PROCEEDINGS

OF THE

a

Biological Society of Washington

Volume VI.
February 8, 1890, to December 26, 1891.

WASHINGTON, D. C.
PRINTED FOR THE SOCIETY.

1892

I

PUBLICATION COMMITTEE.

CHARLES D. WALCOTT, Chairman.
R. E. C. STEARNS, F. H. KNOWLTON,

T. S. PALMER, F. V. COVILLE.

II

CONTENTS.

PAGE

Officers and Committees for 1891 iv

Proceedings, February 8th to December 26th, 1891 v-xix

Addresses and Communications :

On Dynamic Influences in Evolution, by Wm. H. Dall (read

March 8th, 1890) i-io

Neo-Darwinism and Neo-Lamarckism, by Lester F. Ward

(January 24th, 1891I 11-71

III

LIST OF THE OFFICERS AND COUNCIL

OF THE

BIOLOGICAL SOCIETY OF WASHINGTON.

Elected January io, 1S91

OFFICERS.

PRESIDKNT.
C. HART MKRRIAM.

VICE-PRESIDENTS.

C. V. RILEY, RICHARD RATHBUN,

FRANK BAKER, C. D. WALCOTT.

SECRETARIES.
L. O. HOWARD, F. A. LUCAS.

TREASURER.
F. H. KNOWLTON.

COUNCIL.

C. HART MERRIAM, Presidetit.

FRANK BAKER, RICHARD RATHBUN,

T. H. BEAN, THEOBALD SMITH,

WM. H. DALL,* R. E. C. STEARNS,

THEO. N. GILL,* F. W. TRUE,

G. BROWN GOODE,* GEORGE VASEY,

L. O. HOWARD, C. D. WALCOTT.

F. H. KNOWLTON, LESTER F. WARD,*

' F. A. LUC.\S, C. A. WHITE,*

C. V. RILEY.

STANDING COMMITTEES— 1891.

Delegates to the Joint Commission of Scientific Societies of Washington.

C. HART MERRIAM,
LESTER F. WARD, RICHARD RATHBUN.

Committee on Com m unications .
RICHARD RATHBUN, Chairman.
W. B. BARROWS, JOHN MURDOCH.

Committee on Publications.
C. D. WALCOTT, Chairman.

R. E C. STEARNS, T. S. PALMER,

F. H. KNOWLTON, F. V. COVILLE.

Committee on Trees and Shrubs.

LESTER F. WARD, Chairman.
GEORGE VASEY, THEODORE HOLM,

F. H. KNOWLTON, F. V. COVILLE-

* Kx- Presidents of the Society.

IV

PROCEEDINGS.

One Hundred and Fifty-fifth Meeting.
Febrtiar}- 8, iSgo.

The President in the chair, and thirty-eight members and
guests present.

The following active members were elected on recommenda-
tion of the Council : T. \V. vStanton, U. vS. Geological Survey ;
Dr. E. Roome, Columbian University.

Dr. Frank Baker presented a communication upon An
Undescribed Muscle from the Infraclavicular Region
OF Man. Discussed by Drs. Merriam and Riley.

Mr. C. D. Walcott presented a note upon A Xew Genus
and Species of Ostracod Crustacean from the Lower
Cambrian.*

Dr. Cooper Curtice read a paper on The Moultings of
the Cattle Tick {Ixodes bovis).!: Di.scu.ssed by Drs. Riley
and Theobald Smith.

Prof. Lester F. Ward spoke of Flowers that Bloo^i in
the Winter Time.

One Hundred and Fifty-sixth Meeting,
February 22, 1890.

The President in the chair, and thirty members present.

Mr. F. V. Coville presented a paper on The New Arrange-
ment OF Genera in the Herbarium of the Department
OF Agriculture. + Discussed by Messrs. Riley and Ward.

* Tenth Annual Report of the Director U. S. Geol. Survey, Pt. I, 1890,
pp. 625, 626.

tjournal Comp. Med. and Vet. Archives 1S90, p. 313 ; reprinted in
Veterinarian 1891, p. 680.

X Bot. Gazette, xv, 1890, p. 68.

VI BIOLOGICAL SOCIETY OF WASHINGTON.

Dr. T. H. Bean presented Notes on Some Fishes from
British Columbia.*

Dr. Merriam read a paper on the Evidence of Sonoran
Origin of the Flora and F'auna of the Gulf States.
Discussed by Messrs. Ward, Gilbert, Coville, and Dall.

One Hundred and Fifty-seventh Meeting,
March 8, 1890.

The President in the chair, and fort3'-one members present.

Mr. B. T. Galloway read a paper giving the results of some
observations on an apple disease caused by the fungus Gym-
nosporanoitiDi macropus. I^iscussed by Messrs. Van Deman
and Marlatt.

Mr. C. L. Hopkins presented some NoTES on the Animal
LIFE above the Snow Line on Mt. Shasta. t Discussed by
Messrs. Mann, Riley, Howard, Diller and Hasbrouck.

Dr. W. H. Dall read a paper entitled On Dynamic Influ-
ences in Evolution. j: Discussed by Messrs. Coville, Mann,
Fernow and Ward.

One Hundred and Fifty-eighth Meeting,
March 22, 1890.

The President in the chair, and thirty-nine members present.

Dr. C. H. vStowell was elected an active member.

Dr. D. W. Prentiss read a paper entitled Change in the
Color of Human Hair,§ Change in the Color of Plum-
age OF Birds, and in the Fur of Mammals. ||

* Proceedings U. S. Nat. Mus., Vol. xii, pp. 641, 642.
t Insect Life, Vol. 2, p. 355.
X Proc. Biological Society, Vol. vi, pp. i-io.

§ Phila. Med. Times, xi, 1880-81 ; also, Therap Gazette, Detroit, Mich.,
1889, viii.

llJournal Amer. Med. Assoc, xiii, 1889.

PROCEEDINGS. VII

Prof G. B. Goode read a paper on the Colors of Fishes.*
Prof. C. V. Riley spoke on the Colors of Insects.
The papers were briefly discussed by Messrs. Mann, Dall,
Seaman and Ward.

One Hundred and Fifty-ninth Meeting.
April 5, 1890.

The President in the chair, and twenty-five members
present.

Dr. Theobald Smith read a paper entitled Some Illus-
trations OF Ferments and Fermentation among Bac-
teria.t Discussed by Professor Atwater.

Dr. R. R. Gurley presented a paper on the American
Graptolites.

