
that ours may be the first continent of which this is true ? 

The failure of all attempts to deal with this vile enemy 
may be traceable to lack of a vivid realization of what the 
" last pair " may do in the way of increase. The brown rat 
may breed five times in a season and have from 6 to 23 young 
at a litter. Allowing 8 young, the increase from a single pair 
in a season may amount to 880 ; and if we figure 10 in a litter, 
this number is increased to 1250. In three years with only 6 
young in a litter Laiitz has computed the possible increase at 
20,155,392. From these data it is clear that any scientific 
method of dealing with this problem in any home or locality 
must catch the last pair, and also, under existing conditions, 
insure catching the first pair as soon as it comes. 

173 



174 CIVIC BIOLOGY 

Damage annually caused by rats has been figured for several 
countries as follows : 

Denmark . ... . . . . ' . ... $3,000,000 

France . .. . . 40,000,000 

Germany . . . . . : ' . . . . 50,000,000 

England ....... ~. . . . 73,000,000! 

United States 100,000,000 2 

This estimate of $100,000,000 worth of grain is based on the 
amount actually eaten by rats, and Lantz maintains that they 
destroy and pollute " fully as much as they consume." But a 







FIG. 83. Common. brown rat and mouse 
Photograph by the author 

damage tax of $200,000,000 levied annually on cereal crops 
is by no means the whole story. The poultry industry yields 
$600,000,000 annually, and rats take an enormous toll of eggs 
and young chicks. " I have known them to take nearly all 
the chicks on a large poultry ranch, and in the same neighbor- 
hood and over a large territory, to destroy nearly 50 per cent 
of the season's hatching " (Lantz). The writer learned of an 
instance of a large rat killing and carrying away an entire 
brooder lot of over two hundred newly hatched chicks in a 
single night. Ducks, turkeys, pigeons, game, and song birds 

1 Great Britain and Ireland, rural damage, and does not include losses 
in towns and cities and that inflicted upon shipping. 

2 For destruction of grains only. 



THE EAT PROBLEM 



175 



suffer likewise from their attacks. Finally the rat is the 
orimary boast of trichina which causes so much damage and 
oss in the raising of swine. One of the prime requisites in 
;ill such industries, if they are to be conducted with safety 
;md success, is rat-proof construction. 

The depredations of rats on fruits and vegetables, bulbs and 
seeds of all kinds, and all manner of merchandise, meats, and 
stored provisions are too well known to require more than 
passing mention. Buildings are damaged, water pipes gnawed 




FIG. 84. A small night's work for a rat 

Eleven chicks have heen killed and dragged into the hole and three bitten so that 
they died. Photograph by the author 

;ind buildings flooded, the insulation of electric wires de- 
stroyed, which, together with matches carried into their nests 
;md ignited, cause numerous fires. " It is conservative to place 
the entire yearly loss to the people of Washington from rats 
;md mice at $400,000 " (Lantz). For Baltimore, Lantz esti- 
mates the yearly damage at $700,000 ; and for cities in the 
United States of over 100,000 inhabitants these studies would 
indicate an annual loss of $20,000,000. 

Black death, the bubonic plague, beginning in China in 
1334, swept westward over Europe, and in that single epi- 
demic killed, it is estimated, 25,000,000 people in Europe 



176 



CIVIC BIOLOGY 



alone. One half the people of Italy were killed by it. Whole 
villages and towns were left without a living inhabitant, and 
cattle ranged at will among the unharvested fields. In the 
recent epidemic it is estimated that the plague has killed in 
India, up to 1907, no less than 5,250,000. It has gained a 
foothold in this country, but San Francisco, in the most thrill- 
ingly interesting civic effort ever recorded in human history, 
and with the best assistance the national government could 

give, stamped it out after 




taking a meager toll of 
seventy-seven lives. 

* He died of the plague and 
all my family with him. I have 
no home or wife or relation to 
go to so I will take no leave this 
year." Reply of a native sol- 
dier in India to a question about 
his brother. 



Bubonic plague in man is 
entirely dependent on the dis- 
ease in the rat. 

The infection is conveyed 
from rat to rat and from rat to 
man solely by means of the rat flea. Lantz, quoted from " Etiology 
and Epidemiology of Plague," p. 93. Calcutta, 1900 



FIG. 85. Lead pipe gnawed by rats 

This flooded a house and fortunately caused 
only $7 damage 



Thus a bacterium, an insect, a mammal, and man are 
bound together in a biological relation which has cost the 
world hundreds of millions of human lives and centuries of 
misery and horror. At last modern biology has discovered 
this relation, and the fact that an intelligent people can learn 
and realize its truth and act together for the common good has 
made the difference between the San Francisco epidemic and 
that of India 77 lives to 5,250,000. If the rat did no other 
damage, is not this sufficient reason to induce every citizen of 
a civilized community to exterminate rats from his premises ? 



THE HAT PROBLEM 177 

It lias been said that " of all highways a rat loves a drain 
the best." Our whole scheme of sanitation depends upon the 
principle of washing all filth and disease germs into our sew- 
ers. Here then we have an animal which wallows and crawls 
and swims in this filth and nightly distributes it over exposed 
foods, merchandise, markets, and homes. In this way rats are 
often responsible for persistent local epidemics of any disease 
whose germs are washed into sewers, typhoid, diphtheria, 
scarlet fever, and many others. These facts, together with 
common decency and intelligent cleanliness, are again suffi- 
cient reasons for extermination of such filthy pests. 

On all three counts, therefore, general destructiveness, 
carriers of Black death, distributers of disease and filth 
rats deserve absolute extermination. They were formerly con- 
sidered valuable as scavengers, but modern methods of sani- 
tation are thwarted by them, and these have rendered their 
further services in this line doubly undesirable. 

The simple duty of every citizen is to exterminate the rats 
from his own premises. Modern methods traps, poisons 
and poisonous gases, concrete and rat-proof construction 
render this entirely possible, and at a fraction of the cost 
which the presence of the pests yearly entails. 

All methods of driving rats away, scattering them among 
the neighbors, accomplish no real good and are besides uncivic. 

Trapping is at once the safest and, for boys, the most edu- 
cative method of keeping a home free from rats. It is no more 
expensive and much more interesting to keep traps set all the 
time than to allow them to be lying idle. If we could fire a 
pistol that could be heard across the continent, and from that 
day on have all the boys of the country keep all the idle rat 
and mouse traps set and baited in the most likely places 
about their homes all the time, the battle would be nine 
tenths won. Stores, mills, stables, factories, depots, and 
wharves could then deal with their own problems effectively 



ITS 



CIVIC BIOLOGY 



and not have the constant stream of rat and mouse immigra- 
tion from surrounding homes. 

To work for days and finally outwit a wise old rat and 
catch him often gives one a game and a story almost as instruc- 
tive in animal cunning as that of old Lobo Rex Currumpre. 
Being chiefly nocturnal, and living, as they do, in the total 
darkness of burrows and drains, rats sense danger mainly by 
smell, and the smell of man, his archenemy, will scare a rat 
away from a trap recently handled. But leave the trap, care- 
fully covered with earth or bran or loft sweepings, in a natu- 
ral runway or at the mouth of a burrow a week, the man 

scent disappears, the wisest 
old rat has a moment of 
absent-mindedness, and the 
last one " puts his foot in it." 
A study of rat traps is 
interesting, but is apt to 
suggest that their manufac- 
turers are chiefly concerned 
FIG. 86. A durable and effective trap with making something 

which will not exterminate 

their business by catching rats. All authorities to the con- 
trary, notwithstanding, the writer, after ten years' active study 
of the problem, would discard all rat traps which depend upon 
being baited, except the cage or box traps to be described 
below. Give him an old-fashioned steel spring trap, and, by 
keeping it set year in and year out, he will guarantee, with the 
aid of other methods to be described, to catch the last and the 
first rat on any home premises. This does not apply to mouse 
traps which require baiting, and which, if kept baited and set 
all the while, insure catching the last and first mouse in any 
house or barn. 

If the focal method described below cannot be adopted, a 
French cage trap may prove of some use about a home, if it is 





THE RAT PROBLEM 



179 



kept well baited all the time, and open. As soon as it is noted 
that the rats are feeding in it freely, close the trap end and 
make a catch. 

Poisons are rather " unbiological " and require some care in 
handling. The Department of Agriculture has recommended 
barium carbonate as the cheapest and safest poison to use for 
cats and mice. It is tasteless, and in the small quantities used 
is not dangerous to domestic animals. Another advantage is 
that it is slow in acting and the vermin leave the premises to 
die. Mix oatmeal with one eighth of its bulk of the poison 
into a stiff dough with water, and place a teaspoonful in a 




FIG. 87. A good design for a runway trap 

These traps were so poorly made that they were likely to fly to pieces when 

snapped, and never caught a good-sized rat for the author until he had put in a 

row of tack points along the end of the bottom board 

-plate about likely places. Or moisten a slice of bread and rub 
in a quantity of the barium powder on both sides, spreading 
'i mtter over it ; cut into inch cubes and place in the runways. 
Or mix two teaspoonfuls of the barium with an egg, thicken 
10 a stiff paste with oatmeal, corn meal, or bread crumbs, and 
distribute as before. Pieces of raw Hubbard squash with the 
poison rubbed well into all the cut surfaces, and with cuts 
made in the flesh and filled with it, make excellent baits. It 
is well to change the kind of bait and at first to feed freely 
with the same material unpoisoned, and even then, according 
to the writer's experience, you will not succeed in fooling the 



180 



CIVIC BIOLOGY 



last old wise ones. Above all, use clean scalded dishes and 
utensils and avoid all possible taint of man-smell on the bait. 
Arsenic is one of the most common ingredients of rat poisons 
and has the advantage also of being tasteless and of causing 
intense thirst so that the animals leave the premises in search 
of water. It may be used in combination with any of the baits 
described above. In mixing with corn or oatmeal take one 
twelfth by weight of the poison. In putting the above poisons 
in houses or barns be sure to have no water accessible inside 
the buildings ; but leave doors and windows open, and, if a 
pan of water is sunk in the ground in the yard, rats and mice 



Bait 



FIG. 88. The poison box 

The inner box, where the bait is put, should be about 4-6 inches smaller in hori- 
zontal dimensions. The strip a, \ X 1 inch, is nailed all around the bottom of the 
larger box to prevent scattering of poisoned material. Bait with pieces too large 
to be carried out. Leave holes in lower corners small for rats to enlarge 

in numbers may be seen dying and dead around it. They even 
lose all fear of man and crawl to the water to drink in broad 
daylight, and commonly remain at the water until they die. 

To destroy rats on farms. Each evening when the cows are milked 
place a little fresh milk in a shallow pan w r here the rats can get it. 
Continue this for a week or more until the rats get bold and impatient 
to get at it. Then mix arsenic with the milk and await results. This 
plan is said to entirely clean a barn of rats. Quoted by Lantz from 
E. H. Reihl, in Cohnan's Rural World, January 29, 1908 

Strychnine acts so quickly that there is danger, when used 
about buildings, that the animals may die in the walls. In 



THE HAT PROBLEM 181 

other places it may be used very effectively, and still, on 
account of its intensely bitter taste, it seldom catches the sly 
old ones. Strychnized grain used in poisoning sparrows is 
equally effective for rats and mice (|- oz. strychnia sul- 
phate dissolved in 1 pint of boiling water, thoroughly stirred 
into 2 quarts of cracked corn or wheat, dried and labeled 
jind stored safely for use). The writer has been told of 
clearing a barnyard and large stable by first feeding the 
rats with raw, unbroken eggs, then substituting eggs heavily 
charged with strychnine, the crystals of the poison being 
pushed through small holes in the shells. The ground near 
~hese eggs was described as " strewn with dead rats." 

Phosphorus pastes commonly sold as rat and mouse poisons 
cannot be recommended, as they are too likely to cause fires. 
The other ingredient, glucose, is likely to be leached or weath- 
ered away, leaving the phosphorus strong enough to ignite 
spontaneously, and lumps of the material may be carried by 
rats from perfectly safe places in a cemented cellar up 
into the nests anywhere in the building. Even fields of grain 
have been fired in this way. 

Fumigation with poisonous gases is perhaps the most effec- 
tive method of dealing with vermin that burrow. It is such 
sport to absolutely exterminate rats from fields, dumps, poultry 
yards, and cellars that the game is worth the expense. 

Carbon bisulphide is the agent most commonly used. Moisten 
a tuft of cotton or a rag the size of an egg with about a table- 
spoonful of the bisulphide, push it down the hole, and tamp 
bightly with earth. If the hole is dug out, and remains inhabited, 
which can be ascertained by filling the mouth with earth a 
few times, repeat, using a double dose. Carbon bisulphide is 
poisonous to breathe and is not only highly inflammable but 
very explosive ; therefore keep all lights away while using. 

What we have called the " focal " method of dealing with 
civic pests consists in discovering something which attracts 



182 CIVIC BIOLOGY 

them above everything else. This is a method of attracting 
(focusing) all vermin to a particular place, and is diametri- 
cally opposite to all the common devices for " driving away " 
or scattering our pests among our neighbors. When we find 
something which will attract every fly, mosquito, flea, rat, 
English sparrow, stray cat to a certain spot and catch and 
kill them there, the work of control or extermination will 
be easy. A dog is a natural focus for every flea about the 
premises. Lather him with soap daily or once a week for a 
few weeks and every flea will be exterminated. 

The natural focus of any animal is its preferred food, and 
for rats and mice about the home this is the granary, feed 
room, pantry, or- storage cellar. It is only necessary to make 
these absolutely rat and mouse proof, easily accomplished 
now with cement, sheet metal, or wire net, and then leave no 
food exposed outside these places, and, to all practical intents 
and purposes, we have our premises rat proof. We can then 
easily establish a focus which will catch or kill every rat or 
mouse which comes to us for food. 

Take the example of a home which has a horse and cow 
and poultry. Each place will present its own problems, but 
the following scheme will apply to all sorts of conditions. 

If possible, have all feed for poultry and stock kept in a 
rat- and mouse-proof feed. room. The wall of this room is 
tight, preferably steel lath and cement, except a space six 
inches high by one foot long in one of the corners against 
the outer wall of the barn. This space is closed by both 
heavy wire net of one-quarter-inch mesh to exclude all rats 
and mice, and also with fine wire gauze to keep out all in- 
sects. Rats and mice seek their food by smell, and this 
opening will focus to that place all the animals as they come 
to the premises, if no other food is accessible anywhere else. 
Keep the bag of Spratt's dog biscuit and the poultry scrap 
meat and a bag of sunflower seeds near this hole, and if rats 



THE EAT PROBLEM 183 

and mice are coming in rapidly, as they often do in the fall, 
keep and feed well for a while a female rat in a wire cage 
against this opening. Now bore a hole through the side of 
the barn close to this corner. It is well to make this hole 
me inch in diameter and allow the rats themselves to en- 
large it so that it will be an actual " rat hole." Fasten 
securely a cage trap so that all rats and mice which enter 
the barn must do so through this trap. If all doors and 
windows are properly screened and kept closed and all holes 
ire stopped up, this will insure catching the first rat or 
mouse that comes and thus prevent even the beginning of 
breeding foci about the premises. 1 

Possibly enough expense is incurred annually in many 
cowns and cities and enough effort expended to effectually 
exterminate rats and mice, but the work is not organized. 
A. may exterminate the pests from his place in October, B 
from his in November, C from his in April, and all three of 
their premises be infested again for the season's breeding, the 
work of one driving the old cunning rats over to neighbors. 
We have effective methods enough to accomplish the com- 
plete extermination with a small part of the effort and ex- 
pense wasted by our communities annually. What we lack is 
effective organization. Rats and mice tend to leave buildings 
in the spring and migrate back to them in the fall. Since our 
experience with rats and the plague in San Francisco, and in 
view of the fact that other cities or even towns may be called 
upon at any time to fight the plague, every home ought to do 
its part, and every community ought to be able to extermi- 
nate its own rats. The disease to-day is widely distributed, 

1 An even more serviceable trap which will set itself and thus catch a 
continuous stream of animals may be made by any ingenious boy, possibly 
n connection with the manual-training work. If vermin are likely to gain 
iccess to the building by other openings, it is well to have an entrance to 
he trap inside the building as well. 



184 



CIVIC BIOLOGY 



Jft 



and no one can tell where some migrating rat will carry it 
next. Thus while other considerations of damage and general 
public health make this work expedient, danger from plague 
renders it imperative. People who do not know have no right 
to opinions in such vital matters, and the time must come 
when the ignorant and negligent shall not continue to vitiate 
the best civic efforts of our towns and cities. 1 

Cannot the biology class in the high school or local acad- 
emy, assisted by the boys of the upper grades, supply the 
intelligence and generalship, and bring about the cooperation 

and organization of the civic 
effort to render the work of 
extermination effective 
even to the last pair in the 
town, or the first pair that 
migrates to it ? Might not 
this work alone go far 
toward repaying to the com- 
munity the cost of public 
education ? 

Mice should be dealt with as thoroughly as rats in all these 
campaigns, and they possess so little cunning that they can 
easily be exterminated from any premises. Aside from nuisance 
and damage caused by mice the theory has been advanced that 
germs of pneumonia become more virulent on passing through 
the mouse, and thus cause severe and often fatal infections. 




FIG. 89. The only rat this trap caught 
A poor design wholly dependent on bait 



1 The thing to do, brothers, is to get together ; cooperate with the health 
officers ; lend them your moral support as freely as you have your material 
aid ; and, above all, do your part in suppressing the scoffer, the man who 
laughs in his ignorance, and who in that ign6rance wants to trifle with a 
situation like this. 

Remember, in these matters each one of us is in a measure his brother's 
keeper, and let us show this man that if he is not willing to do his part, we 
are not only willing to do ours, but we are going to see that he does his, 
whether he wants to or not. San Francisco Report, 1909, p. 254 



TILE RAT PROBLEM 185 

PRACTICAL PROBLEMS 

The practical laboratory work of this section shall consist in 
actually exterminating rats and mice from your home premises. 

Make a complete survey and locate every rat hole in the 
ground and in the walls of buildings, and draw a careful 
diagram with all holes located. Stop all holes with earth 
and mark on your diagram in red ink all that are reopened. 
Locate on your diagram also rooms or buildings of rat-proof 
construction. 

Make as complete a collection of rat and mouse traps as the 
neighborhood affords. It will be well to have each member of 
the class bring in all the traps he has used at the end of this 
campaign, and compare and discuss the merits and demerits 
of different traps. 

Devise and construct a better rat trap than any used. 

Write a brief statement of your own experience in clearing 
your home of these pests. 



CHAPTER XVIII 

FUNGI : BACTERIA, YEASTS, MOLDS, MILDEWS, RUSTS, 
SMUTS, AND MUSHROOMS 

Although the great mass of material phenomena elsewhere had been 
brought into apparent orderliness and system, here was a region in which 
the unscientific imagination rioted in mystery and extravagance. The pene- 
tration of this realm of obscurity by the discoveries of bacteriology gave 
the human race for the first time in its history a rational theory of disease, 
dispelled the myths of spontaneous generation, and set the process of decay 
and kindred phenomena in their true relation to the great cycle of living 
and nonliving matter. 

The new conception of the microscopic underworld which bacteriology 
brought into biologic science must be reckoned as a conspicuous landmark, 
and, ip so far as it has changed the attitude of man toward the universe, 
should be regarded as one of the most important triumphs of natural 
science. JORDAN, "General Bacteriology," p. 23 

The role of fungi in the life of the world. Saccardo's " Syl- 
loge Fungorum" has described to date 66,615 species of fungi. 
This means that somewhat more than one fourth of all the 
plants known to science belong in this group, and over 1000 
new fungi are being described each year. Food supply is the 
vital problem of plants, animals, and man, and in order to 
appreciate the position of the fungi in nature we must study 
the continual flow of food material and try to understand how 
the world is fed. 

Fungi lack chlorophyll ; hence they are dependent for food 
upon other plants and upon animals. Some tend to be omnivo- 
rous, like the common molds of the household, and take almost 
any food that comes their way, while others are close feeders, 
living on some one animal or plant or even upon certain 
organs, tissues, or substances produced by their necessary 

186 



FUNGI 



187 




host organisms. The great work of fungi in nature is thus to 
break down organic matter and return the elements to Mother 
Earth, that they may be caught up in the circle of food supply 
and live again. Without this beneficent work of the fungi 
all the animals and plants 
that have died since the 
beginnings of life in the 
world, if they had not been 
eaten or burned, would still N ^ 
cumber the earth ; that is, sXJ 
the food of the world would 
be locked up in dead forms. 
Burning returns the nitro- 
gen to the air, a most 
wasteful process, while 
'the decay of the dead bod- 
ies and waste matters of 
animals and plants caused 
by fungi holds this most 
precious of all foodstuffs 
in chemical combination as 
nitrates, ready again to be 
built up into the grains, 
seeds, fruits, and other food 
products of green plants 
(see Chapter IX). Thus, 
in burning wheat straw the 
farmer may rob his land 
of twenty-five pounds of 
nitrogen in combination, worth $3.75 per acre per year, and 
an acre of corn stover or cotton stalks may contain respec- 
tively $7.50 and $15.30 worth of nitrogen. Where it is cus- 
tomary to burn these materials is it any wonder that the wheat, 
cotton, and corn fields are worn out? 



'NITRATES 

FIG. 90. Circulation of protein food 
materials in nature 

Nitrogenous food (protein) is the one essen- 
tial food of both animals and plants. The 
green plants build up this entire food sup- 
ply from the chemical elements by the 
energy of sunlight working through leaf 
gre^n, or chlorophyll; nn represents free 
nitrogen from the air, drawn into combi- 
nation by symbiotic bacteria in the root 
tubercles of clovers, beans, etc. The non- 
nitrogenous foods starches, sugars, gums, 
fats, and oils are built up along with the 
proteins and are finally oxidized to carbon 
dioxide and water, whether in the animal 
or plant body or by rotting or burning 



188 CIVIC BIOLOGY 

Functional subdivisions, saprophytic, parasitic, and symbiotic 
fungi. Saprophytic fungi are those that live upon the dead 
bodies or waste matters of animals or plants. Parasitic fungi 
attack living animals and plants and injure or kill them. They 
are the causative agents in the larger part of contagious or 
infectious animal and plant diseases. Symbiotic fungi live 
with other organisms, to the advantage of both. Bacteria in 
root tubercles of the legumes are familiar examples. While 
convenient, these lines of classification are not hard-and-fast, 
because it may be difficult, or even impossible, to tell whether 
an organism, or any part of it, is really dead or alive. The 
rough bark and the heartwood of a living tree are as dead as 
they ever will be,- so may be the hair or cuticle of a living 
animal, or the rind or pulp of a ripe fruit, or the food material 
of a seed or egg. Who can say whether the sap of a plant or 
the blood or milk of an animal is dead or alive ? So there are 
all degrees of liveness or deadness, and a usually beneficent 
saprophyte may attack a half-dead plant or animal, which we 
would call alive, but the fungus may know better. Accord- 
ingly we have Jtemiparasitic and hemisaprophytic, or, so-called, 
facultative parasitic or saprophytic, fungi that attack the living 
or the dead according to degrees of vitality or variations of 
external conditions. 

Botanical position of fungi. All fungi are devoid of chloro- 
phyll, but not all plants that lack " leaf green " are fungi. 
Dodder and the Indian pipe are flowering plants that have 
adopted the parasitic habit, and with this degenerate life they 
have lost the mechanism and the power of making their own 
food. So we find from a study of their ways of growth and 
methods of reproduction that fungi have developed from the 
algae. Flowering plants reproduce by seeds, which are embryo 
plants provided with food for the start in life. The ferns, 
mosses, algse, and fungi reproduce by spores, which, compared 
with seeds, are almost inconceivably small. Many seeds are 



FUNGI 189 

provided with hairs or wings to cany them in winds, and 
many float in. the water in order to be widely scattered; but 
the spores of the fungi are so light and small that they float 
invisible in either air or water, and so they far outstrip in dis- 
tribution the best devices of the higher plants. As a result, 
while the flora of seed plants is very different in different 
countries, the molds and mushrooms, yeasts and bacteria, are 
more likely to be the same species the world over. 

Compare seeds and spores as to size and numbers pro- 
duced. For spores use the dust from a patch of mold and 
from a puffball, and try to see, feel, smell, and taste them. 
The finger tips may be black or green with millions of mold 
spores, but how much can we feel them ? We can see the 
cloud of " smoke '' from a puffball, but as the spores scatter, 
can we see them in the air (unless in a ray of sunlight in a 
darkened room), and have we ever tasted them in food ? 
Some people enjoy the tastes of certain molds and bacteria in 
cheese, Camembert, Roquefort, Stilton, Limburger, and 
they may be as wholesome as any other vegetable. How do 
the different kinds smell ? How many spores may we be 
breathing in with every breath in a musty room ? How does 
the number of seeds of a grain plant or weed compare with 
the spores produced by a puffball ? 

Size and power of growth. A baby grows to double its 
weight at birth in five months. A yeast plant or bacterium 
may double in size in twenty or thirty minutes. The fungus 
thus has from seven to ten thousand times the power of growth 
of the baby. Why this difference ? 

Food, again, is the basis of growth. To dissolve, digest, 
absorb, circulate to every part of a large body, assimilate 
(that is, build over the foreign matter into the particular pro- 
toplasm of the species) are slow and laborious processes. Solu- 
tion of food substances, especially the proteins (white of egg, 
gluten, casein, lean meat), is difficult, and absorption through 



190 



CIVIC BIOLOGY 



the cell membranes is slow. The amount absorbed is pro- 
portional to the absorbing surface exposed to the solution. 
With these points in mind we may understand why the ac- 
tive mechanisms in living things are so minute, for only in 
this way are they able to present the largest possible sur- 
face for both the escape ' of waste matters and the absorption 

of food. The diagram 
on this page presents 
these relations in sim- 
ple form. A one-inch 
cube is seen to have 
six square inches of ab- 
sorbing surface, while 
in a ten-inch cube each 
cubic inch has only six 
tenths of one square 
inch of surface. The 
rate of absorption be- 
ing the same, the 
smaller cube could 
absorb ten times as 
fast as a similar bulk 
of the larger cube. So 
we see why the small- 
est organisms may be 
the most efficient in ab 
sorbing food and have 
the greatest power of 
growth. It is estimated that a bacterium J^QQ- ^ a milli- 
meter in diameter, which can double in size in twenty min- 
utes, given food and suitable conditions, might grow to a 
mass the size of the earth in about five days. A yeast plant, 
which is much larger but which can double in thirty minutes, 
might grow to a similar mass in about two weeks. How 




FIG. 91. Diagram to show relation of surface 
to bulk in large and small organisms 

The law is: Bulk increases as the cube, while 
surface for absorption increases only as the 
square. Since bulk so rapidly outstrips surface, 
this relation tends to limit the size of organisms, 
and suggests one of the fundamental reasons 
why minute organisms possess such phenom- 
enal powers of growth and reproduction 



FUNGI 191 

long would it take a pair of elephants to multiply to a mass 
of the same weight ? 

Size. As we have seen, mere size counts for little. Bac- 
teria, the smallest plants known, are infinitely more powerful 
than sequoias or whales. Fungi range in size from the giant 
puffball (the fruiting body of which may grow to three or even 
.'our feet in diameter) to microscopic bacteria, and some of 
these are quite possibly too minute to be visible under our 
best microscopes. In the fruiting portion of a large mushroom 
\VQ see but a small part of the whole fungus. This consists, as 
we shall see later, of a feltwork of microscopic threads (the 





jr-=7 

--=B 

J5 
FIG. 92. Size of microscopic fungi 

Comparative size of : A, a, molds ; b and c, yeasts ; d, bacteria equally magnified ; 

B, e, minute particle of dust; f, point of finest cambric needle; g, bacteria under 

less magnification. After Conn 

feeding, or vegetative, portion), which permeate the soil, leaf 
mold, wood of a tree, or other substance in which the plant is 
growing, possibly for many feet in every direction. 

Yeasts (Saccharomycetes, the sugar fungi saccharon, ' ' sugar " ; 
myces, "fungus"). Yeasts are the "sweet tooth" fungi, and 
their work in nature is to break down sugars by the process 
known ^fermentation. The end products are alcohol, carbon 
dioxide, and various oils and flavors characteristic of different 
species of yeast. The process of fermentation is represented 
by the following simple chemical equation : 



Sugar Alcohol Carbon Dioxide 

Size and color. Common yeast plants are spherical or ellip- 
soidal bodies about - of an inch in diameter ; a cake of 



192 



CIVIC BIOLOGY 



compressed yeast contains approximately 10,000,000,000 of 
them. In order, once for all, to gain a notion of the minuteness 
of microorganisms, perform the following simple experiment : 

Sharpen the point of a teasing-needle to a fine knife blade ; take a 
bit of moist compressed yeast, the size of a large pinhead, on a piece of 
clean, polished glass (a microscope slide) and cut the lump in halves. 
Throw away one half and repeat the operation and continue as long as 
you can see to divide the particle. At the last division carefully plant 
one half in a vial half full of filtered, boiled molasses and water (a table- 
spoonful of molasses in half a pint of potato water makes a good cul- 
ture fluid), to watch it grow from day to day. Then, with the point of 
a clean needle, on a perfectly clean part of the glass, cover the other half 

with a minute droplet of 
water. Cover with a per- 
fectly clean cover glass 
and try to count the tor- 
ulse (yeast plants) in the 
speck that you can just 
see with the naked eye. 




FIG. 93. Yeast plants, highly magnified, show- 
ing successive stages of growth by budding 

After Conn 



In color most of the 
common yeasts, when 
seen in mass, are whit- 
ish or slightly yellowish gray, the color of a fresh yeast cake, 
but a few species are pink, red, or black. 

Distribution. Yeasts are everywhere; so the question is 
not, Where shall we go to- find them, but, Where go to escape 
them ? We eat them by billions, baked, in our daily bread ; 
we drink them by millions, alive, in our cider, beer, or wine ; 
we breathe them in, alive, with every breath, and drink them, 
alive or dead, according as the water is raw or boiled; with 
every drink of water we take ; they are all over us all the 
time, in our hair, on our skins, in all our clothes, and we 
cannot possibly beat them out, brush them off, or even wash 
them away the harmless, useful, patient, persistent, omni- 
present little sugar-hunting yeast plants. We might suck 



FUNGI 193 

most of them out of our carpets and homes with a vacuum 
cleaner, but this would not be worth our while if it were 
not for the fact that they are associated in the dust with less 
ropu table bacteria. 

There is just one point that we should learn in a way we 
can never forget. The skins of fruits, of course, are covered 




FIG. 94. Experiments in growing yeast 

1, yeast planted in molasses 1 part, water 5 parts, kept at room temperature; 

L', same, kept in dark; 3, planted in filtered, boiled, or distilled water; 4, same 

as 1, not planted : 5, 'same as 1, kept in cracked ice 

^ ith yeasts and with spores of molds. This fact is related to 
one of the large industries of the world the picking, hand- 
ling, and marketing of fruits. 

EXPERIMENT 1. Have the class collect a number of the fruits avail- 
al >le at the season. Scrape the surface lightly with a sharp, clean scalpel 
point or knife-needle (or wash with a fine brush into a drop of water on 



194 CIVIC BIOLOGY 

a slide). Mount scrapings in a small droplet of water and examine 
under a microscope. Be particular to scrape especially in the little crack 
around the stem. Can you see from results why stems should not be 
pulled out in picking fruit ? 

EXPERIMENT 2. Pull out the stems and make slight punctures and 
scratches through the skins of a number of apples or pears, set them 
aside with an equal number of perfectly sound fruits, and examine from 
time to time for signs of decay. 

EXPERIMENT 3. Plant scrapings from the skins of the various fruits 
in vials of dilute fruit juice (filtered cider, the juice from canned fruit, 
diluted with half water if too sweet), plug with cotton, and examine 
later for growth of yeasts and molds. 

If microscopes are not at hand, Experiments 2 and 3 can be done 
perfectly well without them. What do these experiments mean with 
reference to honest hand picking and packing of fruits ? If one decayed 
fruit wets or touches another, what is likely to happen? Contagion? 

Uses. In making bread we use the carbonic acid which the 
yeast plants give off to form bubbles in the dough. These 
bubbles are hardened in baking, the alcohol is driven off, and 
the bread remains light. In making alcohol we use the sugar 
of fruits or the starch of potatoes, barley, corn, rye, which 
has been changed to sugars by digestive ferments; then either 
the wild yeasts that were on the fruits or the pure-culture 
yeasts that we add to the fruit juice mash or wort ferment 
the sugars, and the alcohol may be distilled off by heat. 

If the yeast fermentation has been too slow, or if the mate- 
rial is allowed to stand after alcoholic fermentation is complete, 
other microorganisms, with which yeast is always associated, 
begin to turn the alcohol into acetic acid, and we have sour 
bread, sour beer, and vinegar. This process may be roughly 
represented by the equation 

C 2 H 6 + O g = C 8 H 4 2 + H 8 

Alcohol Oxygen Acetic acid Water 

Then if vinegar is exposed to the air, another organism may 
change the acetic acid further into carbonic acid and water, 
and the decomposition- of the starch or sugar is complete. 



FUNGI 



195 



EXPERIMENT. To a quart of warm potato water, not filtered, add a 
lalf pint of molasses and a yeast cake, previously mixed to a smooth 
cream in a gill of fresh milk. Keep in a dark place at between 75 and 
'.)0F., and observe from time to time. When bubbles are rising rapidly, 
conduct the gas into a vial of 
imewater, as shown in Fig. 95, 
noting that the same change 
1 akes place that occurs when we 
expire into lime water : 

CaO + CO 2 = CaC0 3 

Lime Carbon Chalk or 
dioxide limestone 

Test the liquid by odor and 
especially by taste. As soon as 
fermentation is complete (that 

s, when the sweet taste has dis- 
appeared), pour out half a pint 
into a flat dish and set in a warm 
>lace, protected from dust, to 
study the formation of vinegar. 
With the remainder attach the 
lask to a small still, heat care- 
:'ully, and test the first gill for 
dcohol by taste, smell, and by 

burning. 

In doing this experiment dif- 
r'erent members of the class, or 

lifferent class groups, may use different materials fruit juices, potato, 
,'orn or rye mashes, malt decoction and thus add to the interest. 

Pure cultures. Before reading the next experiment try 
hard to think how you would make a pure culture of a plant 
T _i__ of an inch or -g^oT of an inch in diameter. Let each 
nember of the class write out his method and then compare 
his result with those of the rest of the class. This is a test 
and measure of power to think, imagine, and reason. When 
Louis Pasteur first thought this out, he marked the greatest 
opoch in control of disease that history records. Pasteur did 
tfiis first with the yeast plant in 1856. Up to this time 




FIG. 95. Testing the gas from yeast 
fermentation with limewater 




196 CIVIC BIOLOGY 

fermentation was supposed to be a purely chemical process, 
and accordingly brewers and vintners had employed chemists 
to try to relieve them from the great losses caused by diseases 
of wine and beer. We now know that these were caused by 
wild yeasts and other microorganisms, and the problem is a 
logically simple one of weeding them out of the cultures. 
The first requisite is to isolate and study the different organ- 
isms involved, in pure cultures, and this is equally true of any 
germ disease of plants, animals, or men. 

EXPERIMENT 1. First necessary step: Get the yeast plants single; 
that is, make a uniform suspension in water. To do this make a dilute, 

well-rubbed-up suspension 
in a slender test tube or 
straight vial, and force 
down through this a tight, 
hard plug of sterilized ab- 
FIG. 96. A lifter, cut from tin, or, better, sorbent cotton. The liquid 
from thin sheet aluminium a ^ ove the cot ton will be 

It is sterilized by holding the end in a flame for pretty sure to contain noth- 
an instant, giving it only time to cool before ing but single yeast plants, 
using, a. sheet of metal indicating how the lift- -r, 

ers are cut. (One half natural size) EXPERIMENT 2. Second 

step : Get the single plants 

far enough apart so that we can work with them ; that is, dilute the 
suspension. Add a drop to, say, one quart of boiled, filtered water, and 
shake thoroughly. (If too many plants are still present, we may have to 
repeat the dilution.) 

EXPERIMENT 3. Third step : Plant a drop or a few drops (according 
to the dilution) in some medium solid enough to keep them from flow- 
ing together and getting mixed up, and clear enough so that we can sec 
them after each one has grown sufficiently to form a visible colony. 
Starch jelly made with sweetened water (or potato water filtered) 
makes a good medium for yeasts and molds. Stir the drop of sus- 
pension thoroughly into a tablespoonful of the jelly as soon as it is 
cool enough not to injure the yeast (when it feels neither cool nor 
warm to the hand), and pour in a thin layer into a Petri dish (or on 
a clean piece of glass which can be covered securely from the dust). 
Keep in a warm place away from the light, and in a day or two whitish 
specks begin to appear, if the work has been carefully done, scattered 



FUNGI 197 

( venly through the mass. If a speck is spherical and clearly distinct 
irom all others, we may pick it out with a sterilized lifter and be 
i easonably sure that we have yeast plants all descended from a single 
parent plant that is, a pure culture. 

Diseases caused by yeasts. Quite naturally one species of 
yeast causes blight of sorghum, and another, a disease of the 
( rocus, and one or two others attack animals and man. 

Molds and mildews. These are the most troublesome fungi 
of the household. They take everything in the way of food 
or clothing, carpets, linen, and even books, that they can get 
their spores on, if conditions, especially of moisture, favor 
their growth; and since they always can get their spores on 
everything that the air touches, it behooves the home-keeper 
to see to it that nothing of value is left where dampness, air 
stagnation, and darkness may permit growth of these little 
iobber plants. Conn's statement is: "If the air of a room 
becomes damp or ' close/ as we say, it is almost certain that 
molds will begin to grow upon any organic substance." While 
i i common household parlance molds and mildews are sup- 
posed to be distinct, the microscope reveals them as identical, 
the only difference being that they grow less luxuriantly on 
leather, cloth, and paper than they do on richer and moister 
foods. 

Botanical position and structure. The word " mold " is 
merely a popular designation for a variety of different kinds 
of plants. The term has no botanical standing, but is so 
f rmly fixed in common usage that we cannot improve upon 
h to designate the somewhat similar felt-like growth that 
is likely to cover everything damp. This growth is tech- 
rically known as the mycelium of a fungus, and when we 
examine it we find the key to understanding the growth and 
structure of all the higher fungi, molds, and mushrooms 
t hat is, those above the bacteria and yeasts, and some of these 
form similar mycelia. The single element is a microscopic 



198 



CIVIC BIOLOGY 



thread, the hypha, which in some fungi is tubular and in 
others is septate, that is, composed of cells end-to-end. Hyphse 
branch continually and seek the cracks and minutest pores, 
and so are able to burrow and digest their way into all sorts 
of apparently solid substances. The hyphse are functionally 
of two kinds : first, the threads that burrow and feed in or on 




D 



FIG. 97. Two common molds in different stages of growth 

A, B, C, a common blue mold, Penicillium; A, spores germinating; B, as seen 

growing in vial of liquid ; C, aerial (or fruiting) hyphse more highly magnified ; 

D, E, F, similar stages in the growth of a black mold, Rhizopus 

the food material the vegetative hyphse ; and, second, the 
fruiting hyphse, which grow out of the mass into the air (or 
water in case of the water molds) to form the various kinds 
of spore-bearing organs. These ideas are fundamental to 
control of fungi, and we should be sure that they are entirely 
clear in working out the following experiments. As we aim to 
destroy weeds before they go to seed, so we must adopt meth- 
ods to prevent our fungus enemies from ripening their spores. 



FUNGI 199 

Observations and experiments. 1. For at least one hour in preparation 
of this lesson have each member of the class hunt over his home 
premises and collect specimens of everything he can find that appears 
1o be moldy. Compare these, to try to see how many different molds 
we have. The mycelium of nearly all molds and mushrooms is white, 
but the spores and sporing organs may be any color white, red, 
p-een, gray, brown, or black. Xote particularly the kinds of places in 
which molds are found growing best, with especial reference to damp- 
ness, lack of light and direct sunshine, and lack of ventilation. 

2. Select typical specimens and arrange in jelly tumblers (or even in 
straight-necked vials) for further study. Keep covered when not in use. 

3. Make a series of mold gardens in small vials, trying to have as 
pure cultures as possible. Use all- sorts of materials foods and even 
linen and cotton cloth. Plant spores from No. 2 by touching a patch 
of mold with the point of a needle and then touching it to a single 
point in the material in the vial. Watch it grow from day to day, 
noting particularly how long it takes to begin to produce spores. To 
insure dampness the vials should be covered or corked tightly (heavy 
tinfoil pressed over the mouth of the vial makes a convenient cover), 
;ind should contain a little water. The material may be held out of 
i-he water on a bit of glass. 

Stand some of the vials in bright sunlight, and keep the rest in the 
lark, noting differences in growth. Keep some on ice (cold storage) 
and compare. Keep some protected from dust in a dry air, not covered 
lightly, and note influence of dryness on growth of molds. 

In order to see the growth clearly, make a series of mold gardens l in 
a perfectly transparent liquid medium. Fruit juice, diluted with one 
half water, filtered, serves the purpose well. Plant spores from the 
different molds on the surface, study from day to day, make careful 
drawings, and note especially the time required for spores to begin 
co form. 

4. Sketch a plan by which you would keep a home as free as possible 
from molds. 

1 Hodge, "Nature Study and Life," p. 457 ff., describes and figures 
mold gardens. 



CHAPTER XIX 

FUNGI CONTINUED: MUSHROOMS, POISONOUS 
AND EDIBLE 

To know several different kinds of edible mushrooms, which occur in 
greater or less quantity through the different seasons, would enable those in- 
terested in these plants to provide a palatable food at the expense only of the 
time required to collect them. To know several of the poisonous ones also is 
important, in order certainly to avoid them. ATKINSON, ff Mushrooms," p. iv 

General. Persistent search extending through a series of 
years in any favorable locality would reveal the presence of 
about 1000 species of these our largest and most conspicuous 
fungi. In one season one might expect to find from 200 to 
400 species. Of the entire number, according to Mcllvane, 
nine species (all amanitas) are deadly poisonous, about a 
dozen contain minor poisons, and are rated as suspicious or 
dangerous, 735 are edible, while the rest have either not been 
tested or, on account of woodiness, disagreeable taste, small 
size, or extreme rareness, are of interest only to the specialist. 

Form and structure. Mushrooms, like other fungi, are active 
in causing decay, chiefly in waste matters of plants and ani- 
mals, but. a number attack the roots and wood of trees, and, 
naturally timber and wooden structures. 

From our knowledge of the molds it is an easy step to the 
life history of a mushroom. Both organisms begin as spores ; 
in both, these sprout and grow to form a mass of food-absorb- 
ing mycelium. In mushrooms this may extend many feet in 
the soil, in leaf mold, or in the wood of a tree. In both, some 
of the mycelial threads finally grow out of the food substance 
and complete the life cycle by producing the spores with which 

200 



FUXGI 



201 



we started. The conspicuous part of a mushroom is thus a 
small fraction of the entire plant the spore-bearing organ, 
or sporophore. 

Combine the collecting of mushrooms with the field work 
with birds, insects, and trees in the early fall. In fact, this 
is the most favorable part of the school year for all forms 
except the morels, whose season is May or June. Preserve 




FIG. 98. Growth stages of a mushroom 



.1, mycelium with forming buttons, drawn from Agaricua campestrlt. The other 
figures are from Amanita phalloides (the deadly amanita) and show : B, a button 
bursting the volva (or sac) ; C, the same in longitudinal section ; and D, a mush- 
room showing , the pileus (or cap), 6, the velum (or veil), which has torn from 
the margin of the cap and remains as a ring around the stem, and c, the remains 
of the volva, which forms a cup 

the mushrooms collected for winter study by drying ; even 
many of the softer ones may be preserved in this way if they 
are dried in a current of hot air. 

Amanitas. Before collecting mushrooms, fix clearly in mind 
the characters of the deadly genus Amanita. 

Other varieties of fungi may interfere with digestion, but to the 
Amanitse all deaths from toadstool poisoning are traceable. Its subtile 
alkaloid is absorbed by the system, and in most cases lies unsuspected 



202 CIVIC BIOLOGY 

for from six to twelve hours, then its iron grip holds to the death. For 
centuries it has defied all remedies. Me IL VANE, p. 5 

The amanitas are the most conspicuous, beautiful, and, too 
often, the most abundant mushrooms to be found in the woods 
from frost to frost. Of the twenty-eight species nine are 
deadly, ten are doubtful, and nine are considered edible. 

The three characters which infallibly mark an amanita are 
white spores, a ring, and a volva, or cup. In order to understand 
these terms and others that we need to know, study an amanita 
as a type. Fig. 98 shows all the constituent parts and all the 
characteristic stages of growth of Amanita plialloides. 

The parts in order of growth and formation are 

MYCELIUM : extremely fine white threads, uniting here and there to 
form larger strands the nutritive, or vegetative, part of the 
fungus. 