One Hundred and Sixtieth Meeting,
April 19, 1890.

The President in the chair, and fortj^-five members present.

Dr. C. W. Richardson was elected an active member of the
Society.

Dr. Merriam presented a paper entitled Historical Re-
view OF THE FaUNAL AND FlORAL DIVISIONS THAT HAVE

BEEN Proposed for North America. Discussed by Dr.
Dall.

Prof. J. P\ James read a paper entitled Variation with
Especial Reference to Certain Paleozoic Genera.
Discussed b\' Professor Ward.

Dr. Dall exhibited some Original Drawings of the
Fur Seal and Stellers' Sea Cow.t and gave an account
of them.

* Trans. Am. Fisheries Society, 1890.

t Centralblatt fiir Bakteriologie u Parasitenkunde, vii, 1890, p. 502.

X Report U. S. Coast Survey and Geodetic Survey, 1890.

viii biological society of washington.

One Hundred and Sixty-first Meeting,
May 3, 1S90.

The President in the chair, and thirty-six members present.

Mr. J. R. Edson was elected an active member.

Dr. Robert Reyburn read a paper entitled The lyiFE
History of Micro-organisms with its Relation to the
Theory to Evolution.* Discussed by Dr. Theobald Smith,
Dr. Salmon, Mr. True, Mr. Erwin vSmith, Dr. Shaeffer, Mr.
Seaman and Dr. Dall.

Dr. Vasey read a paper entitled A New Grass Genus. t
Discussed bv Messrs. Holm, Coville and Prof. Ward.

One Hundred and Sixty-second Meeting,
May 17, 1890.

The President iri the chair, and thirty -six members present.

Mr. T. S. Palmer read a paper entitled Some Early Views
OF Geographical Distribution of vSpecies. Discussed by
Dr. MerriauL

Mr. F. W. True exhibited a specimen of Lophiomys imhausii.
Discussed by Dr. Merriam.

Prof. W. H. Seaman read a paper entitled The Place of
Biology in the Public Schools.! Discussed by Profs.
Chickering and Ward, Dr. Baker and Messrs. Waite and
Howard.

One Hundred and Sixty-third Meeting,
Ma}' 31, 1890.

The President in the chair, and twenty-six members present.

Dr. C. H. Merriam exhibited specimens of sundry new
species of North American Mammals. Discussed by Dr.
Gill.

* American Monthly Microscopical Journal, June, 1890.

t Bot. Gazette, xv, 1890, p. 106.

J The American Anthropologist for October, 1891.

TROCEEDINGS. IX

Dr. Theodore Gill presented a paper on the Character-
istics OF THE HaLOSAUROID FiSHES.''^

Dr. J. N. Rose read a paper entitled CoultercUa, A New
Genus of Composit.E.I Discussed by Messrs. Seaman, \^asey
and T. S. Palmer.

Prof. Jos. F. James spoke on Organisms in St. Peter's
Sandstone.

Mr. B. P. Mann made some remarks upon the Authorship

OF THE BiBEIOGRAPHY OF ECONOMIC ENTOMOLOGY, published

by Department of Agriculture.

Mr. Howard refuted Mr. Mann's statement.

One Hundred and Sixty-fourth Meeting,
October i8, 1890.

The President in the chair, and twenty-eight members
present.

Mr. H. E. Van Deman spoke of Cultivated Fruits in
THE Mountains of North Carolina.:}: Discussed by Dr.
Salmon .

Dr. Theo. N. Gill presented a communication on the Super
Family Cyclopteroidea.§

Prof. Lester F. Ward spoke on the subject of American
Triassic Flora. 1 1

One Hundred and Sixty-fifth Meeting,
November i, 1890.

The. President in the chair, and thirty-seven members
present.

Mr. Nathan Banks was elected an active member.

* American Naturalist, xxiii, 1889, pp. 1015, 1016. (Pub. May, 1890.)

tr. vS. Cont. Nat. Herb, i, 1890, p. 71.

J Ann. Report U. S. Dept. Agriculture, 1890, pp. 410, 411.

I Proc. U. S. N. M. xiii, 1890, pp. 361-376; pi. 2S-30.

II Geological Society of America, iii, 1891, pp. 23-31. Abstracts in
Science, Vol. xviii, Nov. 20, 1891, pp. 287, 288, and Proc. A. A. A. S.,
Vol. xi.

X BIOLOGICAL SOCIETY OF WASHINGTON.

Mr. F. V. Coville read a paper entitled Fruiting of the
Ginkgo at the Department of Agriculture. Discussed
by Dr. Riley, Mr. Seaman and Mr. Fernow.

Dr. Marx spoke of his recent Investigations of the
Poison Glands of Lathrodectus. Discussed by Drs.
Riley, Dall and Theobald Smith.

Prof. Jos. F. James read a paper called Fucoids and
Other Problematic Organisms. Discussed by Mr. Lucas,
Dr. Dall, Prof. Ward and Mr. Mann.

One Hundred and Sixty-sixth Meeting,
JsTovember 15, 1890.

The President in the chair, and forty-three members present.

Dr. Merriam presented a communication entitled Life in
the Lava Beds and Canons of Snake River, Idaho, in
October.* Discussed by Messrs. Walcott and Howard.

Mr. Theodore Holm spoke of the VEGETATIVE Propaga-
tion OP DiCENTRA CUCULLARIA.f

Dr. Dall presented some Paleontoi^ogical Notes from
the Northwest Coast.]:

Mr. Lucas described a Foot Disease of Captive Birds.

One Hundred and Sixty-seventh Meeting,
November 29, 1890.

The President in the chair, and forty-seven members present.

The following new active members were elected : Jno M.
Stedman, Merwin M. Snell and Rev. Alexis Orban.

Dr. T. H. Bean presented a paper on The Death of
Salmon After Spawning. § Di.scussed by Dr. Gill, Prof.
Goode, Mr. Stejneger, Drs. Dall and Merriam.

*(In part.) North American Fauna No. 5, July, 1891, pp. 6-7.
fBull. Torrey Botanical Club, Vol. xviii, 1891, pp. r-ii, pi. cxi-cxiii.
X Nautilus, Philadelphia, Vol. iv, 1S90, No. 8, pp. 87-89, December.
'i Forest and .Stream, November 27, 1890.

PROCEEDINGS. XI

Dr. Theobald Smith spoke Ox Species Among Bacteria.
Discussed by Mr. True, Dr. Gill, Drs. Riley, Curtice. Mr.
Banks.