BUTTONS : white knots or balls in the mycelium, the beginnings of 
spore-forming bodies (mushrooms). One button cut lengthwise 
shows the parts, which will be more clearly differentiated later 
on. Note especially that the mushroom proper at this stage is 
completely enveloped in a sac. Not all mushrooms have this sac. 

SPOROPHORE, consisting of 

1. Stem: the part which springs directly out of the mycelium 

and supports the pileus. 

2. Pileus, or Cap : the umbrella-shaped part which carries, on its 

under surface, radiating, leaf-like structures the gills. 

3. Gills : the organs from the surfaces of which the spores are set 

free. The shape that the spore-forming surface assumes is a 
prime character in classification. It is produced into gills in 
the Ayaricacew, into spines in the Hydnacece, into tubes in 
the Boleti, and into fine pores in the Polypori. 

SPORES : Place a cap from which the stem has been removed, gills 
down, on a piece of white or black paper, and cover tightly with 
a tumbler or bell jar. Leave for an hour or so, and examine the 
spore print and, if a microscope is available, the spores. 
VOLVA, or SAC : the membranous sac which may envelop the entire 
sporophore in the button stage ; also applied to the portion 
which, after rupture, remains as the cup at the base of the stem. 



FUNGI 203 

WARTS : irregular flecks, or patches, on the surface of the cap, formed 
if the volva ruptures about the equator and the upper portion is 
carried up and remains adherent to the growing pileus (not 
the case with Amanita phalloides). 

VELUM, or VEIL : a membrane which, in some forms, attaches the 
margin of the pileus to the stem. When, in growing, the cap 
tears away from the velum around its margin, the velum re- 
mains attached to the stem as the annulus, or ring. 

The presence of the three characters, white spores, ring, and cup 
(which may be reduced to a scaly, bulbous base to the stem), 
mark the specimen as an amanita. In collecting, why should 
we be sure to have the base of the stem complete? Why should 
we never mix buttons with edible mushrooms ? 



Classification. Sort the mushrooms collected, using the 
outline given below. If you place the dried specimens in a 
jar packed with wet paper the day before beginning the work, 
many of them will absorb moisture and become approximately 
like fresh specimens: 

1. All forms with gills underneath the pileus may or may not have 
stems Agaricacece. 

2. Hedgehog mushrooms : forms whose spore-forming surface is pro- 
duced into spines which hang downward. They may be umbrella-shaped 
or irregularly tuberculate or branched Hydnacece. 

3. Mushrooms with a honeycomb structure of tubes in place of gills ; 
soft and with the tubes readily separable from the cap Boleti 

4. Fungi with fine pores underneath the pileus. Many species become 
corky or woody, the bracket fungi of the woods Polypori. 

5. Coral mushrooms : may be simple, erect clubs or large, branching 
masses, the branches being erect. The spores are produced over most of 
the exposed surface Clavariacece. 

6. The morels and cup fungi. Some of these have stem and cap, but 
produce the spores in pits or irregular depressions on the outer surface 
of the conical or cylindrical cap. Other forms are cup-shaped or saucer- 
shaped Discomycetes. 

7. Puffballs and earthstars : mushrooms in which the spores are pro- 
duced within a closed cavity, which may open by an apical pore or by 
the irregular breaking of the wall (peridium) Lycoperdacece. 



204 



CIVIC BIOLOGY 



8. Stinkhorns, mushrooms which, once snielled, can never be mistaken 
for anything else or forgotten. The immature plants, known appropri- 
ately as witches'-eggs, resemble puffballs externally ; but as one matures, 
out shoots a long, hollow stem bearing pendent from the tip a small 
pileus, and this carries the spores in reticulations of its outer surface 
Phalloidece. 

9. -Trembling mushrooms : soft, gelatinous fungi (witches'-butter) in 
color varying from white to orange, red, or brown, generally found grow- 
ing on wood or parasitic on other fungi Tremellaceix. 

The first purpose of these lessons should be to learn to 
recognize the deadly genus Amanita. Then let each student 
acquaint himself with as many as possible of the abundant 
edible mushrooms. An excellent plan is to have the class 
unite in making a neat card catalogue of the most abundant 
and valuable mushrooms found growing in the locality this 
catalogue to be left in the laboratory as part of its biological 
equipment during the year. A sample card might read about 
as follows : 

ORDER : A GARICA CEJS 
GENUS : Lnctarlus SPECIES : deliciosus SPORES : White 

Delicious Milky Mushroom 

Edible, excellent (first taste a little acrid) 



Space for 
Color Picture 



3-10 cm. high ; 5-13 cm. broad ; funnel-shaped. 

Color: orange, in concentric darker and lighter 
zones around cap ; becomes lighter, often green- 
ish, with age. 

Gills: decurrent, saffron yellow. Milk at first reddish 
orange, quickly turning to dull greenish char- 
acteristic of every part of plant when bruised. 

Odor: aromatic. 

Taste : delicious. 

Habitat : damp coniferous woods. 

Season : July to October. 
Notes': Have found it abundant since our first field work Sejv 
tember 10 up to October 23. 



FUNGI 



205 



TABLE OF GENERA OF AGARICACR.E (GILL-BEARING MUSHROOMS)* 

I'lLEUS DISTINCT FROM FLESHY STEM 



SPORKS 


LEVCOSPOU.K 
(White) 


RIIODOSPOR.V 
(Pink) 


OcttROSPORM 

(Yellow-brown) 


PoRpnruospou.-t: 
(Purple-brown) 


MELAXOSPOR.V 
(Black) 


King and volva 


Amanita z 










Volva, no ring 


Amanitopsis* 


Volmria 3 


Acetabularia 


Cliitonia 




Ring, no volva 


Lepiota * 






Affarii-us 4 


( 'oprinus* 


No ring 




Plutetis 


Kolbitius 


Pilosace 





PILEUS CONTINUOUS M'lTH FLESHY STEM 



King 


Armillaria* 




Pholiota* 
Cortinar'ms* 


Stropharia"' 


Gomphulius 


Sinuate gills 


Tricholoma 4 


Eiitoloma z 


Hebeloma' A 


Hypholoma* 


Panseolus 3 
Anellaria 




Lactarius 3 
(milky) 
Russula* 
(brittle) 


Cl'ifopilxa* 


Inocybe 


Gills often decur- 
rent 


Hy qrop horns* 
Clitocybe* 
Cantharellus* 
Xerotus 
Nyctalis 


Mainniulti 
Paxillus* 






Growing on wood. 
Stem usually ec- 
centric, lateral, or 
wanting 


Lcnzites 
Lentinus 
Pleurotus* 
(fleshy) 
Panus 
(leathery) 
Trogia 
(gills crisped) 
Schizophyllum 


Claud op us 


Crepiflotus 







1'ILEUS DISTINCT FROM CARTILAGINOUS STEM 



Margin of pileus 
inrolled in young 
plant 


Colly bia* 


Leptonia 


Xaucoria 


Psilocybc* 






Marasmitu* 

Heliomyces 










Margin of pileus 
straight in young 
plant 


Mycena, 
Hicitulti 


Xolunea 


Pluteolus 
Calera 


Psathyra 


Psalfiyrella 


Gills decurrent, 
pileus usually um- 
bilicate 


Omphalia 


Eccilia 


Tubaria 


/Jeconica 


Montagnitcs 



1 Arranged by Theodate L. Smith, rii.l). 

2 Contains deadly poison species. No species of Amanita should be eaten 
without identification by an expert. 

8 Contains suspicious species or those having minor poisons. 
4 Contains edible species and none known to be poisonous except those 
given below : 

Lepiota morgani has green spores; it is one of the finest edibles, but makes 

ill about one person in six. 

Russula emetica causes nausea in some people, but is harmless for others. 
Tricholoma sulphureus smells like illuminating gas and is reputed poisonous. 
Hygrophorus conicus is reputed poisrthous. 
Clitocybe illudens smells and tastes like soap and is reputed poisonous. 



206 CIVIC BIOLOGY 

. The table on the preceding page will enable the beginner 
to place any agaric in its proper genus, and indicates the 
genera that contain edible species. The other families, espe- 
cially the puffballs, morels, boleti, coral and hedgehog mush- 
rooms, also contain many edible species. In fact, almost all of 
them that are agreeable to the taste are perfectly safe if taken 
in prime condition. All the soft-skinned puffballs, if perfectly 
white to the center, are free from suspicion, as are all the 
morels, all the hydnums, and all but one of the coral mush- 
rooms Clavaria dichotoma, a rare, pure-white form, in which 
all the branches fork regularly. Among the boleti the group 
luridi, characterized by red mouths of the tubes, contain 
species that are rated as poisonous. 

Raising mushrooms is a growing industry. Can members of 
the class visit local mushroom cellars and report on methods 
employed ? If none are grown locally, cannot a committee of 
the class try the experiment as an industrial project ? Several 
of the state experiment stations and the United States agri- 
cultural department publish bulletins that will give the neces- 
sary information. 

As a people we are permitting a considerable food supply to 
go to waste. As we study the matter, can we estimate the 
amount and value of the mushrooms that grow annually on 
our home premises and in our gardens, lawns, woods, and 
meadows ? What might these figures be for our township, 
county, and state ? 



CHAPTER XX 

FUNGOUS AND BACTERIAL DISEASES OF PLANTS 

Estimates which have been placed upon the damage caused by preva- 
lent plant diseases during a single season amount frequently to a very con- 
siderable per cent of the total value of the crops. In the United States 
alone the destruction wrought by fungous diseases is sometimes not far from 
half a billion dollars. DUGGAR, "Fungous Diseases of Plants," pp. 7-8 

Civic aspects. Line fences of farm or city lots offer no 
barriers to clouds of fungus spores in the air. So the spores 




FIG. 99. Mummied plums destroyed by brown rot (Sclerotinia fructigena). 
At left, tumor on branch, caused by black knot (Plowrightia morbosa) 

of rusts and smuts of grains may sweep over the fields from 
Texas to Manitoba, or they may live unseen on seeds and 
thus be distributed the world over. The spores or myce- 
lium, as is the case with smut of corn and onion, scab and 
rot of potato, and clubroot of cabbage and turnip, may re- 
main alive in the soil from year to year. Such fungi can 
be controlled only by strict rotation of crops. We thus be- 
gin to realize the size of our problem in its world-wide 

207 



208 CIVIC BIOLOGY 

scope, and may be prepared to conclude that its final solution 
must depend on intelligent, world-wide cooperation. 

Irish famine. It was the great famine in Ireland in 1845- 
1847 that opened the eyes of the whole world to what a 
fungous disease of a plant might mean to a people, and the 
awakening that followed marks the beginning of modern 
plant pathology. The case illustrates, too, the apparent 
suddenness of the attack, and also the total destruction of 
the crop the second year if rotation is not resorted to. 
Ireland had become densely populated, a large part of the 
people were almost wholly dependent on the potato for 
food, and the fungus that caused the famine was the late 
blight, or rot, of the potato Pliytophthora infestans. 

The harvest of 1845 promised to be the richest gathered for many 
years. Suddenly, in one short month; in one week it might be said, 
the withering breath of a simoom seemed to sweep the land, blasting- 
all in its path. I myself saw whole tracts of potato growth changed in 
one night from smiling luxuriance to a shriveled and blackened waste. 
A shout of alarm arose. But the buoyant nature of the Celtic peasant 
did not yet give way. The crop w r as so profuse that it was expected 
the healthy portion would reach an average result. Winter revealed 
the alarming fact that the tubers had rotted in pit and storehouse. 
Nevertheless the farmers, like hapless men who double their stakes 
to recover losses, made only more strenuous exertions to till a larger 
breadth in 1846. Although already feeling the pinch of sore distress, 
if not actual famine, they worked as if for dear life ; they begged and 
borrowed on any terms the means whereby to crop the land once more. 
The pawn offices were choked with the humble finery that had shone 
at the village dance or the christening feast ; the banks and money- 
lenders were besieged with appeals for credit. Meals were stinted, 
backs were bared. Anything, anything to tide over the interval to 
the harvest of " Forty-six." O God, it is a dreadful thought that 
all this effort was but more surely leading them to ruin ! It was 
this harvest of Forty-six that sealed their doom. Not partially but 
completely, utterly, hopelessly, it perished. As in the previous year, 
all promised brightly up to the close of July. Then, suddenly, in a 
night, whole areas were blighted ; and this time, alas ! no portion 






FUNGOUS AND BACTEKIAL DISEASES 209 

of the crop escaped. A cry of agony and despair went up all over 
the land. The last desperate stake for life had been played and all 
^vas lost. The doomed people realized but too well what was before 
ilit'in. Last year's premonitory sufferings had exhausted them and 
now? they must die. 

We raised a public subscription, and employed two men with horse 
and cart to go around each day and gather up the dead. One by one 
they were taken to a great pit at Ardnabrahair Abbey and dropped 
through the hinged bottom of a trap-coffin into a common grave 
below. In the remoter rural districts even this rude sepulcher was 
impossible. In the field and by the ditchside the victims lay as they 
i ell, till some charitable hand was found to cover them with the 
itdjacent soil. LORD E. FITZMAUHICE and J. R. THURSFIELD, in 
Larned's "History for Ready Reference," Ireland, 1845-1847 

Here we have our problem in the large and in concrete 
:'orm. An enemy has killed by starvation nearly a million 
people. 1 What is this enemy? Who saw it come or go? 
Mow does it operate ? Why did it do this ? How can we 
prevent future calamities of this kind ? The world had to 
:iwait alleviation of fears and superstitions, discoveries in 
many fields, and growth of the science of botany before 
many of these questions could be answered. Nothing can 
surpass in human value and interest, however, the quality 
of mind that works out solutions for such problems. In the 
light of the Irish famine, what may be the human value of 
such discoveries ? 

To get an insight into growth of knowledge in this field, call for at 
east three volunteers. Let number one read up the story of this 
:'amine further and report to the class. This is to develop a feeling 
'or the need and motive for such study. Let number two look up and 
eport on the story of discoveries leading up to determining and 
laming the fungus and devising methods for its control. 2 Number 

1 Returns to date (September 15, 1915) give total losses, killed, wounded, 
ind missing in the British army, after more than a year of the great war, 
it less than 400,000. 

2 See work of Dr. Berkeley (1846), Louis Pasteur (1856), especially De 
Bary (1861 and later), and Millardet, discoverer of Bordeaux mixture (1883). 



210 CIVIC BIOLOGY 

three may collect specimens showing all stages of infestation of leaves 
and tubers for actual demonstration, make pictures of the fungus and 
diagrams showing how it attacks the potato plant, and finally give the 
best methods for its control. 

Infection. The process of infection is as simple as that of 
planting seeds in a garden plot and raising the particular 
kind of flower or vegetable or of inoculating mold spores in 
any sort of food cultures. The spores of the parasite germi- 
nate in contact with their host plant, and the hyphse enter 
through wounds or stomata or actually eat their way through 
the cells of the surface. 

In order to develop perfectly clear ideas, perform all sorts of in- 
oculation experiments with fungi that happen to be available. Let 
members of the class use different kinds and demonstrate methods 
and results. Use any of the following, or others of local importance. 
Inoculate by touching point of pin to spores and pricking surface : 
A potato tuber or leaf with spores of blight or scab ; 
Seedlings of corn, or other grains, with smuts or rusts ; 
Lettuce plants with spores of " drop " (Sclerotinia libertiana) if 

locally important ; 
An apple with spores of bitter rot ; 
A plum, peach, or cherry with spores of brown rot (Sclerotinia 

fructigena), always at hand everywhere ; 

Bean seedlings with germs of bacterial blight (Pseudornonas 
phaseoli) or spores of pod spot or anthracnose (Colletotrichum 
lindemuthianurn). 

In these days of quack nostrums, illogical thinking, and even 
hysterical denial of cause and effect in matters of disease, these 
lessons with plants, which are not subject to fears and perverted 
mentality, may help to keep us sane. 

Wound infection of trees. A search through the orchard 
or wood lot is all too likely to show trees with mushrooms 
of different kinds polypori, hydnums, oyster and honey 
mushrooms growing upon trunks or roots. Inspection 
seldom fails to reveal the wound in the bark through which 
the fungus entered the wood. It is probable that these 



FUNGOUS wVND BACTERIAL DISEASES 



211 



parasites destroy more timber annually than do forest fires. 
The visible portions, the sporophores, of these tree-destroying 
Jungi are pushed out at certain seasons, or during certain 
weather conditions, and pour clouds of spores into the air to 
infect surrounding trees. These disease breeders should be 
the first to be made into firewood in annual cutting from the 
wood lot. The sporophores should also be destroyed as soon 
us they appear. By a little intelligent cooperation a- commu- 
nity could bring these pests under control, and however 

valuable the trees may 

be in themselves, the 
study will be worth 
while as an example 
of spread and preven- 
tion of disease. 

Root rot of fruit trees 
is a matter that will call 
for special attention in 
certain sections. Two con- 
spicuous mushrooms, Cli- 
f ocybe parasitica and the 
common honey mush- 




._, 

FIG. 100. Apple inoculated, at pin, with 

gpores of brown rot from mummied plum> 

Control apple 
Ag instructive as a case of gmallpox 



room (Armillaria mellea), show strong parasitic tendencies when brought 
into contact with the roots or crowns of apple, peach, or cherry trees. 
En clearing land for orchards it is advisable to remove all stumps and 
roots that are likely to harbor these fungi. 

Invite the local forester or tree surgeon to discuss these problems 
with the class. Learn from him the best treatment for tree wounds. 
(Wounds of any size made in pruning should be sealed with paint or 
gas tar.) As laboratory work let the class, in convenient groups, make 
some experiments in tree surgery where most needed about homes, 
school yard, or streets. 

Civic types for study. Duggar describes, or mentions, in 
his book " Fungous Diseases of Plants," 238 fungi that 
attack the common plants and trees of forest, orchard, 
garden, and field. He also gives a most useful Host Index 



212 



CIVIC BIOLOGY 



(the host is the organism that supports a parasite), in 
which he lists 174 plants, with the fungi that attack each. 
From this we see that everything we try to raise has its 
fungus enemies : alfalfa has anthracnose, leaf spot, root gall, 
European root disease, and root rot ; the apple has 24, among 
them anthracnose, or bitter rot, fire blight, crown gall, rust, 

and scab ; beans have 7 ; 
corn, 6 ; cotton, 9 ; the 
grape, 9 ; potato, 6 ; 
tomato, 8 ; wheat, 7 ; 
violet, 6 ; pine, 6 ; oak, 
7; and so on through 
the list. 

The following bacte- 
rial diseases are common : 
Pear and apple blight. 
Leaves turn brown as 
though burned with fire. 
The germ was supposed 




FIG. 101. Loose smut of oats (Ustilago 
avence) and normal heads 



to be carried by bees to 
the blossoms, but it is 
probably inoculated by 
aphides. Limbs that show symptoms of the disease should 
be cut below traces of the blight and burned. 

Wilt disease. This disease affects tomatoes, cucumbers, 
melons, cotton, and Irish potatoes, and causes the plants to 
wilt rapidly and die. 

Black rot of cabbage. The germ attacks cabbage, turnips, 
rutabaga, and .cauliflower. Leaves turn black and the plant 
dies. This disease is common in America and Europe. 

Try, at least, to make a preliminary survey, and then 
choose for intensive study the local types that are most im- 
portant, and especially those that require general knowledge 
and united effort of the community to control the civic 



FUNGOUS AND BACTERIAL DISEASES 



213 



types. It may be possible for each pupil to make a table 
giving for each fruit, vegetable, and farm crop the loss caused 
by fungi that is, to answer the question, What part of the 
half -billion-dollar tax does my home pay? A suggestion for 
such a table is given below. 

LOSSES CAUSED BY FUNGI ON A GRAIN FARM OF 320 ACRES l 





NUMBER 
OF ACRES 


YIELD IN 
BUSHELS 


PER CENT 
INJURED 


PRICE 


PRICE OF 
SMUTTED 


TOTAL Loss 


\V heat . . . 


280 . 


47 


17 


$1.30 


f.85 


$8,843.80 


Outs . . . 


40 


30 


10 


.40 




140.80 


Corn . . . 


10 


75 


7 


.75 




42.00 


Potatoes . . 


2 


48 


75 


.50 




144.00 


Orchard . . 


4 










26.50 2 


Total . . 








$9,197.10 



National and world problem. The general situation is aptly 
expressed by the complaint heard on every hand: 

The world is not fit to live in any more, and it 's getting worse and 
worse every year. We never used to hear about all these new-fangled 
diseases all the time, and everything didn't use to rot and smut and 
blight when I was a girl back on the old farm. 

This is literally true and for several good reasons. People 
did not then know what was eating them out of house and 

1 Wheat is supposed to be affected with stinking smut, which Duggar says 
sometimes takes "from one half to two thirds of a crop" of some sections. 
L >ose smut, corn smut, and early blight are the fungi supposed to have 
attacked the oats, corn, and potatoes respectively. Estimates are not ex- 
ec ssive. The percentages for the wheat, oats, and corn are figured by count- 
ing 100 stalks taken at random in ten different parts of the field. (Save 
st veral of these bundles of wheat or oats for demonstration in the labo- 
rs tory and at neighborhood meetings.) The potatoes are estimated from 
u-oial results in case of sprayed and unsprayed field plots. The cost of 
ti eating the wheat and oats with formalin would have been a trifling 
h surance against the loss incurred. 

2 Cost of three sprayings and one pruning for blight, bitter rot, etc. 



214 



CIVIC BIOLOGY 



home. They called it Providence and did not talk about 
it. Again, modern commerce and travel are rapidly mixing 




FIG. 102. Tree (on the right) infected with peach yellows 

Peach yellows is a contagious disease, exterminative of the peach in northeastern 

United States, that has baffled all attempts to discover its cause. The tree shown 

on the right is in the last stages of the disease ; the one on the left is healthy 

the bacteria, fungi, and insects of all the world, and these are 
the forces that have often determined both the floras and the 
faunas of continents. More American Indians have been 



FUNGOUS AND BACTERIAL DISEASES 215 

killed by European bacteria than by bullets. Measles struck 
the Fiji Islands like a deadly pestilence. So we inspect and 
quarantine against the importation of such germs as those of 
bubonic plague, Asiatic cholera, and foot-and-mouth disease, 
but they slip by in spite of all precautions. The canker, or 
chestnut-bark disease, appeared about ten years ago, coming 
probably from Japan. Working as it does, between wood 
and bark, it cannot be reached by sprays, and there are 
not men enough available to prune and burn the diseased 
trees. It is said to have destroyed over $30,000,000 worth 
of chestnut trees, and predictions appear to be well founded 
that it may not leave a single one alive in eastern North 
America. 1 A third reason is that we are planting large areas 
to the same crop, with field against field. This is like piling 
up kindling for a fire, when a disease gets a start. 

Control measures. Methods are improving continually, and 
the only safe course to pursue in this field is to correspond 
with our nearest experiment station and. secure their latest 
spray calendars, take the monthly list of publications, and 
keep abreast of discoveries. The underlying principles, how- 
ever, should be generally understood. 

1. Be sure to plant healthy, uniiifected, free-from-disease seeds, 
tubers, bulbs, or nursery stock. This refers to germs of disease inside 
the seed, tuber, or stock, and applies, of course, to buds and scions. 

Peach yellows, while the germ has not been discovered, is known to 
be transmitted from diseased trees in seeds, buds, or scions. Wilt dis- 
e ase of sweet corn, or Stewart's disease, sometimes destructive to from 
80 per cent to 100 per cent of the crop, is transmitted on, and prob- 
fibly in, the seed. Seed should not be saved, or distributed to uncon- 
1 animated land, from infected fields. The same is true of anthracnose 
( 'f beans and cotton ; bean blight ; bacterial blight, or wilt, of potato ; 

1 The species might be saved to the continent if nuts from sections as 
yet uninfected could be sent to suitable places on the Pacific coast and 
planted and reared beyond probable reach of infection. The United States 
Bureau of Forestry would probably be glad to supply safe seeds to biology 
Classes that would agree to follow out directions for planting and culture. 



CIVIC BIOLOGY 



late blight, or rot, and dry rot, or stem blight, of potato ; and crown gall 
of grapes, berry bushes, and fruit trees. So, too, pear and apple blight 
have often been scattered broadcast from nurseries because disinfec- 
tion of pruning tools was neglected. In general, disease shows up 
clearly in the nursery or field, while it would require bacteriological 
and microscopic methods to find the germs within the seeds or stocks. 
Go out and hunt over local nurseries or seed farms. Ask experts from 
them to come in and demonstrate and discuss their methods. All who 




FIG. 103. Corn smut (Ustilago zece) 

propose to distribute these important supplies to the public ought to 
know their business by this time. The best firms employ trained ex- 
perts to see to it that stock is free from disease, and then they may 
send it to branch farms, far away from any possible contamination, to 
have it propagated for the market. 

2. If spores are alive on the seeds or tubers, ready to attack the 
embryo plant when it germinates, kill them before planting. 

Scab of potatoes and smuts of grains are examples. Soak seed potatoes 
for two hours in formalin solution (1 ounce to 2 gallons of water) or in 
mercuric chloride (corrosive sublimate) solution (1 ounce to 8 gallons of 
water). External spores of the smuts on wheat, oats, and barley are 
killed by soaking for from ten to twenty minutes in formalin solution 
(1 pint to 30 gallons of water) or by warming up the seed in water at 
110-120 and then holding it for ten minutes in water at 132-133 F. 



FUNGOUS AND BACTERIAL DISEASES 217 

3. If living spores are continually sifting down from the air, we 
must keep the surface of leaf or fruit covered with something that 
will kill them as they germinate. If we wait till they get in, the crop 
will be ruined. Various Bordeaux solutions and lime-sulfur washes are 
effective for this purpose, and, naturally, while leaves are unfolding 
ripidly or fruit is growing, we must spray every few days. 

4. If the spores are alive in the soil, there is nothing to do 
but rotate. Plant something they cannot grow upon something that 
v ill starve them out; there is no other way of killing them out of 
t.'ie ground. 

5. Seek continually for resistant varieties and strains. With every- 
body on the lookout for these valuable variations, we may hope for 
more rapid progress in the control of fungous diseases of plants. 

6. Observe general soil and plant hygiene. With the soil mellow and 
well drained we may minimize danger from root rots and damping-off 
fungi; with plants well spaced to let in sunlight and allow free circu- 
1 itioii of air, or pruned with this in view, and with fruits thinned so as 
not to touch, we may greatly reduce danger from air-borne spores. 

Every community organization, rural or suburban, ought 
to have a committee on fungous diseases of plants and their 
practical control. The local class in biology might well be 
the laboratory right arm of such a committee. By working- 
out cooperative plans, thoroughly agreed upon, which might 
spread from neighborhood to neighborhood as they were de- 
veloped and perfected, many of our worst fungus enemies 
might be completely stamped out. No real estimate of the loss 
Caused by them has ever been even attempted. We do not 
tmow enough about them. Duggar's guess of $500,000,000 
i year is very low, and, while it might approximate the losses 
to the large markets and channels of trade, we must certainly 
add to this all the damage to the home garden and orchard, 
with the labor and expense of fighting, fungi in them. The 
class in civic biology which gives us even a first attempt at 
a detailed account of the expenses and losses chargeable to 
fungous diseases of plants in any community will mark a 
distinct forward move in this field. 



CHAPTER XXI 
BACTERIA 

Size. Bacteria, the smallest plants known, range in size 
from ultramicroscopic to 6 microns thick by 80 microns long. 
Even the largest single bacterium known is far too small to 
be seen with the unaided eye, and for the smaller species, 
like the germ of grippe, Bacillus influenzce, which is .3 //. thick 
by .75/>i long, we might have 2,867,417,289 spread in a 
single layer over one square inch of finger tip, and the 
smear might be even 100 germs deep, that is, contain 
286,741,728,900 bacteria, and still be invisible to the eye 
and too thin to feel. 

Form. Bacteria appear under the microscope as spherical 
(the micrococci), as slender rods (the bacilli), and as forms 
bent like commas or twisted into spirals (the spirilla). 
Humorously they are said to resemble " balls, cues, and 
corkscrews." 

Distribution. Bacteria are everywhere in nature except in 
the air at high altitudes, over perpetual snows and over mid- 
ocean, in the deeper layers of sand or clay soils (they may 
be carried to almost any depth and almost any distance by 
streams in crevices of rocks), and, most important of all, 
in the blood or sap and internal tissues of healthy animals 
and plants. 

Bacteria of the air.- Bacteria are blown about as free dust 
with every current of air. The table on the next page, made 
in France from data collected monthly for ten years, shows 
the variation in number of bacteria in the air of city and 
country at different seasons of the year. 

218 



BACTERIA 219 





COUNTRY BACTERIA 


CITY BACTERIA 


Winter 


170 


4 305 


S orin " 


295 


8 080 


Suinnier 


345 


9 845 


A iitunin 


195 


5 665 


Average . . 


250 


6 975 









Bacteria of water. Streams ordinarily contain about 500 
bacteria per cubic centimeter, collected from the air and soil 
over the area drained. The river Seine, as it enters Paris, has 
about 300 bacteria per cubic centimeter, but after it receives 
the sewage from this city it contains 200,000 bacteria per cu- 
bic centimeter. The supposed self -purification of streams is 
found to be mainly due to dilution. Experts are impounding 
running water in reservoirs previous to supplying cities, since 
bacteria disappear from still water. Microscopic organisms 
( plankton) upon which young fishes feed are found in greater 
abundance in quiet water, and it is thought that they in turn 
feed upon bacteria. 

Water in wells varies greatly in number of bacteria. Arte- 
sian wells are practically free from them ; ordinary wells may 
contain from 1000 to 8000 bacteria per cubic centimeter. Ice 
varies in number of bacteria according to water from which it is 
1 aken. Clear ice from the Hudson River contained 398 bacteria 
per cubic centimeter, while its snow ice contained 9187. Why ? 

Bacteria of the soil. The number of bacteria of the soil 
varies with the amount of moisture and organic debris. Su- 
perficial layers contain from 10,000 to 5,000,000 bacteria per 
gram ; if polluted with organic debris, they may contain as 
high as 100,000,000 per gram. The number of bacteria di- 
minishes rapidly as we pass down into the earth ; at a depth 
of from ten to fifteen feet few if any can be found. This is 
the reason that in many cities water is passed through sand 
lilters before it is used for drinking purposes. 



220 CIVIC BIOLOGY 

Reproduction in bacteria. Bacteria multiply by division, 
which is even more simple than the budding of yeast. The 
cell, when mature, divides transversely into equal halves. 
Under favorable conditions, a bacterium may divide every 
twenty minutes to half an hour. Can you calculate the 
progeny of a single bacillus for twenty-four hours ? 

Bacteria do not grow and reproduce without food, and their 
astonishing power of multiplication helps us to understand the 
altered condition of milk and meat if kept in a warm place for 
even a few hours. 

Some species develop spores within the cell and these are 
much more difficult to kill than the bacteria themselves. 

Conditions favorable for the multiplication of bacteria. Like 
other plants, bacteria demand food, moisture, oxygen, and 
warmth for growth. Remove any one of these conditions and 
they will either cease to multiply or die. 

Moisture. Bacteria grow only in liquids or moist sub- 
stances. Dry foods and those containing less than 20 or 30 
per cent of water they cannot attack. Drying weakens and 
kills many bacteria. Spores, however, are much more resis- 
tant to continued drying than the vegetative or growing cell. 

Why should houses not be allowed to become damp? Why is meat 
salted and dried ? Why is canned fruit sealed ? What influence has 
sugar in preserving fruit? Why are such foods as molasses, condensed 
milk, flour, seeds, and grain bacteria-proof? 

Temperature. Temperature affects growth of bacteria. As 
in higher plants, there is a temperature known as the optimum 
at which each species thrives best. A tubercle bacillus grows 
within a range of 5 degrees, while a few other species can 
grow anywhere within a range of 50 degrees. 

Bacteria do not multiply during the time they are exposed 
to low temperature, but their vitality is not affected ; the tu- 
bercle bacillus has been exposed to a temperature of liquid air 



BACTERIA 221 

( 190 C.) for periods varying from six hours to forty-two 
days without killing it. The retardation of bacterial growth 
ri low temperature is of importance from the public-health 
standpoint, since it makes possible the shipping and temporary 
preserving of perishable foods in cold storage. . 

Heat in sufficient amount kills all bacteria whether in the 
i?pore or vegetative state. Steam heat is more effective than 
dry; a few minutes of steam heat at 120 C. will kill spores 
that would take 180 C. of dry heat to destroy. 

Light. Contrary to the effect produced upon green plants, 
light has an unfavorable action upon bacteria. Bright sunlight 
serves to kill the vegetative cell and weakens the spores ; 
diffuse light retards growth;- in the absence of all light they 
grow best. This destructive action is intensified by moisture 
and fresh air. 

Oxygen. Pasteur was the first to demonstrate that some 
bacteria live without free oxygen. He divided all bacteria into 
chree classes : aerobic, those species that can grow only in the 
presence of air ; anaerobic, those that can grow only in the 
absence of air ; and facultative, those that can grow either 
with or without air. Bacteria that grow in the inner tissues 
of the body of a plant or animal are examples of anaerobic 
species ; they do not grow without oxygen, but get a supply 
by breaking down organic substances that contain it. The 
majority of bacteria are aerobic, as evidenced by the many 
cases of decay which begin on the surface and work toward 
the center. 

Work of bacteria. Like other fungi, bacteria are parasitic 
(attacking living plants and animals), saprophytic (feeding 
upon dead or waste animal or plant matters), and symbiotic 
(living in plants to the mutual benefit of bacterium and 
plant). Because some species can attack living" tissue and 
produce disease, all bacteria have come to suggest disease 
to the popular mind. This reputation is as unjust to the 



222 



CIVIC BIOLOGY 




saprophytic bacteria as it would be to condemn all higher 
plants because a few of them are poisonous. In general, sap- 
rophytic bacteria do no more harm than dust if breathed, or 
than vegetables if eaten. 

Nitrifying bacteria. Certain bacteria of the soil are symbi- 
otic upon the roots of leguminous plants, such as clover, alfalfa, 

beans, and peas, and cause 
tubercles to form. These 
bacteria gain entrance 
through the root hairs 
of the plant and cause 
smooth young roots to as- 
sume a nodular appear- 
ance (Fig. 104). 

Experiment shows that 
if a legume, notably clo- 
ver, is grown upon soil of 
known composition, a part 
of which has been ster- 
ilized (baked), the crop 
upon the unsterilized soil 
will be notably larger and 
the soil will have nitro- 
gen added to it. These 
bacteria are important, 
since they can fix the free nitrogen of the air and give it to 
the soil in the form of nitrates. The benefit to the soil result- 
ing from clover cropping was discovered and practiced by 
farmers long before the cause was known. 

Much experimental work is being done with these nitrifying 
bacteria, and pure cultures are being sold to inoculate soil 
that does not contain them. To prevent extravagant and mis- 
leading claims of dealers, the United States government has 
issued the following statements : "No beneficial results can be 



FIG. 104. Clover plant with many 
bacterial nodules on roots 



BACTERIA 223 

expected for a particular crop if the bacteria for the crop are 
already in the^ soil. But little, if any, benefit can be expected 
from the use of these bacteria if the ground is decidedly in 
need of other fertilizers, such as phosphates, potash, and lime. 
But little, if any, benefit can be expected from inoculation if 
the soil is already rich in nitrogen." 

Carefully wash the roots of different clover plants. Are the nodules 
of nitrifying bacteria present ? Are they found upon alfalfa and peas in 
Your region? Are pure cultures of these bacteria sold in your state? 
Read the state and government bulletins upon these bacteria. 



CHAPTER XXII 
BACTERIA CONTINUED : LABORATORY METHODS 

Apparatus and material. To grow bacteria in the labora- 
tory the following apparatus and material are necessary : a 
steam sterilizer, hot-air sterilizer, two platinum needles 1 ; test 
tubes, Petri dishes, absorbent cotton, litmus paper, sheet gela- 
tin, agar-agar, extract of beef, potatoes, caustic soda solution, 
and hydrochloric acid. 

Gelatin medium. Dissolve in 1000 cubic centimeters of 
distilled water 10 grams of peptone, 5 grams of common salt, 
2|- grams of beef extract, and 100 grams of sheet gelatin, and 
place in the steam sterilizer until dissolved. 2 

Let the mixture cool to 55 C. (you can hold it in your 
hand) and add a teaspoonful of albumen dissolved in cold 
water, or the whites of two eggs. Boil until the liquid looks 
clear. 3 Line a funnel with wet absorbent cotton or with filter 
paper designed for gelatin or agar-agar filtration. Pour the 
gelatin mixture into the funnel and catch in a sterilized 
flask. Place in a steam sterilizer. If the funnel is kept 
thoroughly warm, the gelatin will pass through the filter in 
about an hour. Test the gelatin with litmus paper. It will 
be found to be acid. Add a weak solution of caustic soda to 
it, drop by drop, until blue litmus paper does not change 

1 Cut platinum wire (No. 27) into two-inch lengths. Fuse one end of each 
into a glass rod, and bend the free end of one of the needles thus made into 
a small loop, to be used in measuring drops in liquid cultures. 

2 A portable sheet-iron oven and an ordinary steam cooker may be used 
if necessary. 

3 A fact that must be borne in mind in preparing gelatin is that its gelat- 
inizing power is injured by prolonged heating during the process of prepa- 
ration or sterilization, and is lost immediately when heated to 140 C. 

224 



BACTERIA 225 

color. Pour about one and one-half inches of gelatin into each 
iest tube and plug with cotton. Sterilize the tubes twenty 
ninutes for three consecutive days, so as to kill all spores. 

Agar-agar medium. [Mix the same as the gelatin medium, 
using 15 grams of agar-agar in place of the 100 grams of 
gelatin. The preparation of agar-agar medium, however, is 
nore troublesome than the gelatin. Agar-agar does not dis- 
solve easily and is difficult to filter. To obtain a quick result it 
,s best to perform the filtration in parts. If the funnel, lined 
svith absorbent cotton, is well heated, about one half of the 
igar-agar mixture will have passed through the filter in fifteen 
minutes. Remove the funnel and reboil the remaining agar- 
igar and pass through a fresh filter. Repeat the process until 
the mixture is filtered. 1 

Potato medium. Pare the potatoes and cut with a cork borer 
of suitable size for the test tube. Divide the cylinders into 
two-inch lengths and then cut diagonally across. Place the 
' potato slants " thus prepared in water for several hours, to 
extract the product which turns them black when exposed 
to air. 

Put into test tubes, slant side uppermost, plug, and sterilize 
in a steam sterilizer for twenty-five minutes at 100 C. for three 
successive days. A small piece of glass rod placed in the bottom 
of the test tube holds the potato above the condensed steam. 

Rules and methods of manipulation. (1) Learn as early in 
the course as possible that all dishes should be washed and 
sterilized in the hot-air sterilizer before using. All micro- 
organisms are killed when they are heated as follows: three 
hours at 150 C., or until paper is brown ; one half hour at 
160 C. ; one fourth hour at 170 C. ; one minute at 190 C. 
(2) Before sterilizing, wrap the Petri dishes in paper and 

1 If time is limited, obtain the prepared gelatin or agar-agar from a local 
hospital laboratory or board of health, or order from a regular dealer in 
such supplies. 



226 



CIVIC BIOLOGY 



plug the test tubes. To make plugs, tear a strip of cotton 
about two inches wide and as long as needed, fold length- 
wise, and roll into a plug. Insert this not more than half 
an inch into the test tube. Cotton plugs are quite generally 
used in bacteriological work, since they allow a free circu- 
lation of air and prevent the entrance of germs. If material 




FIG. 105. Preparing culture media 
Photograph by the author 

is properly sterilized and plugged with cotton, it will keep 
indefinitely. (3) Do not open the hot-air" sterilizer until the 
temperature is down to 40 or 45 C. It is preferable to leave 
the dishes undisturbed in the sterilizer until used. 

Before planting (inoculating) your culture media with 
bacteria observe the following: 

Unless otherwise directed, always inoculate media with 
platinum loop or needle. (1) Heat the wire in the flame 
just before and immediately after using. (2) Avoid having 



BACTERIA 



227 



currents of air in the room. (3) Upon opening a culture 
medium for inoculation, pass the mouth of the tube through 
the flame (flaming) ; if it has stood for some time, flame the 
cotton before opening the tube. (4) Never allow the tube 
end of a plug to come in contact with anything while re- 
moved from the tube. (5) If a plate culture is to be made, 
melt the gelatin in a test tube (placed 
in warm water) and pour into a ster- 
ile Petri dish. If Petri dishes are not 
available, test tubes may be substi- 
tuted, provided the gelatin in them 
is allowed to cool while they are lying 
in a nearly horizontal position. (6) In- 
oculation should not take place before 
ilie gelatin hardens, unless germs from 
a liquid are to be grown. In this case 
the gelatin is inoculated in the test 
tube and then poured into the Petri 
dish. (7) Unless otherwise directed, 
all cultures that have been inoculated 
should be kept in the dark, or in dif- 
fused light and at room temperature. 
(8) If possible, duplicate each experi- 
ment, using both potato and gelatin 
media. Note appearance of growth in 
each case. Label and keep careful records of each experi- 
ment. (9) After your experiments are finished, do not allow 
the media to dry; place all dishes in water and boil for 
fifteen or twenty minutes before cleaning them. 

Experiments for bacteria of the air. 1 (1) Expose a Petri 
dish of gelatin for five minutes in the laboratory before the 
class enters. (2) Expose another for the same length of time 

1 Each member, or group of members, of the class should perform one or 
more of these experiments. 




FIG. 106. Exposing Petri 
dishes 

Photograph by the author 



228 CIVIC BIOLOGY 

iii the same room just after the class has left. (3) Expose a 
Petri dish of gelatin in a room for five minutes immediately 
after wiping up the dust, with a dry cloth or after using a 
feather duster. Compare this plate with one that was exposed 
for the same length of time in a room immediately after it 
had been dusted with a damp cloth. (4) Expose a plate in 
a living room for five minutes and compare with the air in 
the yard. (5) Compare the number of bacteria in the air 
upon the ground with that of the first and fourth stories of 
the same building. Is it true that a child breathes less pure 
air than a man ? Is it more desirable to sleep upstairs, as 
far as air is concerned ? (6) Expose a plate of gelatin in a 
busy street before and after it has been sprinkled, or before 
and after a rain. (7) Compare the number of bacteria in a 
well-cleaned street with the number in one that is not cleaned. 
What do you think of the system that cities are using for 
flushing their streets ? (8) Compare as to number of bacte- 
ria the air before and after a snowstorm or rainstorm. Inocu- 
late plates with rain or fresh snow. Keep these experiments in 
a drawer in the laboratory. In a day or so count the colonies 
of bacteria and record results. (9) Sweeten and cook fruit, 
such as apples, in a test tube. Plug with cotton. Does 
canned fruit keep if ah- is present and bacteria are excluded ? 
(10) Discuss the desirability of having children's playgrounds 
upon the roofs in large cities. 

Experiments for bacteria of water. (1) Make a culture of 
water from a stream (dip your platinum loop three times) 
and compare with the same amount of water from the reser- 
voirs and lakes of the locality. (2) Compare the water above 
and below the point where the sewage is emptied. (3) Com- 
pare the different drinking waters of the locality. (4) Make 
cultures of water that is rich in organic debris and compare 
with the same water that has been boiled for fifteen minutes. 
(5) Filter some of the water used in the above experiment 



BACTERIA 



229 



through several inches (twelve or fifteen) of clean sand. Is 
a sand filter effective ? (6) Make cultures of milk. How 
does fresh milk compare in the number of its bacteria with 
that which has stood for some time ? (7) What is meant by 
Pasteurizing milk? If possible, visit a milk station where 
milk for babies is sold. What measures render it safe ? 




FIG. 107. Inoculating gelatin tubes with platinum loop 
Note the way iu which cotton plugs are held between the fingers 

Additional experiments. (1) Scrape the surface of a silver 
'oin with a sterile knife and make a plate culture. Compare 
\vith cultures made from copper coins and paper money. No 
paper money is used in the Hawaiian Islands because of the 
danger of transmitting disease. (2) Make plate cultures from 
the surface of a pencil that a child has used for some time ; 
from the edge of a common drinking cup, door handle, straps 



230 CIVIC BIOLOGY 

in a street car. (3) Make a culture from a dishcloth that is 
washed and boiled once a day, and from one that is not. 
(4) Compare the number of bacteria in rancid and fresh 
butter. (5) Allow a fly to walk across a plate of sterile 
gelatin ; record results. (6) Make a stab culture by running 
a straight platinum wire, with germs upon it, down through 
several inches of sterile gelatin in a tube. Upon removing the 
wire the gelatin closes around the germs left in its track, and 
serves to cut off the air supply except at the surface. Do you 
find three classes of bacteria growing in the culture ? 

The excretions of bacteria render the most favorable medium 
unfavorable. In general, bacteria do not grow as well upon acid 
as upon slightly alkaline media. (7) Make a culture from the 
dust of a dark corner of a room; from a surface in diffused 
light; from one in bright sunlight. Can you think of more 
favorable conditions for the growth of bacteria than that 
offered by the mouth ? How can you keep your teeth from 
being destroyed by them ? (8) Inoculate a plate with clean- 
ing of a finger nail, dandruff, single human hair, cat hair. 
(9) Breathe into a gelatin tube without touching the lips to 
the glass; make a plate culture. Can the breath carry bac- 
teria ? (10) Make a plate culture of some of the substance 
that has gathered upon the back of the teeth. (11) A bacillus 
has a characteristic growth upon a culture medium. From the 
appearance of the colonies do your experiments show that you 
have grown different species of bacteria? Can you see that 
by selecting a species of bacteria and inoculating a fresh cul- 
ture with it, and then from it again selecting and inoculat- 
ing a fresh medium, you would soon obtain a medium with a 
"pure culture" of that species of bacteria? (12) Can you 
now explain the need of such rules and precautions as are 
given in the early part of this chapter ? 



CHAPTER XXIII 

CONTROL OF BACTERIAL DISEASES 

Aristotle (384-322 B.C.) instructed Alexander the Great to have his sol- 
diers boil their water in order to prevent epidemics of disease in camps. 
Possibly to this bit of practical biology Alexander owes his conquest of 
:,he world. 

Advertendum etiam, siqua erunt loca palustria, et propter easdem causas, 
ot quod (arescunt) crescunt animalia quaedam minuta, quae non possunt 
oculi consequi, et per aera intus in corpore per os ac nares perveniunt atque 
efficiunt difficilis morbos. 1 VARRO (B.C. 116-27), "De Re Rustica," Lib. I, 
11-12 (Keil, 145) 

Already in his studies on silkworms, Pasteur's first experience in the 
domain of disease, the dawn of a new era in the contest of man with con- 
tagion opens up before him. He says: "II est au pouvoir de l'homme 
de faire disparaitre de la surface du globe les maladies parasitaires, si, 
comme c'est ma conviction, la doctrine de la generation spontane"e est une 
chimere." 2 FRANKLAXD, "Life of Pasteur," p. 123 

Bacteria and disease. The majority of bacteria are harm- 
less or beneficial. A few are venomous, as are a few species 
of snakes, fishes, trees, or mushrooms. The venomous bac- 
teria strike plants, animals, and man just as really as do lead 
bullets, and wound and kill in essentially similar ways. The 
notion is current that bullets hit the fittest, while bacteria 
seek out the unfit, but there is not much ground for this 

-1 " One should be on guard, if there should be any swampy places, both 
for the same reasons and because there grow certain minute animals, which 
the eyes cannot perceive, and which, permeating the air, enter the body 
through mouth and nostrils and cause serious diseases." Professor S. F. 
DUNN, University of Oregon, Translator 

2 " It is within the power of man to cause to disappear from the surface 
of the globe the parasitic diseases, if, as is my conviction, the doctrine of 
spontaneous generation is a chimera." 

231 



210 




1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 



FIG. 108. Death rate per 100,000 population in the registration area 
of the United States 

From the Census, Mortality Statistics, 1912 



232 



CONTROL OF BACTERIAL DISEASES 233 

idea. 1 Ignorance aside, there is no more reason for allowing 
ourselves to be bitten by bacteria than by rattlesnakes. 
About two people die from snake venom annually in the 
United States; 20,000 die yearly in India from snake bite, 
because cobras are accorded superstitious protection. We 
eligiously preserve our bacteria, with the filth in which they 
hrive and the flies that distribute them ; the Hindus, their 
relatively harmless snakes. 

A few of the more familiar germs, with the disease and 
death they are causing, are presented in the table on page 234. 
When we all know how to kill and avoid these bacteria, as 
\vell as we know how to deal with rattlesnakes, we may be 
as free from them as we are from the snakes. All must 
know and each must do his part, for one ignorant person 
can scatter bacteria by the million from Maine to California. 

The table is by no means complete. In the next chapter \ve shall 
study a similar list of diseases caused by parasites of animal origin. 
There is another list, known to be infections, smallpox, yellow 
fever, scarlet fever, measles, spotted fever, and foot-and-mouth disease, 
the specific causes of which have baffled all' attempts to discover. 
Still another class of ailments, noninfectious, chronic and organic, 
of the heart and arteries, brain and kidneys, of heavy and increasing 
fatality, may have to do with organs weakened by parasitic attack. 
Finally, we have no statistics of the number of the wounded, the 
weakened or crippled, and the number of minor ailments, very numer- 
ous and of constant occurrence, that impose their burdens of sheer 
misery the millions of cases of rheumatism, tonsillitis, boils, felons, 
carious teeth and toothache, indigestions, diarrheas and dysenteries, 
and " colds," most wretched of all, probably not less than 200,000,000 
of them a year. When we add to all this the bacterial diseases of 
animals (hog and fowl choleras, bovine, avian, and other tuberculoses 
and pneumonias, white diarrhea of chicks and foul brood of bees, 

1 "Neither regularity of life nor bodily strength was any preservation 
against it. The strong and the weak were equally struck down ; and death 
spared not those of whom care was taken, any more than the poor, desti- 
tute of all help." (The fleas of that time bit all alike.) GASQUKT, "The 
Black Death." p. 12 



234 



CIVIC BIOLOGY 



! 



! 



11 



Ur 

Ifil 

O 



*l 

1? 

i 



, 

! 



" 

i 







as^s 



O O 

CO I- 



O O 



XUMBER OF T 
WOUNDED 



' 



- 



t 


!, 



Illl 



5 s a <B 

111! 

g p- ^ 
<g rf a s 







CONTROL OF BACTERIAL DISEASES 235 

anthrax and glanders, and many others) and the long list of bacterial 
diseases of plants, already briefly considered, we begin to realize that 
-,he very, edge of the struggle for existence lies between mankind and 
:he bacteria. 

The three questions. The following questions apply to the 
parasitic diseases bacterial, protozoan, vermian, and all the 
rest. When Pasteur was " wasting his time " disproving 
spontaneous generation, one of his friends wrote : " He makes 
me uneasy, he does not recognize the limits of science, he 
only loves insoluble problems." Now that we know that 
' la generation spontanee est une chimere" the problem of the 
control of disease becomes the comparatively easy one of 
preventing the spread of the living germs from the sick to 
the well. In every case of contagion or infection the germs 
escape alive from the body of the sick, are carried to the 
well, and gain entrance. Therefore the three fundamental 
questions are: 

1. How do the germs of each disease escape from the 
body of the patient? 

2. How is each kind of germ carried ? 

3. How does each kind of germ gain access to the body? 
Paths of escape. Parasitic germs of the lungs, nostrils, 

throat, or mouth (of diphtheria, tonsillitis, pneumonia, tuber- 
culosis, rhinitis, bronchitis, and influenza, as well as stomach 
and intestinal diseases that involve vomiting typhoid fever, 
enteritis, and cholera) escape with any discharges from mouth 
or nose. Careless coughing and sneezing may scatter the 
germs over anything or anybody within a distance of about 
six feet. Spitting in any public place is an abomination, and 
laws against it should be rigidly enforced in the interests 
of public education as well as health. 

Bacteria from the digestive and renal-reproductive organs 
pass out with the dejecta dysentery, choleras, typhoid. 
Typhoid bacilli have also been found in the perspiration. 



236 



CIVIC BIOLOGY 



Germs circulating in the blood are usually drawn off by 
blood-sucking insects, ticks, or mites ; malaria and yellow 
fever, by mosquitoes ; typhus fever, by body lice (and per- 
haps by fleas and bedbugs) ; plague, by fleas (possibly also 
leprosy) ; typhoid, by bedbugs ; Texas fever and spotted 
fever, by ticks; infantile paralysis (?) and anthrax, by the 



Miei-oeoeci 



Bacilli 



Spirilla 



{Pneumonia, 
Rheumatism, 
Sores. Boils) 




Gripp 



Diphtheria 



FIG. 109. Pathogenic bacteria modeled to scale in plasticene (micra = 
centimeters), magnification of models being 10,000 diameters 

A suggestion for a laboratory collection. Mount in insect cases under glass. 
Photograph by the author 

stable fly ; and sleeping sickness, by one of the tsetse flies. 
Diseases marked by lesions of the skin measles, scarlet fever, 
smallpox, and probably dandruff and eczema may escape 
with the scales of cuticle or the contents of blisters or sores. 
How living disease bacteria are carried. The greatest barrier 
to the learning of truth is apt to be a firm belief of an error. 
No set of ideas has cost the world more misery, suffering, 
and loss than false notions, prejudices, and superstitions re- 
garding the transmission of diseases. First they were carried 



CONTROL OF BACTERIAL DISEASES 237 

by angry gods, demons, and witches; next, by the air as 
r liasms and effluvia ; then, by fomites in dust of clothing or 
Merchandise; and, finally, we have come down to the sure 
evidence of science that contact infection, chiefly by the 
hands, accounts for almost all the spread of common diseases, 
tind insects, by contact or inoculation, for most of the rest. 

Air not an important carrier. Just now the air is rapidly 
losing all its terrors, smallpox being the only disease which 
may possibly, though not probably, be carried from house to 
house by this agency. (This does not mean that insects that 
:ly may not transmit many infections by contact.) Chapin 
puts the case carefully and sensibly as follows : 

Only a few authorities now assert that disease is carried by the 
itmosphere outside of dwellings, and this assertion is made only in 
regard to smallpox. . . . Infection by air, if it does take place, as is 
ommonly believed, is so difficult to avoid or guard against, and so 
universal in its action, that it discourages effort to avoid other sources 
of danger. If the sick-room is filled with floating contagium, of what 
use is it to make much of an effort to guard against contact infection? 
If it should prove, as I firmly believe, that contact infection is the chief 
way in which the contagious diseases spread, an exaggerated idea of 
the importance of air-borne infection is most mischievous. It is impos- 
sible, as I know from experience, to teach people to avoid contact in- 
fection while they are firmly convinced that the air is the chief vehicle 
of infection. . . . Without denying the possibility of such infection, it 
may be fairly affirmed that there is no evidence that it is an appreciable 
factor in the maintenance of most of our common contagious diseases. 
We are warranted, then, in discarding it as a working hypothesis and 
devoting our chief attention to the prevention of contact infection. It 
will be a great relief to most persons to be freed from the specter of 
infected air a specter which has pursued the race from the time of 
Hippocrates; and we may rest assured that if people can as a conse- 
quence be better taught to practice strict personal cleanliness, they 
will be led to do that which will, more than anything else, prevent 
aerial infection also, if that should in the end be proved to be of 
more importance than now appears. CHAPIN, "Sources and Modes 
of Infection," p. 20o ff, 



238 CIVIC BIOLOGY 

Even the air of the sick-room has no dangers if modern 
methods for bacteriological cleanliness are strictly observed 
that is, if all waste matters or discharges go straight from 
the patient into the fire or sterilizer, and if the rubber gloves 
with which all handling of the patient is done are disin- 
fected immediately after using. Except by the cough spray 
a bacterium cannot leave a moist surface, and by the above 
precautions no living germs can become dry and so enter 
the dust of the room. 

Fomites. " Persons and not things transmit diseases." 
This slogan is coming more and more to dominate the whole 
field. Ships, in numbers, have been sunk, cargoes and all, 
to insure against purely imaginary fomites. No sharp line 
can be drawn between infection by contact and infection 
by fomites. Contact infection implies the more immediate 
transfer of germs, as in shaking hands, exchanging pipes, 
swapping gum, using the same drinking cup or towel, inter- 
changing dishes at successive meals, touching foods, candies, 
fruits, etc. with unwashed hands ; while the theory of fomites 
implies infection by germs carried alive and virulent in cloth- 
ing, merchandise, baggage, and mail matter for long distances 
and during considerable periods of weeks or even years. As 
we shall see in the next paragraph, when we begin to pay 
attention to them, there are so many ways by which bac- 
teria are carried fresh and green from mouth to mouth, by 
direct or indirect contacts (and not only from mouth to 
mouth but from dejecta to mouth), that it is sheer dis- 
honesty to crowd our own responsibilities for really inex- 
cusable contacts over onto the theory of fomites. If common 
notions of fomites were true, we should have to arm our 
postal mail clerks with fumigator masks and rubber gloves 
or bury the whole force every night. As a matter of fact, 
bank tellers, handling " dirty money " all the time, mail 
clerks, handling letters sealed and stamped in everybody's 



CONTROL OF BACTERIAL DISEASES 239 

saliva, second-hand clothing dealers, and even rag sorters, 
all live in average freedom from infections. Doty's testi- 
mony on this point is as follows: 

The author has carefully investigated the influence of money as a 
m -ans of infection. The results show that those who are constantly 
handling money, such as bank officials, do not contract infectious dis- 
eases any oftener than others. The Treasury Department at Washing- 
ton furnishes exceedingly valuable information on this subject. Here 
large quantities of filthy and offensive paper money are being constantly 
In ndled and rehandled prior to destruction, and not the slightest evi- 
dence has been presented at that place to show that infectious diseases 
are transmitted by this material. Than this, no more important or con- 
clusive evidence on this subject can be presented. DOTY, "Prevention 
of Infectious Diseases," p. 10 

Even epidemics in schools of measles, diphtheria, and scarlet fever 
have been found by the medical examiners of New York City to be 
caused by mild or incipient cases and by unsuspected "carriers " that 
is, by contacts of persons and not of things. 

Terminal disinfection (fumigation or disinfection at termination of a 
disease or of quarantine) was abandoned in Providence in 1905, "except 
^in those very few instances in which the family was willing to wait for 
tv/o successive negative throat and nose cultures from each of its mem- 
bers," the idea being that it was a waste of public money to disinfect 
rooms while members of the family were carrying living diphtheria 
gv.rms, and there has been no marked increase of recurrent cases. "The 
!N ew York City Health Department has given up fumigation after cases 
01 infectious disease, as a costly procedure, the inutility of which has 
boen well established." 1 A more conservative opinion is expressed by 
a:u eminent authority as follows : " Though the results obtained in some 
cities since abandonment of terminal disinfection after certain diseases 
srem to show that heretofore much useless disinfection has been done, 
ii is not felt that the evidence thus far adduced fully justifies its dis- 
continuance." 2 The idea underlying this position is that if terminal 
disinfection saves even a few infections, it should not be entirely aban- 
doned. The above is sufficient to show that this important matter is 
si ill an open problem ; for the best light upon which we should consult 

1 American Journal of Public Health, Vol. I (1915), p. 166. 

2 H. S. Hasseltine, United States Public Health Reports (July, 1915), 
p. 2060. 



240 CIVIC BIOLOGY 

our local health authorities (when possible) and the best current health 
literature. All are agreed that in case of gross uncleanliness or of new, 
rare, and exceptional infections, the means of transmission of which may 
not be known, terminal disinfection is advisable. It may take years, or 
even centuries, of hard work, but nothing can ever take the place of 
exact knowledge of the definite means by which each parasitic germ is 
harbored or transmitted. Knowing this, we now exterminate the guilty 
mosquito instead of sinking the ship to prevent spread of yellow fever, 
and we pay attention to the rats and fleas in case of plague instead of 
burning the village, inhabitants and all. 

Contact infection. It was a lesson, never to be forgotten, 
when his family physician once confessed to the writer that 
he had caused the death of a young mother by failing to 
scrub the little-finger edges of his hands carefully enough. 
Upon such honesty as this we can depend for progress of 
both science and practice. Could we be as honest with our 
own hands for one day, we might each learn a lesson of life- 
long value to our own ideas of rational cleanliness. Suppose 
we mark with red ink every spot on fingers or hands moist- 
ened by saliva or mucous secretions from the nose, and with 
black ink all areas soiled by contacts with things which it 
would be utterly disgusting or dangerous to put into the 
mouth the fly we crush, the cat we touch (that has licked 
her own saliva over her fur), the dead mouse we have taken 
from a trap, the pus from a pimple or sore, and so down 
the list. If we did this for half a day even, could we ever 
again go to the table without obeying the scriptural injunc- 
tion to wash the hands before breaking bread ? And we 
would not l>e content with ceremonial touching of water, 
but would wish to scrub them with soap until all the ink 
spots were off. If such definite instruction were universal, 
we might not have examples like the following: 

Spread of gonococcus infections, persistent and impossible to prevent 
or trace, in the New York City Babies' Hospital, uncontrolled for sev- 
eral years by laborious disinfection of buildings and equipment (after 



CONTBOL OF BACTERIAL DISEASES 241 

finally discovering that the same night nurse tended the infected cases 
anl new infections in a distant ward) ceased completely when the 
nurses began disinfecting their hands after attending each case. 
HOLT, Neic York Medical Journal, Vol. LXXXI (1905), p. 521 

Men detailed as hospital orderlies were, after they had performed 
the duty of emptying bedpans, seen to go directly to their meals 
without washing their hands, and even to distribute food to their 
comrades. 1 CHAPIN, p. 120 

Thus, at one of the finest hospitals in this country, with separate 
wards for scarlet fever and diphtheria, a considerable number of cases 
hav r e arisen in the general wards. The germs were supposed to be air- 
borne, as it was said there was no other possible avenue of infection. 
AY hen I saw the head nurse lick her finger to facilitate turning the bed- 
sic e charts of diphtheria patients, I suspected that the principles of 
nu-dical asepsis had not been entirely mastered. CIIAPIX, p. 160 

The superintendent of another hospital invited another visitor and 
myself to* eat ice cream from the same spoon with himself, which spoon 
wiis then replaced in the freezer which was to supply the wards. I was 
most of all impressed with the fact that at the International Congress on 
Tuberculosis in 1908 a large number of the readers of papers moistened 
their fingers with their tongues when turning the pages, and in each of 
th<} sections only one drinking glass was provided for all the speakers ; 
and this continued for a day or two without protest. CHAPIX, p. 16f> 

The following observations were made by the author 
in 1915. 

1. Stopped to buy candy in order to observe "home manufacture"; 
savv elderly man molding nut drops lick off his fingers and go on mold- 
ing. Threw candy away. 

2. Asked for pound of preserved ginger at a fine confectionery store ; 
waitress clawed it out of tray with hands. Paid for it and threw it 
avay. 

3. Called for glass of milk at railway-station lunch counter; swarthy 
foreigner removed cap from quart jar, put his dirty hand over bottle, 
turned it bottom up and shook it violently, scraped palm of hand on 
m :>uth of jar, and poured out the glass. He was told to drink it 
hi in self . 

1 From a description of an army typhoid epidemic. 



242 CIVIC BIOLOGY 

4. Observed l flies swarming on crates of raspberries and black- 
berries, absolutely open and unprotected (caught about sixty flies with 
one sweep of the hand over such a crate). 

Carriers and contact with food. Typhoid Mary was dis- 
covered by Soper in 1906. She was apparently healthy, but 
wherever she served as cook typhoid fever was sure to fol- 
low, and she was found to be alive with virulent typhoid 
bacteria. She had already caused several small and at least 
one large epidemic. From 1907 to 1910 Mary was detained 
in the isolation hospital of the New York Board of Health 
and then was released upon her promise to change her occu- 
pation. Early in 1915 an epidemic of 25 cases broke out 
in one of the New York hospitals, and there in the kitchen, 
under an assumed name, was found Typhoid Mary. 

About 4 per. cent of those who recover from the- disease 
remain as typhoid carriers, either continuously or intermit- 
tently, and some may not even know that they have ever 
had typhoid at all. For some unaccountable reason there 
are about five women carriers to one man. A typhoid epi- 
demic occurred at Hanford, California, March, 1914, the 
study of which by the health officers proved most instruc- 
tive. A church dinner, of which 150 partook, resulted in 
93 cases and 3 deaths. The infection was traced to a woman 
who had cut the bread and prepared a dishpan of Spanish 
spaghetti. She had nursed her daughter through typhoid 
thirty-five years before, but did not know that she herself 
had ever had the disease. In order to test the matter a 
dish of spaghetti, not so large, was similarly prepared, and, 
although baked much more thoroughly than that served at 
the dinner (until the top was brown, the points on the sur- 
face were charred, and the edges were boiling furiously) 
living typhoid bacilli were found within half an inch of the 

1 In a public market, Washington, D.C., July 3, 1915. 



CONTKOL OF BACTERIAL DISEASES 243 

surface and at the center of the mass they were swarming, 
and the temperature there was only 28 C. This proved 
that " ordinary baking merely incubates the interior of these 
masses of food." 1 

At a Gettysburg soldiers' reunion one of the men " not feeling very 
well" was assigned mess duty. As a consequence (probably of his 
handling the bread) fifty-five of the company developed typhoid. 

Naturally extreme danger attaches to contact infection of foods in 
wlich bacteria may multiply lobster, shellfish, cooked meats, and es- 
pecially milk. Formerly epidemics following the eating of these things 
were explained on the theory of "ptomaine poisoning" that is, that 
poisons (ptomaines) were formed by bacterial growth in the substance, 
wlich were not destroyed by heat. Jordan says of this': "Many of the 
epidemics of 'meat poisoning ' etc. are now known to be due to infection 
wish a specific microorganism rather than to the action of a formed 
poison." 2 Milk is a most favorable culture medium for bacterial growth, 
and naturally many epidemics are traced to it. Chapin gives the follow- 
ing figures : 315 outbreaks of typhoid, 125 of scarlet fever, 51 of diph- 
theria, and 7 of tonsillitis (epidemic sore throat). Immediate report to 
the board of health of the milk route on which a .case of illness occurs 
makes it possible to nip many an epidemic in the bud, a visit to the dairy 
generally revealing the source of the infection. 

Recent outbreaks of typhoid on two milk routes in Hartford, Con- 
necticut, 12 cases in September, 1914, and 34 cases in November, 
were traced to the same carrier, an occasional milker, who had moved 
from one dairy to the other. 

All the typhoid, 21 cases, in a Minnesota town for five years was 
traced to one carrier in a dairy. 3 

An epidemic of diphtheria in Lincoln, Nebraska, of 110 cases and 
2 deaths (97 received antitoxin promptly, and none of these died) was 
traced to a diphtheretic "sore throat" of a milker. The money cost to 
th''< community of this "trifling sore throat " is estimated at $10,000, in 
addition to the suffering, labor of nursing, and the 2 deaths. 4 

1 Sawyer, Journal of the American Medical Association, 1914, p. 1537. 

2 Jordan, General Bacteriology, p. 101. 

3 H.W. Hill, American Journal of Public Health, Vol. IV (1914), p. 667. 

4 Wait, ff Report of Milk-borne Epidemic of Diphtheria," American 
Journal of Public Health, Vol. IV (1914), p. 418. 



244 CIVIC BIOLOGY 

Clean milk. For many, possibly for all, communities no better health- 
conservation work could be undertaken than solving, each member of 
the class for his own home and the whole class for the home commu- 
nity, the problem of safe and clean milk. Milk is safe when all disease 
germs are kept out of it, and it is clean when free from filth of all sorts, 
usually indicated by numbers of other bacteria. As secreted by healthy 
cows, milk is pure, and by observing hospital-operating-room precau- 
tions it can be kept so. l Yon Behring's statement that milk should not 
be used for infant feeding if it contains more than 1000 bacteria per 
cubic centimeter is rarely lived up to. Boston's standard of purity 
(which Spargo thinks is worse than no standard at all) allows 500,000 
bacteria per cubic centimeter, and "certified milk" may run as high as 
10,000 bacteria per cubic centimeter. Secure copies of specifications for 
local certified dairies. 2 If possible, have a committee of the class, or 
each member, work up the technique of making the bacterial count and 
examine local milk supplies. 3 

We have been too long scoring dairies according to buildings and 
equipment, and nothing could be more convincing for the truth of 
Dr. North's contention that dirty milk is 90 per cent due to dirty or 
ignorant dairymen than his demonstration in ten Kelton dairies. Ten 
trained Oxford dairymen were shipped over to Kelton in time to do the 
evening milking in ten of the dirtiest Kelton dairies, with the result 
shown on the next page : bacteria in the milk reduced from millions 
to less than 10,000 per cubic centimeter, in all but Xo. 6, a most in- 
structive exception. 4 

Four things necessary to production of clean milk : 

1. Milking with dry hands into covered pails. 

2. Proper washing and sterilization of milking pails and milk cans. 

0. Cooling milk by placing cans in tanks of cold water or ice water. 

1. Regular laboratory testing of milk for bacteria, and payment 
based on the laboratory tests. 

Pasteurized milk. Dangerous milk can be made safe by heating to 60 
for twenty minutes, and this does not seriously injure its nutritional 
value. This treatment kills all non-spore-forming disease germs of 

1 Kosenau, The Milk Question, p. 73. (Tells how Mr. 8. L. Stewart, New- 
burgh, New York, produces milk free from bacteria.) 

2 Rosenau, Requirements for "Certified Milk," pp. 151-160. 

3 Russell and Hastings, Experimental Dairy Bacteriology, p. 122. 

* North, "The Dairyman versus the Dairy," American Journal of Public 
Health, Vol. V, pp. 510-525. 



CONTKOL OF BACTERIAL DISEASES 245 

BACTKKIAL TESTS or MILK PRODUCED IN KELTOX DAIRIES 
(BACTERIA PKR CUBIC CENTIMETER) 



BY KELTOX DAIRYMEN 


BY OXFORD DAIRYMKN 


April 5: .April 6: 


1,830,000 3,300 


1,520,000 3,100 


4,830,000 


4,600 


4,000,000 


7,000 


1,450,000 


4,100 


3,600,000 


61,000 s 


60,000 J 


800 


9,000 2 


2,500 


70,000 


1,600 


500,000 5,600 



tuberculosis, typhoid, dysentery, diphtheria, tonsillitis, cholera, and the 
vir is of scarlet fever. This does not make the milk any cleaner, nor does 
it kill the more resistant bacteria, hut if it is dangerous, it renders 
it safe. 

Flies, vermin, house pets as transmitters of contact in- 
fections. After the human hand come other active germ 
earners, and among these the house fly probably stands 
first not only in transmitting germs of filth and disease to 
foods but in combining air-carriage with contact. This prob- 
lem has been treated in a previous chapter. Roaches and rats 
and mice . should be universally recognized as too filthy to 
eat with, and should be completely exterminated, along with 
tin; flies, from every household. Cats, on account of their 
oflen intimate contact with children, have been responsible 
for innumerable infections, especially of diphtheria. Since 
this germ attacks cats virulently, they assume the double role 
of irresponsible patients and mechanical carriers in the family. 

1 This dairy, on April 3, had a count of 8,000,000. 

2 This count was made March 30. 

3 Due to Kelton dairymen raising dust by sweeping at milking time. 



246 CIVIC BIOLOGY 

Every case of " cold " or " sore throat " in a cat should be 
considered diphtheretic or tubercular until proved otherwise. 
Serious epidemics of diphtheria have been traced to cats, and 
these have had to be killed or rigidly excluded from homes 
before spread of the disease could be stopped. Cases of scar- 
let fever are sometimes traced to cats as passive carriers. 1 
While dogs may act as mechanical carriers of bacteria, and 
are responsible for harboring several animal parasites, which 
we shall have to consider later, they are almost immune from 
bacterial attack. 

Recent civic advances due to acceptance of contact infection. 
Public drinking-cups and common towels have vanished as if 
by magic. Sanitary regulation of dishwashing and bed linen 
in hotels and restaurants, sanitary protection of drinking- 
straws and cleansing of glasses in soda fountains, wrapping 
and boxing of bread, other foods, and candies to prevent 
contact in handling, liquid and individual soaps, and many 
other items of modern improvement are active steps in the 
direction of rational prevention of contact infections. As 
with the dairies, when we all realize that intelligence in per- 
sonnel is of more importance than equipment, we shall see to 
it that only the healthy and cleanly and those who know are 
allowed to work in dairies or take care of foods in markets 
or eating houses. No man who does not know better than 
to put his bare hand- over a milk bottle, or woman who 
does not know better than to take candy from a tray with 
her bare fingers, has any right to serve the public. Our mil- 
lions of preventable infections and our more than 500,000 
deaths annually are the measure of our need in this direction. 

Resistance, susceptibility, and immunity. Possibly every 
American chestnut tree on the continent is susceptible - 

1 Caroline A. Osborne, M.D., "The Cat a Neglected Factor in Sanitary 
Science," Pedagogical Seminary, 1907 ; also ff The Cat and the Transmission 
of Disease," Medical Recorder, Chicago, 1912. 



CONTROL OF BACTERIAL DISEASES 247 

unable to offer resistance to the fungus of bark disease. In 
thut case, unless some specimens can be taken beyond reach 
of the spores, every chestnut tree in America will be killed. 
If immune trees can be found, it may be possible to propa- 
gate from them a strain of immune trees and so save the 
species to the continent. It is possible, though not probable, 
that something may be discovered which, injected into the sap 
of the tree or fed into the tree from the soil, will enable it to 
resist the fungus, that is, give the tree an artificial or acquired 
immunity. It is conceivable that we might inject some of 
the sap from an immune tree into a susceptible tree vacci- 
nate, or inoculate and so immunize it and save its life. 

Every animal or plant offers some resistance to being eaten 
alive by a parasite. This resistance may be natural or ac- 
quired; it may be mechanical (skin, bark, cuticle, too resist- 
ant for parasites to break through) or, as is more common, 
it may be chemical (some poisonous, toxic substance is pro- 
duced that weakens or kills parasites). As a nation stung 
by foreign attack begins to make ammunition, so cells of the 
host may be stimulated by the toxins of a parasite to produce 
defensive substances antitoxins or antibodies. In this case 
the acquired resistance, or immunity, is said to be active. 
If the defensive substance, antitoxin, is injected from some 
other person or animal, as if a foreign nation sent in its army 
and ammunition, the immunity conferred is said to be pas- 
sive, and this is not likely to last so long as active immunity. 
Recovery from certain diseases (whooping cough, measles, 
mumps, scarlet fever, smallpox) generally leaves the body 
armed with acquired immunity against a second attack by the 
same germs that is, leaves an experienced army that can 
prevent another invasion. This, in a true sense, is the case, 
the white blood corpuscles (phagocytes) often gaining the 
power to eat the germs, probably alive, instead of being 
eaten by them. The process is not always as simple as this. 



248 CIVIC BIOLOGY 

The white corpuscles may not be able to ingest some bac- 
teria unless there are certain substances in the blood to help 
them. These are called opsonins (Gr. otycovea), I prepare food 
for), and their amount in the blood as compared with a nor- 
mal standard is known as the opsonic index. The injection of 
killed bacteria of the exact kind that are causing the trouble 
(made with cultures taken from the patient autogenous 
bacterins) often results in a sharp rise in the opsonic index 
and with this a quick defeat of the invading germs. 

Great prejudice has existed against the use of these vac- 
cines, antitoxins, bacterins, and serums, and one accident 
attributed to them, perhaps falsely, is often made to out- 
weigh in popular prejudice the literally thousands of deaths 
caused by the natural course of infections. Beginning with 
vaccination, discovered by Jenner, in 1796, we now have 
safe and effective vaccines, antitoxins, bacterins, and serums 
for rabies, diphtheria, tetanus (lockjaw), pneumonia, boils, 
pimples, and inflammatory fevers, cholera, bubonic plague, 
bacterial dysentery, cerebrospinal meningitis, and typhoid 
fever, and, among animal diseases, anthrax, distemper of 
dogs, hog and fowl choleras, blackleg, and tetanus, with 
many more that are on the way toward perfection. It is 
claimed by some high in authority that the present great war 
will result in lengthening the average of human life by as 
much as fifteen years, by breaking down apathy and ancient 
prejudice and demonstrating the value of modern bacterio- 
logical science. Typhoid has been banished from our army 
by preventive inoculation. Let some pupil volunteer to look 
up the story of this and report to the class. 

Asepsis, antisepsis, germicides, and paths of entrance to the 
body. Blood wells from a wound, carrying out the germs 
that may have entered, rendering it germ-free, or aseptic, and 
then it clots to seal it over. This is nature's primitive aseptic 
surgery. The saliva is somewhat antiseptic, and the acid 



CONTROL OF BACTERIAL DISEASES 249 

gastric juice of the stomach is strongly germicidal, these being 
nature's provisions for turning the food over to the absorp- 
tive organs germ-free. Breaks in the skin and mucous mem- 
branes and the mouth are the great channels of entrance for 
germs, and the fact that there are so many preventable in- 
fections proves that under modern conditions of life nature's' 
provisions need constant reenforcement. In normal breathing 
through the nostrils the germs are caught before they reach 
the lungs, so that even pulmonary tuberculosis is coming- 
in ore and more to be considered a mouth infection, reaching 
the lungs either by way of inflamed tonsils or by way of 
stomach, intestine, thoracic duct, and circulation. 

When the role of . bacteria in causing disease was first dis- 
covered, chemical poisons were sought which might kill the 
gorms without quite killing the patient. Carbolic acid (phe- 
nol), mercuric chloride (corrosive sublimate), and formalin 
were the germicides first used most extensively, and the gov- 
ernment standard of efficiency, " the phenol coefficient," is 
the germ-killing power of phenol. Later came the delicate, 
specific, exact antitoxins and resistance serums that kill the 
particular germ and have no poisonous action on the cells 
ot' the body. Other nonpoisonous germicides, especially the 
hypochlorites, from general use in purification of drinking- 
water and sewage, are being adapted to dairy, home, and 
personal use. Here oxygen is the active germicide, and the 
end products of the reaction are harmless calcium chloride 
in case of hypochlorite . of lime, and, with sodium hypo- 
cnlorite, sodium chloride, or common salt, 1 

1 "Three grains of a practically harmless substance will kill the myriads 
cr: germs in a barrel of water. To do the same work with the poisonous cor- 
r< >sive sublimate would require at least one ounce, or of the equally poison- 
o is carbolic acid five pounds (p. 23). . . . Hypochlorous acid is one of the 
n ost powerful oxidizing agents known to chemists. The ' acid mixture ' 
v ill, within a minute, kill spores which resist 5 per cent solution of carbolic 
a iid for weeks" (p. 54). Hooker, Chloride of Lime in Sanitation, 1013 



250 CIVIC BIOLOGY 

Keeping abreast of discovery. Bacteriology is a young 
science, and hundreds of students are pushing discovery 
forward so rapidly that we must " step lively " to keep up. 
Have committees of the class invite members of the state 
and local boards of health and public-spirited physicians to 
'come in and discuss their problems. Try to gain clear ideas 
of just those problems in dealing with which the community 
most needs to develop " cooperative good will," and make 
a test of what a biology class can do to help. No matter 
where it is, or how large or how small it may be, any com- 
munity that can, by intelligent, united effort, demonstrate 
accomplished control of such infections as tuberculosis, grippe, 
common colds, pneumonia, diphtheria, typhoid, and summer 
choleras of infants, may " go to the head " ; and the class of 
young men and women who help to attain this result will 
have a story to tell that the sick and tired old world has 
waited thousands of years to hear. 

Problem summary. What do we mean by " clean hands " ? Are our 
fingers generally clean enough to put into our own mouths or into the 
mouths of other people, that is, to handle our own food with and that 
of others ? . Tests : Touch finger tips, unwashed and washed, to agar 
plates, incubate, and compare growths. To determine how many germs 
we may collect on the hands in a half-day's work, wash the hands with- 
out soap (cleaning the nails thoroughly) in two liters of sterile water. 
Inoculate a plate with 1 cubic centimeter, incubate, count colonies, and 
estimate total number. Read " Dirty Hands and Typhoid Fever," 
American Journal of Public Health, Vol. IV (1914), p. 141. 

Study conditions in local stores, bakeries, and candy shops. Are 
foods and confections that go directly into the mouth handled with the 
bare hands? Can you devise practical ways and means of doing away 
with all such handling? 

Look up thoroughly hygiene of mouth, throat, and nose, and adopt 
a definite plan that shall insure perfectly sound teeth, uninfected 
tonsils or nares, and absence of adenoids. Arrange a campaign to see 
that ordinances against spitting in public places are obeyed. Report 
infractions to board of health. 



CONTROL OF BACTERIAL DISEASES 251 

Let each member of the class work out one of the following problems 
in detail and present results to class : How would you plan to take sole 
care of a case of typhoid (to insure against catching it yourself or 
permitting it to spread to others) ? of tuberculosis ? of grippe ? of 
pneumonia? of diphtheria? of dysentery? of erysipelas? of leprosy? 
of scarlet fever? of measles? of pellagra? of smallpox? (Refer to 
best available manuals for trained nurses.) 

What precautions would you take if you were a typhoid carrier? 
i: you were a diphtheria carrier? if you were infected with tubercu- 
losis? if you had the grippe? if you had tonsillitis? if you had a cold? 
Is the Schick reaction used in your district to test immunity to diph- 
theria? Look up use of Widal reaction in detection of typhoid carriers. 

Make out a complete list of diseases of man and other animals for 
vhich we have reliable antitoxins, vaccines, or bacterins. Discuss their 
iise in your district and get reports from those who have tested them. 
File this list in the laboratory and note changes and growth from 
year to year. 

It is estimated that in 1914 diseases of farm animals caused damage 
io the amount of $212,000,000. Can the class work out plans of coop- 
eration by which any of these diseases may be brought under control? 

Compare the merits, for various purposes, of different disinfectants, 
antiseptics, and germicides on the market. Study especially the home 
and dairy use of the hypochlorites. Get the reports on all these things 
from the United States Public Health Service, Washington, D. C. 

Collect and discuss national, state, and local quarantine and health 
]aws and ordinances. 

Visit as many of the local dairies as possible. Obtain the official 
score cards from your dairy inspector and study the scoring he has 
4 ; iven. Are the dairymen included in the scoring? 

In the light of all you have learned about bacteria, discuss the prob- 
lem of washing dishes properly. Should we banish the tf common dish- 
towel " along with the " common roller towel." Make plate tests for 
numbers of bacteria in "dishcloths," in "dish-towels," in "dishwater," 
and on the dishes after different methods of washing and drying. How 
do these tests compare with those made on dishes after actually boiling 
for five minutes in the rinsing water ? after treating with hypochlorite 
in rinsing water, without wiping ? 

It is being claimed that spread of infections in families, especially 
of colds, grippe, and tonsillitis, might be greatly reduced by steriliza- 
tion of dishes. Can the class find a test for this in their own homes? 










I ^ "& & 



8 ... 3 * 



O 13 






S .23 O .2 




252 



CHAPTER XXIV 

CONTROL OF ANIMAL PARASITES 

1. To what is hookworm disease due ? Describe the worm. 2. What are 
tUe symptoms? 3. How is the disease spread? 4. Give the life history of 
tiie hookworm from the time the egg is laid until the worm is back in the 
i.itestine. 5. Can the disease be cured? Which is better, cure or preven- 
tion ? 6. How can it be prevented ? 7. Suppose you had charge of a hook- 
worm patient, describe your treatment and precautions. 8. What can 
s-t'hool children do to eradicate the disease in Essex County? From a 
<[iiiz given in a Virginia high school 

With this as a part of public-school work for boys and girls, one might 
be tempted to call the disease a blessing ; for what else could have brought 
the old "education" on such a long journey toward common sense? Of 
course it will not stop with this particular subject. It will deal more and 
more with the kinds of subjects that have to do with healthful living here 
;ind now. How whimsical Fate is, that we should be mightily helped to the 
ilght kind of schools in the United States by an intestinal parasite that poi- 
.soned the Pharaohs! WALTER H. PAGE, "The Hookworm and Civiliza- 
tion," The World's Work, Vol. XXIV (1912), pp. 515 ff. 

But that the mosquito bite not only annoys but may kill, by infecting 
.he punctured tissues with the germs of malaria or yellow fever or lilariasis, 
diree of the most wide-spread and fatal diseases of man, this alarming- 
fact is a matter which has come to be really recognized only recently, and 
the general recognition of which has given to the practical study of insects 
an importance which years of warning and protesting by economic ento- 
mologists have been wholly unable to do. ... In addition I may simply 
say, when in malarial regions avoid the bite of a mosquito as you would 
that of a rattlesnake. One may be quite as serious in its results as the other. 
KELLOGG, "American Insects," pp. 303, 630 

Importance. The world over, it is quite within the range 
of possibility that animal parasites are sapping half the life- 
blood and strength of the human race, and many other 
plant and animal species are similarly afflicted. This one 
parasite, the hookworm, belts the world between 36 north 

253 



254 CIVIC BIOLOGY 

latitude and 30 south, influencing, more or less, the lives of 
940,000,000 people more than half the population of the 
globe. " In Porto Rico the disease has reduced the average 
efficiency of the labor on the coffee plantations to 50 per cent 
of normal efficiency, and in some cases to 35 per cent." 1 

Theory of control. Precisely the same argument applies to 
animal parasites as was developed in the preceding chapter 
with reference to parasitic bacteria. All must know the 
facts in order that each may be able to do his part for the 
safety of the whole community. 

A case in point is the following : 

The caretaker of an expensive pheasant farm was recently observed 
laboriously twisting the gape worms out of the windpipes of his young 
pheasants and scattering them on the ground of his breeding pens. 
They were killing hundreds of his birds, but he did not know the life 
history of the parasite. It would have saved him time, labor, and worry, 
and cost him nothing, had he simply wiped them on a bit of newspaper 
and burned them. 

It may be easy to prevent outbreaks of trichinosis, hook- 
worms, tapeworms, malaria, yellow fever, and all the rest, 
as soon as each one knows exactly what to do to prevent 
multiplication and spread of the organisms. 

Stiles's argument in regard to scattering hookworms applies 
to all infections. 2 We have the parasites concentrated in the 
wastes of the patient, and we can kill them by the good old 
Hebrew " cleansing by fire," or with chemical disinfectants 

1 Thus there is a distinct loss of 10 to 20 per cent in the wages and a cor- 
responding loss in crop returns. In some places (this refers to our own 
South) I should estimate the loss at even a higher percentage, say an aver- 
age of 25 per cent, while in several families which I have examined I should 
say that uncinariasis is reducing the laboring capacity, hence the produc- 
tiveness, of the family to as low as 30 to 40 per cent, thus entailing a loss 
of 60 to 70 per cent. C. WARDELL STILES, "Prevalence and Geographical 
Distribution of Hookworm Disease," Hygienic Laboratory Bulletin No. 10 
(Washington, 1903), p. 96 2 Stiles, loc. cit., pp. 93 ff. 



CONTROL OF ANIMAL PARASITES 255 

(chloride of lime), before they become scattered in sewage or 
water or in the soil, or are carried, no one can know where, 
by flies, earthworms, or other living agencies. This is an 
effective method and can be definitely worked into the habits 
and sanitary regime of every home, and will eventually free 
us from all dangerous infections ; whereas the most intelli- 
gent and conscientious of us cannot possibly keep our hands 
clean enough, boil or filter all our drinking water, or con- 
sistently and always observe all the precautions necessary 
to prevent infection if the organisms are scattered every- 
where in soil, water, and food. 

Practical problems. The field is so vast and difficult, and 
knowledge is growing so fast, that the only course for the 
student to follow is to make connection with the best sources 
of information, local boards of health and the scientific de- 
partments of each state and of Washington, so as to keep 
abreast of important discoveries. In this way all will be able 
to help themselves and one another. Apply the quiz at the 
beginning of this chapter to all the parasitic diseases of 
plants, animals, or man of local importance. Braun 1 has 
described nearly 400 animal parasites of man 31 protozoa, 
40 flatworms, 43 threadworms, 39 ticks, and over 250 insects. 
The mere figures indicate how little we know about what is 
literally "eating" us most of the time. Our present knowl- 
edge marks little more than a beginning, and in addition to 
human parasites other hundreds prey upon plants, and prob- 
ably thousands upon other animals, domesticated and wild. 
We shall be able to suggest but a few types, and all the rest 
may be studied along lines similar to those indicated. 

Parasitic protozoa. Although discovery of protozoan para- 
sites in the blood of animals began with the studies of 
Ohaussat (1850) and Lankester (1871), and several others 
in the interim, it was the work of Laveran (1880) on the 
1 Braun, The Animal Parasites of Man. 1908. 



256 CIVIC BIOLOGY 

parasite of malaria that aroused the scientific world to Ihe 
possible importance of this subject. This was about the time 
Koch demonstrated the tubercle bacillus as the cause of con- 
sumption ; but while bacteriology has made enormous prog- 
ress, owing to definiteness of form and ease of culture of 
most bacteria, the growth of protozoology has been compara- 
tively slow because it has been so difficult to distinguish 
animal cells in and among animal cells, and so hard, or im- 
possible, to discover methods of cultivating the protozoan 
parasites in artificial media. Probably most infectious dis- 
eases the parasites of which are still unknown smallpox, 
yellow fever, measles, scarlet fever, spotted fever, typhus 
fever, infantile paralysis, foot-and-mouth disease are caused 
by protozoa. 

Amoeba of dysentery Entameba histolytica. This parasite is said to 
have killed more northern soldiers during the late war than bullets. 
It is most active in the tropics, but is not rare in temperate zones. It is 
carried in drinking water and on vegetables that are eaten raw. 