Mr. Sudworth presented a communication entitled XoTES
ON Nomenclature. Discu.ssed bv Dr. Merriam.

One Hundred and Sixty-eighth Meeting.
December 13, 1890.

The President in the chair, and twenty-five members present.

Mr. A. B. Baker was elected an active member.

Mr. Wm. Palmer read a paper on The Occurrence of
THE Asiatic Cuckoo on the Pribylov Islands. Dis-
cussed by Dr. Dall.

Dr. Riley presented some New Notes on the Genus
Phylloxera.

Mr. True spoke on The Teeth of the Muskrat.

Mr. Lucas read a paper on The Wing of Metopidius.
Discussed bv INIr. True.

One Hundred and Sixty'-ninth Meeting,
December 27, 1890.

The President in the chair, and twenty-six members
present.

The following active members were elected : J. M. Holzin-
ger, Frederick C. Test.

Dr. Cooper Curtice presented a communication entitled A
Preliminary Study of Ticks in the United States.
Discussed by Dr. Smith.

Dr. C. Hart Merriam exhibited A New Rabbit from the
Snake Plains of Idaho.*

Dr. W. H. Dall read a paper entitled On the Topography
of Florida w^th Reference to its Bearing on Fossil
Faunas, t

* {Lepus idahoensis) North American Fauna No. 5, July, 1891, pp. 76-78.
t Bulletin 84, U. S. Geol. Survey. (In press.)

xii biological society of washington.

One Hundred and Seventieth Meeting.
(Tenth Annual.)

The President in the chair, and forty-two members present.

The annual reports of the Secretary and Treasurer were
read and accepted.

The following board of oflBcers was elected for the ensuing
year :

President — C. Hart Merriam.

Viee-Presidenis — C. V. Riley, Frank Baker, Richard Rath-
bun, and C. D. Walcott.

Secretaries — L. O. Howard and F. A. L^ucas.

Treasurer — F. H. Knowlton.

Mernbers of Council— V . W. True, T. H. Bean, R. E. C.
Stearns, Theobald Smith, and Geo. Vasey.

One Hundred and Seventy-first Meeting,
January 26, 1891.

(Eleventh Anniversary Meeting.)

The eleventh anniversary meeting was held in the law
lecture-room of Columbian University, January 26, 1891,
in the presence of members and invited guests.

The President, L^ester F. Ward, delivered his annual address
on the subject Neo-Darwinism and Neo-Lamarckism.*

One Hundred and Seventy-second Meeting,
February 7, 1891.

The President in the chair, and twenty-five members present.

The President announced the following committees for the
ensuing year :

Joint Commission — C. Hart Merriam, Lester F. Ward, Rich-
ard Rathbun.

* Published in this volume. See pp. ii-71.

PROCEEDINGS. XIII

Comjnittee on Comnninications — Richard Rathbuii, Walter
B. Barrows, John Murdoch.

Co}mnittee on Publicatiojis — C. D. W'alcott, R. h^. C. Stearns.
F. H. Knowlton, T. S. Pahner, F. \'. Coville.

Committee on Trees and Shrubs — Lester F. Ward, Geo.
Vasey, F. H. Knowlton, Th. Holm, F. V. Coville.

Mr. C. D. Walcott presented a paper on the Discovery
OF Vertebrate Life in Lower Silurian (Ordovician)
Strata.* Discu.ssed by Dr. (.rill.

Prof. Henry F. Osborn gave a Review of the Discovery
OF Cretaceous Mammals. t Discus.sed bv Dr. Gill.

One Hundred and Seventy-third Meeting,
February 21, 1891.

The President in the chair, and twelve members present.
Dr. Cooper Curtice read a paper entitled Some Little
Known Worms in Cattle. Discussed by Mr. Holzinger.

• One Hundred and Seventy-fourth Meeting,

March 7, 1891.

The President in the chair, and twenty-five members
present.

Mr. F. A. Lucas exhibited and described .some young
Hoatzins. Discussed by Dr. Dall.

Mr. Lucas also drew attention to a Specimf:n of Bison

LATIFRONS FROM PEACE CrEEK, FLORIDA.

Dr. Bean spoke of the Fishes of Gre.yt South Bay.;}:
Mr Rose spoke of A New Aster from Southern Cali-
fornia.! Discussed by Mr. Holzinger and Mr. Waite.

*Bull. GeoL Soc. Amer. VoL iii, 1891 {in press). See also Proc. Phila.
Acad.

t American Naturalist, xxv, Juh-, 1S91, pp. 295-611. See also Proc.
Phila. Acad.

X Nineteenth Report of the Commission of Fisheries of New York,
1891, pp. 237-281.

^Bot. Gazette, Vol. xvi, 1891, p. 113.

XIV BIOLOGICAL SOCIETY OF WASHINGTON.

Mr. Slid worth presented a communication on the Color
AND Odor of Flowers in Attracting Insects. Dis-
cussed by Messrs. Howard and Marlatt.

Mr. Stedman exhibited and described a fine specimen illus-
trating the Embyro of a Chick with Two Protovertebr.'E.

Dr. Merriam spoke of Distribution of Animal and
Vegetable Life. Discussed by Dr. Curtice and Messrs.
Waite, Test and Holzinger.

One Hundred and Seventy-fifth Meeting,
March 21, 1891.

Ex-President Ward in the chair, and twenty-eight members
present.

Mr. W. A. Taylor was elected an active member.

Dr. Dall presented a paper on the Age of the Peace
Creek Bone Beds in Florida.*

Dr. Shufeldt read a communication on A Collection of
Fossil Birds from the Equus Beds of Oregon, t

Mr. F. A. Lucas spoke of A Point in the Anatomy of
Hesperornis.

Mr. F. H. Knowlton presented a communication entitled
What Are Cypress Knees ? Discussed by Prof. Ward and
Mr. R. L. Garner.

One Hundred and Seventy-sixth Meeting.
April 4, 1891.

Vice-President Walcott in the chair, and thirty-two mem-
bers present.

Dr. Cornelius B. Boyle was elected an active member of the
Society.

* Bulletin 84, U. S. Geol. Survey. (In press).

t To be published in the Acad, of Nat. Sciences of Phila. Abstracts
<Amer. Nat. Sept. 1891, pp. 818-821. The Auk, Vol. viii, Oct., 1891,
PP- 365-368.

PROCEEDINGS. XV

Dr. Bean read a paper on Kexnerly's Salmon.* Dis-
cussed by Dr. Dall, Mr. C. D. Walcott and Mr. Waite.

Dr. Theobald Smith made some Remarks on Recent
Bacteriological Progress in the Prevention and Cure
OF Disease.

Dr. V. A. Moore spoke of the Production of Immunity in
Guinea Pigs with Sterilized Cultures of Hog Cholera
Bacillus. Discussed by Drs. Curtice, Schaeffer and Sal-
mon, and Mr. Walcott.

Mr. E. M. Hasbrouck read a Monograph of the Caro-
lina Parrakeet.I

One Hundred and Seventy-seventh Meeting,

April i8, 1891.

Vibe- President Riley in the chair, and twenty members
present.

Prof. L,. H. Dewey, was elected an active member of the
Society.

Mr. Van Deman presented a communication on The Recent
Introduction of Date Palms. t

Dr. Curtice read a paper entitled Practical Value of In-
vestigating Parasites of Dive Stock.

Prof. Lester F. Ward spoke of Some Florida Plants.

One Hundred and Seventy-eighth Meeting,

May 2, 1 89 1.

Vice-President Riley in the chair, and twenty-eight members
present.

Dr. Gill spoke of the Classification of the Apodal
Fishes. § Discussed by Mr. Lucas.

* Forest aud Stream, July 9, 1891.

tThe Auk, Oct., 1891, pp. 369-379-

J Ann. Report, U. S. Dept. of Agriculture, 1890, p. 415.

§ Proc. U. S. Nat. Museum, Vol. xiii, 1890, pp. 157-242.

XVI BIOLOGICAL SOCIETY OF WASHINGTON.

Mr. Galloway read a paper entitled Recent Progress in
THE Study of Pl.ynt Diseases. Discussed by Dr. Erwin F.
Smith.

Dr. Frank Baker presented some Notes on Dwarfs. Dis-
cussed by Messrs. Ward, Gill and Riley.

Mr. F. A. IvUcas read a paper, by Mr. Chas. Hallock, en-
titled Distribution of Fishes by Underground Water
Courses.* Discussed by Dr. Gill.

Mr. F. C. Test presented some Notes on the Dentition
of Desmognathus.

One Hundred and Seventy-ninth Meeting,
May 1 6, 1S91.

Vice-President Riley in the chair, and twenty-two members
present.

Prof. Riley read a paper on The Mexican Arrow Weed
AND Jumping Bean.I Discussed by Dr. J. N. Rose, Prof.
Ward, and Dr. Vasey.

Mr. J. M. Holzinger read a paper entitled Incentives to
Natural History Stud\\

Mr. Wm. Palmer described The Distribution of Certain
Mammals, Birds and Plants on the Pribylov Islands.

Dr. Vasey read some Notes on the Recent Field Work

OF THE BOT.\NICAL DIVISION OF THE DEPARTMENT OF AGRI-
CULTURE.

Mr. Lucas presented some Remarks on a New Tortoise
FROM THE Galapagos Islands, t

One Hundred and Eightieth Meeting,
October 17, 1891.

The President in the chair, and fifty-three members present.
Mr. W. T. Swingle was elected an active member of the
Society.

* Amer. Angler.

t Scient. Amer., Juue 13, 1891 ; Anier. Nat., July, 1891, pp. 673-675.

.t Nature, June 4, 1891, p. 113.

PROCEEDINGS. XVII

Mr. F. V. Coville read a paper entitled Food Plants of
THE Indians of the Death Valley Region. Discussed
by Mr. Van Deman, Dr. Merriam, and Dr. Vasey.

Dr. R. W. Shufeldt presented some NoTES ON Paleopa-
thology.* Discussed by Mr. Lucas and Mr. Gilbert.

Mr. Wni. Palmer read a paper on The Fate of the Fur
Seal in xImerican Waters. t Discussed by Dr. Dall, Dr.
Merriam, Mr. Lucas, Dr. Bean, and Dr. Schaeffer.

One Hundred and Eighty-first Meeting,
October 31, 1891.

The President in the chair, and thirty members present.

The following were elected active members of the Society:
Mr. A. G. Masius, Prof. B. W. Everman, Dr. W. F. Morsell,
Dr. C. W. Stiles.

Dr. Theo. Gill presented a communication on The Classifi-
cation of the Tetraodontoidea.;!:

Dr. T. H. Bean made some remarks on Some Fishes New
TO New England Waters. § Discussed by Dr. Gill and Mr.
Barrows.

Mr. W. B. Barrows read a paper on Cuckoo Stomachs and
Their Contents.

Dr. N. H. Egleston read a paper on The Temperature
OF Trees.

Dr. C. W. Stiles presented some Notes on Parasites —
THE Development of Echinorhynchus gigas.|| Discus.sed
by Mr. Howard and Dr. Merriam.

* The Popular Science Monthly, 1892.

t Forest and Stream, Oct. 29, 1891.

jProc. U. S. Nat. Museum, xiv, 1891.

i; P'orest and Stream, Dec. 17, 1890.

!| American Journal for Comp. Med. and Vet. Archives, Dec, 1S91.
French translation in Comp. rend, de la Soc. de Biologic, Paris, 1891,
pp. 764-766.

xviii biological society of washington.

One Hundred and Eighty-second Meeting,
November 14, 189 1.

The President in the chair, and thirty-one members present.
Mr. T. S. Palmer read a paper entitled The Winter Aspects

OF THE MOJAVE DESERT REGION.

Dr. V. A. Moore spoke of a case of Echinococcus in
Swine.* Discus.sed by Drs. Smith and Stiles.

Dr. C. W. Stiles pre.sented a paper entitled NoTES ON Para-
sites, describing Coccidium bigeminuni a.n<X Filaria gasterostei.'\

Prof. Eester F. Ward .spoke of Haeckel's Radiolaria of
THE Challenger Expedition, and presented a communica-
tion entitled Three Days in the Tropics. The latter was
discussed by Dr. Merriam and Mr. Coville.

One Hundred and Eighty-third Meeting,

November 28, 1891.

The President in the chair, and thirty-six persons present.

The following active members were elected on recommenda-
tion of the Council :

Mr. W. E. Clyde Todd and Mr. J. D. Figgins.

Dr. George Marx read a paper on The Structure and
Construction of the Geometric Spider Web. Dis-
cussed by Dr. Th. Gill.

Mr. David White presented a paper entitled Some Peculiar
Forms in an Uplajstd Carboniferous Flora. ;]; It was dis-
cussed by Prof Eester F. Ward.