Rabies, or hydrophobia. The evidence, while not entirely conclusive, 
points to a protozoan present in the saliva of rabid animals as the canst- 
of this disease. All mammals are susceptible to the virus, which attacks 
the nervous system, following up the nerves from a bite or scratch of 
a rabid animal until it finally reaches the brain. The animals trans- 
mitting the infection, in order of decreasing severity, are the wolf, cat, 
dog, skunk, and other domestic animals. In case of a suspicious bite 
the brain or head of the animal should be immediately sent to a phy- 
sician or to the nearest laboratory, where the organisms, known as 
negri bodies, can be quickly demonstrated, if present. As it requires 
from fourteen to sixty days for rabies to develop in man, there is time 
for the patient to reach a Pasteur institute for treatment, if the exami- 
nation indicates that the germs are present. Spread of the disease is 
prevented by muzzling and confining dogs when there is danger of an 
epidemic, and it should be more generally understood that control of 
cats may be equally important. 

Parasites of malarial fevers Plasmodium vivax, P. malaria, P. immacula- 
tum or falciparum. The malarial sporozoa are a group of parasites that 
have thrown a girdle around the earth wider than that of the hookworms. 



CONTROL OF ANIMAL PARASITES 257 

from 40 north latitude to 40 south, rendering many of the most 
fertile valleys uninhabitable. Manson declares that malarial parasites 
cause more death, and more predisposition to death from other causes, 
than all other human parasites taken together. Howard estimated 
(in 1909) that they caused 3,000,000 cases of malaria and nearly 
12,000 deaths annually in the United States, and actually imposed a 
ye irly tax upon this country of not less than $100,000,000. 

The malarial parasite is carried to man by the bite of an anopheline 
mosquito. The minute vermicides, or sprorozoites, enter the red corpuscles 
and grow until the substance of the corpuscles is absorbed, when they 
divide asexually into, generally, from 16 to 24 spores, merozoites. These 
burst out of the corpuscles, and this, probably on account of their 
poisonous waste products set free in the blood, causes the "chill." 
While thus unprotected in the blood plasma the parasites of our com- 
mon, temperate-zone malarias (P. irivax and P. malarice) may be killed 
by heavy doses of quinine. The parasites of the malignant malarias of 
the tropics are not affected by this drug. Our common malaria is caused 
by P. vivax, which passes through its life cycle in the blood every forty- 
eig'ht hours the usual time between chills. This is also known as 
tertian malaria. Quartan malaria, the other temperate-zone type of 
the disease, caused by P. malarice, which requires seventy-two hours 
to complete its life cycle, is characterized by chills every third day. 
Some authorities distinguish two types of malignant tropical malaria, 
the quotidian, in which the parasite completes its asexual life cycle 
iii twenty-four hours, and the tropical tertian, in which the cycle is 
forty-eight hours. All these parasites multiply sexually within the 
auopheline mosquitoes. 

Reasoning from the above data, we see that there are three ways by 
which malaria may be banished from a locality: 1. Exterminate the 
n osquitoes (see Chapter XI). 2. Prevent the mosquitoes from biting 
healthy people. 8. Prevent mosquitoes from becoming infected by 
biting malarial patients. As soon as every responsible member of 
;i'iy community becomes able to grasp these simple facts, that com- 
munity may free itself completely from the most vicious blood parasites 
tiiat afflict mankind. 

The Piroplasmas ; Texas fever, or bovine malaria. While the cattle 
lick acts as carrier, the parasite of Texas fever is Piroplasma (Latin 
y >/>*.<?, "a pear") Inyeminum, which attacks the red blood cells of cattle. 
Tick extermination is banishing this costly parasite from our South- 
ern states (see Chapter XV). Horses, sheep, dogs, and other animals 



258 CIVIC BIOLOGY 

have malaria-like diseases caused by different species of the genus 
Piroplasma P. equi, P. ovis, P. canis, etc. ; and birds, frogs, turtles, 
and many other animals serve as hosts for blood parasites of other 
kinds. 

Yellow fever. No one has been able to demonstrate the parasite of 
yellow fever, although many investigators have hunted for it diligently. 
It is so small that it passes through the pores of a Berkefeld filter and 
is therefore supposed to be too small to see with a microscope. This may 
be true, or the organism may be soft and elastic enough to squeeze 
through the pores of a filter, and so transparent and unstainable that 
no one could recognize it in the field of the microscope. It is generally 
agreed that the organism is a protozoan, because it is proved to have 
a life cycle in a certain species of mosquito (Aedes calopus, formerly 
named Stegomyia fasciata) and is transmitted solely by its bite. It 
has been transmitted experimentally by injecting into nonimmunes 
a few drops of blood (or the serum of such blood after passing 
through a Berkefeld filter) drawn from yellow-fever patients during 
the first three days of the attack. After filling with yellow-fever 
blood the mosquito is not infective for at least twelve days, indicating 
a definite life cycle, and then the mosquito remains infective as long 
as she lives fifty-seven days in one case. (For discussion of this 
topic in relation to mosquito extermination see Chapter XI. 1 ) Few 
stories of discovery are more instructive or fuller of inspiration and 
hope for the future than this work upon the cause and prevention of 
yellow fever. Will some member of the class volunteer to look it up 
and report? 

Smallpox. This is clearly a parasitic disease, the germ of which has 
eluded discovery, as have the organisms that cause measles and scarlet 
fever epidemic disorders of the same class. We have, however, gained 
control of it by vaccination. About 1770 Edward Jenner happened to 
hear a woman say : " I can't take smallpox, because I have had cowpox." 
The idea was common at the time in several countries. Jenner studied 
the problem of immunity among the dairymaids for twenty-six years. 
On May 14, 1796, he made his first experimental vaccination, upon 
James Phipps, son of one of his friends. On July 1 he vaccinated James 
again with virus from a case of smallpox, at the same time vaccinating a 

1 Sternberg, "The Transmission of Yellow Fever by Mosquitoes," Popu- 
lar Science Monthly, Vol. LIX (1901), p. 225 ; Kelly, Walter Reed and Yellow 
Fever, New York, 1907 ; McCaw, Walter Reed Report, Smithsonian Insti- 
tution, 1905, p. 549. 



CONTROL OF ANIMAL PARASITES 259 

Donimmune man with the same virus. The man took smallpox as usual ; 
James did not. Crude methods at first, making inevitable mixed inocu- 
lations with other germs, raised violent objection to vaccination, but 
at that time the disease itself was so much more serious than any such 
complications, that the practice spread rapidly over the world. Modern 
bacteriological methods have made the virus safe, so that countries 
like Germany, in which vaccination under two years, with revaccination 
between ten and twelve, is compulsory, have reduced smallpox to the 
vanishing point. In England, however, the old opposition has persisted, 
and this has resulted in many serious local epidemics. The same is 
true of our own country and Canada. A new difficulty has also arisen. 
The disease has been so nearly exterminated that even the most con- 
scientious people are saying : " Why vaccinate our children against a 
disease to which they wil-l never be exposed?" This argument is suf- 
ficiently answered by the many local epidemics of recent years. Study 
carefully the history of at least one such epidemic. 1 

No less than eighteen other cities and towns in New York State, and 
several more in other states, were infected with smallpox from Niagara 
Falls in 1914, and Canada was obliged to quarantine against the city. 
Js it right for one person, or one city, to endanger the safety of others 
in this way? Look up the prevalence and mortality of smallpox, and 
iftethods of "inoculating" from mild cases, before 1800, and compare 
with present conditions. Study also the story of the introduction of 
smallpox into America by the Spaniards. It is said to have killed 
o,500,000 natives in Mexico. 

The trypanosomes (trypanon, "auger"; soma, "body"). This genus 
( ontains about sixty known species, which live as free-swimming para- 
sites in the blood plasma of many vertebrates, from fishes to man. Their 
] irimary hosts are probably bloodsucking flies, which, at any rate, act as 
carriers. Surra, a disease of cattle, horses, and camels in India and the 
.Philippines, is caused by T. euansii; and nagana, or tsetse-fly disease, 
which long made impossible the introduction of European cattle, horses, 
and sheep into East Africa, is caused by a similar blood parasite, 
1\ brucei. Nearer home a serious disease of horses, dourine, long known 
in Europe, and more recently reported from western Canada, is caused 
1>y T. equiperdum. This forms a notable exception among diseases of 
ihis class in being spread exclusively by breeding, and has no known 
-onnection with biting insects. 

1 Dr. L. R. Williams, ff Smallpox Epidemic at Niagara Falls,' 1 American 
Journal of Public Health, Vol. V (1915), p. 423. 



260 



CIVIC BIOLOGY 



Undulating 
\ /Membrane 



Flagellum 



Trypatwsoma gambiense, which has long been the scourge of the west 
coast of Africa and is now spreading rapidly up the Congo, is the para- 
site of sleeping sickness in man. It is found in the blood of a number 
of native animals and is carried to man by the bite of one of the tsetse 
flies, Glossina palpalis. 

The flatworms, flukes, and tapeworms Platyhelminthes 
(platys, "flat"; helminthes, "worms"). The flatworms 
comprise a group of diverse forms which vary in size from 

almost microscopic 

Nucleus flukes to tapeworms 

60 feet in length. 
Two large classes, 
the trematodes (to 
which the flukes 
belong) and the 
cestodes (to which 
the tapeworms be- 
long) contain only 
forms that are par- 
asitic on or in other 
animals. Two hosts 
are commonly re- 
quired for one of 
these parasites to 

complete its life cycle, which depends on the practice, com- 
mon among animals, of eating one another raw. So, in parts 
of the world where fish, pork, beef, and other meats are com- 
monly eaten raw, man comes in for his full share of these 
parasites. People with raw-flesh-eating habits, coming to us 
from the ends of the earth, bring their internal pets with 
them 1 and proceed to take up a collection of American 
forms. The eggs are minute, and flies swallow them and 




FIG. 112. Trypanosoma gambiense, from a case of 
sleeping sickness, different forms 

After Manson 



1 A tapeworm has been known to live in man for thirty-five years. 
BRA UN 



CONTROL OF ANIMAL PARASITES 



261 



Man 



pass them uninjured or may carry them to human foods 
as dust on their feet eggs of eighteen worm parasites 
have been found on or in flies. It is estimated that a tape- 
worm produces 12,000,000 eggs a year, and the flukes may 
be equally prolific. Such powers of reproduction demand a 
number of different hosts, or host and parasite would die 
together. One authority 
si ates the problem thus : 

If a liver fluke were to de- 
posit its million or so of eggs 
in. the bile ducts of the sheep, 
and these were to develop in 
situ, the host could not with- 
sl and the increased drain upon 
its vital resources, and host 
and parasites would perish to- 
gether. Hence it is clear that 
the infection of a second host by 
trematodes is highly necessary. 

Bovine 




fcysticercu8\ 

FIG. 113. Life cycle of human tape- 
worm ; infection from raw beef 



So, while many of the 
bacterial parasites " don't 
know any better" than to 
kill their hosts outright, 
these animal parasites, as a rule, sap and drain slowly and 
are the cause of prolonged misery rather than of death. 
Reasonable cleanliness in rearing of farm animals, proper in- 
spection of meats, and, above all, proper cooking of meats 
on the part of everyone will finally relieve us from these 
disagreeable pests. The life history of one or two types 
should be generally known, and any of the following that 
may be of local interest should be worked out to practical 
conclusions in nature and in the books. 

Liverfluke Fasciola hepatica. The adult is most commonly found 
in the liver of the sheep, but may occur in the horse, deer, camel, ante- 
lope, goat, pig, rabbit, kangaroo, beaver, squirrel, and, rarely, in man. 



262 



CIVIC BIOLOGY 



The eggs pass out through the bile ducts and hatch into minute, free- 
swimming embryos (the miracitKa), which bore into fresh-water snails. 
Within the snail the parasite develops into a sporocyst, which produces 
still another form of the worm, known as the r/ia. The redise, in turn, 
produce asexually other rediie or still another form (the ceiroria). The 

cercarise are tadpole-shaped, 
and, passing out of the snail, 
swim about in the water 
until the tail drops off and 
they encyst upon the leaves 
of plants. Here they are 
eaten by animals and make 
their way up the bile d 
and so the life cycle is re- 
peated. The adults in the 
liver are hermaphroditic. A 
large species (Distomttm map- 
fiunt), probably imported 
from Italy, may become a 
serious obstacle, especially 
to sheep-grazing, in portions 
of the West. The main rem- 
edy is avoidance of low pas- 
tures during wet seasons. 

Tapeworms ctstodfs\cts- 
tas, "a girdle")- An idea of 
the general form of a com- 
mon tapeworm, adult and 
bladder stages (cysticercus), 
is given in Fig. 114. In the 
adult the head is a small 
knob provided with four suckers and a circlet of booklets. This head 
has no mouth or sense organs, but serves merely to anchor the worm 
to the wall of the intestine. The neck is the short, unsegmented por- 
tion close to the head, and behind this the characteristic segments 
begin to form. These grow by absorption of the digested food through 
the skin; hence there is no need of digestive organs, the entire con- 
tents developing practically into reproductive cells, eggs, and sperm: 
and finally the joints (proglottide*} break off and pass out. containing 
each its many thousands of minute fertilized eggs. In 1861 Leuckart 




FIG. 114. Tapeworms 

After Leuckart 



CONTKOL OF ANIMAL PAKASli - 

fe i the ripe proglottides from man to calves, ami was thus able to dis- 
cover how man acquires this tapeworm from eating measly beef. The 
tiny egg hatches iu the stomach of the cow, burrows through the wall 
of the intestine, and in from three to six months has grown to a 
bl idder, or cyst (the cysticercus). the size of a small Wan, and is then 
found in the muscles. After the cysticercus passes through the human 
st )niach, the head everts (pops out like turning a glore-finger), bringing 
the hooks and suckers to the 
outside; these anchor in the Man 

intestine and begin a new life 
ojcle. While the beef tape- 
w rm ( Ttrnia saginata) may 
e use some irritation, and un- 
doubtedly steals some digested 
t\od. it seldom does serious 
iijury. This is due to the 
simple fact that its eggs can- 
nit hatch and pass into cysti- 
cr-ici in the muscles or other 
o-gans of man. The cystioer- 
c is stage is confined closely to 
cattle, and the adult stage as 
c osely to man. The eggs of se v- 
e ! of the other species do, how- 
e ,er, develop cysticerci in man, j- IO> n5. Life cycle of pig tapeworm ; 
v hich renders them much more infection from uncooked pork 

d.mgerous and sometimes fatal. 

The pig tapeworm Taenia solhan. This j^arasite is distributed the 
v orld over, wherever the pig is raised and eaten raw or rare. It is found 
also in the wild boar, sheep, deer, dog, oat, bear, and monkey. The eggs 
atid newly hatched. embryos (t^caqptores) are microscopic, the latter 
only 0.02 millimeter in diameter so small that they are easily carried 
t > foods on dirty hands, eaten with polluted vegetables, or even swal- 
1 *wed by flies and carried to foods anywhere. These eggs, if swallowed, 
i lay find their way to any part of the body muscles, eyes, brain, and 
t ven heart, and there become cysticerci. These, too, are large (t>-*20 niilli- 
i leters long by 5-10 millimeters thick), so that even one may prove fatal. 
1 a expelling this tapeworm great care must be used to avoid causing nau- 
s ?*, for a single ripe proglottis, forced back into the stomach and releas- 
i ig its myriad embryos, would leave little chance for a patient's recovery. 




264 



CIVIC BIOLOGY 



Tapeworms of the dog T<snia echinococcus. Unfortunately our faith- 
ful friend has been found to harbor twelve different species of tapeworms. 
The most dangerous of all is T. echinococcus, which has a different life 
history and mode of growth from those just described (see Figs. 116, 117). 
The adult worm is minute (from 2.5 to 6 millimeters long) and occurs 
only in the dog, wolf, and jackal, often in enormous numbers. The 
cysticercus stage is found in twenty-seven different mammals, including 
man. Instead of forming a cyst with a single sco- 
lex, or head, this worm forms a cyst that may 
grow for several years, to the size of a goose egg 
or even a " child's head," and its wall forms num- 
bers of vesicles which may develop hundreds of 
scolices. Dogs infested with this tapeworm should 
be mercifully killed and cremated, and dogs, 
generally, should not be permitted to lick the 
face or hands or to eat out of dishes used by man. 
Tapeworms of fishes Dibothriocephalus latus. 
Fishes harbor a number of tapeworms, which, 
chiefly in oriental countries, naturally find their 
way into men, who consider raw fish a delicacy. 
The broad tapeworm, D. latus, is found in the 
muscles of various fresh-water fishes, among 
them the pike, salmon, and perch. 

Tapeworms vary in size from almost micro- 
scopic to ribbons half an inch broad and many 
feet in length, but this signifies little. The rate 
of growth for T. saginata and D. latus has been 
determined as 7 centimeters and 8 centimeters 
per day respectively. At this rate, in thirty-five 
years a broad tapeworm might grow to be 
3406.6 feet in length. 

Roundworms (nematodes) and threadworms (nemathelminthes) 
(nema, " thread " ; helminthes, " worms' '). These worms attack 
plants, all sorts of animals, and man, and are the real terrors 
among vermian parasites. One species, Heterodera radicicola, 
has been found infesting the roots of four hundred and fifty 
different plants, the list including all garden-truck crops, 
many field crops, and a great variety of fruit trees, orna- 
mental trees, shrubs, and flowers. They infest greenhouses 




FIG. 116. Dog tape- 
worm ( T. echinococ- 
cus), twenty-five times 
natural size 

After Braun 



CONTROL OF ANIMAL PARASITES 265 

everywhere, often destroying entire crops and making it 
necessary to sterilize the soil with live steam or to remove 
all the earth frequently and disinfect the benches. In the 
South they are often most serious pests of outdoor garden 




FIG. 117. Portion of cyst wall (T. echinococcus) 
After Braim 

and Held crops. This whole side of plant injury, however, 
we must leave for interested pupils to work up, with the aid 
of their experiment stations. 1 

General characters. Familiar nematodes are vinegar eels, 
hair snakes, and the large, round worms so common in dogs, 
horses, and man. As seen from these examples, they vary 
from microscopic size to 1 or 2 feet in length. Many are 
free-living in water (marine and fresh) or in damp ground, 
but great numbers are parasitic. The life cycle of parasitic 

1 Nematodes bore into the roots and cause worm-swellings, galls, and knots. 
The plants most seriously attacked (Schofield) are beets, carrots, celery, 
cucumber, eggplant, lettuce, muskmelon, watermelon, clover, cowpeas, rape, 
soy beans, catalpa, cherry, elm, and peach. They are most often distributed 
in nursery stock and seed potatoes, which should be most carefully examined 
for them before planting, especially strawberry and tomato plants. See 
Bessey, ff Root-Knot and its Control," Bulletin No. 217, Bureau of Plant 
Industry, United States Department of Agriculture, 1911 ; Schofield, Bureau 
of Plant Industry, United States Department of Agriculture, Circular 91 : 
and Cobb, Yearbook, United States Department of Agriculture, 1914, 
pp. 457-490 (19 illustrations). 



266 



CIVIC BIOLOGY 



//a/e 



Female 



forms may be direct (that is, worm, egg, worm in -the same 
host), or it may require two or even three hosts for its com- 
pletion. The sexes are usually distinct. Typical nematode 
parasites are 

Roundworm Ascaris lumbricoides. This is the most common para- 
site of man; it is reddish-yellow, resembles the earthworm in general 

shape, and may attain a length of from 
12 to 15 inches. It lives in the small in- 
testine, and, being unattached, is easily 
dislodged. The life cycle is direct, the 
eggs being taken in with polluted water 
or dirty foods. Since they have been 
found to pass through flies uninjured, 
these insects are thought to be one of 
the active means of distributing the 
eggs to human foods. 

Pinworm Oxyuris vermicularis. This 
is a minute nematode, from 4 to 12 mil- 
limeters long, that affects children the 
world over. Its life cycle is direct. 

Gapeworm Syngamus trachealis. The 
habitat of this parasite is the trachea 
or bronchi of birds. The male is smaller 
than and permanently attached to the 
female, and the eggs are not laid, but 
are set free by the disintegration of the 
mother in the soil. Here they hatch in 
about a week, in warm weather, the 

embryos are picked up by the birds, and the direct life cycle is repeated. 
Trichina worm Trichimlla spiralis. The presence of this parasite in 
man causes the well-known disease trichinosis ; and our constantly re- 
curring epidemics prove that, with all the publicity given to the matter, 
we have not reached a solution of the problem. Has proper attention been 
directed to extermination of rats from premises where swine are raised? 
The course of infection is indicated in Fig. 119. The adult worm, 
the size of a very fine hair 2-4 millimeters long, lives in the wall of 
the small intestine, where the female gives birth to from 1000 to 1500 * 




FIG. 118. Gapeworms, female 
with small male attached 



1 The Cambridge Natural History (Vol. II, p. 146) estimates 12,000. 



CONTROL OF ANIMAL PARASITES 267 

living young about 0.1 millimeter long. These burrow their way, or 
are carried by the blood, into the muscles, where they feed actively and 
grow rapidly. They go to all parts of the body, but gather in greatest 
numbers in the respiratory muscles, intercostals, and diaphragm. The 
iemales live and produce young in the intestine for from five to seven 
weeks, and the first young begin to reach the muscles in nine days after 
infection; hence the disease is pro- 
]onged, and, from the nature of the 
attack, is extremely painful. After 
ihus feeding in the muscles for an 
undetermined time the full-grown 
]arva encysts (Fig. 120) and may live 
j'or years (thirty-one in man, accord- 
ing to Braun) or until the flesh is 
<>aten raw by some other animal, 
when the life cycle is repeated. The 
rat is continually eating its fellows, 
:ind since this is the most common 
iiost of the parasite, infection of these 
pests is continuous. The pig eats the 
dead rats, or the cysts in filthy sties 
j^et into its food, and so it becomes 
;i common host. Cats, naturally, are 
often badly infested. Cooking all 
pork thoroughly is the safeguard of 
man, but we should always remem- 
ber the dish of spaghetti and the Man 
typhoid epidemic (p. 242), and real- FIQ ng Life cyde and hogt _ 
ize that the center of a roast, a pork relations of trichina worm 
chop, or a cake of fried sausage may 

he scarcely warmed through when the outside is browned to a crisp. 
Here is a fine problem in civic biology. In connection with rat 
extermination, why not examine the diaphragms of all rats and mice 
killed, and tabulate and plot on a map the results obtained? Then 
examine diaphragm and intercostal muscles of all hogs slaughtered in 
the district, and tabulate and map the results. Placing this map over 
the other, note whether there is more trichina in the hogs where rats 
are numerous and badly infested. File all these maps and tabulations 
in the school library, so that when the rats and mice are exterminated, 
the next year's class can examine the pork and thus record progress. 




268 



CIVIC BIOLOGY 



The first school able to report complete freedom from this parasite should 
write up the story for the benefit of other communities. This one job 
might be worth the total cost of the public schools in some communities. 

Hookworm disease, uncinariasis 
Uncinaria americana. It only remains to 
add a word as to life history and mode 
of infection. The adult worms live in 
the small intestine, where they gnaw 
holes in the lining membranes and 
suck blood. Besides this the patient is 
likely to bleed badly from the wounds. 
How long the adults may live in the 
intestine, if the case is not treated and 
no new infection occurs, is stated by 
Stiles to be certainly six and a half 
years and probably from ten to twelve 
years. With this rich food supply, 
eggs are produced in great numbers. 
These hatch in about twenty-four hours 
and feed and grow in the soil for about 
five days. The microscopic embryos 
may then be swaltowed with polluted 
foods or water (carried to foods espe- 
cially by flies), or, on coming in contact 
with the skin, most commonly of bare 
feet, they bore in, causing "ground 
itch," and make their way to their 
final destination in the intestine. Stiles 
says that the embryos live in the soil 
" probably eight to twelve months." 

This is a sectional problem, and 
every school (especially every high 
After Leuckart school) in the South should have in its 

school library the latest information ob- 
tainable from the Rockefeller Sanitary Commission for the Eradication 
of Hookworm Disease, 1 and also the bulletins of the United States Bureau 
of Public Education, notably Bulletin No. 20, " The Rural School and 
Hookworm Disease," Washington, D.C., 1914. Knowledge is growing 
so fast that the latest and best should be secured from year to year, 

1 Address, Washington, D.C. 




FIG. 120. Trichina worm embryo 

cysts in human muscle and adult 

female from intestinal wall 



CONTROL OF ANIMAL PARASITES 269 

While the study of these parasites of disease may seem 
iisagreeable at first, where can we find keener inspiration 
than in the thought of their control by human cooperation 




Fi<;. 121. Class with state inspector ; meats in cold storage 

arid intelligence ? By this road only can mankind free itself 
from these time-old and world-wide tormentors and sappers 
of human life. So may even the parasites of the Pharaohs 
help to teach us lessons in cooperative good will. 




270 



CHAPTER XXV 

CIVIC PROBLEMS RELATING TO MOLLUSKS 

It is doubtful whether there is any farming land in the United States 
which yields as great a profit to the acre as the bottoms which are used for 
oyster-planting in Rhode Island. W. K. BROOKS, "The Oyster," p. 135 

The sea mussel (Mytilus edulis) is one of the most important food re- 
sources of the ocean, and as yet France, Belgium, and Holland are the only 
nations that appreciate its real food value, No shellfish grows so rapidly 
and abundantly. Natural beds often contain as many as 8000 bushels to the 
acre, and planted beds yield at the end of three years from 4000 to 6000 
bushels per acre. At present prices this means from $ 1600 to $2400 per acre 
every three years. 

The high nutritive value and low cost of sea mussels make them the most 
economical shellfish on the market. The same money will buy four times as 
much food in mussels as if spent for long clams, and ten and twenty times 
as much as if invested in oysters and, lobsters respectively. They are also 
most palatable and easily digested. As these facts come to be better under- 
stood it is hoped that the American people will no longer neglect this 
vast source of food supply, but convert it into the wealth of the nation. 
IRVING A. FIELD 

Possibilities of marine food supply. " Four feet square of 
the ocean is capable of producing food enough to support a 
human being." 1 This statement, made in a public lecture 
by an eminent authority, may seem incredible, but it may 
also serve to indicate that we have scarcely begun to realize 
the wealth of life in the waters. Of the 518,900 species 
of animals known, 61,000 are mollusks, almost all aquatic. 
In regard to how many of these do we know anything? 
Oriental peoples utilize a considerable number of them, and 
Europeans, since remote antiquity, have feasted upon deli- 
cious mollusks, common but unknown to us. 

1 Statement by Major McGee in an address at the University of Wis- 
consin, 1892. 

271 



272 



CIVIC BIOLOGY 



Sea mussels. These most abundant mollusks of our coasts 
might supply the soup and fish courses for every dinner in 
North America without strain upon their reproductive pos- 
sibilities. How many have ever heard of them ? How many 
have tasted them in prime condition, or even at all ? Some 
may have heard from irresponsible sources that sea mussels 
are poisonous. So are oysters or clams that are taken from 
sewage-polluted waters or that are dead and half decayed ; and 

stale lobsters, crabs, 
chicken, veal, and even 
milk may be poisonous. 
r Mussels taken from 
pure water which has 
free circulation have 
never been known to 
produce injurious ef- 
fects. .V New York 
dealer who has been 
selling mussels for 
years has never known 
of a case of poisoning 
from them. Neverthe- 
less, too much emphasis cannot be laid on the fact that care 
must be exercised in choosing proper localities for the culti- 
vation and collection of mussels for market. They must be 
sold to the consumer in a perfectly fresh condition or serious 
results will be likely to follow." l 

It would be an interesting problem for any community 
unit to figure out its aquatic resources and possibilities, ana- 
lyze the different elements, and estimate the percentage of 
present utilization. For the United States as a whole this 
is roughly attempted in the following table. 

1 Irving A. Field, " Food Value of Sea Mussels," Bulletin No. 742 of the 
United States Bureau of Fisheries, 1911, p. 125. 




FIG. 123. Cleaning sea mussels commercially 
Photograph by I. A. Field 



CIVIC PROBLEMS RELATING TO MOLLUSKS 273 



AMOUNT AND VALUE OF MOLLUSCAN PRODUCTS IN THE UNITED STATES l 





t'REi 


SENT 


ross 


IBLE 




Yield, pounds 


Value 


Yield, pounds 


Value 


Clams, hard 


7,805,000 


$1,317,000 






Clams, soft 


8,654,000 


553,000 






Clams, razor 


259,000 


25,000 






Clams, surf . . . , . 


265,000 


21,000 






Sea mussels 


8,542,000 


12,000 




$35,000 * 










|5,000,000 3 


Fresh-water mussels . . 


81,869,000 


692,000 






Abalones, shells . . . 


1,005,000 


16,000 






Abalones, meat .... 










Cockles, conchs. . . . 


146,000 


35,000 






Oysters, Atlantic . . . 


231,146,000 


15,020,200 






Oysters, Pacific .... 


2,163,100 


693,500 






Oyster shells 










All other shells ... . 


952,000 


8,400 






Squids 


2,562,000 


43,000 






Scallops 


2,432,000 


317,000 














. 



The most instructive factor in such problems is likely to 
be the causes that work to depress actual below possible 
resources. Here we shall find ignorance of values, lack of 
knowledge as to life history of forms and hence of practical 
means for development, and, above all, in any development 
of aquatic resources, the old, uncivic spirit of piracy, handed 
down from the times of natural oyster beds, which still holds 
that anything whatsoever under water belongs to the one 
who can get it. " Oh yes, this is a fine location for oysters, 
and J did go to considerable expense and planted a lot, but 

1 Statistics furnished by the United States Bureau of Fisheries for 1908. 
At present the Bureau cannot supply any estimates of possible yields. Fill 
out the table and keep it up to date as figures become available. Make a 
similar table of actual and possible yields for local waters. 

2 Dr. Field's estimate of value of sea mussels produced in 1915. 

3 Dr. Field's estimate of possible value of sea mussels produced in any 
one year. 



274 . CIVIC BIOLOGY 

I never got an oyster. As soon as they grew to amount to 
anything the oyster pirates came along and cleaned them up 
in a night. So I had to give it up." 1 

Classification. Our common mollusks may be classified into three 
main groups : 

1. Lamellibrancks (lamella-gilled) : Clams, mussels, oysters, scallops, 

bivalves, all are aquatic (marine and fresh-water). All the great 
food mollusks belong in this class, because their gills enable them to 
filter out and feed upon the inexhaustible supply of algae and other 
organisms floating in the water. 

2. Gastropods (stomach-footed) : Snails, conchs, periwinkles, aba- 
lones, typically coiled univalve shells, and many shell-less forms 
(garden slugs) are marine, fresh-water, and terrestrial. Most gastropods 
are carnivorous, but a number are vegetarian, like the edible snails, 
the slugs, and the periwinkles and abalones, which feed upon the algse 
and seaweeds of the bottom. 

3. Cephalopods (head-footed) : Squids, cuttlefishes, devilfishes, octo- 
puses, nautilus, are all marine, the molluscan over- (or under-) lords of 
the ocean. The cephalopods are all carnivorous, and many of them are 
used for food by oriental peoples. Our common squids, used now for 
fish bait, are good food mollusks. 

Typical problems and life histories. While schools along the seacoasts 
have the advantage, the mollusks of our rivers, lakes, and ponds, and 
even of our woods and gardens, offer problems of no mean interest. 

Oysters. Ostrea virginica is the native oyster of the Atlantic coast 
from Cape Cod to the Gulf of Mexico. It has the reputation of being 
the finest edible oyster in the world. A small, starveling variety, the 
" coon oyster," forms extensive natural beds throughout the salt-marsh 
sedges and mangrove swamps of the Southern states. A small but 
delicious species, 0. lurida, is native to the American Pacific, and 
young 0. virginica, since 1870, have been shipped across the continent 
to grow and fatten in the favored coves of the Pacific coast. Almost 
the entire Pacific coast line, however, from Puget Sound to Mexico, is 
a waste of desert sand, unindented and open to the ocean front, with 
line after line of huge beach combers out as far as the eye can reach 

terrific instead of "pacific," and not at all suited to the oyster. The 
United States Bureau of Fisheries has made repeated experiments in 
colonizing Atlantic oysters in favored places along the Pacific, but, 

1 Experience of a shore owner on the Chesapeake. 



CIVIC PROBLEMS RELATING TO MOLLUSKS 275 

while they evidently find food and conditions generally favorable to 
growth, there has been difficulty in getting them to spawn. It is 
claimed that they have now become acclimated and are spawning 

'reely in some of the inlets of the Washington coast. If this is true, 
such oysters ought to be used exclusively for seeding all available coves 
of the Pacific coast, which are few at best. To use them otherwise, 

mtil this is done, would be monumental folly. Pacific-coast schools 
should give special attention to this problem. 

Ostrea edulis is the native oyster of the European Atlantic, and, like 
0. lurida, is hermaphroditic, while O. virginica is bisexual. For a com- 
munity interested in oyster culture a good topic would be a comparison 




FIG. 124. Ostrea virginica 

Left, old shell covered with young oysters ; middle, shells of four large specimens 
about 6 inches long ; right, shell of an old oyster riddled by boring sponges 

of local with European methods. Possibly France has attained nearest 
to 100 per cent efficiency in the use of her available oyster beds. The 
French attend not only to the rearing of the oysters but to the propa- 
gation of certain kinds of algae which impart desired colors and flavors 
to the finished product. 

The civic problem which must be solved by the rising generation is 
that of developing the oyster industry to as near 100 per cent efficiency 
as possible. Much as we have already done in this direction, probably 
not more than 2 per cent of the possible production of American waters 
has been attained. How we can develop to 100 per cent efficiency in 
each community is the problem for each community to solve. 

Sea mussels Mytilus edulis (and other species). The range of Mytilus 
is circumpolar, fringing the northern coasts from Japan around to the 



276 CIVIC BIOLOGY 

Mediterranean and from North Carolina around through the Arctic 
Ocean to San Francisco. In depth it ranges from halfway between tide 
marks to probably 100 fathoms. Under most favorable conditions, in 
American waters, the mussels may grow to an average length of from 
2 to 3 inches in a year. In England, by the bed system of cultivation, 
they require two and generally three years to attain a length of 2 inches ; 
but in France this size is secured, by the buchot method, in a year and 
a half. A female mussel has been observed to lay 12,000,000 eggs in 
fifteen minutes, almost the entire substance of the animal, except 
the heart and gills, being transformed into eggs or sperm, which are 
thus quickly shed once a year. The spawning season varies with lati- 
tude and with the temperature of local waters, extending from Feb- 
ruary to September ; and since the mussels are in prime condition when 
full of reproductive products, the beginning of the spawning season 
should be determined for each typical bed in a locality, to the end that 
the yearly crop may be harvested at the right time, that is, just before 
spawning occurs. Thus mussels may be made to fill the gap in the 
markets from May to August, when oysters are out of season ; and, in 
fact, according to the extended investigations of Dr. Field, sea mussels 
may be found in fair or prime condition every month in the year. Of 
course, as long as no one knows how good they are, this vast food 
supply will continue to go to waste. As a matter of practical biology, 
then, why not arrange for a course of mussels in class banquets or 
other entertainments, and agree to call for them frequently in local 
restaurants and hotels. When once mussels have been tried, the de- 
mand for them, and consequently the supply, will grow until the whole 
country is benefited. 

Soft, or long-necked, clams Mya arenaria. This is popular for clam- 
bakes along the New England shore and far inland. Mya ranges from 
South Carolina to the Arctic Ocean, but, unlike Mytilus, has not as yet 
reached the Pacific by that route. It was, however, introduced into San 
Francisco Bay in 1870, and spread rapidly. It appeared in Willapa Bay, 
Washington, in. 1880, was transplanted to Puget Sound a little later, 
and has become abundant at many points in the Sound. Pacific-coast 
schools may well lay emphasis on this problem ; for in this burrowing 
clam we may possibly have the form best able to transform the endless 
barren sand wastes of the Pacific into productive sea gardens. Mya can 
be much more easily, cheaply, and quickly raised than oysters, coming 
to market size in a year, under favorable conditions ; and the young, in 
passing from the free-swimming, larval stage to the adult stage, often 



CIVIC PROBLEMS RELATING TO MOLLUSKS 277 

Bather in solid masses iu tide pools, a single find of this sort often suf- 
icing to plant acres of barren beach at almost no cost. Antiquated and 
itterly destructive beach laws and customs, remains of piracy, are keep- 
ing barren and totally unproductive thousands of acres of New England 
reaches and flats that might, under enlightened civic management, be 
yielding per acre from $300 to $500 worth, or more, of these delectable 
mollusks. These places are not adapted to the culture of either sea 
mussels or oysters. 

Hard, or little-neck, clam (quahog) Venus mercenaria. As relations 
now stand, Venus ranks second in commercial importance among the 
Atlantic-coast mollusks. It is par excellence the chowder clam of the 
country, and when young it is also relished on the half shell. In range 
Venus is a southern form, thus supplementing Mya. The two overlap from 
Cape Cod to South Carolina, and from the Chesapeake southward and 
through the Gulf of Mexico Venus lives in enormous beds, unknown 
and consequently unutilized. This clam has short siphons (whence the 
name " little-neck "), and buries itself only about the depth of its shell. 
It supplements the oyster in marine aquiculture, growing best on soft, 
muddy bottoms from between tide lines out to water ten fathoms or 
more in depth. 1 

Scallops Pecten irradians and P. magellanicus. Epicures have assured 
us that "the scallop is the daintiest of all foods the waters produce." 2 
The smaller pecten, 7^. irradians, occurs in the shallow, eel-grass waters 
south of Cape Cod, down the southern Atlantic, and in the Gulf of 
Mexico. While piratical methods are exterminating it from its north- 
ern range, farther south there are quantities, totally unknown and 
unutilized, which might support profitable fisheries. 

The northern, or "giant," scallop (/*. magellanicus) lives in water 
from 40 to 60 fathoms deep, over rocky bottoms difficult to dredge, which 

1 Kellogg figures the crop from an acre, one year after planting with small 
seed little-necks, at 600 bushels, worth at least |3 per bushel, that is, $1800, 
the net profit being probably about $1000. ff Present prices for this baby 
clam are high, the clammer sometimes receiving four dollars a bushel for 
his catch, while one who orders them on the half shell at a Boston or New 
York restaurant pays for them at the rate of fifty dollars a bushel. "- 
KELLOGG, Shellfish Industries, p. 229 

2 Demurrer filed in favor of Mytilus, taken in prime condition and fried 
or roasted brown in cracker crumbs. To make a practical test and settle 
this controversy, have both scallops and mussels prepared alike and served 
at a biology-class banquet. Decide by ballot at end of banquet, and print 
result, with discussions that may arise, in local papers. 



278 



CIVIC BIOLOGY 



makes it scarce in the markets except along the Maine coast. This 
scallop reaches a diameter of 7 inches, and the sexes are distinct, while 
the southern pecten is hermaphroditic and seldom grows over half this 
diameter. The life history of P. irradians has been studied carefully 
and has a direct bearing on its practical utilization. These pectens are 
spawned in midsummer, grow rapidly, and spawn when a year old. They 
continue to grow, but rarely survive to spawn a second time, most of 
them dying in the early spring of their second year. It is thus clear 




FIG. 125. Digging soft clams 
United States Bureau of Fisheries 

gain to utilize all of these pectens over one year old. This will not 
cause any decrease in the species if all those under a year old are left 
on the breeding grounds. 

The fine Pacific clams, the geoduck, or giant clam (Glycimeris gen- 
erosa), that grows to weigh 6 pounds, the gaper clam (Sckizotkcenu 
nuttalli), now becoming rare in the western markets, the western little- 
neck (Tapes staminea), and the butter clam (Saxidomus nuttalli), along 
with the western species of Mytilus and the closely similar, and equally 
edible, Modiolus, are all fine subjects for study in western-coast schools. 
The Pacific has also two valuable scallops. 

Life history. In general outline, the life histories of all the marine 
bivalves described above are similar. Eggs are produced by the millions, 
and hatch within a few hours into free-swimming embryos entirely 



CIVIC PROBLEMS RELATING TO MOLLUSKS 279 

unlike the parent. This free-swimming period enables the species to 
be distributed widely by tides and currents, and it also offers opportu- 
nity for the culturist to increase his stock almost beyond belief by mak- 
i ig conditions more favorable for the young. - The embryo oyster, for 
example, swims for from one to six days. By the end of this time the 
shell begins to form and it must sink to the bottom. If it happens to 
land on a clean, hard surface, it may survive ; if it falls in an ooze of 
slime or silt, it is quickly smothered. So the oyster culturists scatter clean 




FIG. 126. Pearl fishing in the Mississippi River 
Photograph by the author 

shells "cultch " over the bottom about the beginning of the spawn- 
ing season. If too many of the young oysters succeed in attaching to 
these, they must be dredged up and the clusters broken apart and re- 
planted evenly over the bottom, so that all may find food and have 
room to grow. The left valve of the oyster, which is spoon-shaped, 
always makes contact with the support and is quickly cemented to it by 
a secretion like that which forms the shell. The other marine bivalves 
anchor by means of a peculiar mechanism, the byssus (byssos, " fine textile 
iiber "), which is secreted by a gland in the foot as a viscous fluid that 
iiardens on contact with the water. The byssus is retained in Mytilus, 
out is lost in the clams and scallops soon after they assume adult form. 
Fresh-water mussels (" clams ") Uniomd&. The fresh waters of east- 
ern North America - contain about 600 species of lamellibranchs. 
Tough, and muddy of taste, they were considered as food only for 



280 



CIVIC BIOLOGY 



muskrats until discovery of their pearls and still more valuable shells 
turned prosaic farming districts into " pearl fisheries " and developed a 
nourishing industry. As with everything else, from forests to clams, 
when it is discovered to possess commercial value, the American public 
has hastened to kill the goose that laid the golden eggs ; so the waters, 
many of them, are already depleted and the shell industry is in danger. 




FIG. 127. Mussel in sand, moving in direction of large arrow, foot pro- 
truding from anterior, and inhalent and exhalent, siphons from posterior. 

end of shell 

As a consequence the United States Bureau of Fisheries has made exten- 
sive surveys to discover the distribution of useful species, and has estab- 
lished a biological station at Fairport, Iowa, to study practical methods 
of propagating mussels in the great Mississippi basin. All this is likely 
to prove a futile expenditure of time and money, unless communities can 
learn to control their piratical impulses and members, and unite upon 
rational plans for conservation of these industrial resources. 

It is estimated that a " niggerhead " requires from fifteen to eighteen 
years to grow to a diameter of four and one-half inches, and pearls of 
value are never found in mussels less than five years old. Other species 
of nearly equal value may be grown in a shorter time possibly in from 
four to six years. Growth lines on the shell are commonly taken to indi- 
cate age, or at least the years required for a mussel to reach adult size. 



CIVIC PROBLEMS RELATING TO MOLLUSKS 281 

It is quite possible that these humble creatures are doing a work of 
value many times greater than that represented by their shells and 
pearls, in the constant purification of our lakes and streams. Experi- 
ment has shown that a good-sized mussel filters about four gallons 
of water through its gills per hour, and since it breathes and feeds 
continuously, this means nearly 100 gallons daily year in and year out. 




FIG. 128. Fresh-water mussels, female, male, and side view, showing 
growth lines 

Set up two perfectly clean glass aquaria exactly alike, put a mus- 
sel in one of them, and note the difference in clearness of the water. 
What may this mean in keeping reservoirs and park waters clear and 
wholesome ? 

Glochidia (glochis, "arrow point"). Life littory. The eggs develop in 
the gills of the parent mussel into minute bivalves so unlike the adult 
that they were long considered parasites. These are the glochidia and 
when ripe they are extruded into the water. Here further development 
depends upon their attachment to gills, fins, or other parts of fishes. 
A long byssus thread is present and probably helps in catching the fish, 
and some species have the valves tipped with sharp-barbed hooks, which 
catch into the skin of the fish when they are snapped together. The 



282 



CIVIC BIOLOGY 



species that do not have hooks are taken in with the breathing currents 
of fishes and clamp on to the gill filaments. The tissues of the fish grow 
over the glochidia, and within the sac thus formed they grow and 
change into the adult form. Finally, at the end of from two to ten 
weeks, according to their species and the temperature of the water, 

they kick themselves out of these 
cysts and begin their free life on 
the bottom. So far as we know, this 
is the only way a young fresh-water 
mussel can be carried over this criti- 
cal stage from glochidium to adult, 
and this means that extermination 
of fishes must result in extermina- 
tion of mussels as well. 

Problems. Ascertain from the 
nearest markets which species of 
mussels produce the most valuable 
shells, and make a collection of these 
for the school museum. 

Examine specimens of valuable 
species and make a table showing 
the months when the gills contain 
glochidia. Discuss the advisability 
of a closed season including these 
months. Estimate the number of 
glochidia per adult mussel. 

Examine all fishes caught for 
glochidia in gills or fins and skin. 
How many may a fish carry? 

Try, possibly with the help of 
the state fish commission or the 
United States Bureau of Fisheries, 

to make a plan for the best possible utilization of streams, ponds, and 
lakes in the locality, for both mussel and fish culture. 

Gastropods. Comparatively slight civic values attach to this group. 
The abalones are of interest in California, and the periwinkle (Littorina), 
brought to the Atlantic coast from Europe, where it is used for food, has 
become abundant from New England southward. It is also of value in 
cleaning oyster beds of seaweeds. A number of other marine forms, the 
oyster drill (Urosalpinx), Fulgur, and Natica, feed upon oysters and clams. 