Prof F. H. Knowlton presented a paper on Fruiting
Ferns from the Laramie Group. Discussed by Professor
Ward, Mr. C. D. Walcott and Dr. Cooper Curtice.

*Amer. Journal of Comp. Med. and Vet. Archives and Annual Report
of the Dept. of Agriculture, 1891. Report on Animal Parasites for 1891,
C. \V. Stiles.

t Proc. U. S. Nat. Museum, 1892. Note preliminarie sur quelques
Parasites, Bull. d. 1. Soc. Zool. d France, 1891, pp. 163-165.

t Bulletin 98, V. S. Geological Survey. (In press.)

PROCEEDINGS. XIX

OxE Hundred and Eighty-fourth Meeting,
December 12, 189 1.

The President in the chair, and thirty-eight members
present.

Mr. F. V. Coville read a paper entitled A Review of
Kuntze's Revisio Generum Plantarum. Discussed b}^
Mr. J. N. Rose and Dr. C. Hart Merriam.

Mr. E. M. Hasbrouck presented some Remarks on Di-
CHROMATISM. Discussed by Dr. W. H. Dall, Dr. Ervvin F.
Smith, Dr. C. Hart Merriam, and Mr. F. W. True.

Prof. Ivester F. Ward spoke of Recent Discoveries of
Potomac Fossil Plants near Washington.

One Hundred and Eighty-fifth Meeting,
December 26, 1891.

The President in the chair, and twenty-six members present.

Mr. F. H. Knowlton presented a paper entitled A FossiL
Bread-F^ruit Tree from the Sierras of California.
Discussed b^- Prof. Ward.

Prof. Lester F. Ward presented a communication entitled
Alphonse de Candolle on the Transmission of Ac-
quired Characters.

Dr. C. Hart Merriam made extended Remarks on the
Affinities of the North American Squirrels, Chip-
munks. Spermophiles, Prairie Dogs, and Marmots.
Discu.ssed by Dr. Erwin F. Smith, Dr. Stiles, Dr. Dall, and
Professor Ward.

ON DYNAMIC INFLUENCES IN EVOLUTION.

By Wm. H. Dall.*

It is generally admitted that in the doctrine of Natural
Selection we have a theory which accounts for the perpetuation
of favorable variations in organic beings and their progeny,
and for the elimination in the long run of those which vary in
unfavorable directions. It is equally admitted that the origin
of variation is not accounted for by this theory. In order to
round out our conception of the mode of evolution of the or-
ganic universe it is necessary that this deficiency should be
supplied, and that to it should be added some conception of the
mode by which variation is sustained in any given direction
until it has reached a point where its usefulness is sufficiently
marked to enable the selective process to operate. Besides
this it is hardly doubtful that there are many characters devel-
oped in organisms, especially those of the lower rank, in which
selection of an}- sort is but little concerned.

It is not necessar}' to recapitulate the names of those who
have turned to the relations between the organism and its
environment as the onty nidus of the influences sought. Such
an enumeration would comprise nearly all American biologists
of prominence and many foreign naturalists.

On the other side of the Atlantic a small but not unimpor-
tant number of biologists, of whom Weismann and Lankester
may be taken as spokesmen, have recently endeavored to show

*Read before the Biological Society of Washington, Mar. 8, 1890.

I BIOLOGICAL SOCIETY OF WASHINGTON.

•

that the current of hypothesis most favored in America, though
not confined to our naturalists, is running in a wrong direc-
tion, although they do not seem to have any satisfactory alter-
native to offer.

For convenience in discussion those who accept the ideas re-
ferred to, in greater or less degree, may be termed Dynamic
Evolutionists. Their position has been very fairly and tem-
perately stated by Osborne in his article on the paleontological
evidence of the transmission of acquired characters.* With-
out attempting to speak for others I have felt that a statement
of the position to which I have been led bj' my own studies
might not be without use in the present status of the question.

In the first place, in opposition to the notion that characters
acquired in other than the embryonic or larval condition are
not transmitted to the progeny ; — I maintain that a direct or
indirect transmission of acquired characters is absolutely es-
•sential to any theory of evolution and that, speaking broadly,
the whole system of Darwinism must stand or fall with this
hypothesis. It is as axiomatic as the ' ' survival of the fittest ' '
itself.

It therefore becomes necessarj- to define what is meant by
"acquired characters" and their "transmission-."

The environment stands in a relation to the individual such
as the hammer and anvil bear to the blacksmith's hot iron.
The organism suffers during its entire existence a contin,uous
series of mechanical impacts, none the less real because invisi-
ble, or disguised by the fact that some of them are precipi-
tated by voluntary effort of the individual itself. So far as re-

*Nature Jan. 9, 1890, p. 227; Science, 1890, p. no. The name Neo-
Lamarckian is objectionable, as it tends to connect with the modern
hypothesis the different and obsolete theory of the distinguished French
naturalist.

ON DYNAMIC INFLUENCES IN EVOLUTION. 3

suits are concerned, for the ground to strike the horse's hoof
would be the same as for the horse to strike the ground with
his hoof ; direction and dynamic value of shock being as-
sumed to be equal in the two cases. Since individual organ-
isms usually appear free to wander about or remain quiescent,
the idea that they are under constant stress does not ordinar-
ih- suggest itself. To this habit of superficial observation I
ascribe the slowness with which the dynamic element in evolu-
tion has received recognition, though pointed out clearh' so
long ago, b}^ Herbert Spencer.

That which distinguishes the organic individual from the in-
organic fragment of matter is the complexity of its reaction
to these impacts, which reaction we term physiological in con-
tra-distinction to the simply mechanical, though both, at bot-
tom are doubtless similar.

The characters which develop in an organism in response to
these impacts are acquired, but that which is transmitted
is a facilit}' of response in the same line, which may, under
favorable circumstances, lead to a similar response in the
progeny, and, in the course of time with a continuation of
similar impacts through successive generations, promote and
establish the physiological habit which is the directive influ-
ence toward the regular development of the characters in
question.

It is, I believe, generally admitted that such is the case in
relation to mental stimuli and reactions in man and some of
the higher animals and that the growth of intellectual life in
the human race depends upon it.

It is a matter of indifference, dynamically, whether the par-
ticular series of impacts concerned in developing a special
physiological response is the result of conscious effort by the
organism or not ; but, as it is highly unlikely that au}^ volun-

4 BIOLOGICAL SOCIETY OF WASHINGTON,

tary effort, no matter how seconded bj^ habit, should be as con-
stant and unceasing as the impacts due to ordinary mechanical
forces, we should expect the responses due to conscious effort
to be feeble in intensity and numerically few in comparison
with those arising from the dynamic forces undirected by con-
sciousness.

The dynamics of the environment, so far as we are able to
understand them, in their principal features must be remark-
ably constant. The weight and consistency of the water or air
which forms the surrounding medium, the character of the
supporting surface, the range of temperature, the supply of
light, the friction of adjacent bodies, the attraction of gravita-
tion, var}' within comparatively^ narrow limits, when consistent
with organic existence. We should therefore expect that
their influence would on the whole be conservative and tend
toward the preservation of the main characteristics of organ-
isms once brought into substantial equilibrium with their
surroundings.

On the other hand, owing to the very narrowness of the
limits within which life is possible, the dynamic variations,
within those limits, to which organic forms are subjected be-
come relatively more important. It is probable that since the
initiation of life upon the planet no two organisms have ever
been subjected to exactly the same dynamic influences during
their development. Differences of impact necessarily imply dif-
ferences in response, hence a certain amount of variation is the
inevitable result. It is absolutely impossible that any two in-
dividuals can be or ever have been strictly similar and the ap-
plication of a conception of exact similarity to any two actual
beings becomes more and more difficult as the complexity of
their organization is increased.

The origin of variation therefore presents no difficulties ;

ON DYNAMIC INFLUENCES IN EVOLUTION. O

rather the presence of two strictl}' similar beings, could it be
shown, would border on the miraculous.

The question which demands an answer is, how are the
small necessarj' and admitted differences stimulated to develop
into the obvious differences which are recognized by systematic
biologists ?

To this I would answer that the reactions of the organism
against the physical forces and mechanical properties of its
environment are abundantly sufficient, if we are granted a sim-
ple organism, with a tendency to grow, to begin with ; time
for the operation of the forces ; and the principle of the sur-
vival of the fittest.

It is often assumed in discussing variation that the possi-
bility of variation is equal in every direction. A considera-
tion of the dynamic conditions of life show that this is not the
case, or at least, if we grant its theoretic truth, in practice it
never can be true. Under any conditions which would permit
it, the resulting organic forms would all be sub-spherical, and
would have to pass their existence in constant rotation.

The moment that any one of them came to rest it would be-
gin to be subjected to unequal stresses relatively to its different
parts. lyight, gravity, friction, opportunities for nutrition,
would be unequally distributed, with the result of forcing an
unequal growth, development, and specialization of its regions.
Inequality of form once established, if it were a moving or-
ganism, friction and resistence of the circumambient medium
would confirm the inequality and put individuals of its kind at
a disadvantage when they varied toward the original shape.
Flexure of an elongated body would mechanically institute
changes analogous to segmentation, as pointed out by Spencer.
Any organic mass possessed of mechanical continuity must de-
velop surface tension and initiate a superficial film.

6 BIOLOGICAL SOCIETY OF WASHINGTON.

The fact that these portions of matter are organic, in no re-
spect releases them from the common servitude of matter to
the laws of mechanics through the operation of phj-sical
forces.

If then development of structure is constrained to operate
within a limited field, which can hardlj^ be denied, all those
calculations based upon the assumption that the field is unlim-
ited fall to the ground and may be safely disregarded as
irrelevant.

The operations of biologic selection may be divided into two
categories, ist. those in which fitness and unfitness are deter-
mined b}' the perfection in adjustment of the individual to the
mechanics of the environment, which will include the great
mass of the lower organisms ; and 2nd., those in which intelli-
gence becomes a factor. The latter will include all forms of
sexual selection, mimicry, protective coloration, and every
case in which discrimination on the part of pursuer or pursued
may come into play. It is by no means necessary that the or-
ganism which becomes modified should possess even conscious-
ness, but one of the two parties to the modification, at least,
must possess intelligence of a certain grade. The mental
qualities of the insect are necessary to the modification of the
colors of the orchid, as far as they serve to attract its attention
or direct its movements, while the modifications of the stigma
or pollen mass to facilitate cross fertilization, fall into the other
category. .

While the operations of the first category must always have
been active, and probably were not supplemented by those of
the second category for an immense period of time, yet I be-
lieve the latter also to be verv' ancient. It is probable, how-
ever, that influences of the second category operate more
rapidly and are productive of much greater diversity in devel-

ON DYNAMIC INFLUENCES IN EVOLUTION. 7

opnient than could ever have been expected from the unas-
sisted working of the physical forces.

Passing from these general considerations to those of a more
special character, the contention of Weismann that "not a
single fact hitherto brought fonvard can be accepted as proof"
of the transmission of acquired characters demands attention.
This reminds one of the familiar statement of twenty years
ago that the Darwinians had not brought forward a single in-
stance of the conversion of one species into another species.
If the Dynamic Evolutionist brings forward an h3-pothesis
which explains the facts of nature without violence to sound
reasoning, that hypothesis is entitled to respect and considera-
tion until some better one is proposed or some vitiating error
is detected in it. No one has yet " proved " that one species
is developed out of another species in the sense in which
Weismann uses the word proof in his criticism. But pl*ent\- of
facts which support the hypothesis that acquired characters are
transmitted in the sense hereinbefore explained have been ac-
cumulated, of which Osborne's paper, above cited, affords evi-
dence in one direction. Can anyone believe that the perma-
nent limb-callosities of the horse and deer, for instance, are
selective, developments of fortuitous larval corns ? Our knowl-
edge of the physiolog}' of any animal, except too or three
which have been domesticated for ages, and excepting man, is
so contemptibly meagre that it cannot be quoted as evidence
on either side.

The question has been much obscured b}- the attempt to
quote the effect or non-effect of mutilations upon progeny, on

one side or the other.

For the Dynamic hypothesis onh- those characters can be
considered which arise from permanent physiological reactions
due to the impact of external forces. Mutilations rarely fall

8 BIOLOGICAL SOCIETY OF WASHINGTON.

into this category and are essentially sporadic. In the case of
circumcision, so often cited, they affect, at most, half the indi-
viduals of a race and only half of any one generation.

There is not a particle of reason to believe that the excision
of a trifling scrap of cuticle from an infant would lead to any
physiological reaction worthy of attention. One might with
greater warrant seek such an effect in the growth of hair and
of the nails in civilized races accustomed to trim them.
Neither case has been shown to afford valuable evidence.