FIG. 129. Garden slugs spinning 
mucous threads 

Photograph by the author 



CIVIC PEOBLEMS RELATING TO MOLLUSKS 283 



The edible snail (Helix pomatia) is imported from Europe and is 
raised in specially fenced gardens and fattened for market. This may 




FIG. 130. A common land snail 

be studied as an interesting novelty in most American communities. 
For all we know, may not our big, fat garden slugs be food delicacies? 

Compare garden slugs with marine or fresh-water snails, which they 
may be seen to resemble, except in respect 
to -the rudimentary shell. These slugs are 
often as destructive in gardens as any in- 
sect, and, being nocturnal, are little known. 
Collect the eggs (translucent, yellowish, 
about the size of buckshot, in masses of 
thirty or more, found in damp places under 
boards) and keep them in a glass jar or 
aquarium to watch their development. If 
the life history of these pests were better 
known, we might control them more effec- 
tively about our gardens and greenhouses. 

In connection with other field work, 
make a collection of common marine, 
fresh-water, and terrestrial gastropods. 
Keep them in suitable aquaria or vivaria, 
to study habits and foods. Note that some 
snails are "left-handed" and most are 
" right-handed." (If held with opening up 
and spire pointing away from you, the 

dextral shells have the opening to the right, the sinistral, to the left.) 
The commonest and most . interesting are the pond snails, belonging 
to the genus Physa, which can be readily distinguished by their sinistral 




FIG. 131. Common snails, 
sinistral and dextral 



284 



CIVIC BIOLOGY 



shells. If kept in a balanced aquarium, Physa will serve to demonstrate 
most of the interesting reactions locomotion, spinning mucous threads, 
feeding, breathing, egg-laying of this group of mollusks. The eggs 
will be laid in transparent masses of jelly on the glass, and will thus 
afford opportunity to observe the embryological development of a 

gastropod. 

Tyrian purple, the dye, was obtained 
from marine gastropods, which have 
been known as purpuras since remote 
antiquity. 

Cephalopoda. No more interesting 
specimens for the marine aquarium can 
be had than the young of our common 
squids, with their flashing changes of 
color, their hiding, ink-cloud maneuvers 
(equaled only by the most astute politi- 
cians), and their lightning-like efficiency in catching fish nearly as 
large as themselves. It is almost impossible to believe that these keen, 
active, intelligent creatures are really mollusks. 

The cephalopods furnish bait for our cod fisheries, sepia for artists, 
and cuttle bone for canaries, and are used extensively for food along the 
Mediterranean and among oriental peoples. Some of the deep-sea forms 
reach enormous size ; we hear thrilling stories of their encounters with 
whales, and they probably furnish whatever basis there may be for 
sailors' yarns of sea serpents. 




FIG. 132. Atlantic squid 



CHAPTER XXVI 
CRUSTACEA 

The fishes in a school of mackerel are as numerous as the birds in a flight 
of wild pigeons. Goode, in his " History of Aquatic Animals," tells of one 
school of mackerel which was estimated to contain a million barrels, and 
of another which was a windrow of fish half a mile wide and at least twenty 
miles long ; but while the pigeons are plant eaters, the mackerel are rapa- 
cious hunters, pursuing and devouring the herrings, as well as pteropods and 
pelagic Crustacea. 

Herring swarm like locusts, and a bank of herring is almost a solid wall. 
In 1879 three hundred thousand river herring were landed in a single haul 
of the seine in Albemarle Sound ; but the herring are also carnivorous, each 
one consuming myriads of copepods every day. In spite of this destruction 
and the ravages of armies of medusae and siphonophores and pteropods, the 
fertility of the copepods is so great that they are abundant in all parts of 
the ocean, and they are met with in numbers which exceed our powers of 
comprehension. 

On one occasion the Challenger steamed for two days through a dense 
cloud formed of a single species, and they are found in all latitudes from 
the Arctic regions to the equator, in masses which discolor the water for 
miles. We know, too, that they are not restricted to the surface, and that 
banks of copepods are sometimes a mile thick. When we reflect that thou- 
sands would find ample room and food in a pint of water, we can form some 
faint conception of their universal abundance. 

Modern microscopic research has shown that these simple plants [the alga; 
in the water], and the globigerinse and radiolarians which feed upon them, 
are so abundant and prolific that they meet all the demands made upon 
them and supply the food of all the animals of the ocean. 

This is the fundamental conception of marine biology. The basis of all 
the life in the modern ocean is to be sought in the microorganisms of the 
surface. W. K. BROOKS, "Salpa," pp. 146-147 

All the ingenious men, and all the scientific men, and all the fanciful 
men, in the world, with all the old German bogy painters into the bargain, 
could never invent . . . anything so curious, and so ridiculous, as a lobster. 
KINGSLEY, " Water Babies " 

285 



286 CIVIC BIOLOGY 



| SPECIES 
Jj TIME > 
W II ^ 




S UNDER UNDER > 
$ NATURAL HUMAN y^=^ 
3 CONDITIONS CONTROL ^E-^r^Iti 

Attack ml /^^--^-^r^-^ 

Afato. IJ^T:::::::::::::::::::::::: 

7 Lobsteriings \ j^T: :::::::: EGGS::AND: -1 


\My~idesined^iiirnKer^f: 
mits-pf- food-supply-.^: 

;. : . : :-:-;;. : ;;;;;;:-;. : -:-:g 

Hi!::: : .:::::!H;i!i| 

A -Z? T/'-J7 T ^ 


\ * * i -i 4-- ; sjfo : 

[Natural* Enemies i~ \l\ 
^^^^^^^^^^^^^^^^^ 


::::::jj::::::::::::i 

.^Tiem^siswpjo^ssea-iU 



FIG. 133. Diagram expressing Brooks's law of the extermination of a species 
by man as applied to the lobster problem 

The species is shown flowing along from an indefinite past under natural condi- 
tions, with minor fluctuations, hut maintaining a practically constant population, 
having adjusted itself to its natural enemies hy developing great fecundity, as 
seen in the wide stream of eggs and larvae, most of which are taken in the larval 
stage hy natural enemies. At the large arrow civilized man attacks the slender 
stream of adult lobsters which nature has selected to keep up the supply of eggs. 
This strikes the species as a "catastrophe." Man's attack is unlike that of all 
other enemies. Instincts of self-preservation, thickness of shell, and large size, 
which made the adult lobsters almost immune from attacks by other enemies, 
all are of no avail. Although man takes but a small number of adults, the bal- 
ance is disturbed, fewer eggs are produced, natural enemies crowd and tend to 
take a larger proportion, and the species swiftly approaches extermination. Even 
if man ceases his attack when the numbers have become reduced so as to render 
their further pursuit unprofitable, natural enemies may kill off the stragglers, and 
before we realize what has happened, the race is extinct. If we did shut off all 
the streams of young and adults at the point of the large arrow, we should have 
a picture of the extermination of the lobster. Under human control, if even a 
few adult breeders are left, man can increase the number to any desired amount ; 
he can lift the eggs and young above the reach of natural enemies, or crowd 
them down, or both, and so increase the species to the limits of room or of food 
supply. This is what we hope is now being done, and we shall watch the future 
curves of increase in the expectation that the price of lobsters may begin to 
decline toward reasonable limits. This diagram is applicable to any species ex- 
terminated or in danger of extermination by man passenger pigeon, dodo, great 
auk, and many other species now lost to the world 
286 



CRUSTACEA 



287 



General. Crustacean problems parallel those of the mol- 
lusca. Lobsters, crabs, shrimps, and crawfish are valuable for 
food. Some of the most highly prized species require to be pro- 
tected by law, and we are beginning to work out methods for 
their artificial propagation. Some of the terrestrial crawfish 
are locally injurious to vegetation. There is this difference : 
crabs and lobsters move about more freely than clams and 
oysters, and hence are not so well suited to stable aquicul- 
ture. On this account the United States Bureau of Fisheries, 
and the fish commissions of the states concerned, must assume 
responsibility for keeping up the supply by propagation, since 
this cannot be done with profit by private individuals. 

Economic value. The table below presents the chief eco- 
nomic Crustacea, and its most suggestive feature is likely to 
be the wide difference between actual and possible utilization 
of these resources. 

CRUSTACEAN PRODUCTS OF THE UNITED STATES IN 1908 





ACTUAL VALUE 


POSSIBLE VALUE 


Lobsters 


$1 931 000 




Blue crabs 


912 000 




Shrimps, prawns 
Pacific crabs . . 


494,000 
127 000 




Crawfish 


32,000 





Classification. The Crustacea are divided into two main 
groups, the Entomostraca (mostly microscopic or small, includ- 
ing the ostracods, copepods, and barnacles) and the Malacos- 
traca (the lobsters, crawfish, shrimps, prawns, and crabs). 

Entomostraca. Although inconspicuous and little known, 
these minute Crustacea are of the greatest biological signifi- 
cance. If we had them all gathered into a ball, and all the 
rest of the animal matter of the world rolled into another 



1 Estimates not obtainable. 



288 



CIVIC BIOLOGY 



ball, it is quite possible that the Entomostraca would be the 
heavier of the two. 1 They form the main food of the young 
of fishes and many other aquatic animals, and also of the 
adult fishes that are provided with gill rakers the herrings, 
smelts, shad, and others. They are thus the connecting link 
between the vast store of floating, microscopical plants and 
animals (the primitive food supply) and all higher life in the 
water. Daphnia and Cyclops are examples that may be found 
in almost any fresh -water aquarium or in streams, ponds, 
and pools everywhere. The fairy shrimp (Branchipus) is 
also found in the icy pools of early spring. 

The Lobster (Homarus americanus). Of the invertebrates 
used for food the lobster ranks next in importance to the 
oyster, and of all marine animals, for the past thirty years, it 
has been in the greatest danger from overfishing. The reason 
for this is seen in the following table, the supply having been 
drained to the utmost on account of soaring prices. 

NEW ENGLAND LOBSTER FISHERY 



YEAR 


POUNDS 


VALUE 


PKICE PER POLM) 


1880 


19,836,233 


$473,341 


$0.024 


1890 


30,449,603 


833,746 


0.027 


1900 


15 567 081 


1 362 962 


088 


1908 
1913 


14,734,000 
11,504,257 


1,855,000 
2,254,486 


0.125 
0.196 



1 The writer has thought, as he steamed through a veritable slush of 
eopepods that colored the ocean for hundreds if not thousands of miles, 
that here must be the greatest of all untapped and unthought-of sources of 
supply of animal matter. If the ship's engines could be geared to some effi- 
cient filtering machine, a cargo could be secured as fast as hoisting and stor- 
ing machinery could handle it. The material might prove as good, or better, 
than lobster for salads (but the microscopic spines and bristles would be 
likely to interfere with human edibility). It might prove of value for poultry 
and swine, for oil production, and, at any rate, for fertilizer. Perhaps it 
would solve the problem of food in fish hatcheries, especially for marine 
species, and make possible the rearing of young lobsters in any quantity. 



CRUSTACEA 289 

Range. The American lobster ranges along the Atlantic 
seaboard from Labrador to North Carolina. Possibly no ven- 
ure in the field of marine aquiculture would prove of greater 
economic valne than the introduction of this species into the 
Pacific ; but although egg-bearing lobsters have been shipped 
across the continent by thousands and in carload lots, up to 
his time all attempts of the "United States Bureau of Fish- 
eries to colonize the Pacific have failed. While hiding among 
he crevices of rocks would seem to suit the habit of the 
obster best, it apparently thrives as well on sandy and even 
muddy bottoms, and it ranges from the tide pools to water 
100 fathoms, or even more, in depth. 1 

Size, growth, and life history. Female lobsters spawn once in two 
\ r ears; the eggs as laid are cemented to the swimmerets underneath 
r,he abdomen, and here they are carried during the long incubation 
period from July or August of one year till May or July of the next. 
The hatchlings delicate, transparent creatures about one third of an 
inch in length swim feebly, or rather "tread water," and so tend to rise 
reward the surface. They feed voraciously upon copepods and diatoms 
i hat they find floating in the water, and they eat one another whenever 
they can a vicious habit which is one of the chief difficulties in rear- 
ing them artificially. They swim thus for two or three weeks, growing 
and molting three times in the interval, all this time at the mercy of 
i 1 very tide, wave, and current and of every open mouth they may 
encounter. This is the critical period in the lobster's life, and probably 
not one in ten thousand, under natural conditions, survives its accidents 
and dangers. 

At the third molt .the young assumes adult form, and the tiny lob- 
sterling tends to seek the bottom and may even begin to burrow for 
greater protection. It is now a little over half an inch in length, still a 
helpless morsel for every sharp-eyed minnow. When it is about twenty- 
five days old, the fourth molt brings the lobsterling to the fifth stage, 

1 Barnes, Methods of Protecting and Propagating the Lobster, E. L. 
Freeman Co., Providence, Rhode Island, 1911. Refer to this for further data 
on the habits and natural history of the lobster. Also, if undertaking 
special work on this problem, write to Experiment Station, Wickford, 
Rhode Island, for up-to-date information. 



290 



CIVIC BIOLOGY 



when the bottom habit is more strongly fixed. It is comparatively easy 
to hatch lobster eggs, but if the fry are liberated as soon as hatched, 
nothing is gained over natural hatching. For about thirty years ex- 
periments have been in progress in this country to discover methods of 
rearing lobster fry through the critical free-swimming stages to the 
fourth, or bottom, stage. For years results were negligible, but at last, 




FIG. 134. Berried lobsters, taken from pound at Boothbay Harbor (Maine), 

in course of transfer to wells of the steamer which is to convey them to the 

hatchery for stripping 

United States Bureau of Fisheries 



in 1910, by holding them in floating cars the Wickford station was 
able to score a record of 8946 fourth-stage lobsterlings from a counted 
lot of 10,000 newly hatched fry. The best European result at that date 
was 6.6 per cent, beginning with 1500 in the second stage. 

By the end of its first year the young lobster has reached the length 
of 2J inches, and not until its sixth year does it attain the respectable 
market length of 10 inches. In the usual effort to save the lobster 
industry and the species, laws have been passed by the states most 
concerned; but these have not been effectual, on account of lack of 
knowledge, and those of different states still conflict seriously. Study 



CRUSTACEA 291 

the lobster law in your own state and in neighboring states and discuss 
p -actical improvements. 1 

Probably no one has ever seen a lobster known to be dead of old 
a.^e. While specimens over 15 inches long and weighing more than 
2 or 3 pounds are now rare in the markets, specimens 2 feet in length 
and weighing 10 pounds were not rare some years ago. The largest 
lobster on record was caught off the New Jersey coast in 1897. From 
end of chelae to tip of tail it measured 42 inches, and it weighed 
JJt pounds. Growth has been followed up to the thirty -third year, at 
M hich time the lobster is almost 2 feet long. If a lobster lives forty 
V'iars and produces twenty batches of eggs, averaging 100,000 each, an 
adult pair would produce 2,000,000 eggs. This would mean, with the 
species holding its own in the struggle for existence, that under natural 
conditions only one egg in a million grows to become adult. If man 
kills the one that nature has preserved out of the million to keep up the 
species, eggs and young will fail and the lobster will become extinct. 
Our laws are based on the totally inadequate assumption of the fisher- 
men that if a lobster is spared until it grows to be 10 inches long and 
lays only one batch of eggs about 10,000 the population of the 
species will be maintained. Both theory and experience prove the 
fallacy of this idea. 

Brooks's law. We must work out a biologically correct solution of 
this problem or lose our lobsters. Dr. W. K. Brooks 2 has given a dis- 
cussion of the problem as applied to marine fishes. This might well be 

1 Rhode Island has led the way by making a closed season, from Novem- 
ber 15 to April 15. All the states except New York fine from $5 to f 100 for 
killing an egg lobster, but the eggs are easily brushed off. Short-lobster laws 
differ. In Maine a lobster must measure 4| inches, body length (equal to 
10 inches long) ; in New Hampshire, 10| inches ; in Massachusetts, 9 inches; 
in Rhode Island, 4J inches, body measure ; and in New York, 9 inches. 
According to the biologically correct view of Dr. Field, of the Massachusetts 
Fisheries and Game Commission, all these short-lobster laws protect the 
\\Tong end of the animal's life. A lobster 10 inches long produces 10,000 
eggs ; one 12 inches long, 20,000 ; a 16-inch lobster, 100,000. The old lob- 
ster is thus ten times as valuable to the species for egg production, and, 
Veing coarser and tougher, may not be as valuable for food as the legal- 
1 mit lobster. According to Field, lobster pots should be made with open- 
ings too small for the large lobsters to enter, 3 or 3 inches in diameter, and 
with slats open enough to permit all lobsters under a certain size to escape. 

2 Brooks, "The Artificial Propagation of Sea Fishes," Popular Science 
Monthly, Vol. XXXV (1889), pp. 359-367. 



292 



CIVIC BIOLOGY 



called " Brooke's Law of Extermination 
his own words, this law is " To marine 
not a natural enemy.'" This means " Man 



Adult perwd,4O(f) 

y years; 2 individ- 
uals, one pair 



Lobster ling period, 

6 years; 200 > 

2 individuate 

Larval (critical) 
period, 1 month; 
2,000,000 * 200 
individuals 




FIG. 135. Diagram representing the indi- 
viduals at different stages in a generation 
of lobsters 

This is another form of expression of Brooks' s 
law. The typical form is a pyramid, with 
a broad base of eggs and young maintained 
by a small apex of adults. Each species of 
animal or plant has a form of its own de- 
pending on number of eggs and duration of 
the different stages. The large number of 
eggs, the long life of the adults, and the 
extreme reduction of numbers in the short 
critical, larval stage reduces the typical 
pyramid in the .case of the lobster to a 
monument with a broad base of eggs which 
shrinks suddenly during the larval stage to 
a slender spire representing the adults 



of Species by Man." Stated in 
food fishes man is a catastrophe, 
takes the adults which natural 
enemies have spared to con- 
tinue the species." Figs. Io3 
and 135 show this law diagram- 
matically as it applies to the 
lobster. It is applicable to 
every species that man attacks, 
from oysters and lobsters to 
whales and pine trees. When 
man disturbs the nice balance 
of nature he must assume 
control (" have dominion ") 
or lose the species. 

Blue crab Callimctes sapi- 
dus. This common crab of the 
Atlantic-coast markets ranges 
from Massachusetts Bay to 
Mexico, and, while it is taken 
by millions every year, shows 
as yet no alarming signs of 
decrease. Two facts in the 
natural history of the species 
may largely account for this : 
the eggs are minute, a female 
laying on the average more 
than 3,000,000 at a batch ; and, 
while molting, each female is 
protected by a hard-shelled 
male. 

Pacific crab Cancer magister. 
This robust crab, 7-9 inches 
broad by 4-5 inches long, 
ranges from Alaska to Lower 
California. In the markets of 
the Pacific it supplies the place 
of both the lobster and the 
blue crab of the Atlantic. 
State laws are beginning to 



CRUSTACEA 



298 



protect these crabs by making closed seasons and by specifying size 
limits, but the natural history of this species has not been adequately 
studied. 

Crawfish Astacus (Pacific) ; Cambarus (Atlantic). Many species of 
lliese two genera inhabit North American fresh waters and lowlands, 
several of them growing to 6 inches in length. They are extensively 
used for food in Europe and are growing in favor in some parts of this 
< ountry. The flesh is delicate and sweet, like that of lobsters and crabs, 
stud there is no good reason why they should not be much more widely 




FTG. 136. Female and male crawfish, the female with eggs 

appreciated and utilized. In the waters they often form the chief food 
of our game fishes, especially of the black bass. 

. Crawfish are found in the fresh waters of the temperate zones of all 
the continents except Africa, and it is evident that they have developed 
from a number of different marine forms. The largest crawfish in 
the world is Astacopsis frankli&ii, found in the small streams along 
the north and west coasts of Tasmania. These often weigh as much 
as 9 pounds ; and if they could be safely introduced, they might give 
us an industry for our fresh waters that would rival lobster culture. 

The land crawfishes, known as " chimney builders," dig holes in soft 
ground, generally down to water. These are about an inch in diameter 
and are surrounded by a chimney of excavated earth. This burrowing 
habit makes them serious pests in embankments and levees. They are 
also, in part, vegetable feeders and are often destructive to young plants 
of field or garden. A few drops of carbon bisulphide in a burrow will 



294 CIVIC BIOLOGY 

kill the occupants. The Biological Survey has designed a special drop- 
ping can to deliver the proper amount, so that extermination of craw- 
fish from land is now quickly accomplished with slight labor or 
expense. Crawfish are also excellent food for poultry. 

The female crawfish, distinguished from the male by her broader 
abdomen, carries the eggs attached to her swimmerets, as do the lob- 
sters and crabs (Fig. 136), the young passing through the nauplius, or 
free-swimming, stage within the shell. Even after hatching, as tiny 
crawfish they remain attached to the mother until after the third 
molt, when they scatter to take care of themselves. 

One or two pairs, kept in an aquarium or vivarium during the 
hatching period (March to June), will afford most valuable opportu- 
nities for observing the instincts and habits of a crustacean. Per- 
haps some member of the class will volunteer to do this. If so, he 
must study carefully to make conditions as normal as possible, and 
must feed well, or they may kill and eat each other, and the females 
may even devour their own eggs. 



CHAPTER XXVII 

PROBLEMS OF FISH AND FISHING 

You might have the rivers as pure as the crystals of the rock, beautiful 
in falls, in lakes, and in living pools so full of fish that you might take 
them out with your hands. RUSKIN 

Now what happens if, after each one of the natural enemies has claimed 
its victims, a new enemy not provided for by Nature suddenly attacks the 
few adult survivors which Nature has provided to perpetuate the species ? 
What happens when the last drop falls into the brimming bucket ? What 
happens when the proverbial last straw is put on the load ? It may be quite 
1 rue that, for each codfish which man catches, the natural enemies destroy a 
million. That has no bearing on the subject. Nature has provided for the de- 
struction of the million. Before their birth they were destined to premature 
death. The one was reserved by Nature for another purpose. W. K. BROOKS 

After all that has been said about anglers and angling, two thirds of the 
line fishing of the world is done by boys. The boy may fish with a fly, but 
lie does not spontaneously take to this method. Fly fishing is an art, a fine 
art beyond a doubt, but it is an art and, like all art, it is artificial. Fishing 
with an angleworm is natural. It fits into the need of the occasion. It fits 
in with the spirit of the boy. . . . The angleworm is perfectly at home on 
iihe hook. It is not quite comfortable anywhere else. It crawls about on the 
sidewalks after a rain, bleached and emaciated. It is never quite at ease 
even in the ground, but on the hook it rests peacefully, with the apparent 
feeling that its natural mission is performed. HOLDER and JORDAN, "Fish 
Stories," p. 237 

Civic problems. Are the waters of your neighborhood 
stocked with the best fishes (for food and sport) that are 
suited to them? Are they supplied with such numbers as the 
Lakes, streams, and ponds can reasonably support ? Are the" 
\vaters clean and clear, unpolluted by the wash of soil not 
properly held on the farms, where it belongs, by chemical 
wastes from factories, or by sawdust from lumber mills, so that 
they remain well adapted to the valuable fishes native to 

295 



296 



CIVIC BIOLOGY 



them? Do all the people have all the good fish and good 
fishing they need to keep them good-natured ? 

There are millions of springs and brooks and flowing wells, 
many of which might be turned to good account in forming 
home fish ponds. These might be made to serve as storage 
reservoirs for irrigation or stock watering, and might be so 
developed over the country as to help in solving problems 




Fi<;. i:->7. Exterminating shad from a Virginia river 

Largest seine in the world, 9600 feet long. The seine was hauled by steam power 
and the labor of 80 men, and was drawn twice daily, at ebb tide, throughout the 
season. As many as 3600 shad were taken at one haul, and 126,000 in one season : 
250,000 alewives were caught at one time. The season's yield of shad fell to 300, 
and the fishing was consequently discontinued in 1905, after having been carried 
on for a century. This seine was a source of eggs for the Bureau's shad hatchery 
on this river, Stony Point, Virginia. United States Bureau of Fisheries 

of increasing floods in the river valleys. Waste hollows and 
ravines might be turned into the most productive areas of 
our farms, acre for acre, when properly stocked with fish. 
Has this been adequately worked out for the district? 1 

1 Johnson and Stapleton, "Fish Ponds on Farms," Document No. 826, 
Bureau of Fisheries, Washington, 1915. 



PROBLEMS OF FISH AND FISHING 



297 



If for any district in the United States or Canada the above 
questions can be answered in the affirmative, there remains 
still one thing for the class in civic biology to do. Write 
up the story to tell how the community did it. It will prove 
the most interesting and instructive "fish story" ever written. 

Survey of district. The first step toward a solution of the 
above problems is a sur- 
vey of local waters. An 
interested group, or com- 
mittee, of the class may 
subdivide the district 
among its members, eacli 
of whom will go over his 
part and make a map, to 
scale, of lakes, streams, and 
ponds, along with available 
pond sites, springs, and 
flowing wells. Indicate 
stream flow by arrows and 
depths by contour lines, 
and adopt some uniform 
method of showing areas 
of vegetation and kinds of 
bottom rocky, gravelly, 
sandy, or muddy. While 
working over the ground 
in this way, observe and 
record condition of water. Is it clear or muddy? Do sources 
of pollution exist ? How might these be remedied ? (Con- 
sult state laws in this connection.) Record all fishes seen, 
and gather records, from neighbors and local fishermen and 
markets, of the numbers and values of the different fishes 
taken during the past season. This should result in a com- 
plete list of the fishes of market value, with their relative 




FIG. 138. Trial fishing on the Albatross 

Experimental catch of cod and halibut taken 
in twenty minutes by the Albatross while ex- 
ploring a new bank off the coast of Alaska. 
United States Bureau of Fisheries 



298 



CIVIC BIOLOGY 



importance, and from these data \ve should be able to con- 
struct a table showing the crop of each kind of fish for the 
entire district. We may then figure per acre production and 
percentage of effective utilization of each water unit. 1 

In making the survey, seek to arouse the interest of the community. 
Ask your fish experts the fish warden, the one who has charge of 
the nearest hatchery, or some of the best local anglers^ to visit the class 
and present their views for stocking the district. Study the publications 
of your state fisheries commission and of the United States Bureau of 



13 



14 



.'11 




FIG. 139. Topography of a fish (Yellow perch) 

1, spinous portion of dorsal fin ; 2, soft portion of dorsal fin ; 3, caudal fin; 4, anal 
fin ; 5, ventral fin ; 6, pectoral fin ; 7, opercle ; 8, branchiostegal rays ; 9, mandi- 
ble, or lower jaw ; 10, prera axilla ry ; 10 a, maxillary ; 11, snout; 12, eye; 13, head ; 
14, lateral line ; 15, series of scales, counting from front of anal fin upward and 
forward to lateral line 

Fisheries. Ferret out all such bulletins in private collections and induce 
their owners to loan or donate them to the school or public library ; and 
write to Washington or to your state department for any others that 
may be needed. 

1 ff It is difficult to estimate the capacity of ponds for the various stages 
in the growth of fish. It depends for the most part upon the amount of ap- 
propriate food available. A 2-acre pond producing 10,000 one-year-old black 
bass from 4 to 6 inches long would be a remarkably successful enterprise, 
and 20,000 one and one-half to two inch yearling crappie or sunfish to an 
acre of water would be likewise notable. These numbers have been realized 
and in some instances exceeded, but the average results are doubtless much 
smaller." JOHNSON and STAPLETON, loc. cit., p. 25. 



PROBLEMS OF FISH AND FISHING 



299 



Finally, draft a plan for stocking and maintaining the 
waters of the district at their maximum production, and 
have this printed in the local papers. 

Fishes Day. 1 We have Bird Day and Arbor Day and 
Apple Day. Why not have Fishes Day ? We ought to 
know our fishes better. We ought to know their habits and 
habitats, their foods, and especially their nesting and spawn- 
ing seasons; and if we did, it would come to be considered 
as much an outrage to 
take a fish from her 
nest as to kill a mother 
bird on hers. When we 
all know these things 
and come, as a whole 
people, to have a right 
feeling for them, we 
may then combine in- 
telligently to have our 
waters teeming with all 

the best fishes they are 

,, . ;. FIG. 140. Bluegill sunfish best fish for 

capable of supporting. pond culture 

Aquarium manage- Photograph by Reighard 

ment. This may be 

used as a key to the solution of our problems. A " balanced 
aquarium " is one in which just the right proportions of animal 
and plant life are maintained, with the right amount of light, 
so that the water remains clear and sweet. This means that 
there are plants enough, under the light admitted to the aqua- 
rium, properly to oxygenate the water for the animals, and ani- 
mals enough to supply the carbonic acid and nitrogenous wastes 

1 Anglers often wonder why the fishes do not interest the public as do the 
birds, as they are also attractive and their habits interesting, indeed, fasci- 
nating. The reason, possibly, is, that birds are always in sight, while it takes 
searching to find the fishes. HOLDER and JORDAN, "Fish Stories," p. 226 




300 CIVIC BIOLOGY 

which the plants require for healthy growth. The commoii 
mistake of beginners is to overcrowd the aquarium with both 
animals and plants ; more waste matters are produced than 
are continuously used, and bacteria develop and foul the water. 
Too much light is the other common danger; this results in 
the excessive growth of algae, which green the water and 
overgrow the glass. A pond receives light only from above, 
while the aquarium may be lighted from the sides as well. 
Hence aquaria do better in north or east windows, and even 
here must be provided with cardboard shades to shut out 
almost all direct sunlight from the sides. South and west 
windows may be used if three sides are shaded and the 
top partially shielded from direct sunlight if algae become 
troublesome. Great care must be exercised not to overfeed, 
because uneaten food will decay and quickly foul the water. 
In an aquarium properly planted with good oxygenators 
temperature of the water not allowed to go over 15-18 
(60 65 F.) two fishes 3 inches long per gallon is the rule. 
Large specimens cannot be made comfortable in small aquaria ; 
consequently small ones must suffice for schoolroom demon- 
stration and study. Predacious fishes (pickerel, basses, and 
sunfish, eels, and all except the smallest catfishes) should 
ordinarily be kept, each kind and usually each size, in a sepa- 
rate aquarium ; and it will be necessary to watch them and 
to remove any vicious specimen or to partition it oft' with a 
pane of glass. In equipping a laboratory or in planning an 
exhibition it is better to have a considerable number of small 
and medium-sized aquaria easy to set up and each with its 
own distinct and clearly labeled exhibit than to have a few 
cumbersome aquaria with impossible or difficult combinations 
mixed up in them. 

The temptation is to make aquaria too big. Taking the dimensions 
on page 14, we have the following data for approximate capacity 



PROBLEMS OF FISH AND FISHING 



301 



in gallons and weight of water. Any size can be figured, 231 cubic 
inches (weighing 8.34 pounds) being a gallon. 



SIZE 


GALLONS 


POUNDS 


NUMBER REQUIRED FOR A CLASS 
OF FORTY 


Width Height Thickness 

5 x 7 x 4 ") 
8 x 10 x 5 > 
10 x 12 x 6 J 


.66] 
1.7 I 
3. J 


5.5-] 
12.8 > 
25. J 


f 40 (1 apiece), used for insects, 
j fungi, and feeding tests with 
I small animals. 


20 x 12 x 9 

24 x IB x 12 


9.4 
22.4 


78.4 
186.8 


4-1 2, used for demonstrations 
2, used for demonstrations 



Demonstration aquaria are usually built into the walls so as to be 
lighted from above and viewed through the glass from inside the 
room. This arrangement can be imitated by setting the aquaria on 
suitable supports just outside the windows, on the window sills, darken- 
ing the outer glass (or making the ends and outer sides of slate). 

When we begin to realize the value of aquatic biology, we shall build 
our aquaria into the basement walls, and then, by proper placing and 
grading of the building, we can have abundance of room for either still- 
water or running-water aquaria, under conditions as normal as those of 
natural ponds and streams, with which to study all manner of prob- 
lems. If the aquaria were figured into the original plans, they might 
cost nothing and the basement walls might be even less expensive 
than the usual solid construction of stone or brick. 

Our commissioner of fisheries says l : " This is a wide field ; I do 
not know of any more promising field in the government service than 
in the culture of fish. The possibilities of making new discoveries, 
especially in the line of intensive breeding and selective breeding, are 
almost inexhaustible. I would expect that a tremendous boom to the 
fish industry of the entire country would be given by a fisheries school 
such as this if established here." 

The still-water aquarium is the only kind recommended for ordi- 
nary school use ; running water is not at all necessary for most fishes, 

1 H. M. Smith, California Fish and Game, Vol. I (July, 1915), p. 189. 
(From remarks before the Pacific Fisheries Society, Seattle, on the plan of 
establishing a school of fisheries in connection with the University of 
Washington on a par with schools of forestry and agriculture, mining 
and commerce.) 



302 CIVIC BIOLOGY 

and danger of a stoppage of escape pipe, and consequent flooding of 
building, is too great a risk. The absolute rule should be that one person 
shall take the sole responsibility for an aquarium, and no one else be per- 
mitted to put anything in or take anything out of it. As long as the aqua- 
rium is properly balanced and managed, the water need never be changed. 
Water is always water, and as it evaporates, clean pond or brook water 




FIG. 141. Biological Laboratory, Cleveland Normal Training School 

View of the west end, showing three of the four large aquaria built into the wall 
under the windows, and a small greenhouse opening out of the laboratory 1 

must be added to keep the level about constant. If adding any consider- 
able quantity, allow the water to stand in the room a day, or until it is 
of the same temperature as that in the aquarium; for even small 
changes of temperature, if sudden, may be injurious, or even fatal, to 
some fishes. The hand should never be put into the aquarium ; it carries 
too many troublesome bacteria. Use the proper tools dipping-tubes and 
siphons, dip-nets and scrapers. A spirit of good-natured rivalry should be 

1 The architect overruled the location of these aquaria in the north wall 
and changed their specifications. They should be two feet, instead of about 
one foot, deep, bringing the bottom two feet from the floor and giving 
double the depth of water. The glass roof, if present at all, should be raised 
to the middle bar of the window, and the flap, which can be lowered to 
shut the space above the aquaria from the room, should be two feet wide. 



PROBLEMS OF FISH AND FISHING 



303 



encouraged, to see who can have the most beautiful aquarium and the 
most instructive one, and hold it longest without change of water. A de- 
i lerit mark is deserved, and may be given, for every time a pupil permits 
the water in his aquarium to become foul enough to require changing. 

In this way, by gaining experience through the year, the students 
i lay keep the aquaria running in fine balance, each with some specimen 
of native fish, and so afford a most instructive exhibition. This may be 
held in connection with appropriate lec- 
tures by specialists and a general discus- 
sion of the plans which have been worked 
out for the adequate stocking of local 
waters. Whether we call it Fishes' Day 
< >r make it a feature of more general exer- 
cises will depend on community interests 
and preferences. 

A few important features of such an 
exhibition may be 

1. Species of value and relative impor- 
tance of each. 

2. Habits and proper habitats of each 
species (so far as these can be shown by 
arrangement of aquaria). 

3. Table of spawning seasons ; pre- 
served specimens of eggs and fry ; photo- 
graphs and other pictures of fish nests ; 
diagrams of local waters, with distribution 
of nesting places of different species. 

4. Eggs actually being hatched (Fig. 
142) and fry being fed and reared for 
distribution. 




FIG. 142. Tumbler hatchery 

Water running through funnel 

keeps eggs aerated. Author's 

design 



5. Foods of different species, with natural food supplies. 

6. Extermination of mosquitoes by fishes, with data from feeding 
tests in the school aquaria and from park or pond waters properly stocked. 

7. Data of growth of different fishes, fed in different ways. 

8. Diagrams and records of production of home fish ponds. (Why 
not have fish projects and fish clubs as well as corn clubs and pig 
clubs ?) 

9. Enemies of different fishes, and means -of their control. 

10. Fish course, composed entirely of local varieties in season, 
prepared by domestic-science classes for the exhibit luncheon. 



304 CIVIC BIOLOGY 

11. One or two of the most wonderful curiosities of fish natural his- 
tory : a nest of sticklebacks, "nothing short of marvelous " (Hornaday), 
or a paradise fish with his nest of bubbles; or exchange with coast 
schools and devote one of the large aquaria to artificial sea water and 
marine forms. 

Classification and species. About as many different kinds 
of fishes as of birds are known to science (13,000, Galloway), 
but more than four times as many fishes as birds are found 
in the inland and marine waters of North America (3263 
species). 1 Any list (published by your state fish commission 
or by the United States Bureau of Fisheries) giving the dis- 
tribution of fish and fish eggs for the preceding year will 
contain about fifty of the more valuable food and game 
species, and from this we may choose the most instructive 
types for study. 2 

Ponds as balanced aquaria : foods and overstocking. The 
work with aquaria may be made to help in understanding 
how to keep park waters and reservoirs in good condition. 
Lack of proper balance results in fouling the water, and 
is accompanied with offensive odors and appearance. The 
fishes die, beginning with the more overcrowded or more 
sensitive kinds, and ending with the catfishes, which can live 
in fairly wholesome mud. Probably in most such cases the 
prime reason why the fishes die is because they lack proper 

1 Jordan and Evermann, Descriptive Catalogue of North American Fishes, 
3313 pages, 392 plates. "The work has been carefully devised to be of no 
use whatever to anyone save an ichthyologist 1 ' (Hornaday). 

2 The list recommended for pond culture is as follows : black basses 
(small-mouthed and large-mouthed), crappie, calico, rock, and warmouth 
basses, the bluegill sunfish, and the catfish, or bullhead (either Amdurus 
nebulosus or A. n. marmoratus, a variety known in the South as the marble 
cat). Strong local prejudice and lack of outward beauty are against the 
humble catfish, but for edibility Dr. Jordan has placed it above all the 
basses, perches, and pikes, and just below the trout, salmon, and whitefish. 
The bluegill is the only sunfish recommended for use by the Bureau of 
Fisheries, ff and it is believed to be the finest pond fish available for private 
culture.'' JOHXSOX and STAPLKTOX, loc. cit., p. 18. 



PROBLEMS OF FISH AND FISHING 



306 



food; that is, if they were thriving and growing, they would 
resist attacks of saprolegnia or other disease germs. A variety 
of plants and animals is essential in a balanced pond if it is 
to supply food continuously to all its inhabitants. As with 
similar problems on land, the most necessary thing is an 
abundance of plants, to supply food for snails, mussels, in- 
sects, worms, Crustacea, and vegetable-feeding fishes; then 
mussels should be present in sufficient numbers to strain out 
any excess of floating 
algse and fungi ; and, 
finally, there must be 
enough carnivorous 
forms to prevent exces- 
sive multiplication of 
t he vegetarians. Of 
course this natural bal- 
ance of lakes and ponds 
H a more complex mat- 
ter than that of our 
aquaria, since these are 
never required to pro- 
duce all the foods of 
Ihe fishes. 




Fic " 143< Tray of wild - trout e s^ with mos- 
quito net and moss in which they were packed 

United States Bureau of Fisheries 



Even good-sized lakes 
may lose balance, and cer- 
lain species may suffer. The white bass in Lake Mendota, Wisconsin, in 
the summer of 1889, died in such numbers that windrows of them were 
washed upon the shores, necessitating the removal of over 200 wagonloads 
-rorn the mile or so of beach in Madison. They had become overcrowded 
and weakened by starvation. Lake Louise, in Pennsylvania, was stocked 
with black bass, and the rules of the fishing club that controlled it required 
that all the fish caught be returned to the lake. In a few years the lake 
:iad nothing but black bass in it, and these were so starved that the 
lish were almost all heads and mouths, with shrunken bodies. The case 
vas investigated by the United States Bureau of Fisheries, which 
idvised fishing out the surplus black bass and transferring them to the 



306 CIVIC BIOLOGY 

Susquehanna River, where there was abundance of food, and introducing 
food fishes (perch, minnows, and crawfish) and aquatic insects. The 
starved black bass very soon grew to proper form when well fed. 

Food being practically the limiting factor, self-sustaining ponds are 
said to be capable of producing from 5000 to 6000 pounds of fish per acre. 1 
This yields a cash value, at 10 cents per pound, of from $500 to $600, 
" and this with no expenditure for food." No figures are available for 
limits of possible production in well-planted and aerated ponds if the 
fish are given adequate variety and quantity of food. Estimates might 
prove more amusing than instructive. For example, in a self-feeding 
pond of one acre, 3 feet deep, we have 130,680 cubic feet of water. At 
5000 pounds per acre, we should have 1 pound of fish produced in about 
26 cubic feet of water. Suppose, by proper care and feeding, we could 
produce 1 pound per cubic foot (7.48 gallons) ? Can anyone so feed and 
care for a bluegill or a catfish, in a five-gallon aquarium, that it will gain 
1 pound in a year? 

Successful combinations in aquaria may suggest similar treatment of 
ponds. That is, can anyone manage and feed a bluegill and a catfish 
in the same five-gallon aquarium so that each will gain a pound in a 
year? Thus we see that by learning the habits and preferred habitats 
of different fishes we may have all parts of our pond occupied and so in- 
crease production. The pout will choose the stagnant holes with muddy 
bottoms ; the perch, the deeper channel, where there is some current ; 
the crappies, rock bass, and sunfish, the shelter of stumps and brush and 
weed patches. The water will be purified if the bottom is well stocked 
with the best available mussels, and crawfish (if there is no danger from 
their burrowing) may do the scavenging and turn waste matters into 
food for the fishes. Frogs and toads, if allowed to breed, may further 
help in the balance of life ; and, finally, a few pairs of mallards, teal, or 
wood ducks might fit in, both for ornament and for profit. 2 

1 N. R. Buller, " What an Acre of Water Will Do," Bulletin No. 10, 
Pennsylvania Department of Fisheries, 1914, p. 7. 

2 In a project of this kind, like working for a record production of 
corn, potatoes, or poultry, we open a new field of interesting possibilities. 
Who can produce the largest and best-balanced and most varied crops from 
an acre of water ? Water cress, water lilies (of many rare and beautiful 
kinds), cowslips, gentians, and cardinal flowers, the fishes, frogs, crawfish, 
possibly fingerlings for distribution, perhaps a ton or so of highest-grade mus- 
sel shells, and a fine flock of wild ducks for distribution and propagation 
will results from such a home-pond project bear out the statement that "an 
acre of water may be made to produce as much as five acres of land " ? 



PROBLEMS OF FISH AND FISHING 307 

A record at the end of a - successful year might read somewhat 
a-! follows : 

RECORD PRODUCTION FROM A POND OF ONE ACRE, FROM 
ONE TO TEN FEET DEEP 

3000 pounds catfish $300.00 

3000 pounds bluegills 300.00 

5000 fingerliug catfish, removed in fall to thin stock .... 50.00 

5000 fingerling bluegills, removed in fall to thin stock . . . 25.00 

12 dozen frogs 6.00 

50 dozen crawfish 10.00 

1 ton yellow and green striped mucket shells 80.00 

50 wood-ducks' eggs, early 12.50 

3 pairs wood ducks 45.00 

1000 bunches water cress from clean, fenced intake stream 50.00 

100 dozen water lilies 10.00 

100 dozen cardinal-flower spikes 10.00 

10 bushels cowslip greens -. . . . 4.00 

1000 pounds basket willows from margins and island . . . 50.00 

Total $952.50 

Seeds, tubers, bulbs, and plants of aquatic duck foods, any of which, 
if present in excess, might be made to increase the account, are quoted 
in a price list as follows : 

Duck potato, or wapata (Sagittaria latifolia): bulbs, 15 cents each; $5 

per 100. 

Wild celery (Vallisneria spiralis) (must be wet): 35 cents per pound. 
Water cress (Nasturtium officinale): plants, 10 cents each; $4 per 100; 

$20 per 1000 ; seed, 50 cents per ounce ; $5 per pound. 
American lotus lily (Nelumbo lutea) : tubers, $1 each ; $10 per dozen ; 

seeds, $1 per 100. 

Wild rice (Zizania aquatica) (must be wet): seed, 35 cents per pound. 
Potamogetons (mixed): $1 per quart ; $20 per bushel. 
Wild sago (Potamogeton pectinatus): $1 per quart ; $25 per bushel. 
Musk grass (Chara) (mixed or single species): $7.50 per crate. 
Duckmeat (Lemna): $1 per quart ; $10 per dozen quarts. 
Anacharis, or Elodea (Philotria canadensis): $6 per crate. 
Coontail, or hornwort (Myriophyllum) (various species): $7.50 per crate. 

To this list we might add : 

Cardinal flowers (Lobelia cardinalis), seeds and plants. 

Water lilies (Castalia or Nelumbo) (various species), seeds and rootstocks. 