There is no reason to deny that a pathologic incident of suf-
ficientlj' fundamental character may effect the progeny of an
individual, but it is of no consequence to the Dynamic hypo-
thesis whether it can be proven or not.

Experience shows that it is not single mutilation or loss of
substance which results in permanent physiological reactions
so much as continued impacts which lead to locally increased
nutrition or local anaemia.

The objection to reasoning drawn from pathologic cases is
not that it is not or may not be true, but that the cause affects
only individuals in trifling numbers.

The forces invoked by Dynamic hj^pothesis, on the other
hand, affect every individual of a race and every generation
as long as the environment continues unchanged. Sporadic
modifications must always be finally swallowed up in the gen-
eral average of the organic type, unless carcfull}^ selected by
intelligent agencies. The steady pressure of telluric forces
lets no individual escape.

On the coast of California the soft tertiary sandstones are
drilled by several species of boring mollusks, P/io/as, Lithophagus
and Petricola. In the course of time the borers die and leave their
closely fitting cells untenanted. Into these safe retreats the
young of several non-boring bivalves are in the habit of retiring.

ox DYXA^riC TXFLrENCP:S IX EVOLTTTIOX. y

As they grow they become too large to escape by the
hole through which they entered. Grow they must but the
stone walls of their dwelling permit growth only in certain
directions. The collector breaks the rock and finds Kellia,
Tapes or RupcUaria with the outward conformation of the an-
tecedent borer. Those which refused to conform, if an}^ have
died. Here we have a case where characters have been as-
sumed under an abnormal stress analogous to a pathologic or
traumatic mutilation. The progeny of these nestlers would
probably exhibit no traces of their parents' deformity. But
the pressure of the physical forces on this progeny would be,
though invisible, as constant and effective in its results as the
rock seemed to be with the nestlers. These results in propor-
tion to their harmony with the environment produce upon the
obsen'er the impression which is implied when he speaks of
the appearance of such species as " normal."

In my paper on the hinge of Pelecypods and its develop-
ment,^^ I have pointed out a number of the particular ways in
which the dynamics of the environment ma^^ act on the char-
acters of the hinge and shell of bivalve mollusks.

In a paper now in preparation for publication I have shown
how the initiation and development of the columellar plaits in
Valuta, Mitra and other Gastropods, is the necessary mechani-
cal result of certain comparatively simple physical conditions ;
and that the variations and peculiarities connected with these
plaits perfectly harmonize with the results which follow with
inorganic material subjected to analogous stresses.

Attention once directed to this class of influences and their
effects and it is certain facts will accumulate not less numerous

*Am. Journ. of Science, Dec, 18S9, p. 445.

10 BIOLOGICAL SOCIETY OF 'WASHINCJTON.

and convincing in their establishment of the theorj' than those
which have been taken as ' ' proof ' ' of the survival of the
fittest.

Note. Since this paper was delivered before the society the
discussion of the subject has been continued in the pages of
Natuf'e. I have been interested to note that Prof. Lankester
(in the issue for Mar. 6, 1890, page 414) like the skilled tacti-
cian he is, has begun building bridges in his rear which may
serve as a means of retreat from his present untenable posi-
tion. He now explains that by the " transmission of acquired
characters ' ' he means the obsolete theory of L,amarck in its
purity, which, so far as I have followed the discussion, nobody
has proposed to uphold. Why he has continued to oppose the
►Dynamical theory by arguments intended to demolish a totally
different hypothesis, he does not explain.

Mr. Romanes has also pointed out that recent admissions of
Dr. Weismann are fatal to the ingenious hypothesis and as-
sumptions with which that gentleman's name has been chiefly
connected {Nahire, Mar. 13, 1890, p. 429.)

In fact these and other signs indicate that the most able of
those who have through haste or conservatism been disposed
to ignore dynamical influences in evolution, will before long
join in the procession, and lend their undoubted abilities to the
perfection and elaboration of the only theory yet propounded
which fully and efiiciently supplements that of Natural Selec-
tion and closes the too obvious gaps which have hitherto
existed in the intellectual structure of the modern theory of
organic evolution.

NEO-DARWINISIVI AND NEO-LAMARCKISM.*

By Lester F. Ward.

INTRODUCTORY.

In casting about for a subject on which to address this
Society I have encountered serious difficulties. A presidential
address to a Biological Society should, as it seems to me, fol-
low one of two courses. It should either relate in its general
aspects to the subject with which its author is most familiar,
and so coordinate the facts within his specialty as to correlate
them with the sum-total of biological science ; or else, it should
be an exposition of and commentary upon the most prominent
problem of biology which at the time of its presentation, is en-
grossing the attention of the scientific world. One year ago I
realized these two alternatives as clearly as I do now, and I felt
then that while the second of them was not more appropriate
than the first, the overwhelming prominence of one great biolog-
ical question almost demanded that I should sink my individual
preferences and, as a matter of sheer duty, undertake to grap-
ple with that question. But I have always believed and often
said that the Biological vSociety should choose as its president
one who represents the whole science of biology, and that it
made a mistake in selecting a narrow specialist, and a special-
ist in a department which has the reputation of not keeping

* Annual Presidential Address delivered at the Eleventh Anniversary
Meeting of the Biological Society of Washington, January 24, 1891, in
the Law Lecture Room of the CDlumbian University.

12 BIOLOGICAL SOCIETY OF WASHINGTON.

pace with the rest of the science, and I felt that if compelled
to listen to views growing chiefly out of that narrow specialty,
it was in some degree its own fault. But in view of the fact
that the Society saw fit to repeat its mistake, and that I last
year presented the problems of botany and its geologic history,
there seems no escape from that duty which still confronts me
of closing with the great problem of heredity which continues
to occup3' the foreground of all biological discussion.

There is strictly speaking only one prominent question be-
fore the biological world and that is the question whether qual-
ities that are acquired after birth are capable of being trans-
mitted to descendants. Darwinism in its original entirety, as
expounded by Darwin himself, admits such transmission. But
by the new school of Neo-Darwinists this is denied. On the
other hand Lamarckism, as expounded by Lamarck, explains
all change through the tran.smission of functionally acquired
characters, the law of natural selection not having been per-
ceived by lyamarck. But Neo-Lamarckism, as I understand it,
while recognizing natural selection as the more potent of the
two agencies, also recognizes that the increments of change im-
pressed upon individuals during their lifetime or brought about
by individual efforts or habits are also perpetuated in some
measure through heredit}^ and form an important factor in
the general process of organic development.