308 



CIVIC BIOLOGY 



Professor Forbes of the University of Illinois has made a special 
study of the foods of fishes. He has found that with most fishes foods 
change with age, the life of a fish being, in fact, divided into two and 
often three distinct periods. In the first, which we may call the " fry " 
period, from hatching to one or two inches in length, all species feed 
on small Crustacea. In the fingerliug stage, from one or two to four 
inches, they feed largely on insects but begin to devour their smaller 
fellow fishes as well. When adult, the larger species feed chiefly upon 




FIG. 144. Visiting Municipal Fish Market, Cleveland, Ohio 
Class learn to distinguish fresh fish by the red gills and the unsunken eyes 

smaller fishes, while the smaller species continue to feed mostly on 
insects. Adult fishes possessing fine gill rakers continue to strain out 
the minute Crustacea; those with heavy, blunt teeth feed largely on mol- 
lusks; and worms play but a small part in the food of fresh-water fishes. 

Spawning habits and seasons. Brooks's law, as stated in its 
application to the lobster, with the diagrams illustrating it, 
applies with equal force to food and game fishes. With the 
powerful machinery at his disposal, man strikes all species 
as a catastrophe and not as their natural enemy ; and he 
must make good his attack by intelligent dominion or lose 



PKOBLEMS OF FISH ASD FISHING 



809 



s 



If 



3 O 

3 g Si*- .3 8 

1- s NS-S-gS ^ 

S ri * p ^^ ^ 



M ,rt : > ^- 



5 >S 

|I 

.S 






i|2 



o"c 
gC 



-o-o' 
ISHtf 



fa O 
H 



! 1S| 1 I 

O O >ft Oi ,^ 

>--: cj ^ 55^7 



K a 
P o 



I 14 



HARACTEK 
OF EGGS 



-t-T 0> 4j" 0) 

linn 

I'Slltl 



>> ~ ^ g 

< i ^_| 
t 1 ^^ 









^ 



1 i 



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i?^2 I 11^ isa.ll 

TS 



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1|1^? 5^|| ^2|c-^ 



810 CIVIC BIOLOGY 

the species. The large numbers of eggs produced by fish 
indicate how quickly we may have our waters abundantly 
stocked, as soon as we learn enough to cooperate in leaving 
a sufficient number of adult spawners and in insuring protec- 
tion of eggs and young from their natural enemies. The data 
in this field must be worked out in connection with the local 
surveys suggested above. The table above is offered merely 
by way of further suggestion. The biology class in each district 
should have its own table, developed to give local dates and 
precise breeding places, so that all may know how, when, and 
where to protect effectively all valuable species during their 
spawning seasons. This knowledge may be of advantage in 
exterminating pest species, such as garfish and dogfish. 

Economic and civic values. To doubt the value of fish 
culture would be as absurd as to question that of agri- 
culture. For the United States, including insular posses- 
sions, an invested capital of $79,000,000, with about 165,000 
people employed, results in gathering a food product amount- 
ing to $91,073,000 annually. The fishes do most of the 
work, foraging in the boundless food-wealth of the ocean and 
then, like the shad, salmon, and others, bringing it up our 
rivers and to our very doors. As the cost of food advances, 
we are beginning to ask what are the possibilities of supply 
from our waters. The brief table on the next page may serve 
to indicate the problem for the species named. 

Sport fishing also carries civic values and yields annual 
returns, not only in catch but in health and pleasure, of 
possibly no less importance to the country as a whole than 
the commercial fisheries. It gives employment to thousands 
in the manufacture of tackle and boats, stimulates travel, and 
supports many special outing resorts. Is not good fishing 
an asset to any community, well worth careful study and 
conservation ? 



PROBLEMS OF FISH AND FISHING 



311 





VALUE OF PRESENT 
YEARLY CATCH 


VALUE OF POSSIBLE 
YEARLY PRODUCTION! 


SI ad Atlantic 


f 2 085 200 




Shad, Pacific 
Salmon Atlantic . 


22,000 
3 700 




Salmon, Pacific 
Total fresh-water fish .... 


3,342,700 
12,000,000 





1 This table was submitted to the United States Bureau of Fisheries, but 
no estimates were available. Dr. George W. Field estimates that under 
pioper management the marine and fresh waters of Massachusetts might 
be made to yield $50,000,000 worth of products annually. 



j 



FIG. 145. Toad catching ants 
Photograph by Newton Miller 




Fie. 146. Toad exposed in its hibernation cavity 

Note protective coloration and granulation of skin in relation to earth. 

Photograph by Newton Miller 

312 



CHAPTER XXVIII 

AMPHIBIA. SIRENS, PROTEANS, SALAMANDERS, FROGS, 
TREE FROGS, AND TOADS 

For an insectivorous animal which conforms to every requirement of the 
situation ease of control and rapid increase, noninjurious in any numbers, 
an active feeder in abundance and a patient faster in scarcity the toad 
stands probably first on the list among American insectivorous animals. 
MILLER, "Biology of the American Toad." American Naturalist, Vol. XLII1 
(1909), p. 643 

The amphibia are a relatively small group of about 1400 
species, of diverse kinds (from wormlike ciecilians, through the 
two-legged and four-legged sirens and salamanders, to frogs 
and toads) aquatic, semiaquatic, and terrestrial form- 
ing, as the name implies, a transition series from the fishes 
to the higher land animals. All amphibia are carnivorous, 
many of our common forms ranking with birds as efficient 
destroyers of insects ; and as a group they cover the whole field, 
for salamanders, bullfrogs, and other aquatic species hunt the 
waters of our ponds and streams and their immediate shores, 
wood frogs and toads and many of the salamanders follow 
insects of the ground both by day and by night, and tree 
frogs are especially adapted to feeding upon insects of forest 
and orchard. 1 

Amphibia belong exclusively to fresh waters and the land. 
They are comparatively small, the largest modern amphibian 
being the giant salamander of Japan, which is said to reach a 

1 Hornaday's statement, "With very few exceptions, the amphibians are 
quite useless to man " (Natural History, p. 360), is evidently made without 
due regard to their powers of insect destruction or even to their uses as 
fish bait. 

313 



314 



CIVIC BIOLOGY 



length of 6 or 7 feet. Gigantic species formerly disported in 

the vast swamps that have 
given us our coal forma- 
tions. With few exceptions, 
amphibia deposit their eggs 
in water, and they all pass 
through a truly larval stage, 
the " tadpoles " being fish- 
like aquatic, legless, and 
breathing by gills. In ad- 
dition to insect destruction 
by the adults, the tadpoles 




FIG. 147. Laying of a toad 15,835 eggs 
Photograph by Newton Miller 



perform an important serv- 
ice by eating all manner 
of slimes and scums and 

decaying animal and vegetable matter, thus helping to purify 

surface waters. Aquaria with and without tadpoles may be 

made to demonstrate this 

point in a striking manner, 

and the results may well 

be applied to the problem 

of cleansing local park and 

reservoir waters. 

Natural history of local 

species. In connection with 

other outdoor work, collect 

all the different species 

of toads, frogs, tree frogs, 

newts and salamanders, 

mud puppies, and sirens 

common to the locality. 

Special interest attaches to 

spawning habits and sea- 
sons, since knowledge of 




FIG. 148. Different portions of single 
laying of toads' eggs 

The top specimen shows the usual arrange- 
ment; the other two show the crowding 
and irregular spacing of the eggs in the 
gelatinous tube near the end of the laying. 
Photograph by Newton Miller 



AMPHIBIA 



315 



these data will enable a community to give effective protec- 
tion to valuable species. Frogs and toads proclaim this sea- 
son, each species with its own peculiar note, from the earliest 
shrill whistles of the spring peepers, and the croaks, clucks, 
trills, and warbles of the frogs, toads, and tree frogs, to the 
bass-viol br-wwns and jug-o-rums of the bullfrogs in late 
June and early July. The eggs are most interesting forms 
with which to follow embryological development, and their 
numbers indicate possi- 
bilities of increasing val- 
uable species, when we 
learn to provide favor- 
able conditions. The 
toads' eggs are found in 
strings ; the green frogs' 
and bullfrogs', in loose, 
floating films ; the wood 
frogs', leopard frogs', and 
pickerel frogs', in globu- 
lar masses of jelly; and 
the peepers', single or in 
small clusters. Observa- 
tions by the class may yield a table for local species some- 
what like the one shown on the following page. 

The feeding test. Amphibia afford most convenient ani- 
mals with which to study foods and feeding habits. Imitate 
natural habitats in the arrangement of terraria and aquaria 
moist earth, moss, or sod for toads, wood frogs, and land 
salamanders, with a forked branch and a small pool for tree 
frogs, and a larger pool, with a bank of moss at one end, for 
aquatic frogs and salamanders. Then, for the tests, introduce 
all sorts of insects, spiders, millepeds, crustaceans, slugs, and 
worms, counting the numbers and kinds eaten. No single 
laboratory exercise shows so convincingly the value of the 




FIG. 149. Toad tadpoles as scavengers, eat- 
ing dead pout at margin of pond 
Photograph by Newton Miller 



816 



CIVIC BIOLOGY 



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AMPHIBIA 317 

work of a species. Different members of the class may take 
different species, and the data obtained should be applied to 
solving the insect problems of the locality. 

Almost all insects come to the ground at some time, 
and we have, especially in the toads, a possible force of insect 
police that ought to be better known and utilized. 

Commercial values. Toads are regularly sold in the markets of Europe, 
being used by gardeners to control insect pests. 1 Is there any local mar- 
ket for them? Could such a market be developed as a result of studies 
and demonstrations to prove their value? The following numbers of 
insects have been eaten by a toad at a meal or were found in a toad's 
stomach : 90-100 rose beetles (Ellen M. Foskett) ; 55 army worms, 77 
myriapods, 65 gypsy-moth caterpillars (A. II. Kirkland, in three stom- 
achs) ; 24 gypsy-moth caterpillars (fourth molt), taken in ten minutes 
(Wilcox) ; 86 hous^ flies, snapped up in less than ten minutes (Hodge). 
From examination of 149 stomachs, Kirkland 2 estimates that a toad will 
eat, in the three months of May, June, and July (why he does not in- 
clude August and September is not stated; these months would add 
materially to the account), 3312 ants, 2208 cutworms, 1840 myriapods, 
2208 sow bugs, 368 weevils, and 368 carabid beetles. Subtracting the 
cutworms that might have been killed by the carabids, we have 1988 cut- 
worms to the toad's credit. He estimates the killing of these as worth 
one cent a piece to a gardener, and thus, for cutworms alone, the possi- 
ble value of the toad's work is $19.88 for the season. Miller 3 is more 
conservative and estimates a toad's work for a season at, possibly, about 
$5 " for greenhouses, gardens, and truck farms " and not so much in 
ordinary farming districts. 

Frogs, especially bullfrogs, are much more inclined to feed upon ani- 
mals other than insects fish, birds, crawfish, and, above all else, upon 
other frogs. This is the great obstacle to frog culture except on paper. 
No matter how many we succeed in bringing through the tadpole stage, 
we have few big frogs in the end. The difficulty in feeding frogs arti- 
ficially is that they take only active, moving, hence living, food. It would 

1 Kirkland states (Farmers' Bulletin No. 196, p. 14) that English gardeners 
pay $25 per hundred. 

2 Kirkland, Hatch Experiment Station, Bulletin 46 (1897), p. 27. 

3 Miller, " The American Toad," American Naturalist, Vol. XLIII (1909), 
p. 668. 



318 



CIVIC BIOLOGY 



seem entirely possible to solve the problem of supplying such foods in 
quantity and variety that would largely prevent even the bullfrogs from 
eating each other. We might have lighted insect traps to deliver their 
catches of moths and beetles all night long into the water beneath them ; 




FIG. 150. Toad tadpoles (broad, dark margin of pond); young toads emerged 
and moving landward (irregular gray edge of shore) 

Photograph by Newton Miller 

sweeps designed to catch grasshoppers alive ; blowfly maggot hatcheries, 
made to drop the maggots into the water as they ripen ; or, if all these 
should not suffice, crawfish and the smaller species of frogs could be 
added. Meehan l states that " 30,000 tadpoles have been safely carried 

1 Meehan, "Possibilities of Frog Culture," Country Life in America 
(1908), p. 315. 



AMPHIBIA 



319 




FIG. 151. Common tree frog 

Photograph by Millett T. 
Thompson 



to frogdom in a pond 30 feet by 15, having a depth of 2 feet of water." 
As eggs of leopard frogs, pickerel frogs, and wood frogs can usually be 

gathered in any desired quantity, this would 
indicate almost unlimited possibilities of 
live-food production. 

In addition to their uses, actual and 
potential, as insect traps, frogs have com- 
mercial values which threaten their exter- 
mination in many localities. In some places 
small ones bring from $1 to $2.50 per 100 
for fish bait. The frog is the animal most 
commonly used for laboratory study the 
world over; frogs used for this purpose 
bring from 50 cents to $3 per dozen. More- 
over, while they were rarely used for food 
a few years ago, frogs' legs have now be- 
come a well-known delicacy. "The meat 
is white, delicate, and very wholesome and 
palatable." Hence catching frogs for mar- 
ket often yields good profit, and it affords a mildly humorous form of 
outdoor sport. As these values come to be recognized, valuable species 
can be protected by closed seasons (from the opening of spring until 
after they spawn), local 
waters can be kept stocked 
to their full capacity, and 
an abundant crop can be 
secured each year. 

Some special problems. 
] . In a pond stocked with 
1 >ullf rogs, how can we feed 
^o as to prevent cannibal- 
ism and thus secure the 
greatest number of large 
specimens from a given 
j.rea? 

2. How can the largest number of toads be reared from a pool a foot 
square and a foot deep? (We have one record of 3938 from April to 
August; the main foods were algae, dog biscuit, and fresh fish.) 

3. Are toads being exterminated from agricultural districts by drain- 
ing their breeding pools, by farm animals, and by the operation of farm 




FIG. 152. Pair of spotted salamanders 
Photograph by Millett T. Thompson 



320 



CIVIC BIOLOGY 



machinery? Could this be prevented? If so, how? Might it be worth 
while, as a measure for insect control, to try the experiment of stocking 
a farm with them, and comparing the damage done by insects on such 
a farm with that on a similar farm where there are no toads? 

Elementary classification and distribution. The names at the head of 
this chapter present the main groups of amphibia in ascending order. 

They are placed there to serve 
as handles by which any form 
that is of local interest or im- 
portance may be looked up 
in the dictionaries, natural 
histories, or zoologies. 

Jordan's " Manual of Ver- 
tebrates " describes eighty-one 
species of salamanders for the 
United States. So little is 
known about their habits, 
foods, spawning seasons, and 
general natural history, that 
they offer an almost virgin 
field for young American nat- 
uralists a field that needs 
working the more on account 
of senseless prejudices con- 
cerning the venomous char- 
acter of these harmless and valuable animals. The mud puppy 
(Necturus maculosus") of the upper Mississippi and Great Lakes basins 
destroys the spawn and young of fishes, but this is the only one of the 
tailed amphibia that is considered harmful. 

Recent books describe fifty-three species of the tailless amphibia as 
native to the United States the frogs, tree frogs, and toads. Of the 
fourteen species of toads the greater number occur in Texas and south- 
western United States, indicating this region as the probable center 
from which the group has spread over the continent. 




FIG. 153. Coast newt depositing eggs in 
an aquarium 

Photograph by Loye Holmes Miller 



CHAPTER XXIX 

REPTILES: CROCODILES, ALLIGATORS, TURTLES, 
TERRAPINS, TORTOISES, LIZARDS, SNAKES 

However, the Reptilia take up a very central position in the evolution 
ol the main classes of the Vertebrata. On the one hand, there is not the 
slightest doubt that they are evolved from some branch of the Stegocephali, 
whilst on the other hand the reptiles, probably through some branch of 
the Theromorpha, have given rise to the mammals ; some other reptilian 
branch, at present unknown, has blossomed out into the birds. HANS 
GVIKMV, "Cambridge Natural History," Vol. VIII, pp. 277-278 

In the absence of birds, what, then, holds the devastating hosts of 
insects in check, for insects abound in all warm countries where vegeta- 
tion is luxuriant ? This, in my opinion, is the lizard brigade, those 
spry and cheerful little fellows in brown "homespun," of which La- 
ctrta muralis is the commonest kind, which are seen streaking it over walls 
and along the ground, in town' and country everywhere. F. H. HER- 
RtCK, ff Italian Bird Life as it impresses an American To-day," Bird Lore, 
Vol. VIII, p. 196 

Why may not a good snake merit the same protection 
as a good bird ? The reason is that we have not taken the 
pains to know the good from the bad, and onr prejudice 
and fear, the children of ignorance, have dominated the field. 
As venomous snakes have been almost exterminated from 
inhabited parts of the country, we are coming to be able to 
appreciate the beauty and acknowledge the good there may 
be even in a snake. In general a reptile is a good citizen 
if it does good work in the world, if it feeds upon injurious 
insects or upon rats and mice or other harmful animals, and 
it it is not venomous. In addition to this larger aspect, a 
number of reptiles supply valuable products alligator and 

321 




nfc. 






FIG. 154. Rattlesnake coiled to strike 
After Ditmars 




FIG. 155. Copperhead 

After Ditmars 
322 



REPTILES 323 

snake-skin leathers, the tortoise shell of commerce, and the 
flesh of some of the marine turtles and fresh- water terrapins. 
Here is a wide, almost new, field, and anyone who will make 
careful studies of habits- and life histories, especially of feeding 
tests with snakes, lizards, or turtles, and even tests of edibility 
in case of likely forms, has a good chance of advancing the 
cause of valuable knowledge and common sense. 

Crocodilia. The warm regions of the world contain nineteen species 
of big, burly, bony-armored reptiles, with long tails, powerful jaws, and 
tempers as ugly as their own rough backs. HORNADAY. 

To see a live Alantosaurus immanis 115 feet long said to be the 
" biggest and bulkiest of all animals " (Gadow) would make us real- 
ize that our largest 20-foot crocodiles are mere pigmy survivals of the 
huge reptiles that ruled the world during the Upper Jurassic. Accord- 
ing to Hornaday only three of the nineteen species are dangerous man- 
enters the Malayan salt-water crocodile and two African forms. The 
two that are natives of America, Crocodilus acutus and Alligator missis- 
sippiensisi are not man-hunters. Still, to keep such hulks in food con- 
si sting of fishes, waterfowl and poultry, pigs, and other animals such as 
tLey can catch is expensive and must eventually limit their range to 
zoological gardens and alligator farms. 

Turtles Chelonia. Senseless waste and even cruelty have too often 
cl taracterized man's treatment of these defenseless and valuable crea- 
tures. Their nests have been plundered for the eggs, whose value is 
slight compared with that of the turtles which they might have pro- 
duced; the mother turtles, when they draw out of the sea to lay, have 
b'jen turned on their backs in numbers that could not be utilized, and 
ii ost of them left to struggle under the hot sun until they died; the 
h iwksbill, in some countries, is hung over a slow fire and roasted until 
the precious shell plates loosen from the bone, when they are stripped 
o'f and the turtle is put back into the water under the probably false 
i< lea that it may live to produce another crop of shell. These are some 
o" the abuses that ought to be stopped in the name of humanity. While 
ii may be a far cry to ask savages of cannibal islands to treat sea turtles 
v ith humanity, we might, at least, see that turtles of our own coasts are 
treated in humane and common-sense fashion. They range the tropical 
a ad subtropical oceans the world around, but Gadow says that they prob- 
a bly return to the same beaches to lay. Hence, if we protect the turtles 



324 



CIVIC BIOLOGY 




FIG. 156. Common snapping 
turtle 



of our own southern coasts, and especially their eggs, we may hope to in- 
crease the American supply. May not classes in biology work up local 
statements of this problem and help to develop public sentiment? 

Of the four species the green turtle 
(Efetmockelys mydas) is most highly 
prized for food. While formerly speci- 
mens weighing 600 pounds were cap- 
tured, now specimens weighing more 
than 50 pounds are rarely seen. The log- 
gerhead (Thalassoc.helys caretta) is coarser 
and does not command so high a price, 
but may not be distinguished from prime 
beef even by a butcher (Hornaday). Tlu- 
hawksbill (E. imbricate?) supplies the tor- 
toise shell of commerce, but is not used 
for food. The harp turtle, or leather- 
back (Spharyh roriacea), the largest of all, is said to be unfit for food. 
Terrapins and tortoises. The diamond-backed terrapin (Malacoclent- 
mys paluntris) is so renowned a delicacy with the epicures that extinction 
of the species has seemed imminent. It formerly ranged from Massa- 
chusetts to Mexico (the Chesapeake being a center of special abundance), 
inhabiting the salt marshes and 
feeding upon Crustacea, small raol- 
lusks, and marsh vegetation. Prices 
have risen from $3 a dozen for large 
ones to $70 for small ones, and this 
has so stimulated the hunt for them 
that a well-grown specimen has be- 
come a curiosity in the wild habi- 
tat. Experiments of the United 
States Bureau of Fisheries, the re- 
sults of which are given in a FIG. 157. Common box tortoise 
recent bulletin, have proved that 

this terrapin may be profitably reared in inclosed tide pools. Waste 
tide flats are thus beginning to be used for terrapin farms. 

The common snapping terrapin, or "turtle " (Chelydra serpentina), and 
the alligator terrapin (Macrochelys temmincki) of the Gulf states, while 
valuable for food, are "demons of the deep" (Thompson Seton) for 
destroying waterfowl and fishes. United effort should be made to ex- 
terminate them from waters where rearing of waterfowl is an industry, 




REPTILES 



326 



and from the natural breeding grounds of wild ducks and geese. The 
most effective means of doing this would be to find their nesting banks 
and destroy the eggs or catch the turtles at night, when they leave 
th'^ water to lay. A female may produce from 2 to 4 dozen eggs. The 
soft-shelled terrapin (Aspidonectesferox) is said to be the best of all the 
f sh-water forms, even the shell, properly cooked, being considered a 
de icacy. They are, however, vicious destroyers of fishes and waterfowl. 

Any of the smaller mud, or pond, terrapins, painted or spotted, and 
th} land tortoises, offer interesting problems in the study of foods 
and possible edibility. The common box tortoise (Cistudo Carolina) 
makes an interesting pet, and its appetite for slugs renders it a valu- 
able assistant to gardeners. The gopher tortoise (Testudo polyphcmu*) 
of the South may attain a 
weight of 15 pounds. Tt is 
considered edible. 

The annual catch of food 
tin-ties, terrapins, and tortoises 
amounts to about 1,400,000 
pounds, valued at $114,500. 
What it might be if these re- 
sources were properly handled 
has never been estimated. 

Lizards Lacertilia. The FIG. 158. Common lizard 

lizards are an effective in- 
sect police for hot, dry habitats not covered by amphibia. They 
are difficult to keep in a laboratory, but if we have a sunny 
window, in which we can imitate desert conditions, we may 
make valuable feeding tests with a number of the commoner 
forms the blue-tailed lizard, or skink (Eumeces fasciatus), 
the fence swift (Sceloporus undulatus), and one of the horned 
toads, or the chameleon (Anolis carolinensis). This may help 
u^ to realize the importance of the group in nature. Lizards 
are clearly distinguished from all salamanders of somewhat sim- 
ilar form by being covered with scales. None of our 97 species 
of small, agile lizards are in any way harmful or dangerous. 
Tne G-ila monster (Heloderma, suspectuni) of the arid South- 
west is the one venomous lizard native to the United States. 




326 CIVIC BIOLOGY 

Snakes Ophidia. About 140 species of snakes are native 
to the United States, of which 17 are venomous. They are 
all strictly carnivorous, and the nonpoisonous species are 
beneficial or injurious, according to their foods. It is clear 
that snakes which specialize on insects or on rats and mice 
should merit general protection. Our little brown and green 




FIG. 159. Aquarium (24" x 18" x 12") made by student and stocked for study 

of native snakes 
Photograph by the author 

snakes feed on insects, and the corn snake (Coluber guttatus), 
often called the rat snake, and the gopher snake {Spilotes 
corais couperii) are often protected about the farmsteads of 
the South for their services in holding rodents in check. 
The snakes that feed upon birds and birds' eggs (the black 
snakes or the blue or green racers), those that feed on frogs 
and toads (the garter snakes and the blowing adder, or 
spreading adder), and those that feed on fishes (the water 
snakes) must be studied with care and treated according to 
local conditions and interests. 



KEPTILES 327 

Poisonous snakes. Fortunately none of our venomous 
snakes tend to infest houses, as does the hooded' cobra of 
India. In consequence, snake bites are extremely rare with 
us, and probably not more than two deaths occur annually 
from this cause (Hornaday). Of the 17 venomous species 
13 are rattlesnakes, belonging to the genera Crotalus and 




FIG. 160. Blowing viper, trying to make room for one more 
Photograph by the author 

Sifstrurus (the massasaugas), so well known, so clearly dis- 
tinguished by the rattles, and so nearly extinct from all 
sectled regions, that they require no description. It is proba- 
bly safe to say that a rattlesnake strikes only in self-defense 
and that it never gives chase. When coiled it cannot strike 
more than one third of its length, and much less if the neck 
is drawn into an S-shaped loop, and its rasping buzz gives a 
warning that is readily understood by both animals and man. 

Closely related to the rattlesnakes are the two moccasins the 
lip Land moccasin, or copperhead (Ancistrodon contortrix), and the ugly 
wiiter moccasin (A. piscivorus), often called the cottonmouth. The 
copperhead is found among rocks and in woods from Massachusetts 
to Florida, ranging westward to Texas and northward to Indiana. The 
wsiter moccasin inhabits the swamps and grassy shores of the bayous 
of the Gulf states, feeding largely on fish and frogs, and on other snakes. 



328 



CIVIC BIOLOGY 



The two coral snakes complete the list of venomous species for the 
United States. These snakes do not in the least resemble the rattlers 
and moccasins. Their heads are slender, not broad and spear-shaped ; 

the pupil of the eye is round 
and there is no pit between 
the eye and the nostril. They 
look so harmless that, as Horn- 
aday says, " it is difficult to see 
how anyone can be bitten by 
this serpent without having it 
done by special appointment." 
This is all the more reason 
for having it definitely known 
that these snakes are venom- 




Fio. 161. Use of forked stick and noose 
in catching a snake 



ous. They belong to the same 
family (Elapidce) as the deadly 
king cobra of India. They are 

instantly recognized by the brilliant yellow, red, and black rings that 
encircle the body from the head to the tip of the tail. The two species 
are the harlequin snake (Elaps /Wrw.s), which ranges from South 




FIG. 162. Coral, or harlequin, snake, with yellow band around head and 
also between the red and black bands of the body 

After Ditmars 



Carolina throughout the Gulf states to Texas, and northward up the 
Mississippi to southern Indiana, a persistent ground dweller, most 
often seen when turned out of the furrow by the plow, and the 
Sonoran coral snake (E. euryxanthus), confined to Arizona, New Mexico, 
and northern Mexico. 



REPTILES 



329 



Snake venoms and the treatment of snake bites. Dr. Calmette, of the 
Pasteur Institute, succeeded in proving that snake venoms act upon 
the body and are reacted against by the tissues like any other toxins. 
From this it has followed that antitoxic sera may be developed for 
different snake poisons, the antivenins, which are able to neutralize 
t le poisons and thus confer certain degrees of passive immunity. When 
t lis subject has been thoroughly worked out, we may have specific and 
s ire remedies for all snake poisons, and this will do away with the 
old, ineffectual remedies whisky, sucking the wound (very dangerous 
unless the mouth is perfectly sound), or instant ligature above the bite 
and quick excision of the poisoned tissues. 1 

1 NOGOUCHI, " Snake Venoms," Publication 111, Carnegie Institution, 
A Washington, 1909. 



CHAPTER XXX 
PRACTICAL LAWS OF LIFE 

GEOMETRICAL INCREASE AND STRUGGLE FOR LIFE. VARI- 
ATION. SELECTION AND SURVIVAL OF THE FITTEST. 
HEREDITY. GENETICS. EUGENICS 

It is good thus to try in imagination to give to any one species an advan- 
tage over another. Probably in no single instance should we know what 
to do. This ought to convince us of our ignorance on the mutual relations 
of all organic beings ; a conviction as necessary as it is difficult to acquire. 
All that we can do is to keep steadily in mind that each organic being 
is striving to increase in a geometrical ratio ; that each at some period 
of life, during some season of the year, during each generation or at inter- 
vals, has to struggle for life and to suffer great destruction. When we 
reflect on this struggle, we may console ourselves with the full belief, that 
the war of nature is not incessant, that no fear is felt, that death is gener- 
ally prompt, and that the vigorous, the healthy, and the happy survive and 
multiply. CHARLES DARWIN, " Origin of Species," p. 96 

An exact determination of the laws of heredity will probably work more 
change in man's outlook on the world and in his power over nature than 
any other advance in natural knowledge that can be clearly foreseen. 
BATESON, ff Mendel's Principles of Heredity," 1902, p. 1 

To unravel the golden threads of inheritance which have bound us all 
together in the past, as well as to learn how to weave upon the loom of the 
future not only those old patterns in plants and animals and men which 
have already proven worth while, but also to create new organic designs of 
an excellence hitherto impossible or undreamed of, is the inspiring task 
before the geneticist to-day. WALTER, "Genetics," p. 5 

It is as impossible now to take the ideas of descent and of natural selec- 
tion out of the world as to take a star out of the sky. CRAMER, ff Method 
of Darwin," p. 61 

Mankind is slowly discovering the laws of life. Ignorance 
cannot, in the nature of the case, bring exemption from the 
consequences of breaking laws ; hence failure even to try to 

330 



PRACTICAL LAWS OF LIFE 



331 



l^arn the laws under which we live may amount to criminal 
carelessness. We discover and learn, laws in order that we 
may be able to obey them, that is, bring our lives into har- 
mony with them. Charles Darwin, by lifelong application 
and sacrifice, marked the greatest advance in discovery of 
the laws of life that the world has known. These are not 
far-away abstractions of thought, and nothing can be of more 
intense practical value than a knowledge of them. Work 
clone or life lived in accordance with them is always effective 
and successful, while that done or 
lived in opposition to them is 
always futile. 

While it may be sufficient that 
a few specialists learn how to 
control the chemical and physical 
forces of nature in accordance with 
the laws of physics and chemistry, 
the forces of living nature are so 
numerous, affect the lives of all 
alike so intimately, and are so 
powerful that common welfare re- 
quires of every member of a civi- 
lized community that he know enough about them to do 
his part. 

Law of geometrical increase. All living things tend to in- 
-rease in geometrical ratio. This is the problem of the farmer 
who promised to pay the blacksmith one kernel of wheat for 
the first nail in his horse's hoofs, two for the second, four for 
the third, and so on. The sixty-fourth nail alone would cost 
him 6,141,451,656,032 bushels of wheat more than the en- 
tire wheat crop of the world for 2000 years. The farmer did 
not know the law of geometrical increase when he promised 
co pay the wheat. Millions of " farmers " who do not know 
this law are promising to pay, in control of insects or fungi 




FIG. 163. Diagram showing five 
generations doubling by geo- 
metrical progression 



332 CIVIC BIOLOGY 

and in many other ways. Fig. 163 expresses this relation to 
the eye, showing how quickly the world may be covered or 
any limit be reached, whether of space or food supply, by the 
geometrical increase of a living species. 

Each species has its own formula or equation of increase, 
its terms depending on the number of eggs, seeds, or offspring 
and the length of life of a generation. Every species that 
we need to control or exterminate, or which we wish to save 
or increase, finds expression for its power of good or evil in 
this law of increase. The mythical labors of Sisyphus typify 
humanity struggling with these problems. He was condemned 
to be eternally rolling a heavy stone up a mountain, the stone 
slipping and rolling down again when he had almost reached 
the top. Flies, rats, mosquitoes, or some other plague, become 
unendurable, and the community tries to rid itself of them. 
It rolls the stone almost to the top of the mountain. A little 
more effort, and extermination would be complete, the stone 
would be rolled over the summit and disappear; but those 
who do not know this law say, " Never mind these few, 
they can't do much harm." In a short time the work is all 
to do over again. So effective control or conservation can- 
not be developed until we have clear ideas of these equations 
of increase. 

Work out formulas of increase for all sorts of types, good or bad, and 
develop clearly their significance in solving local problems. 

The native American oyster-shell scale produces one generation (about 
50 eggs) a year. Its equation of yearly increase is 2 (a pair) = 50. 

The Chinese (or San Jose") scale brings forth about 500 living young 
in a period of 45 days, having four or five generations a season. Its 
equation of increase for a year is 2 = 3,216,080,400. What bearing has 
this upon thorough spraying of trees ? The native insect rarely injures 
a tree perceptibly. The imported scale threatens to exterminate many 
species of trees from the continent. 

The bobwhite has been known to produce 100 eggs in a season. 
Suppose each pair rears 10 young a year ; how long would it take, if 



PRACTICAL LAWS OF LIFE 333 

everyone cooperated, beginning with present numbers, or with ten pairs,, 
to increase them to limits of insect and weed-seed food supply? 

Figuring the number of buds produced by a grape, peach, apple, 
i-trawberry, or other fruit, the number of eyes by a potato, the number 
( >f seeds by a grain or vegetable plant, how long would it take to supply 
t very farm or garden with a favorable variation ? This introduces us to 
the second practical law of life. 

Law of variation. No two liviny things are exactly alike. 
Oan we find two forest leaves, blades of grass, or human 
'aces exactly alike ? Living organisms are too complicated 
for it to happen, even by chance, that any two should be 
ilike. So this universal law of living nature has given us all 
our different kinds of plants and animals. 

Domesticated plants and animals early attracted Darwin's 
attention as showing variations most clearly. 1 Horses, cattle, 
sheep, dogs, pigeons, and all manner of cultivated plants have 
varied in the brief centuries of human control, and are still 
varying, in most wonderful fashion. We have horses, from 
Clydesdales and Norman Percherons to Shetland ponies, all 
produced by human breeding and selection. Ages before 
man appeared on the earth little Eohippus, not much larger 
than a fox, with five toes, four of them hoofed, trotted over 
the bogs of the times ; and we can now trace in successive 
strata of rocks how the modern horse developed from this 
earliest form. The story of other animals and even of man 
himself we have not as yet been able to trace so clearly. 

The great practical values attaching to variations in relation 
to agricultural productions are touched upon in Chapter IX. 
Since these depend so largely upon the possibilities of increas- 
ing and propagating favorable variations, we must consider 
this subject further in connection with the greatest of all 
biological laws. 

i Darwin, Variations of Animals and Plants under Domestication, 



334 CIVIC BIOLOGY 

Law of heredity. Organisms tend to produce offspring like 
themselves. Variation is as destructive as it is constructive. 
It may give us the Spitzenburg apple, and the seeds of a Spitz- 
enburg may revert toward the original wild apple. Heredity 
is the force that enables us to conserve the gains supplied by 
variation. Organic reproduction is of two kinds asexual, or 
vegetative, and bisexual. The asexual process is seen in 
growth and simple division, as found among the bacteria, or 
growth with budding, as in the yeasts and in plants generally 
and in many of the lower animals. In all this reproduction 
we virtually have continuity of the organism, and this can go 
on indefinitely with little or no variation. So buds, grafts, 
cuttings (of stems or roots), layers, runners, bulbs, bulblets, 
tubers, and, in short, all purely vegetative parts of plants 
capable of reproduction carry the variety true to name. 
This means that every bud on a Spitzenburg apple tree, 
rooted in the ground or grafted into any kind of apple 
root or branch, will produce a true Spitzenburg tree, while 
not a seed from all the Spitzenburg trees in the world might 
be able to do this. There is some talk, but little evidence, 
that varieties tend to run out, or grow old, under bud 
propagation. Still bud variation does occur. A branch of an 
orange tree may bear lemons, or a bud of a peach tree pro- 
duce nectarines or apricots. Buds may also be weakened by 
association with disease organisms (as in diseased potatoes) 
or, possibly, by lack of proper nutrition, and so give rise to 
weakened stock. So we are beginning to hear of pedigree 
selection of seed potatoes from healthy, vigorous, productive 
hills, and of buds and scions from healthy and fruitful trees. 
If these points are attended to, there seems to be no reason 
why any variety may not by bud propagation be held true to 
type indefinitely. 

All higher plants have adopted bisexual reproduction as 
one method of multiplication (all seeds), and all animals 



PRACTICAL LAWS OF LIFE 335 

higher than the worms and some insects have come to de- 
pend upon it entirely. In sexual reproduction each indi- 
vidual is built up by the mingling of the germinal elements 
of two parents, and not only that, but of four grandparents, 
eight great grandparents, and so on. This mingling, by pre- 
potence of some characters and recession of others, causes 
active variation, and this seems to be the chief purpose of 
bisexual reproduction. By statistical analysis Galton proved 
that an individual receives on the average 50 per cent of his 
characters from his 
parents, 25 per cent 
from his grandpar- 
ents, and the rest 
from more remote an- 
cestors. Given all the 
forces of increase, va- 
riation, and heredity, ^l&im/T 

another law comes into 

FIG. 164. Diagram illustrating Mendel's law 
play, the discovery of of dihybridS: white being dominant and 

which was Darwin's black recessive 

great contribution. 

The law of natural selection. Nature selects the fittest to 
survive. From the beginning, man has imitated nature in 
selecting the plants and animals that suit his need or fancy, 
and this is commonly distinguished as artificial selection. 
Combination of these two processes has resulted in the spe- 
cies and varieties, strains and breeds, that we now see in the 
world. Progress has been made in the past chiefly by pick- 
ing up chance variations as they have occurred in nature and 
accidentally among domesticated plants and animals. Only 
within recent years have we begun to learn how to select 
the parents in order to cause desired variations. By eight 
years of most accurate and painstaking experiments in cross- 
ing and rearing varieties of garden peas, the Austrian monk, 




336 CIVIC BIOLOGY 

Gregor Johann Mendel, discovered a law of heredity, claimed 
to be equal, for biology, to the law of gravitation in physics 
or to that of atomic equivalents in chemistry. 

Mendel's law. Characters are represented in germ cells by 
units which tend to segregate or combine in definite propor- 
tions, the result of mating together first crosses falling in the 
ratios 1DD + 2DR + 1RR for characters D ami R. 

Illustration. A tall and a short pea are crossed. The seeds resulting 
from the cross produce only tall plants. When the seeds (self-fertilized) 
of these plants are grown, they are found to produce 75 per cent tall 
plants and 25 per cent short, or 3 tall to 1 short. Here tallness is 
dominant (character D) and shortness recessive (character R). A 
dominant character dominates the outward form of the plant or animal 
body, while a recessive character has its units persisting unchanged in 
the germ cells. When male and female germs again combine, they do 
so according to the law of chance (like dice, or any other free units) 
and so fall out 1DD + 2DR + 1RR. Since we cannot distinguish the 
DD plants from the DR plants, except by planting the seeds and analy/- 
ing the progeny, we have 3D to 1R. All the RR plants are found to be 
as pure and to breed as true as if they had never been crossed, and so 
are all the DD plants when we propagate them. The DR plants will 
continue forever to produce 1DD -I- 2DR + 1RR. A hybrid can never 
be fixed so as to breed true. 

The above is the law for monohybrids forms in which a single 
character or pair of characters is involved, and instead of assuming 
the presence of a unit (determiner) for a character (for example, 
"shortness), the tendency is to assume merely the absence of the germi- 
nal determiner for tallness. In cases of two characters being involved 
in each parent, that is, in dihybrids (characters Dd and Rr), there is 
IDd-Dd and IRr-Rr, that is, 1 pure dominant and 1 pure recessive in 
10. In case of trihybrids only 1 offspring in 64 is pure dominant or 
pure recessive. If ten characters are involved, the offspring of the sec- 
ond generation would fall into 1,048,576 different kinds, of which only 
1 would be pure for each set of characters. 

When we consider that this law of inheritance applies to fixation of 
all kinds of characters, from tallness of peas to tallness of men, from 
rust resistance in \vheat, egg production in poultry, or milk production 
of cows to feeble-mindedness or normal intelligence in men, we begin 



PRACTICAL LAWS OF LIFE 



337 



10 realize what Mendel has done for the world. As Walter sums up the 
case: "Thus in a few generations of properly directed crosses there 
an be obtained combinations of characters united in one strain that 
; ormerly were never obtained at all or were only hit upon by merest 
Chance at long intervals. Herein lies the scientific control of heredity 
.vhich the trinity of Mendelian principles, namely, independent unit 
characters, segregation, and dominance, has placed in human hands." 1 

Historical. Mendel presented the re- 
mits of his era-making experiments 
Before the Natural History Society in 
Brtmn. early in 1865, and they were 
published in the Proceedings in 186(5. 
STeither the reading nor the publication 
Caused a ripple of interest. No one un- 
lerstood its significance. Had Darwin 
learned of Mendel's law in 1865, the 
history of human science, philosophy, 
and even religion might have been 
[nished forward fifty years. Mendel died 
January 6, 1884, bitterly disappointed 
chat no one could be found to share his 
vision, and his discovery slumbered for 
sixteen years longer. 

In 1900, three men, working independ- 
ently, rediscovered Mendel's law almost 
at the same time. These were De Vries 
in Holland, Correns in Germany, and 

Tschermak in Austria. The time was ripe for its appreciation, and it 
immediately transformed the subject and, from a matter of abstract 
disquisitions, made heredity the most intensely practical concern of the 
experimental breeding plot and pen, of the hunt for variations in nature, 
and of even sociological analyses and surveys. " The practical breeder 
of animals or plants, basing his methods on a determination of the 
Mendelian units and their properties, will in many of his operations 
be able to proceed with confidence and rapidity. Lastly, those who as 
evolutionists or sociologists are striving for wider views of the past or 
of the future of living things may by the use of Mendelian analysis 
attain to a new and as yet limitless horizon." 2 

1 Walter, Genetics, p. 144. 

2 Bateson, Mendel's Principles of Heredity, 1909, p. 17. 




FIG. 165. Diagram illustrating 

relation of germ plasm (straight 

lines) to somatoplasm (circles) 

in bisexual reproduction 



338 CIVIC BIOLOGY 

Evolution, mutation, and Mendel's law. In his scheme of evolution 
Darwin emphasized the influence of slight variations continued through 
long periods of time. He realized at the outset that in heredity, in the 
power to pass on variations, lay the heart of his problem, but he went 
far astray in his own theory of heredity, pangenesis, 1 and so failed to 
attain the goal he might have won. No one realized this more keenly 
than Darwin himself. 

De Vries found that from the same seed capsule of Lamarck's eve- 
ning primrose he could rear as many as nine distinct kinds of plants, so 
different that, had they occurred consistently in nature, they might 
have been named as separate species. On the basis of these and similar 
experiments he advanced his recent theory of mutation. This theory 
supposed that evolution goes forward by leaps and sudden changes. It 
now turns out that this evening primrose, Qlnothem Idmarckiana, is 
a Mendelian cross, a hybrid ; and this suggests that all mutations may 
be merely cases of segregation and recombination of unit characters in 
the germs of plants and animals, that is, outworkings of Mendel's law. 

Weismann made a solid contribution when he distinguished sharply 
between germ plasm and body plasm, or somatoplasm. He called atten- 
tion to the fact that the germs are all formed in the embryo long 
before the body; the egg-germs, and many more than a hen can ever 
hope to lay, are all set aside at almost the very beginning of incubation. 

1 Pangenesis (pan, "all," or ff the whole," and genesis, ff origin" that 
is, "from the whole body") is the theory that the germ cells are built up 
by the streaming together, from all the organs of the body, of minute parti- 
cles (gemmules, or pangens) an infolding or involution of the body into 
the germ. Then when a germ unfolds or develops, each pangen reproduces 
the part of the body from which it came. This theory implies an active 
influence of the body upon the germ plasm, and if parts of the body or brain 
should be specially developed by exercise or training, or if parts or organs 
should be removed or lost by disease or accident, we should expect to find 
such additions or subtractions reproduced when the germs from such bodies 
developed. This we never find. There is no evidence that any acquired 
character is ever inherited. Lambs' tails have been bobbed for thousands 
of years, and lambs are born with tails as long as they ever were. Galton 
disproved pangenesis experimentally by exchanging the blood of animals. 
Since the blood is the only means by which the pangens could possibly 
circulate from the body to the reproductive cells, if we exchange blood 
between white and black animals, we ought to get some of the pangens 
mixed. Galton's experiments disproved the theory absolutely, as does every 
case of budding and grafting. 



PRACTICAL LAWS OF LIFE 339 

Germ plasm forms germ plasm and builds up the body, but the body 
eaniiot form or reproduce a single pangen or minutest particle of 
germ plasm. 

Organized study of genetics. What is your own community 
doing to improve its plants and animals ? Many investi- 
gators and students in our universities and colleges, our 



I looked at out to .See I JW 

atnon$ our Hildin^S- The next tiling to do wa$ to find 
the he$t and earliest grape for $eed and this I ">unJ in 
an accidental seedling at the foot of the Kill . The crop 
ua$ abundant ripe in Augy$! and of very good cpality I 
for a nild grape. 1 ^owed tfie S ee ^ 1TI the autunm of 
1843. Alflong them the Concord M85 the only 
one north javin^. 



FIG. 166. Quotation from Mr. Ephraim Bull on the wooden tablet marking 
the original Concord grapevine at Concord, Massachusetts 

Agricultural Department and experiment stations, practical 
seedsmen, farmers, and independent plant and animal breed- 
ers, are studying and experimenting and pushing discovery in 
this field. Invite local experts to visit the class and discuss 
their problems. Often by community cooperation better stock 
can be introduced than any one member could afford, and its 
rapid increase insures enormous profits to such undertakings. 
Railroad companies and the International Harvester Company 
have agricultural experts who are helping along these lines. 
Hunt out stories of the discovery and introduction of new 
fruits, vegetables, grains, breeds of animals, and in the spirit 



340 CIVIC BIOLOGY 

of these try to find valuable variations in the neighborhood. 
Our native nut trees have been neglected in this matter, and 
the Department of Agriculture is calling for a special search 
of the entire continent for valuable varieties. With the whole 
country organized for the search and with breeding in control 
of experts, we may hope for better progress in even* line of 
plant and animal improvement than ever was known before. 
Injury of germ plasm. Germinal substance is, of course, 
obliged to draw its nourishment from the body; hence we 
may expect to find vigorous germs in strong, healthy bodies. 
Animals that become too fat are likely to have enfeebled 
germs or to be totally sterile, and conditions that show no 
appreciable injury to the body may prove fatal to the germ 
plasm. This is seen in Stock ard's experiments with alcohol 
tabulated below: 



EXPERIMENTS WITH GllNEA Pli> Tu 1 KST IXFLUEXCK "K ALCOHOL 

ox GEKM CELLS 





XCM- 










BER OF 


ABOR- 


AT 


LlVEI> 


JttAT- 

- 


TIVE 


BIRTH 




Alcoholic males and normal females 


M 


19 


- 


5 (all runts) 


Normal males and alcoholic females 


4 


. 


a 


2 


Alcoholic males and alcoholic females 


14 


13 


i 


" 



Normal males and normal females i 17 (all vigorous) 

The germ cell from each parent builds half the embryo, and 
the twenty-four matings in which the sperm alone is alcohol- 
ized are a proof that an alcoholized sperm cell of a guinea 
pig cannot do its share toward building up a normal offspring. 1 

1 Stockard allowed the guinea pigs to breathe fumes of alcohol for one 
hour a day, six days in the week. The animals showed no outward injury, 
in fact they gained somewhat in weight. 



PRACTICAL LAWS OF LIFE 



341 



The following table shows similar results obtained by 
Hodge from carefully balanced experiments with selected 
t.ogs. The males were brothers and the females sisters from 
t\vo unrelated litters of pedigree cocker spaniels. Demme's 
observations upon men are added for comparison. 

INFM KNCK OF ALCOHOL ON PIUHJKNY 
Dogs (Hodge) 





ALCOHOLIC PAIR 


NORMAL PAIR 


Number of whelps . . 
Deformed 
Horn dead 
Viable 


(7-7-6-3) 23 
(2-3-3-0) 8 
(2-2-2-3) 9 
(4-0-0-0) 4 (17.4',) 


(5-3-8-8-5-6-3-7) 45 
(1-0-0-2-0-0-0-1) 4 
(0-0-0-0-0-0-0-0) 
(4-3-8-6-5-6-3-6) 41 (90.2 %) 



Men (Deinme) 



TEN ALCOHOLIC 
FAMILIES 



TEN NORM A L 
FAMILIES 









lumber of children 


57 


61 


Deformed 
idiotic 


10 
6 


2 



Epileptic, chore! c 
Died at birth . . . 


6 

25 


(2bkw) 
3 


formal, viable 


10 (17%) 


54(88.5%) 



Moderate, nonintoxicating doses of chemically pure alco- 
hol were fed to the dogs with their meals, and Demme's 
normal families were not total abstainers. In further study 
of the human problem Bezzola found that out of 8190 idiots 
in Switzerland the majority occurred in the wine districts, 
and that the larger per cent of these were born nine months 
after the great national drinking feasts. Schweighofer dis- 
covered a similar relation between stillbirths and the drink- 
ing festivals of Austria. 

To keep the germ plasm of the nation on the up-grade, 
free from any injury, taint, or tendency to degeneration, is 
the most worthy subject for lifelong study by every man 




B-r-0 



* 



FIG. 167. Diagram outlining history of Kallikak family 

Squares stand for males, circles for females ; N for normal people, F for feeble- 
minded. Five generations on the side of the feeble-minded girl contain 480 indi- 
viduals 143 feeble-minded, 33 immoral, 24 drunkards, and 3 epileptics. On the 
normal side are 496 descendants, none of whom are feeble-minded. After Goddard 



342 



PRACTICAL LAWS OF LIFE 343 

and woman. We are now just beginning to learn facts in 
this field which may save our present civilization from the 
decays that have overtaken those of the past. Whatever a 
man may claim for personal liberty, no one can claim any 
right to even risk mental or physical impairment of his 
own offspring or to impose the care of defectives upon the 
community. Alcohol is being barred from athletics, from 
the army and navy, from public service, and from all busi- 
ness, public and private, where strength, endurance, and 
dependability are required, and the evidence given above 




Fi<3. 168. Recessive character of feeble-mindedness and effects of alcoholism 

Siiiall black circles indicate stillbirths; d, died ; d. inf., died in infancy : T, tuber- 
cular; u, unknown. For other symbols see Fig. 167. After Goddard 

would seem not only to give society the right but to impose 
upon it the duty of banishing alcohol from any possible 
contact with the supreme business of evolving the race. 
" You can't be strong and well unless you live rights 
These words of Jess Willard are life-wide in their applica- 
tion. We are just beginning to learn from the new view- 
point of eugenics. Drugs like morphine and opium, cocaine 
ai id heroin, must be studied with special reference to their in- 
fluence upon the germ plasm. The same is true of nicotine, 
and it may be that we shall have to set the age at which 
indulgence in tobacco may safely be begun at fifty-five 
years instead of at the usual sixteen or twenty-one. Any 



344 CIVIC BIOLOGY 

excess in the use of coffee or tea must be viewed with 
suspicion, and many of our best hygienists look with appre- 
hension at the possible consequences to the race of our 
sudden, enormously increased gorging of sugar. We can 
only suggest these as possible lines of study. 

Eugenics and Mender s law ; bad blood and good. '' Peo- 
ple say one must be able to read and write in order to get 
along in the world. Now there is Miss . She cannot 
read or write, yet she gets along all right." 1 

This judgment of a feeble-minded woman by an imbecile man 
helps to explain the rapid increase of such defectives. Avoided 
by the normal, defectives generally marry defectives. Since 
they are permitted to multiply at will and are shielded by 
modern charity from operation of the law of survival of the fit, 
this process has gone on until we now have nearly 3,000,000 
dependents and defectives one in thirty of -our population. 2 
By far the larger part (quite possibly, when we have studied 
to the real genetic root of the matter, we shall find that al- 
most all) of the heavy burdens imposed upon society by the 
idiotic, imbecile, and insane, the paupers, alcoholics, and 
criminals, is caused by inherited mental and moral defect. 

The exhaustive studies of Goddard seem to leave no room 
for doubt that feeble-mindedness is a recessive, Mendelian, 
unit character. Hence, according to Mendel's law, the chil- 
dren of feeble-minded parents must forever all be feeble- 
minded. Goddard finds this to be true. Normal-mindedness 
is a dominant unit character. Hence, if one parent is pure 
normal (duplex) and the other feeble-minded (nulliplex), the 
children will appear normal but will all have feeble-mindedness 
recessive (that is, be simplex). When such people become 
parents, the children will be 1DD 4- 2DR + 1RR, that is* 
three normal to outward appearance and one feeble-minded. 

1 Goddard, Feeble-mindedness : its Causes and Consequences, p. 85. 

2 Kellicott, Social Direction of Human Evolution, p. 34. 



PRACTICAL LAWS OF LIFE 345 

Since these people are a burden to themselves and to 
society, no right-minded person could risk the responsibility 
f 3r bringing them into the world ; and as the facts come to 
be generally known, all such streams of bad blood will be 
prevented from increasing their kind and also from spread- 
big out to contaminate streams of normal blood. 

Color of eyes and hair, night blindness, color blindness, 
albinism, germinal deaf -mutism, and many other human 
characters have been found to follow Mendel's law, but dis- 
covery is only beginning to break into this field, and we 
merely suggest it for future individual study. Most impor- 
tant studies have been made on typical streams of bad 
1 eredity. Let different members of the class volunteer to 
bok up the following and report : ?? The Jukes Family," by 
Dugdale ; '' The Zero Family," by Jorger ; " The Hill Folk," 
by Danielson and Davenport ; :t The Nam Family," by 
Estabrook and Davenport ; and | The Kallikak Family," 
by Goddard. 



CHAPTER XXXI 
KNOWING HOW TO KNOW HOW 

NATIONAL ORGANIZATION FOR BIOLOGICAL INSTRUCTION 
AND RESEARCH 

I do not know what I may appear to the world ; but to myself I seem to 
have been only like a boy playing on the seashore, and diverting myself in 
now and then finding a smoother pebble or a prettier shell than ordinary, 
whilst the great ocean of truth lay all undiscovered before me. SIR ISAAC 
NEWTON 

It 's easy enough to do it if you only know how. It ? s easy enough to 
do everything, if you if you only know how. SMALL BOY (overheard 
on the street) 

Conclusion of the whole matter. The best " knowing how '' 
there is in the world is none too good for the humblest child 
of the nation to try to live and to work by. If there were 
one wish that the writers of this book could have granted 
for the asking, it would not be that everybody should know 
everything, but that every child of the nation should know 
how to learn only the best truth there is to help him with 
each day's life and work. The doing may be easy and cheap ; 
the knowing how is very precious and may have cost years 
or centuries of trying, thinking, and experimenting. Still the 
knowing how may be easy, too, if we really know how to 
know how. Is it not being continually baffled by false, 
wrong, bad knowing how that makes all learning hard and 
work futile ? It is easy to keep well and strong if we know 
how, but the knowing how must be right. It would be easy 
to exterminate tubercle bacilli if everybody knew how, but 
we cannot do this as long as even a few think they know 

346 



KNOWING HOW TO KNOW HOW 347 

how to do it with Dr. Muck's compound of punk, alias 
cheap whisky. It would be easy to breed and raise 100- 
bushel wheat, 200-bushel corn, 1000-bushel potatoes, 1000- 
pound-butter-fat cows, 300-egg hens, and so on down the list, 
it' we only knew how. We are gaining ground yearly; the 
doing is step by step a test of the knowing. 

Fake sources of truth like poisoned wells. Sometime we 
may be organized as a people, so that only the truth can be 
printed. Our pure food and drug laws are beginnings in this 
direction, but the millennium is still a long way off, and so 
far attempts at assumption of human infallibility have been 
failures. All we can do is to appeal for information to our 
best authorities. These pretend to no secrets for a price ; 
they always present the evidence, the proofs, the experi- 
ments, 011 which their conclusions are based; and it ought to 
be possible to add, they never say they know a thing when 
1 hey do not ; that is, they never lie. No one can long remain 
an authority if often mistaken on this most important of all 
points, and a real authority is never afraid to say, " I do not 
know." Successful farmers in different lines, our county 
agricultural expert, local nurseryman and florist, local forester 
or tree warden, local bird man or woman (unfortunately we 
seldom have any local insect students), local health officers 
and reputable physicians, state and national experiment- 
station experts and health officers, and the extension faculties 
< f our state universities these are our best authorities. 
' They belong to us ; we pay some of them their salaries to 
give us the best knowing how there is ; and they are gladder 
to do it than we are to wake up enough to ask them for 
help. By the divine right of being alive the best knowing 
how there is in the world belongs to any child of humanity 
who is hungry for it and who knows enough to ask for it 
and to learn it. Our country is organized, through its edu- 
cational forces, public press, and public libraries, to meet this 



348 CIVIC BIOLOGY 

right, as any child of the nation can test as often as he pleases. 
The great lack is that we are not educated to know and to 
utilize the resources for knowing how that belong to us. 
Another great difficulty is that the world is flooded with 
fake, false, selfish-motived misinformation, and we need to 
learn to shun all bad and second-rate sources of truth as we 
would poisoned wells. In proportion as one uses the best 
sources of information, he will develop the power to discrimi- 
nate and to detect the bad. Civic biology should, first of all, 
save us from fake solutions of our health problems. 

No, Mrs. Bonebrake, 1 am not going to try your religious fad in 
order to heal my sore feet ; no, Mrs. Hardscrabble, I will not use your 
number rigmarole to improve my prospects ; and no, Mrs. Likenbowcr. 
I will not wear your amulet to get rid of my rheumatism. 

Why ? Well, because I am honest. I may not be very holy or soul- 
emancipated, but I pride myself on being an honest man. 

And I'm going to be as honest with myself as I am with my neighbor. 

The fundamental ethics is the ethics of the intellect. 

And that means that I will believe only upon examining the facts. 
My judgment shall remain absolutely automatic, and shall bend only 
by weight of evidence. 

I shall not say I believe a thing just to see if it will not help me. 

I shall refuse to proclaim a faith in order to help anybody else. 

Ladies, you touch the quick of my virtue. I will not be disloyal to 
my reason no, not even to get to heaven. 

History is full of pious and learned men who put expediency before 
honesty. They did not believe what they professed they did not even 
understand it ; but they said they did, because they thought it would 
aid others, would not offend the weak, and would save their own 
souls. 

But I will take my chances with intellectual integrity alongside of 
all the earnest souls who deceived themselves and everybody else be- 
cause, so doing, they verily thought they were doing the will of heaven. 

I know, Mrs. Bonebrake, you claim that your peculiar faith, resting 
upon a plain denial of facts, has healed many ; so, Mrs. Hardscrabble, 
your cabala; and so, Mrs. Likenbower, your amulet. Why not try it? 
Ft has benefited others ; why not me ? 



KNOWING HOW TO KNOW HOW 349 

Simply because every one of your cures can be traced as justly to the 
strange, mysterious, recuperative powers of nature as to your particular 
n )strum or form of self -hypnotism. 

Thousands of invalids have got well after being given up by phy- 
sicians, and got well without crossing their fingers and reading your 
bx>k. In fact, most people, some time in their life, have miraculously 
recovered when it seemed they should have died. 

Hence, if you bottle Chicago river water and get enough people to 
"just try " it, you can collect innumerable testimonials. But doubtless 
il you published these you would not include in your report the equally 
innumerable cases where the victim did not get well. 

No, ladies ; I appreciate your kindly interest in my bodily health 
and my. soul's salvation, but I'm going to stay honest and see what 
happens. 

When 1 am met by a proposition that is based on facts, and not on 
t le ignoring of them, that is reasonable and convincing, and that is 
substantiated by the known laws of evidence and squares with common 
S'mse, I will embrace it. Otherwise, no ; and thank you all the same. 

Nothing doing on the esoteric, the fuzz-wuzzy, the ecstatic, the self- 
1 ypuotic, the what-if-it-is-true-after-all-you-can't-tell. 

My intelligence may be pretty poor, but it 's all I have. I'm going 
t > stand by it and refuse to prostitute it, 110 matter what the bribe. 

The web of destiny is. complex, I know, and none of us knows the 
secret springs of life and events; but I have a notion that if a man 
s kicks to the truth as he sees it, and declines the lure of truth as he does 
not see it, even if the latter promises health, wealth, and a happy here- 
after, he will be likely to come out about where his Creator intended. 1 

Using a library. The best investment any community can 
make is to buy, catalogue, and keep up to date a library 
relating to its interests and industries ; and, in any modern 
^erise of the word, that one is most efficiently educated who 
1 >est knows how to use such a library. If our local and school 
libraries are properly managed and catalogued, it ought to 
]>e easy to find quickly all that is known on every subject 
discussed in this book. If every member of the class is col- 
lecting bulletins up to date and doing his share to help, 

1 By Dr. Frank Crane, in the Associated Newspapers. 



350 CIVIC BIOLOGY 

the laboratory bookshelf ought to be made to answer 95 per 
cent of the questions that arise. Individual pupils should 
also be gathering libraries relating to their own problems, 
interests, and projects. A really practical working method 
in using a library is of lifelong value to everyone. How 
many have acquired this at the end of their school or even 
college courses? This is the one thing necessary to reason- 
ably intelligent modern living, and if many have failed to 
acquire it in the course of their schooling, is it not because 
they have not had any real problems to solve that required 
such use of libraries ? Lincoln stated the case in a word 
when he said : "A capacity and taste for reading gives access 
to whatever has already been discovered by others. It is the 
key, or one of the keys, to the already solved problems. 
And not only so : it gives a relish and facility for success- 
fully pursuing the unsolved ones" (p. 92). 

Catalogues, publication lists, and indexes. A library may be 
too poor to buy many books, but still be 100 per cent efficient 
if it keeps these indispensable helps in order and up to date. 
People can then find everything that has been written on any 
subject or by any author, and the local library can usually 
borrow from the state library or from that of their nearest 
university; or people might often buy books and donate them 
to their local library when they have finished with them. 

Every laboratory bookshelf must have for constant refer- 
ence the Monthly List of Publications (which is sent free to 
all who apply for it) and the Experiment Station Record. 1 
The first lists every bulletin of the central Department at 
Washington, as it appears, and the Experiment Station Record 
gives a well-annotated monthly bibliography of everything 
relating to the practical biology of agricultural advancement 
for the entire country and, in fact, for the world. Another 

1 For both these publications address United States Department of Agri- 
culture, Washington, B.C. Subscription price of the Record is f 1 a year. 



KNOWING HOW TO KNOW HOW 351 

publication of the Department is the Weekly News Letter, 
which contains brief, timely articles and notes. Some mem- 
ber of the class might subscribe for this and keep it in 
orderly file on the bookshelf. 

The question with which we started is, How can AVC get 
the best information most quickly ? A. concrete case will 
answer this question for thousands of similar problems. 

A botany class in a city was beginning the study of fungi, and in 
addition to the elementary book work each member was assigned an 
interesting fungus to work up and report upon. One of the boys, instead 
of the fungus assigned him, asked permission to take the black knot. 
The teacher was wise and honest enough to tell him that she knew 
nothing about it, but would be glad if he would learn all he could and 
give them all the benefit. He went to the library with a pack of postal 
cards and, going through the recent numbers of the Experiment Station 
Record, took down on the cards references to all likely articles on the 
black knot, addressed them, and within a week he had everything that 
everybody knew about the black knot. 

The boy then went to work out doors, hunted through the woods, and 
collected the fungus on native wild plums and cherries, and he made a 
survey of the city in order to form an intelligent estimate of the damage 
caused to cultivated fruits. He mounted a typical series of specimens 
in a glass case, all neatly labeled. He studied the fungus with the 
microscope and made careful drawings of all the important stages in its 
growth and reproduction. He drew colored wall charts from his pictures, 
supplemented by those in the books, and finally presented his results 
on the life history, distribution, and treatment of the black knot in a 
carefully prepared lecture which occupied an entire period of the class. 
One of his classmates happened to be a reporter on a local daily, and 
she presented the subject to the public in a well-written article of about 
two columns, and there followed such a cleaning up of black knot as 
that city had not seen in at least fourteen years. 

" What do you think about that work you did in school on the black 
knot?" the boy was asked some years later. He replied, "It exactly 
fitted my bent, and on that account I think I got more real good out of 
it than from any other one thing in my high-school course." Better 
than all, this wholesome little try at real study quite probably helped 
him to decide what he wanted to do for the rest of his life. 



352 CIVIC BIOLOGY 

Special organizations and journals. The science of our 
country and the world is not the dead, cut-and-dried facts, 
"classified and arranged" in books. Real science has been de- 
nned as the "everlasting struggle of the human mind after 'the 
truth " (Lessing). Or, as Huxley put it, " Science is trained 
and organized common sense." In essence, science is the liv- 
ing, growing, forward-moving stream of discoveries the best 
knowing how that all the stragglers after truth are daily find- 
ing out. As long as there is progress it must always be that 
the best that someone is able to discover to-day will be ex- 
celled by the discoveries of to-morrow, and all that we know 
is but a handful of pebbles on the shore of the ocean of truth 
still to be discovered. Thus, in order to make sure that prog- 
ress in discovery shall never cease, men have organized univer- 
sities and research foundations and the scientific departments 
and bureaus of the state and national governments. 

In addition to the above are the many special associations 
of people drawn together -by mutual interest in various prob- 
lems. These associations contain our best authorities on all 
sorts of subjects, and many of them publish special journals in 
which members first announce their discoveries. It may be 
years before these discoveries find their way into the books of 
our libraries. Hence, if we are to find the best knowing how 
up to date, we should learn what these organizations are and 
keep track of the articles in their journals from month to 
month. We should first make a list of all local organizations 
pertinent to civic biology. Some of these may be branches 
of larger societies, national or international. As we learn 
about their purpose and work we should consider joining 
any that may seem desirable, and so begin to take our places 
in the organization of the community for progress. A few 
of the national organizations are indicated below : l 

1 See Handbook of Learned Societies and Institutions of America, 
Carnegie Institution, Washington, B.C., 1908. The World Almanac gives 



JvNOWLNG HOW TO KNOW HOW 

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 
Dr. L. O. Howard, permanent secretary, Washington, D.C., was founded 
in 1847 and has 11,000 members. The biological sections are F, 
Zoology; G, Botany; K, Physiology and Experimental Medicine; 
sind M, Agriculture. Sister organizations are the British and French 
associations for the advancement of science. The official organ is 
Science, published weekly, and sent gratis to all members in the United 
States as part return for the annual dues of $3. .The Scientific Monti ti/ 
(continuation of the, Popular Science J/V//,//////) may be substituted if 
preferred. 

AMERICAN SOCIETY OF NATURALISTS was first organized in 1840 
(reorganized in 1883) and is the parent from which many of the more 
special scientific societies have split off. It has 400 members. 

CENTRAL ASSOCIATION OF SCIENCE AND MATHEMATICS TEACHERS 
(and many similar societies of science teachers). The official organ for 
all is School Science and Mathematics. 

AMERICAN NATURE STUDY SOCIETY, founded in 1008; official organ, 
Nature-Study Review, Ithaca, N.Y. 

AMERICAN PUBLIC HEALTH ASSOCIATION. The official organ, 
American Journal of Public Health, should be in every biological library. 

NATIONAL ASSOCIATION FOR THE STUDY AND PREVENTION OF 
TUBERCULOSIS, founded in 1904, has about 2500 members and pub- 
lishes accounts of annual meetings. 

SOCIETY OF AMERICAN BACTERIOLOGISTS, founded in 1899, limited 
to 75 members. 

AMERICAN ASSOCIATION OF PATHOLOGISTS AND BACTERIOLOGISTS, 
founded in 1900. 

AMERICAN CANCER RESEARCH SOCIETY, headquarters, 1430 Wells 
Street, Chicago, 111. 

AMERICAN SOCIETY OF ZOOLOGISTS, founded in 1902, 137 members. 

BOTANICAL SOCIETY OF AMERICA, founded in 1893, has 496 mem- 
bers and publishes the American Journal of Botany. 

AMERICAN FORESTRY ASSOCIATION, founded in 1882, has 15,000 
members and publishes American Forestry, Washington, D.C. 

AMERICAN FISHERIES SOCIETY, organized in 1870, has 700 members. 

NATIONAL ASSOCIATION OF AUDUBON SOCIETIES, founded in 1905, 
now has about 4000 members, with branch societies in nearly every 

a list of learned societies, with dates of founding, number of members, 
addresses of some of the officers, and names of journals published, with 
their places of publication. Local libraries may supply more extended lists. 



354 CIVIC BIOLOGY 

state. The official organ is Bird Lore, edited by Frank M. Chapman 
and published at Harrisburg, Pa. 

AMERICAN ORNITHOLOGISTS' UNION, founded in 1883, has 1126 
members, publishes the Auk, the official journal of American ornithology, 
and also prints and keeps up to date the A. O. U. Check-List, giving the 
authoritative names, popular and scientific, of all birds of the United 
States. 

AMERICAN ASSOCIATION OF ECONOMIC ENTOMOLOGISTS, founded in 
1889, has about 500 members; official organ, Journal of Economic Ento- 
mology, Concord, N.H. A complete set of this journal ought to be 
accessible in every city and town library. 

AMERICAN ENTOMOLOGICAL SOCIETY, founded in 1859, has 140 mem- 
bers and is devoted to purely systematic entomology. 

AMERICAN PHYTOPATHOLOGICAL SOCIETY. 

AMERICAN POMOLOGICAL SOCIETY, founded in 1849, has about 500 
members and publishes biennial reports and special catalogues of fruits. 

AMERICAN SOCIETY OF LANDSCAPE ARCHITECTS. 

AMERICAN GENETIC ASSOCIATION (continuation of the American 
Breeders Association), founded in 1903, has about 1200 members and 
publishes the Journal of Heredity, a monthly publication devoted to 
plant breeding, animal breeding, and eugenics. Washington, D.C. 

We have given dates of founding and number of mem- 
bers in order to emphasize the fact that organization for know- 
ing how to do things is only just beginning, and that as yet 
very few are actively concerned with these vital problems. 



CHAPTER XXXII 

PROGRESS IN DISCOVERY 

Anything which sheds light on the nature of life and of man himself, 
his organic constitution and equipment, the laws and possibilities of his 
mind and body, his place and fate in and relation to the rest of the universe, 
will appear immeasurably more important than the fate of individual men 
or nations, because those things have a fundamental significance for the 
whole human race everywhere and for all time, and likewise have the deep- 
est sort of personal significance for everyone who is reflective enough to be 
conscious of the questions presented by his own being. 

The great battles of man have not been fought on Grecian plains or 
Spanish mains or over European hill and dale, but within the skulls of the 
great investigators, up and down the brain valleys and ridges of the great 
thinkers and the immortal poets. It is the great captains of thought and 
feeling that have led forth the bright-shining forces of the human mind and 
soul in the only wars that have results of permanent and universal impor- 
tance, wars in which thoughts, ideas, facts, conceptions are deployed 
and maneuvered in phalanxes and battalions to the greater issues of our 
human fate. 

Measured against such Himalayas of the human mind and soul as Darwin 
and Marx and Newton, Napoleon and Bismarck and Alexander are not even 
among the foothills of human significance. The publication of "The Origin 
of Species" was a more vital event in human history than the battle of 
Waterloo. COURTNEY LEMON, Pearson's Magazine, February, 1917, p. 183 ff . 

I am impressed with the fact that the greatest thing a human soul ever 
does in this world is to see something and tell what it saw in a plain way. 
Hundreds of people can talk for one who can think, but thousands can 
think for one who can see. To see clearly is poetry, philosophy and religion 
all in one. EMERSON 

Beginning at home. What biological discoveries have you 
made? Write down a list of them and tell in each case 
how you happened to make the discovery. Have you told 
anyone about them or published your discoveries so that 

355 



356 CIVIC BIOLOGY 

others may be helped or benefited by them ? How do you 
know that someone else has not discovered the same thing 
before you ? Has your father or mother, or some other 
member of your family, discovered anything of value to the 
community ? Do you know of anyone in your town or city 
who has discovered anything? If so, can you find the story 
in print or can you go to the person and get the story at 
first hand? 

Do we know of anyone in the United States or Canada, 
South America, Europe, Asia, Australia, or Africa, who has 
made notable biological discoveries ? Who is he, and what 
is the story of his work ? l 

Kinds of discoveries. Discoveries may be big or little ; they may be 
easy, made at a glance, or even stumbled on by accident, though in 
this case one must be intelligent enough to know what he has found, 
and be able to think what his discovery may mean to the world 
(" Accidents never happen among the Hottentots," it is said) ; or 
they may require years of application, complicated apparatus, and 
costly laboratories. 

A little girl of eight, by working from daylight till dark, discovers 
that a bobwhite will eat 1286 rose slugs in a day, and that when fed 
abundantly on insects, she will lay eggs. These are valuable little 
discoveries and have doubtless influenced efforts to protect the bob- 
white. A young woman devotes three years to studying the foods 
of the bobwhite, and publishes what is probably the most complete 
statement of the food of any bird. This will exert still more influ- 
ence for bird protection and must hasten the day when we shall have 
enough bobwhites to reduce weed seeds and insect pests, and it may 
suggest to others similar studies of other birds. 2 

1 As early as practicable, when the course is well begun and interest 
aroused, bring up these questions and make them the main subject of a 
lesson period ; or appoint a date and ask the class to prepare brief written 
statements in answer to the questions, and have them read and discussed. 
Invite some local discoverer to visit the class and tell of his aims, methods, 
and discoveries. 

2 Margaret Morse Nice, "Food of the Bobwhite.'' Journal of Economic 
Entomology, June, 1910, p. 295 ff. 



PKOGKESS IX DISCOVERY 357 

lu 1816 Mrs. Isabella Gibbs discovered the Isabella grape, and this 
liscovery is said to have turned attention to the culture of American 
grapes. Four years later Adlum discovered the Catawba. " A woman 
liscovered it growing wild," and we have a vigorous new blackberry, 
fche Blowers, added to the American list. Judge Logan discovers a 
hance seedling, and the Loganberry is saved to the world. Mr. Bull 
works a few years, and the Concord grape, and with it a new industry, 
is added to American horticulture. Mendel works eight years in his 
g-arden, and discovers his law of heredity. Jenner and Darwin each 
work twenty years, and the ideas of vaccination and the origin of 
species are placed at the service of mankind for all time. 

Importance. " One single idea may have more value than all 
the labor of all the men, animals, and engines for a century.'' 
Here are " mines," free to all alike, that dwarf our Kimber- 
leys, Nomes, and Klondikes to the small change of the passing 
hour, whose output is as much above gold and diamonds 
as mind is higher than matter. What kind of progress shall 
we make when all the people of the nation appreciate this 
point of view and begin to " know enough to work together" 
in pushing forward needed discoveries? 

We are approaching this degree of civic organization, as is 
evidenced by the growth of research departments in our uni- 
versities, by our experiment stations, and by the state and 
national scientific departments and the endowed private re- 
search foundations. All these are reaching down to search 
out talent, and ought to be inspiring every boy and girl to the 
most careful seeing and thinking of which they are capable. 
It is often said that Pasteur repaid to France the entire 
cost of her system of public education, from primary schools 
to university and from the beginning down to his time, by 
his one discovery of the cause and prevention of silkworm 
disease. So, as such values are being appreciated, the country 
and world are being searched for ability to discover. As its 
discoveries are the most priceless possessions of the race, 
and since advance in every field waits upon the discoverer 



358 CIVIC BIOLOGY 

to lead the way, the scientific organization of the nation and 
of the world says, virtually, to every young man and woman: 
" Show your mettle, demonstrate your ability to discover some- 
thing worth while, and equipment and material support will 
be supplied, and every avenue of opportunity will be opened to 
you. Shoiv power to think and to discover, and scholarships 
and fellowships are ready to place university apparatus and 
laboratories at your disposal" 

Historical. How have discoveries been made in the past ? 
How have we learned to make two blades of grass PTOW 

o o 

where one grew before ? How may we make ten blades 
grow where one grows now ? What does it matter that we 
know the value of fresh air, of pure water, of good food; 
that we know that the blood circulates ; that we have brains 
and nerves and muscles which require exercise and care ; 
and that we know about bacteria and parasites and the dis- 
eases they cause ? Do not these things, and all the rest for 
which the science of biology stands, mean the difference 
between a world of jungles and barren deserts, scourged by 
famines and pestilences, and a world of farms and gardens, 
full of happy, healthy people ? 

Men have lived in the world for at least five hundred 
thousand years, and astronomers tell us that the earth will 
be habitable for about five million years to come. Is it not 
remarkable how little we know, how little all the millions and 
billions of men and women who have lived have been able to 
discover, the handful of pebbles on the shore of the ocean 
of truth still to be discovered ? How incredibly slow progress 
in discovery must have been at first. How much do animals 
really " see " (in the sense in which Emerson uses the word) 
of the flowers and trees, birds, insects, and fungi in the fields 
they roam? And how little the best of us really see of all 
the things that happen in our fields, roadsides, and gardens. 
Without doubt thousands of choice varieties of flowers, 



PKOGKESS LN DISCO VEK1" 359 

grains, fruits, and nuts have lived and died out because 
no one saw the difference clearly enough to be able to 
think what they might mean to the world; and thousands 
more will go the same road until we learn to see and 
think civic ally. 

Our present-day discoverers. A number of names referred 
to in the text under various topics may be used for refer- 
ence. Our best authorities, as indicated in the preceding 
chapter, are often discoverers in their respective fields. 
They have probably won their positions by some creditable 
research work. Instead of trying to give a list of these it 
is better to gather the names as they appear as authors of 
our best books on birds, insects, forestry, agriculture, bacteria, 
health problems, and so on, or as they come to us from 
month to month in the biological journals or scientific bul- 
letins. We should be thankful to our discoverers for what 
they write, realizing that their work requires patient appli- 
cation and great sacrifice of time ; and while we follow their 
investigations in the libraries and journals, we should be 
very careful about encroaching upon their precious time by 
personal letters. Perhaps the most discouraging feature 
of our present situation is the overwhelming of our dis- 
coverer with inquiries by people who are too indolent to go 
to their libraries and read what he has written. For any 
special field we may have one or one hundred discoverers 
lor our one hundred million people. Figure out about how 
much time it would take to answer a million letters. 

Biological discoverers. From the following brief list, or 
I'rom any history of science or of medicine, let each member 
of the class choose some one discoverer, with whom he will 
become intimately acquainted during the remainder of the 
year. Let him go to the biographies and histories and strive 
10 catch the spirit that prompted the man to make his dis- 
coveries. Then, toward the close of the year, let each one 



360 



CIVIC BIOLOGY 



prepare a five-minute story to tell to the class. By timing 
these stories so that they follow in orderly sequence we may 
have the history of our science presented in an effective 
way. The aim is to kindle and foster the spirit of these men, 
so that increase in knowledge and progress in discovery may 
he assured from generation to generation. A number of names 
have been included for sake of completeness. The more im- 
portant and those especially interesting on account of their 
contributions to civic biology are printed in black-faced type. 1 

1551 Gesner: gathered first botani- 



B.C. 

540 Xenophanes : first to recog- 
nize fossils as proving that 
the earth was formed under 
the sea and rose out of it 

500 Heraclitus: often called the 
first evolutionist ; he first 
advanced the principle, irdv- 
TO. pet (all things flow) 

450 Empedocles : first to suggest 
natural selection and sur- 
vival of the fittest 
400 Hippocrates: called "the Father 

of Medicine" 
--350 Aristotle: founder of zoology 

320 Theophrastus : first botanist 

320 Erasistratusl 

, ., ^ first anatomists 
300 Herophilus J 



A.D. 

-. 79 
160 

^-1542 
1548 



Pliny : wrote first popular nat- 
ural history 

Galen : founded medical physi- 
ology 

Vesalius: founder of modern 
anatomy 

Falloppio : anatomist 



cal garden (of fruits and 
flowers) and first zoological 
museum 

1560 Eustachio : anatomist 

1583 Csesalpinus: classified plants 
by flowers 

1 590 Janssen, J. and Z . : discovered 
compound microscope 

1603 Fabricius: discovered valves 

in the veins 

v 1603 Harvey : discovered circulation 
of the blood 

1622 Ascello: discovered the lac- 
teals 

1649 Kudbeck: discovered the lym- 

phatics 

1650 Swammerdam: first great stu- 

dent of insects in relation 
to plants and medicine 
1661 Malpighi: discovered the capil- 
laries in the lungs ; founded 
modern embryology by a 
study of the incubation of 
the chick (1672) 

N 1667 Leeuwenhoek: first to see bac- 
teria 



V 1 Historical books to which the class should have access for this work 
are Locy, Biology and its Makers, New York, 1908 ; Baas, Outlines of the 
History of Medicine (translated by Handerson), New York, 1889 ; Mial, 
History of Biology, New York and London, 1911. 



PROGRESS IX DISCOVERY 



361 



1668 Redi : disproved spontaneous 
generation of insects by 
the discovery of eggs and 1794 
larvae ; wrote ff Esperienze 
intorno alia Generazione 
degl' Insetti " 

1070 Mayow : studied animal res- 1796 
piration 1796 

1671 Hooke : worked out micro- 
scopical structure of plants 1800 

1680 Borelli: proved that all the 
movements of animals are 
caused by muscles pulling 1801 
on bone levers; wrote "De 
Motu Animalium" 

1682 Grew : studied structure of 
plants 

1693 Kay : classified plants 1801 

1727 Hales: investigated respiration 
of plants 

- 1743 Haller: father of modern 

physiology 

1744 Reaumur : studied insects 1804 

* 1749 Buffon : wrote a natural his- 

tory 1807 

1 7 ">3 Linnaeus : classified plants 

1761 Kolreuter: studied hybridiza- 
tion of plants 1811 

1 76 1 Bonnet : evolutionist ; grouped 
animals in an ascending se- 
ries 1818 

1772 Rutherford: discovered ni- 
trogen 1823 

1774 Priestley: discovered oxygen 

and studied the breathing 
of plants 

1775 Spallanzani : disproved spon- 

taneous generation of bac- 1830 
teria and molds and demon- 1835 
strated presence of living 1838 
germs in the air 

1789 Galvani : discovered animal 1838 

electricity 

1790 Goethe: worked out a scheme 



for the metamorphosis of 
the parts of plants 

Darwin, Erasmus: grandfather 
of Charles Darwin ; wrote 
"Zoonoinia," a long poem 
outlining evolution of life 

Jenner : discovered vaccination 

Sprengel : studied fertilization 
of plants 

Cuvier: studied comparative 
anatomy ; wrote " Le Regne 
animal," 1817 

Lamarck: invented a scheme - 
for the evolution of animals 
(by conscious effort and in- 
heritance of acquired char- 
acters ; not proved) 

Treviranus : introduced the 
name "biology" as dis- 
tinguished from "botany," 
' f zoology, " f ' physiology, ' ' 
"anatomy," etc. 

Humboldt : studied distribu- 
tion of plants 

Rumford, Count : demon- 
strated absorption of car- 
bonic acid by plants 

Bell, Charles : discovered mo- 
tor and sensory nerve roots ; 
founder of modern neurology 

G. St. Hilaire : pointed out 
unity of plan in animals 

Baer : discovered the law of 
embryological development 
(higher forms repeat the 
evolutionary series as the 
embryos develop) 

Brown : described cell nucleus 

Dujardin : studied protoplasm 

Schleiden : discovered the cell 
as unit of structure in plants 

Schwann : discovered the cell 
as unit of structure in ani- 
mals 



362 



CIVIC BIOLOGY 



1839 Agassiz : wrote on fresh- water 
fishes 

1841 Helmholtz : discovered rate of 
nerve impulse 

1853 Mohl : studied protoplasm (liv- 
ing substance) 

1857 Pasteur: studied fermentation 

1858 Darwin : reported his work 

upon the origin of species 
by natural selection 

1858 Wallace : reported his work 
upon the origin of species 
by natural selection 

1858 Virchow : worked out cellular 
pathology ; founder of mod- 
ern pathology 

1863 Huxley: wrote "Evidence as 
to Man's Place in Nature" 

1863 Lyell: wrote ff The Antiquity 
of Man" 

1865 Sachs: studied structural bot- 
any 

"1865 Mendel: discovered the law of 
heredity 

1867 Lister : worked out aseptic 
surgery 

1875 Galton : studied inheritance 



1875 
1880 
1880 
1886 



1893 
1898 
1888 
1898 
1898 



1900 
f^/wv 
1900 

1903 
1914 
1915 



Hertwig, O. : studied ferti- 

lization 
Koch : proved the relation of 

bacteria to disease 
Laveran : discovered malarial 

parasite (in the mosquito) 
Leuckart: settled the modern 

classification of animals ; 

specialized on parasites 
Weismann: studied germ-plasm 
Reed "] discovered relation 
Finlay \- between yellow fever 
Lazear J and the mosquito 
Howard : discovered relation 

between typhoid fever and 

the house fly 



Correns 

mi i covered Menders 

Tschermak 

^ law of heredity 

Stiles : discovered hookworm 
in the United States 

Goddard : proved feeble-mind- 
edness a unit character 

Stockard: discovered influence 
of alcohol on offspring 



INDEX 



Abalones, 273, 274 

Acetic acid, 194 

Actinidia arguta, 88, 90 

Adder, 326 

Aedes calopus, 124-128, 130, 132, 134, 
154, 258; breeding places, 132; 
pictures of egg, larva, pupa, and 
adult, 124, 125; relation of, to 
yellow fever, 126, 127 

Aerobic bacteria, 221 

Agaricacece, 201-205 ; orders of, 204, 
205 

Agriculture, 91-106; breeding se- 
lected strains, 96-98; efficiency 
of, 93-96; fungous and bacterial 
diseases, 207-217; practical biol- 
ogy of, 91-106; problems of ani- 
mal industry, 102-104; relation 
of weeds to, 68 ; soil fertility. 98- 
100 ; value of land, 100-102 

Alcohol, 165, 191 ; influence of, on 
germ plasm, 340, 341, 343 ; manu- 
facture of, 194, 195 

Alfalfa, 101, 212, 223 

Algje, 188 

Alkaloid, 201 

Alligator, 321, 323 

Alligator terrapin, 324 

Almond, 165 

Amanita, 73, 76, 200-205; descrip- 
tion and picture, 201, 202 

American birds, orders of, 38-40, 
42-51 ; pictures of, 22 

American Bison Society, 171 

American cockroach, 154 

American crow, 48 



American elm, 84 

American false hellebore, 76 

American goldfinch, 49 

American goshawk, 45 

American insects, 253 

American laurel, 75 

American lobster. See Lobster 

American lotus lily, 307 

American magpie, 48 

American mammals, 169-172 

American osprey, 45 

American redstart, 50 

American robin, 51 

Amphibia, 313-320, 325 

Anaerobic bacteria, 221 

Animal diseases, 110 

Animal industry, 102-104 

Animal parasites, 253-269 

Anopheles, 127, 130, 131, 134, 154, 
257 ; breeding places of, 132 ; pic- 
ture of eggs, larva, pupa, and 
adult of, 125; relation of, to ma- 
larial fever, 123, 124 

Antelope, 169, 261 

Anthracnose, 210, 212, 215 

Anthrax, 235, 236, 248 

Antimeningitis serum, 111 

Antisepsis, 248 

Antitoxins, 243, 247-249 

Antivenins, 329 

Ants, 141-147; carpenter ant, 146, 
147; economic importance, 141; 
food, 143; rearing of, in labora- 
tory, 145-147 ; red ants, 155 ; spe- 
cial senses, 143; warfare, 144; 
white ants, 153, 155 



364 



CIVIC BIOLOGY 



Apauteles, enemies of, 140 

Aphids, 61, 142, 162, 166 

Apoplexy, 232 

Apparatus, 11 

Appendicitis, 234 

Apple, 94, 165 

Apple Day, 299 

Apple of Peru, 76 

Apple tree, blight of, 212, 213, 216 ; 

enemies of, 155, 156 
Aquaria, 10, 315; cement for, 15; 

making of, 12-15; management 

of, 299-303 

Aquatic duck foods, 307 
Arachnids, problems of spiders, 

mites, and ticks, 163-168 
Arbor Day, 299 
Arbor vitse, 59, 165 
Army worm, 156, 317 
Arsenate of soda, 71 
Arsenic, poison for rats, 180 
Artesian wells, 219 
Asepsis, 248 
Asiatic poppy, 73 
Asparagus beetle, 156 
Asters, 86 

Atlantic salmon, 309 
Atlantic squid, 284 
Australian duck-bill, 169 

Bacteria, 176, 214; blight or wilt 
from, 215 ; control of bacterial 
diseases, 231-251 ; culture of, 
224-230; distribution and forms 
of, 218; fungous and bacterial 
diseases of plants, 207-217; gen- 
eral discussion and treatment of, 
186-191, 218-251 ; kinds of, 218, 
220, 221, 234, 236, 242; labora- 
tory methods and experiments, 
224-230; parasitic, 187; pictures 
of, 236 ; reproduction of, 220, 221; 
saprophytic, 221; size of. 218; 



symbiotic, 187, 221 ; venomous 

forms of, 234 ; work of, 221 
Bacterins, 248 
Badger, 171 
Bald cypress, 59 
Bald eagle, 45 
Balsam, 59 
Baltimore oriole, 48 
Banana, food for mosquitoes, 131 
Bank swallows, 49 
Banostine Belle de Kot, 103 
Barium carbonate, 1 79 
Bark disease, 247 
Barn swallows, 49 
Barnacles, 287 
Basket willow, 307 
Basses, 309 
Basswood, 59, 82 
Bats, 129, 169 
Bean blight, 215 
Bear corn, 76 
Bears, 155, 169 
Beaver, 171, 172, 261 
Bedbug, 154, 236 
Beech, 59 

Bees, 152, 153, 158; honeybee, 157 
Beetles, 20, 21, 153-156, 317, 318 
Belladonna, 73 
Belted kingfisher, 46 
Benzine, 165 
Bindweed, 71 
Biological library, 16, 17; using of, 

349-351 
Biology, instruction and research in, 

346 

Birch, 59, 83, 84 
Bird Day, 299 
Bird fountain, 29 
Birds, 22-53, 313, 317 ; adaptation of, 

to environment, 37 ; attracting, 

28, 31, 33; conservation of, 63; 

destruction of insects, 23, 24, 25 ; 

divisions of, 32; economic value 



IXDEX 



365 



of, 24 ; food of, 24, 25, 30, 34, 42 ; 
food chart, 33; methods of bird 
study and special problems, 35- 
53 ; migration, 29, 30, 31 ; number 
needed, 28 ; orders of, 22, 37-53 ; 
outdoor laboratory work, 25-31 ; 
plan of course, 23 ; topics for study, 
31,32; topography of, 37; winter 
feeding of, 31 ; work suggested, 31 

Bison, 169, 171 

Bitter rot, 210, 212, 213 

Bittersweet, 76 

Bivalves, 274 

Black basses, 309 

Black carpet beetle, 154 

Black cherry, 59, 75 

Black death, 175, 177, 233 

Black flies, 113 

Black gum, 59 

Black knot, 207 

Black mustard, 70 

Black nightshade, 76 

Black rot of cabbage, 212 

Black snakes, 326 

Black walnut, 59, 60, 82, 83 ; pictures 
of, 61, 66 

Black-and-white warbler, 50 

Blackberry, 94 

Black-billed cuckoo, 46 

Blackbirds, 34, 48 

Blackleg, 248 

Blight, on bean, 215 ; fire blight, 212 ; 
on pear and apple, 212, 213 ; on 
potato, 210, 215 

Blister, or oil, beetle, 156 

Blood, good and bad, 344 

Blood-sucking conenose, 154 

Blowfly, 154, 318 

Blowing adder, 326 

Blowing viper, 327 

Blue crabs, 287, 292 

Blue jay, 48 

Blueback salmon, 309 



Bluebird, 49, 51 

Bluebottle, 112, 154 

Bluegill, 299, 306, 307, 309 

Blue-tailed lizard, 325 

Bobolink, 48 

Bobwhite, 34, 41, 42, 53, 332 

Body louse, 154 

Boils, 233, 234, 236, 248 

Bollworm, 156 

Bordeaux mixture, 209, 217 

Borer beetle, 155 

Botflies, 113, 157 

Bovine malaria, 257 

Bovine tuberculosis, 110, 223 

Box tortoise, 324, 325 

Bright' s disease, 232 

Broad-leaf laurel, 75 

Bronchitis, 234, 235 

Bronzed grackle, 48 

Brook trout, 309 

Brooks's law, 291, 292, 308 ; applied to 
food and game fishes, 308 ; applied 
to the lobster problem, 286, 291, 292 

Brown creeper, 51 

Brown rot, 207, 210, 211 

Brown thrasher, 51 

Brown-tail moth, 20, 156, 160-162 

Bubonic plague, 2, 107, 175-177, 215, 
234, 248 

Bugbane, 76 

Bull thistle, 71 

Bullfrogs, 313, 315, 316, 317, 319 

Burdock, 71, 72 

Burrowing rootstocks, 71 

Butter clam, 278 

Butterflies, 153; cabbage, 21, 136-140 

Butternut, 59 

Cabbage, 94, 98 ; black rot of, 212 
Cabbage butterfly, 21, 136-140; con- 
trol, 138-140; dispersal, 137; fe- 
cundity, 136 ; life history, 136-137 ; 
natural enemies, 136 



366 



CIVIC BIOLOGY 



Cabbage caterpillar, 25 

Cabbage looper, 156 

Cabbage and radish maggot, 156 

Cabbage worm, 156 

Caddis flies, 153 

Calcium, 98, 99, 100 

Calcium chloride, 249 

Calico bush, 75 

Calico mosquito, 127 

California poison sumac, 75 

Camel, 261 ; itch mite of, 166 

Campaign, anti-fly, 119, 120; anti- 
mosquito, 134, 135 

Camphor tree, 73 

Canada goose, 39 

Canada thistle, 71 

Cancer, 232, 234 

Canker, 215 

Cankerworm, 50, 51, 155 

Cannas, 86 

Caper spurge, 76 

Carabid beetle, 317 

Carbolic acid, 71, 249 

Carbon, 98 

Carbon bisulphide, used in destroy- 
ing rats, 181 

Carbonic acid, 187, 191, 194, 195 

Cardinal flower, 67, 154, 306, 307 

Carpenter ant, directions for study 
of, 146, 147 

Carpet beetle, 154 

Carrot, 105 

Casein, 189 

Case-making moth, 154 

Cases, insect-rearing, 10 

Cashes, 75 

Cat, 165, 182, 256, 263, 267 ; relation 
of, to diphtheria, 245, 246 

Catbird, 51 

Caterpillar, 45 

Catfish, 306, 307, 309 

Cattle, 171 

Cattle tick, 167 



Cedar, 83 

Cedar wax wing, 50 

Cephalopods, 274, 284 

Cerebral hemorrhage, 232 

Cerebrospinal meningitis, 248. See 

also Meningitis 
Cestodes, 260, 262 
Chameleon, 325 
Chara, 307 
Cheese, Camembert, 189; Limburger, 

189 ; Roquefort, 189 ; Stilton, 189 
Cheese or ham skippers, 154 
Cherry bird, 50 
Cherry louse, 156 
Chestnut, 59, 60, 82, 83 
Chestnut-bark disease, 215 
Chewink, 49 
Chickadee, 50, 51 

Chickens sick with limber neck, 122 
Chicks killed by rats, 174 
Chickweed, 70, 71 
Chiggers, 165 
Children's bane, 75 
Chimney swift, 47 
Chinchbug, 42, 156 
Chinese pernicious scale, 156 
Chinook salmon, 309 
Chipping sparrow, 47, 49 
Chlorine, 98, 114 
Cholera, 107, 235, 236, 245, 248; 

fowl, 110, 233 ; hog, 110, 248 
Cholera inf antum, 20, 107 
Cicadas, 153 
Cinchona, 73 
Citronella, 128 
Civic biology, definition of, 1 ; plan 

of course, 3-9 

Civic fly campaign, 119, 120 
Civic forestry, 55-66 
Clam, 274 ; butter, 278 ; gaper, 278 ; 

giant, 278 ; hard, 273 ; life history 

of, 278, 279 ; little-neck, 277; razor, 

273 ; soft, 273 ; surf, 273 



INDEX 



367 



Cliff swallows, 49 

Clothes moths, 154 

Clover mite, 165 

Cluster fly, 154 

Clydesdales, 333 

Coal oil, 71 

Coast newt, 320 

Cobra, 327 

Cocaine, 343 

Cockles, conchs of, 273 

Cockroaches, 153, 154. See also 

Roaches 
Cod, 309 

Codling moth, 21,155; type for study, 6 
Coffee, 344 

Cold, 233, 234, 246, 250, 251 
Cold storage, 269 
Coleoptera, 153 
Collecting nets, 12 
Colorado blue spruce, 83 
Colorado potato beetle, 156 
Common stramonium, 75 
Conchs, 273, 274 
Concord grapevine, 339 
Condiments, 71 
Conifers, 59 
Consumption, 234 
Contact infection, 246 
Coontail, or hornwort, 307 
Cooper's hawk, 45 
Copepods, 287, 288, 289 
Copperas, 114 
Copperhead, 322, 327 
Coral snake, 328 
Corn, 93, 94, 95 
Corn cockle, 75 
Corn snake, 326 

Corn-ear and tomato worm, 156 
Corn-root aphis, 156 
Corrosive sublimate, 249 
Cotton, 93 ; pests of, 156 
Cotton worm, 156 
Cottonmouth, 327 



Cottonwood, 59, 165 

Cottony cushion scale, 20, 156 

Cottony maple scale, 156 

Couch grass, 71, 72 

Cow, 102, 103, 165, 263 

Cowbane, 75 

Cowbird, 47, 48 

Cowpox, 258 

Cowslip, 306, 307 

Crab, 287, 292-294 

Crab apple, 82 

Crappies, 306, 309 

Crawfish, 287, 293, 294, 306, 307, 
317, 318 

Crested flycatcher, 47 

Crickets, 153 

Crimson Rambler rose, 97 

Crocodiles, 321, 323 

Crocus, 197 

Crops, standards and percentage of 
efficiency of, 93, 96 

Cross-pollination, 157, 158 

Croton bug, 154 

Croup, 232 

Crown gall, 212, 216 

Crows, 48 

Crude drugs, 71, 73 

Crude sulphuric acid, 71 

Crustacea, 285-294, 315, 324 ; prod- 
ucts of, 287 

Cuban pine, 59 

Cuckoo, food of, 25, 46 

Culex mosquito, 124, 125, 127, 128, 
129, 130, 131, 132 ; breeding places, 
132 ; extermination of, 128 ; flight, 
128 ; picture of eggs, larva, pupa, 
and adult, 129, 130 

Curculio beetles, 155 

Curled dock, 70, 71 

Currant borer, 156 

Currant worm or slug, 157 

Cuttlefishes, 274 

Cutworms, 25, 156, 317 



368 



CIVIC BIOLOGY 



Dahlia, 86 

Dandelion, 72 

Dandruff, 236 

Darwin, Charles, 330, 331, 333, 338 

Datura stramonium, 72, 75 

Death-cup mushroom, 76 

Death-of-man, 75 

Deer, 169, 171, 172, 261, 263 

Deer farming, 172 

Deer flies, 113 

Delaware grape, 85 

Devilfishes, 274 

Devil's apple, 75 

Devil' s-bite, 76 

Diamond-backed terrapin, 324 

Diarrhea, 232, 233, 234 

Diphtheria, 177, 232, 234, 235, 23(5, 
239, 243, 245, 246, 248, 250, 25] 

Diptera, 153, 155 

Discoverers, biological, 359-362 ; 
present-day, 359 

Discovery, history of, 358, 359 ; im- 
portance of, 357-358; kinds of, 
356, 357 ; progress in, 355-362 

Distemper, 248 

Dock, 72 

Dodder, 188 

Dodo, 42, 43 

Dog, 165, 182. 257, 263 ; influenced 
by alcohol, 341 ; itch mite of, 166 ; 
as a transmitter of rabies, 256 

Dog tick, 168 

Dogwood, 75 

Dourine, 259 

Doves, 34, 42, 43 

Downy woodpecker, 6, 46 

Dragon flies, 129, 153 ; nymphs of, 
as enemies to young mosquitoes. 
131 

Drop, a disease of lettuce, 210 

Drug plants, 72 

Drug-store beetles, 155 

Dry rot, or stem blight. 216 



Duck, 38 ; attacked by rats, 174 
Duck hawk, 45 
Duck potato, or wapata, 307 
Duckmeat (Lemna), 307 
Duck-retter, 76 
Dwarf larkspur, 76 
Dysentery, 20, 107, 110, 233, 235, 
245, 256 



le, 44 
Earthworm, 25 
Eczema, 236 
Effluvia, 237 
Egg record, 104 
Egret, 40 
Elderberry, 86 
Elk, 169, 171 
Elm, 59, 82-84, 165 
Elm-leaf beetle, 21, 156 
Elodea, 307 
Endocarditis, 232 
English sparrow, 45, 49, 50, 182 
Enteritis, 107, 232, 234, 235. Sec 

also Gastro-enteritis 
Entomostraca, 287 
Eohippus, 333 
Erysipelas, 234, 251 
Eugenics, 344 
European root disease, 212 
Evening primrose, 70 
Evolution, 338 
Excursions, plans for, 7, 8, U 

Facultative bacteria, 221 
Fall web worm, 155 
Farm crops, relative fertility of, 101 
Feeble-mindedness, causes and con- 
sequences of, 344 
Felons, 233 
Fence swift, 325 
Fermentation, 191, 194, 195, 196 
Ferns, 188 
Field mice. 34. 44 



LSJJE.X 



369 



Field observations and records, 4, 5 

Filariasis, 253 

Filth-disease fly, 107 

Filth-disease infections, 107, 110 

Fire blight, 212 

Fish hatchery made from tumbler. 
303 

Fish hawk, 45 

Fish ponds on farms, 296 

Fishes, 39, 306, 317; classification 
and species, 304 ; economic and 
civic value, 310 ; enemies of mos- 
quitoes, 131 ; habits and spawning 
seasons, 308 ; problems of fish and 
fishing, 295-311 

Fishes Day, 299 

Flat-headed apple-tree borer, 165 

Flatworms, 255, 260 

Flea, 182, 236, 240 ; burrowing 
(chigoe), 155 ; cat, 154 ; dog, 154 ; 
hen, 155 ; rat, 154 

Flea beetle, 166 

Flesh flies, 112 

Flicker, 46 

Flies, 107-122, 152, 153, 182, 242, 245, 
261, 268, 332 ; blood-sucking, 259 ; 
blowfly, 154, 318 ; bluebottles, 112, 
154 ; botflies, 113, 157 ; campaigns 
against, 110, 111, 117, 118, 120, 
122; cluster fly, 154; fecundity 
of, 117 ; fruit fly, 154 ; greenbottle, 
112, 154; hibernation of, 117; 
hornfly, 113, 121, 157 ; kinds, 111, 
112, 113, 118, 154, 318; life his- 
tory of, 116 ; nets for catching, 
119; relation of, to disposal of 
waste, 114, 115 ; screens for, futil- 
ity of, 110 ; stable, 108, 109 ; traps 
for outdoors, 115, 118 ; tsetse, 230 ; 
work of, 107, 1 10 

Flood plane, 56 

Floods, cause of and damage from, 
65, 56 



Flowering beau, 86 

Flowering quince, 97 

Flowers in relation to landscaping, 
86 

Flukes, 260 

Flycatchers, 47 

Fomites, 237, 238 

Food, law of absorption, 189, 190 

Foot-and-mouth disease, 110, 233, 256 

Forest fires, causes of, 61, 64 ; dam- 
age from, 55, 62, 64; laws 
regulating, 66; relation of, to 
tree-planting, 65 

Forest preserves, 171 

Forestry, annual growth of trees, 55 ; 
consumption of wood, 55; effects 
of adequate planting, 57, 58; 
natural enemies of trees, 156; 
study of local problems of, 58 ; 
study of trees and civic viewpoint, 
54-66 

Formalin, as germicide, 249 ; use of, 
to prevent potato blight, 216 

Formicary, 145 

Foul brood, 233 

Fowl cholera, 110, 233 

Fowl tuberculosis, 110 

Fox sparrow, 49 

Foxglove, 78 

Foxtail, 70 

Fresh-water mussel, 273, 279, 281 

Fringed gentian, 67 

Frog, 39, 306, 313, 314, 315, 317, 
318, 320; possibilities of culture, 
318 

Fruit fly, 154 

Fungi, 73, 97, 186-191; bacteria, 
general treatment of, 218-251 ; 
fungous and bacterial diseases of 
plants, 207-217; molds and mil- 
dews, 197-199; mushrooms, poi- 
sonous and edible, 200-206 ; yeasts, 
191-197 



370 



CIVIC BIOLOGY 



Fungous diseases, 207-213; damage 
from, 207 ; organizing for the con- 
trol of, 217 

Fur farming, 172 

Fur-bearing animals, 3 

Gall insects, 157 

Game, 3; killed by rats, 174 

Game birds, 3; conservation of, 53. 

Gaper clam, 278 

Gapeworm, 254, 266 

Garden slug, 282, 283 

Garden spurge, 76 

Garter snake, 326 

Gartered plume moth, 156 

Gastro-enteritis, 111. See also Enter- 
itis 

Gastropods, 274, 282, 283, 284 

Geese, 38, 53, 325 

Genetics, 330, 337 ; organized study 
of, 339 

Gentians, 67, 306 

Geoduck, 278. See also Giant clam 

Geometrical increase, illustrated by 
diagram, 331 ; law of, 331-332 

Germ plasm, 338 ; injury to, 340, 343 

German roach, 154 

Germicides, 248 

Giant clam (geoduck), 278 

Gila monster,. 325 

Ginseng, 73 

Glanders, 235 

Gnat catcher, 51 

Gnats, 111, 153 

Goat, 169, 261 ; itch mite of, 166 

Golden plover, 40 

Goldenrod, 86 

Goldfinch, 49 

Gonococcus infection, 240 

Gonorrhea, 107 

Gopher, 30, 34, 44 

Gopher plant, 76 

Gopher snake, 326 



Gopher tortoise, 325 

Goshawk, 45 

Grackle, 48 

Grain, pests of, 156 

Grain aphis, or green bug, 156 

Grape, 6, 85, 87, 88, 94 

Grape-berry moth, 156 

Grapevine root beetle, 156 

Grasshoppers, 25, 152, 153, 156, 318; 

diagram of, 151 
Great horned owl, 45 
Great laurel, 76 
Green frog, 315, 316 
Green turtle, 324 
Greenbottle fly, 112, 154 
Grippe, 234, 236, 250, 251 
Ground itch, 268 
Grouse, 40 
Grubb, 94 

Guatemalan ant, 141 
Guernsey, 103 
Guinea pigs, experiments showing 

influence of alcohol upon, 340 
Gull, 38 
Gypsy moth, 20, 69, 148, 156, 159, 

160, 162, 317 

Hair snakes, 265 

Hairy woodpecker, 46 

Hard, or little-neck, clam, 277 

Hardy perennials, 86 

Hares, 165, 169 

Harlequin snake, 328 

Harvest mites, 163, 165 

Harvestmen, 164 

Hawks, 30, 34, 44, 45 

Hawksbill, 324 

Heath hen, 42 

Heliotrope, 86 

Hellebore, 76 

Hemiptera, 153 

Hemlock, 69, 75, 83 

Hen, 104 



INDEX 



371 



Hen flea, 155 

Herbicides, 71 

Herbs, 71, 73 

Heredity, laws of, 330, 334, 338 

Hermit thrush, 51 

Heroin, 343 

Heron, 39, 40 

Herring gull, 38 

Hessian fly, 21, 156 

Hickory, 59, 60, 82 

High laurel, 75 

"Hill Folk, The," 345 

Hip disease, 234 

Hog and fowl cholera, 110, 233 

Hollyhocks, 86 

Holstein, 103 

Honey locust, 82 

Honeybee, 157 ; relation of, to tree 
fertility, 157 

Hookworm, 107, 2~53, 254, 256, 268 

Hookworm disease, 254, 268 ; pic- 
tures of victims of, 252 

Horehound, 72 

Horn fly, 113, 157 ; life history, 121 

Horned lark, 48 

Horned toad, 325 

Horse, 165, 257, 261 ; itch mites of, 
166 

Horse botfly, 157 

Horse-chestnut, 75 

House ant, 155 

House cricket, 154 

House fly, 20, 317; breeding places, 
113, 114 ; fecundity, 18 ; relation of, 
to filth, 116, 118. See also Flies 

House pets, 245 

House wren, 51 ; food of, 25 

Household insects, 154, 155 

Hydrogen, 98 

Hydrophobia, 256 

Hymenoptera, 153, 156 

Hypochlorites, 249, 251 

Hypochlorous acid, 249 



Human flea, 154 
Human mite, 166 
Human tapeworm, 260 
Humming bird, 6, 46 
Humming-bird moth, 155 

Ichneumon fly, 136 

Imported currant fly, 21 

Indian corn, 95 

Indian pipe, 188 

Indian poke, 76 

Indian-meal moth, 155 

Indigo bunting, 49 

Infantile paralysis, 20, 122, 236, 256 

Infection, 110, 122, 246 

Inflammation, 234, 236 

Inflammatory fever, 248 

Influenza, 235 

Insect-catching bottle, 131 

Insecticides, 152 

Insectivorous birds, 44 

Insects, 44, 51, 97, 176, 250, 253, 313, 
315 ; attacking animals, 157 ; bene- 
ficial, 157 ; cases for mounting, 11 ; 
classification of, 150, 151, 152; 
damage and loss from, 19, 20, 24 ; 
fecundity of, 18 ; household, 154, 
155 ; injurious to vegetation, 155, 
156, 157; literature on, 149; nets 
for catching, 11, 12 ; orders of, 153; 
parts of, 152 ; size of, 18 ; work 
of, 18; work of controlling, 20 

Ireland, famine in, 208 

Iris, 86 

Iron, 71, 98, 99 

Ironwood, 59 

Itch mites, 166 

Itchweed, 76 

Ivy, 75, 76 

Ivy wood, 75 

Jack pine, 59 
Jamestown lily, 75 



372 



CIVIC BIOLOGY 



Jamestown weed, 75 

Japanese maple, 83 

Japanese quince, 89 

Japanese snowball, 89 

Jays, 48 

Jimson weed, 72, 75 

Jukes family, 345 

Junco, 49 

June beetles, 153, 156 

Kallikak family, diagram outlining 

history of, 342 
Kalmia, 75 
Kangaroo, 261 

Kerosene, remedy for dog tick. 168 
King cobra, 328 
Kingbird, 47 
Kingfisher, 46 
Kinglets, 51 
Kissing bug, 154 

Laboratory, outfit of, 10 

Laboratory work, outdoor, 25 

Lacewings, 153 

Lady beetle, 153; Chinese, 20-21 

Lady's-slipper, 67 

Lamb's-quarters, 69, 70 

Lamellibranchs, 279 

Lancaster elm, 78, 79, 80 

Land, relative value of, 100, 101 

Land salamander, 315 

Land snail, 283 

Landscape gardening. 77-90 

Larch, 83 

Larder beetles, 155 

Lark, 34, 48 

Larkspur, 76 

Late blight, or rot, 216 

Laurel, 75 

Lawn, 71 

Lead acetate, antidote for poison of 

ivy, oak, and sumac, 74 
Leaf spot, 212 



Leaf-eating sawflieg, 157 

Least flycatcher, 47 

Leghorn, white, 104 

Legumes, 188, 222 

Lemna, 307 

Leopard frog, 315, 316, 319 

Leprosy, 107, 234, 251 

Lettuce, 94 

Library, using of, 349 

Lice, 153, 154 

Life, practical laws of, 330-345 

Lilies, 86 

Lily, 94 

Limber neck, chickens sick with, 122 

Lime, 99, 100, 102, 223 

Lincoln, 92, 95 

Linden, 82 

Little black ant, 155 

Little house fly, 112 

Liver fluke, 261 

Lizard, 321, 323, 325 

Loblolly pine, 59 

Lobster, 286-294 ; propagation, 289 

Lockjaw, 234, 248 

Loco weed, 73, 74 

Locust, 59, 82 

Loggerhead turtle, 324 

Long-leaf pine, 59 

Loons, 38 

Louse, 154, 156 

Lupus, 234 

Lycoperdacew, 203 

Lynxes, 169 

Magnesium, 98, 99 

Magpie, 48 

Maidenhair fern, 67 

Malaria, 20, 123, 124, 125, 134, 236, 

252, 254 ; bovine, 257 ; prevention 

of, 133, 257 
Malarial mosquito, 154 
Malarial parasites, 256, 257 
Mallard duck, 39, 306 



INDEX 



373 



Mammals, 34, 167, 176 ; American 
Mammal Problems, 169-172 ; 
orders of, with pictures of habi- 
tats, 170 

Man, 176 

Manganese, 98 

Manure, barnyard, 70 ; disposal of, 
115 ; relation of, to flies, 114, 115 

Maples, 59, 83 

Marigold, 86 

Markweed, 75 

Marsh hawk, 45 

Marsh wren, 51 

Martin, 49, 171 

Massasaugas, 327 

Mayweed, 70 

Meadow lark, 48 

Meal worm, 155 

Measles, 36, 215, 232. 233, 236, 239, 
247, 256 

Medicinal plants, 71 

Mendel's law, 330, 337, 344, 345; 
diagram illustrating, 335, 338 ; 
history of, 336 

Meningitis, 107, 234. See alxo Cere- 
brospinal meningitis 

Meningococcus, 234 

Mercuric acid, cure for potato scab, 
216 

Mercuric chloride, 249 

Mercury, 75 

Miasms, 237 . 

Mice, 30, 34, 44, 174, 182, 183, 184, 
185, 245, 267 

Mildew. See Molds 

VI ilk, pasteurizing of, 244 

Milkweed, 69, 71 

Minks, 169 

Mission grape, 85 

Mites, 163-168, 236; clover mite, 
' 65 ; harvest mite, 163, 165 ; itch 
lite, 166 ; poultry mite, 167 ; red 
' aite, 129 ; sheep-scab mite, 166 



Moccasins, 327, 328 

Mocking bird, 50, 61 

Molds and mildews, 97, 186, 189, 191, 
193, 194, 210; botanical position 
and structure of, 197, 198 ; obser- 
vation of and experiments with, 1 99 

Mole plant, 76 

Moles, 30, 165, 171 

Mollusca, classification of, 274 

Mollusks, 271-284 

Mongolian, or ring-necked, pheasant, 
42 

Monkey, 263 

Moose, 169 

Morphine, 343 

Mosquito, 20, 111, 113, 119, 123-135, 
153, 154, 164, 182, 236, 240, 253, 
257, 332 ; breeding places of, 131, 
132 ; kinds of, 125 ; life history 
of, 124, 128 ; methods of extermi- 
nation of, 133 ; natural enemies 
of, 129, 131 ; planning of cam- 
paign against, 134, 135 

Mosses, 188 

Moth, 153, 318 ; case-making, 154 ; 
clothes, 154 ; codling, 6, 155. See 
also Brown-tail moth, Grape-berry 
moth, Gypsy moth, White-marked 
tussock moth 

Mountain laurel, 75, 80 

Mountain sheep, 169 

Mourning dove, 43, 44 

Mucket shells, 307 

Mud, or pond, terrapins, 326 

Mud puppies, 314, 320 

Mulberry, o9 

Mullein, 71, 72 

Mumps, 247 

Mushrooms, 73, 186, 189, 197, 210 ; 
cause of root rot, 211 ; classifica- 
tion of, 203-206; poisonous and 
edible, 200-206 

Musk grass (Chara), 307 



374 



CIVIC BIOLOGY 



Muskrat, 171 

Muskrat weed, 76 

Musquash root, 75 

Mussels, 273, 274, 279-281, 306 

Mustard, 70, 72 

Mutation, 338 

Myriapods, 317 

Myriophyllum, 307 

Mytilus, 276, 277, 278, 279 

Nagana, or tsetse-fly disease, 259 

Nam family, 345 

Nasturtium, 86 

Native plants, conservation of, 67 

Natural selection, law of, 335 

Nautilus, 274 

Nematodes, 264, 265, 266 

Nephritis, 232 

Nets, collecting, 11 ; fly, 119 ; ma- 
terials for making, 12 

Neuroptera, 153 

Newts, 131, 314, 320 

Nicotine, 343 

Niggerhead, 280 

Nighthawk, 47 

Nightshade, 76 

Nitrates, 102 

Nitrifying bacteria, 222 

Nitrogen, 47, 98-101, 187 

Norman Percherons, 333 

Notebook, instructions for keeping, 
in field and laboratory, 11 

Noxious mammals, 30, 44 ; destruc- 
tion of, 44 

Nuthatches, 51 

Nuts, importance of, and suggestions 
for growing, 60 

Oak, 59, 83, 84 

Oats, 93 

Octopus, 274 

Oil, coal, 71 ; olive, 128 ; of tar, 128 

Onion maggot, 156 



Ophthalmia, 107 

Opium, 343 

Opsonic index, 248 

Orchard orioles, food of, 25 

Orchard pests, 155 

Oregon water hemlock, 76 

Oriental cockroach, 154 

Orioles, 48 

Orthoptera, 153 

Osprey, 45 

Otter, 171 

Ovenbird, 50 

Owls, 30, 34, 44 

Oxygen, 98, 194 

Oyster, 271, 274, 279; Atlantic, 273 ; 

Pacific, 273 ; producing sickness, 

272 

Oyster drill, 282 
Oyster-shell scale, 156, 332 

Pacific clam, 278 

Pacific crab, 292 

Painted tortoise, 325 

Pangenesis, 338 

Panther, 169 

Parasites, use of, to control insects. 

161 

Parasitic bacteria, 221 
Parasitic protozoa, 255 
Parasitic worms, 107 
Parsnips, 105 
Passenger pigeon, 36, 43, 44 ; egg 

of, 43 ; picture of, 30 
Pasteur, 195, 209 
Pavement ant, 155 
Peach, 94, 165 
Peach yellows, 214, 215 
Peach-tree borer, 155 
Pear, 94 

Pear and apple blight, 212, 213, 216 
Pear slug, 157 
Pear-blight beetle, 155 
Pearl fishing, 279, 280 



INDEX 



375 



Peac-tree borer, 155 

Pec in, 60 

Peeper, 310 

Pel agra, 113, 251 

Pei nyroyal, 128 

Pec uies, 86 

Pepper bush, 86 

Peppergrass, 70, 71 

Perch, 306 

Perennial crowns, 71 

Pe Litonitis, 234 

Periwinkle, 274 

Pheasants, 40 

PLenol, coefficient of, 249 

PI loxes, 86 

Phcebe, 47 ; food of, 25 

Phosphates, 223 

Phosphorus, 96, 98, 99, 100, 101; 
used for poisoning rats, 181 

Pickerel frog, 315, 316, 319 

Pied-billed grebe, 38 

Pig, 261 ; as host for trichina worm, 
267 ; itch mites of, 166 ; tapeworm 
of, 263 

Figeon, 35, 36, 42 ; killed by rats, 
174; kinds of : band-tailed pigeon, 
43 ; passenger pigeon, 43 ; red- 
billed pigeon, 43 ; Viosca's pigeon, 
43 

1 Mgeon grass, 70 

Pigeon hawk, 45 

Pigweed, 69, 70 

Pimples, 248 

Pine, 59, 83, 84 ; white pine, study 
of, 4, 5, 6 

Pintail, 39 

Pinworm, 266 

Piroplasmas, 257, 258 

Pitch pine, 59 

Plague, 236 

Plankton, 219 

Plant food, essential elements of, 99 ; 
losses in, due to cropping, 102 



Plant lice, 153, 156, 164 ; fecundity 

of, 18 
Plant problems, 67-76 ; conservation 

of native plants, 67 
Plantain, 71 
Plover, 40 
Plum, 165 

Plymouth Rock, 104 
Pneumococcus, 234 
Pneumonia, 121, 184, 232-236, 248, 

250, 251 
Poison ash, 75 
Poison elder, 75 
Poison hemlock, 72, 75 
Poison ivy, 74, 75 
Poison laurel, 75 
Poison oak, 74, 75 
Poison root, 75 
Poison snakeweed, 75 
Poison sumac, 74, 75 
Poisonous plants, damage from, 73 ; 

list of, 75, 76 

Poisonous snakes, 110, 327-329 
Pokeroot, 76 
Pokeweed, 75 
Poliomyelitis, 122 
Ponds, as balanced aquaria, 304 ; 

possible production from, 307 
Poplar, 165 
Porpoises, 169 
Potash, 102, 223 
Potassium, 96, 98, 99, 100, 101 
Potato, 93, 97 ; blight or scab of, 

210, 215 

Potato beetles, 42, 153 
Poultry, 103, 104 
Poultry mite, 167 
Pout, 306 

Prairie chicken, 53 
Prawns, 287 
Proteans, 313 
Protein, 187, 189 
Protozoa, 255, 256 



376 



CIVIC BIOLOGY 



Puerperal fever, 234 
Puffballs, 189, 191, 203, 206 
Pulmonary tuberculosis, 249 
Purple beech, 83 
Purple cornflower, 73 
Purple finch, 49 
Purple martin, 49 
Purslane, 69, 70 

Quack grass, 72 

Rabbit, 169, 261 

Rabid dogs, 110 

Rabies, 248, 256 

Ragweed, 70 

Railroad worm, 156 

Rainbow trout, 309 

Raspberry, 94 

Rat snake, 326 

Rats, 30, 34, 44, 245, 267, 332; 

damage from, 2, 174, 175, 176; 

extermination of, 3, 177-184; 

fecundity of, 2, 173; poisoning 

of, 179, 180, 181 ; problem of, 

173-185; trapping of, 177, 178, 

179, 182, 184, 185 
Rattlebox, 76 

Rattlesnake, 253, 322, 327, 328 
Red ant, 155 
Red buckeye, 75 
Red cedar, 59 
Red gum, 59 
Red mite, 129 
Red pepper, 73 
Red pine, 59 
Red spider, 163, 164 
Red-backed salamander, 316 
Red-eyed vireo, 50 
Red-headed woodpecker, 46 
Red-humped apple-tree caterpillar, 

156 

Red-legged locust, 156 
Red-shouldered hawk, 44, 45 



Redstart, 50 
Red-tailed hawk, 45 
Red-winged blackbird, 48 
Reptiles, 321-329 ; products of, 321, 

323 

Rheumatism, 233, 234. 236 
Rhinitis, 234, 235 
Rhizopus, 198 
Rhododendron, 76 
Roaches, 245. See also Cockroaches 
Robin, 51 
Rock bass, 306 
Rock pine, 59 
Rocky Mountain spotted-fever tick, 

167 

Rodents, 326 
Root gall, 212 
Root knot, 265 
Root rot, 211, 212 
Root tubercles, 188 
Rosa rugosa, 89, 97 
Rose, 86, 94, 97 
Rose chafer, 156 
Rose slug, 157 
Rose-breasted grosbeak, 49 
Round-headed apple-tree borer, 155 
Roundworms, 264, 265, 266 
Ruby-crowned kinglet, 51 
Ruby-throated humming bird, 47 
Ruffed grouse, 41, 42, 52, 53 
Rum cherry, 75 
Rust, 186, 207, 210, 212 

Sable, 171 

Saccharomycetes, 191 
Salamanders, 313, 316, 319, 320, 325 ; 

enemies of mosquitoes, 131 
Salmon, 309, 310, 311 
San JosS scale, 20, 69, 152, 156, 158, 

332 ; fecundity of, 18 
Sand flies, 113 
Saprolegnia, 305 
Saprophytic bacteria, 221 



INDEX 



377 



Sapsucker, 4G 

Sawflies, 153 

Sayornis phoebe, 47 

Scab, on apple, 212 ; on potato, 210 

Scale insects, 153, 156 

Scallops, 273, 274, 277 

Scarletfever, 177, 232, 233, 236,239, 
243, 245, 246, 247, 251, 256 

Scarlet tanager, 25, 49 

Schick reaction, 251 

Scientific organizations, journals of, 
352, 353, 354 

Scorpion, 163, 164 

Screech owl, 45 

Screens, cost of, 20 

Screw-worm fly, 113, 157 

Scrub pine, 59 

Scurvy scale, 156 

Sea mussels, 271, 272, 273, 275; pic- 
ture of beds of, 270 

Seed, 188 

Selection and survival of the fittest, 
330 

Seneca snakeroot, 73 

Septicaemia, 234 

Serum, 248 ; antitoxic sera for 
snake poisons (antivenins), 329 ; 
Flexner's anti meningitis, 111 ; re- 
sistance of, 249 

Shad, 296, 309, 310, 311 

Shagbark hickory, 82 

Sharp-shinned hawk, 45 

Sheep, 257, 263 ; itch mite of, 166 ; 
liver fluke in, 261 

Sheep botfly, 157 

Sheep laurel, 75 

Sheep-scab mite, 163, 166 

Shepherd's-purse, 70, 71 

Shetland ponies, 333 

Shore bird, 40 

Short-leaf pine, 59 

Shrikes, 30, 34, 50 

Shrubs, 84, 86 



Silicon, 98 

Silver fox, 172 

Sirens, 313, 314 

Sistrums, 327 

Skink, 325 

Skunk, 169, 256 

Sleeping sickness, 236 

Slug, currant, 157; pear, 157 ; rose, 
157 

Slugs, 282, 283, 315 ; eaten by box 
tortoise, 325 

Small laurel, 75 

Smallpox, 107, 211, 233, 236, 237, 
247, 251, 256 ; control, of , by vacci- 
nation, 258, 259 

Smartweed, 70 

Smuts, 186, 207, 210 ; on corn, 213, 
216 ; on oats, 212 

Snails, 274, 283 

Snake venom, treatment of, 329 

Snakes, 40, 321, 323; number of 
species of, 326 ; poisonous, 110, 
327-328 

Snakeweed, 75 

Snapping terrapin, 324 

Sneezeweed, 76 

Snowball, 97 

Snow-on-the-mountain, 76 

Society for the Protection of Native 
Plants, 67 

Sodium, 98 

Sodium chloride, 249 

Sodium hypochlorite, 249 

Soft, or long-necked, clam, 276, 278 

Soft-shelled terrapin, 325 

Soil, effects of washing on, 57 ; ele- 
ments in, 99 ; fertility of, 91, 98 ; 
loss of fertility of, 55, 102 

Song birds killed by rats, 174 

Song sparrow, 49 

Sonoran coral snake, 328 

Sorghum, 197 

Sourwood, 59 



378 



CIVIC BIOLOGY 



Southern clothes moth, 154 

Sow bug, 317 

Sparrow, 34, 45, 47, 49, 50, 182 

Sparrow hawk, 45 

Sphinx moth, 155, 156 

Spiders, 46, 51, 163-168, 315 

Spinal meningitis, 107, 110 

Spirilla, 218 

Spirits of camphor, 128 

Spitzenburg apple, 334 

Spoonwood, 75 

Spotted cowbane, 75 

Spotted fever, 233, 236, 256 

Spotted parsley, 75 

Spotted salamander, 316 

Spotted sandpiper, 40 

Spotted terrapin, 325 

Spruce pine, 59 

Spruces, 58, 83 

Squash bug, 152, 156 

Squids, 273, 274 

Squirrel, 261 

Stable fly, 20, 113, 121, 122, 154, 236 ; 

life history of, 121 
Stable-window fly trap, 108, 109 
Staggefbush, 76 
Staggerweed, 76 
Staphylococci, 234 
Stegomyiafasciata, 258 
Stewart's disease, 215 
Sticktights, 69 
Stinkhorns, 204 
Stinking smut, 213 
Stinkweed, 75 
Stinkwort, 75 
Stork, 39 

Strains, pure-bred selected, 96, 97 
Strawberry, 94 ; enemies of, 156 
Streptococcus, 234 
Striped cucumber beetle, 156 
Strychnia sulphate, 181 
Strychnine used for poisoning rats, 

180, 181 



Sugar, danger from gorging with, 
344 

Sugar, or rock, maple, 82 

Sugar pine, 59 

Sulphate of copper, 71 

Sulphur, 98, 99 

Sulphur ointment, 165 

Sumac, 74, 75, 86 

Summer cholera. See Summer com- 
plaint 

Summer complaint, 107, 110, 121 

Suntish, 306 

Sunflower, 86 

Surra, 259 

Swallows, 49, 129 

Swamp hellebore, 76 

Swamp sumac, 75 

Swan, 38, 42 

Swatter, 119 

Sweet peas, 86 

Swine, 174 

Sycamore, 59 

Symbiotic bacteria, 221 

Syphilis, 107 

Syrphus flies, 112 

Tachina flies, 112 

Tadpoles, 314-318 

Tamarack, 59 

Tanagers, 49 

Tansy, 72 

Tapestry moths, 154 

Tapeworm, 107, 254, 260, 262-264 ; 

of dogs, 264 ; of fishes, 264 ; of 

man, 261 
Tarantulas, 164 
Tea, 344 
Teal, 306 
Teasel, 71 

Tent caterpillar, 155 
Termites, 155 
Terns, 38 
Terrapins, 321, 323, 324, 325 



INDEX 



379 



Tetanus, 248 

Texas fever, 97, 163, 167, 168, 236, 
257 

Thorn apple, 75 

Thrashers, 50 

Threadworms, 255, 264 

Three-leaved ivy, 75 

Thrushes, 51 

Thunderwood, 75 

Ticks, 163, 164, 165, 236, 255 ; cattle 

tick, 167, 168, 257 ; dog, or wood, 

tick, 168; Rocky Mountain, or 

spotted-fever, tick, 167 ; species 

.of, 168 

Titmice, 51 

Toads, 306, 312-320 ; commercial 
value of, 317; eggs and tadpoles, 
314-316, 318; food and feeding 
tests, 312, 315, 317 

Tobacco as an insecticide, 114, 343 

Tomato, 94 

Tonsillitis, 233, 234, 235, 243, 245, 251 

Tools, 13, 14 

Toothache, 233 

Tortoises, 321, 324, 325 

Towhee, 49 

Trailing arbutus, 67 

Tree frogs, 313, 314, 316, 319, 320 

Tree sparrows, 34, 49 

Tree swallows, 49 

Trees, characters of, 82 ; hard woods, 
59 ; light demariders, 59 ; planting 
of, 61 ; relation of, to landscaping, 
81, 83, 84 ; shade bearers, 59 ; study 
of, 59, 60 

Trematodes, 260 

Trichina, 175, 266, 267, 268 

Trichinosis, 264, 266 

Trout, 309 

Trumpeter swan, 39 

Truth, fake sources of, 347 

Trypanosomes, 259, 260 

Tsetse flies, 236, 259, 260 



Tuberculosis, 107, 110, 121, 232, 234, 
235, 236, 245, 250, 251, 252, 256 ; 
avian, 233 ; bovine, 110, 233; pul- 
monary, 249 

Tuberoses, 86 

Tubers, 71, 307 

Turkeys killed by rats, 174 

Turpentine a remedy for dog tick, 
168 

Turtles, 131, 321, 323, 325 

Typhlitis, 234 

Typhoid, 20, 110, 118, 121, 177, 232, 
234, 235, 236, 242, 243, 245, 248, 
251 ; epidemic of, 241 ; relation of 
dirty hands to, 250 

Typhoid fly, 107, 112 ; life history 
of, 113. See also House fly 

Typhoid Mary, 242 

Typhus fever, 236, 256 

Uncinariasis, 268 

Vaccination, 258 

Vaccines, 248 

Van Fleet rose, 97 

Variation, 330, 338 ; law of, 333 

Vedalia beetle, 20 

Vegetables, pests of, 156 

Venomous snakes, 324 

Vermin, 245 

Vinegar eels, 265 

Vines, 87 ; relation of, to landscape 

gardening, 87, 88, 89 
Viosca's pigeon, 43 
Viper, 327 
Vireos, 48, 50 
Virginia scrub pine, 59 
Vivaria, 10, 131 

Walking sticks, 153 
Walnut. See Black walnut 
Wapata, 307 
Warblers, 48, 50 



380 



CIVIC BIOLOGY 



Warbling vireo, 50 

Wasps, 153 

Water beetles, larvae of, 131 

Water bugs, 153 

Water cress, 306, 307 

Water hemlock, 73, 75 

Water lilies, 306, 307 

Water snakes, 326 

Waterfowl, 38, 39, 40, 45, 324 

Waxwings, 50 

Weasels, 169 

Weeds, 67-76; adaptability of, 70; 

classes of, 70, 71 ; damage from, 

68 ; destruction and control of, 34, 

69, 71 ; medicinal, 71, 72 
Weeping willow, 84 
Weevils, 155, 156, 317 
Western little-neck clam, 278 
Western prairie chicken, 42 
Whale, 169 
Wheat, 93, 94, 95, 97 
Whippoorwill, 47, 129 
Whistling swan, 39 
White ants, 153, 155 
White ash, 82 
White cedar, 59 
White diarrhea of chicks, 233 
White elm, 59 
White hellebore, 76 
White man's plant, 75 
White pine, 59, 84 ; type for study, 

4,5,6 

White-breasted nuthatch, 51 
Whitefish, 309 

White-marked tussock moth, 156 
White-throated sparrow, 49 
Whooping cough, 232, 234, 247 
Wicky, 75 
Widal reaction, 251 
Wild boar, 263 
AVild carrot, 71 
Wild cat, 169 
Wild celery, 307 



Wild cherry, 75 

Wild duck, 53, 325 

Wild onion, 71 

Wild rice, 307 

Wild rose, 86 

Wild sago, 307 

Wild trout, 305 

Wild turkey, 42, 53 

Willow, 59, 307 

Wilson snipe, 40 

Wilson's thrush, 51 

Wilt disease, 212 ; bacterial blight, 

215 ; stem blight, 216 
Window flytrap, 108, 109 
Wode-whistle, 75 
Wolf, 169, 256 ; itch mite of, 166 
Wolfsbane, 76 
Wolf's-milk, 76 
Wolverine, 169 
Wood duck, 39, 40, 306, 307 
Wood frog, 315, 316, 319 
Wood laurel, 75 
Wood pewee, food of, 24, 47 
Wood thrush, 51 
Wood ticks, 165, 168 
Woodcock, 40 
Woodpecker, 7, 46 
Woolly apple louse, 156 
Woolly loco weed, 76 
Worms, 51, 315 
Wormseed, 69 
Wrens, 50 

Yeara, 75 

Yeast, 186, 189-197 ; a cause of dis- 
ease, 197 ; description of , 191, 192 ; 
distribution of, 192 ; pure culture 
of, 195 ; uses of, 194 

Yellow fever, 20, 123, 124, 126, 134, 
233, 236, 240, 253, 254, 256, 258 

Yellow perch, 309 ; topography of, 
298 

Yellow pine, 59 



INDEX 381 

Yellow poplar, 50 Yellow-throated vireo, 50 
Yellow warbler, 50 

Yellow woolly bear, 155 Zero family, 345 

Yellow-billed cuckoo, 46 Zinnias, 86 

Yellow-fever mosquito, 124, 125 Zoological parks, 171 



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