STATUS OF THE PROBLEM.

From the appearance of the Origin of Species in 1859 until
within the past four or five years it had been the opinion of
nearly all naturalists that the existing forms of animals and
plants were the result mainly of two cooperating causes, one
of which may be called functional and the other selective. The

PRESIDENTIAL ADDRESS. 13

multitudinous infinitesimal effects wrought by both of these
causes upon the form and character of organisms were
believed to be cumulatively perpetuated b}- heredity in the
modification of species and the production of new and altered
forms of vegetable and animal life. Prior to the date named
the few who conceived that existing forms might be modifica-
tions of ancestral ones ascribed the changes wholly to the first
of these causes, the functional. Mr. Darwin showed that this
could not account for all ca.ses, and in pointing out, simul-
taneously with Mr. Wallace, the existence and mode of opera-
tion of the selective agency he made the most important con-
tribution yet brought forward to the science of biology.

At the date of Darwin's death, 1S82, the general doctrine of
evolution and the theory of development in biology had been
accepted by so nearly the entire body of scientific men that it
was scarcely worth the effort to conciliate the small remnant
who still adhered to the special creation hypothesis. The
only question was : B3' what agency or agencies is evolution
accomplished ?

It would carry me too far to attempt to pass in review the
various theories of the pre-Darwinians — Treviranus, De Mail-
let, Goethe, Buffon, Geoffroy St. Hilaire, Erasmus Darwin, and
the anonymous author of the Vestiges of Creation. This task
has been admirably performed by Professor Haeckel in his
History of Creation, and in the later editions of the Origin of
Species Mr. Darwin has collected quite a number of sporadic
adumbrations not only of the law of evolution itself but even
of that of natural selection. I shall be obliged to confine my-
self almost exclusiveh' to the one great mind, who far more
than all others combined, paved the way for the new science of
biology to be founded by Darwin, namely, Lamarck. His life
was chiefly devoted to the systematic and structural investiga-

14 BIOLOGICAL SOCIETY OF WASHINGTON.

tioh of animals and plants and his earlier works gave little
indication of philosophical tendencies, but his Philosophic
Zoologiqne,* which appeared in i8og, showed that he had
reasoned deeply about the objects he had so long studied, and
in this work is contained the whole of his celebrated system of
the transmutation of species.

LAMARCKISM.

Although most of the members of this Society are doubtless
familiar with the general character of the Lamarckian philos-
ophy, and many have probal)ly read this work, the nature of
my subject seems to demand that some of the more general
principles of lyamarckism be set forth. A few paragraphs
from the work in question will accomplish this better than any
attempt at exposition. The following quotations will serve to
show the sweeping character of Lamarck's generalizations,
and when we remember the time at which they were written
it will not appear strange that his views attracted so few ad-
herents and had to wait half a century for a respectful
hearing.

" In order to judge" says Lamarck " whether the idea that
has been formed of a s/)cr/c's has any real foundation, let us
return to the considerations which I have already set forth ;
they show :

I St. That all the organized bodies of our globe are true
products of Nature, which she has successfully brought forth
{executes) in the course of long periods of time ;

2d. That in her march Nature has commenced, and is still
daily commencing to form the most simple organized bodies,

* Philosophie Zoologique, etc. Par Jean-Baptiste-Pierre-Antoine de
Monet, Chevalier de Lamarck. Nouvelle Edition, revue et precedee
d'une introduction biographique par Charles Martins. Paris, 1873,
2 vols. 8°.

PRESIDENTIAL ADDRESS. 15

and that she only forms these latter directly, that is, only
these first sketches of organization that have been designated
by the expression spontaneous generation;

3d. That these first outlines of the animal and of the plant
formed at suitable places and under appropriate circumstances,
and possessing the attributes of incipient life and organic
movement, have themselves little by little developed organs
and in time multiplied these as well as parts ;

4th. That the power of growth in each part of the organ-
ized body being inherent in the first effects of life, it has given
rise to the different modes of nuiltiplication and reproduction
of individuals, and that in this way the progress acquired in
organization and in the form and diversity of parts has been
preserved ;

5th. That by the aid of sufficient time, of circumstances
which have been necessarily favorable, of the changes which
all points on the surface of the globe have successively under-
gone in their condition; in a word, by the power which new
situations and new habits possess to modify the organs of bodies
and of life, all the organisms that now exist have been insensi-
bly formed such as we see them ;

6th. Finally, that under the influence of such an order of
things, living bodies having undergone each of the changes,
greater or less, in their structure and in their parts, what is
called species thus insensibly and successively brought about
among them has only a relative constancy in its character and
cannot be as ancient as Nature herself." *

It will be seen that both the mutability and the transmuta-
tion of species are distinctly formulated. But in order to make

this more clear he elsewhere says :

*

*Op. cit. Vol. I, pp. 81-83.

16 BIOLOGICAL SOCIETY OF WASHINGTON.

' ' In the same climate very different situations and exposures
cause individuals thus placed at first simply to vary; but in the
course of time the continual differences of situation of the indi-
viduals of which I speak, living and reproducing under the
same conditions, bring about in them differences which become
in some sort essential to their existence, so that at the end of
many generations which succeed each other those individuals
which belonged originally to another species find themselves
transformed into a new species, distinct from the other." *

The two great causes to which he ascribes this transforma-
tion are: i, what he calls the "circumstances," and 2, the
" habits " of the creatures transformed, and to enforce this
idea he lays down the following ' ' zoological principle ' ' the
fundamental truth of which, he says, appeared to him incon-
testable :

' ' Progress in the structure {compositio?i) of the organization
undergoes here and there in the general series of animals
anomalies brought about by the character of the habitat
{cir con stances d' habitation), and by that of habits contracted, "f

Between the "circumstances" and the "habits," however,
Lamarck perceived a casual relation, and this he expressed in
the following argumentative form :

"The true order of things to be considered in all this con-
sists in recognizing :

I St. That every permanent change of any consequence in
the circumstances under which each race of animals finds
itself effects within it a real change in their needs ;

2d. That every change in the needs of animals necessitates
for them other actions to satisfy the new needs, and hence,
other habits ;

♦ *Op. cit., Vol. I, pp. 79-80.
top. cit., Vol. I, p. 145.

PRESIDENTIAL ADDRESS. 17

3d. That every new need necessitating new actions to satisfy
it requires of the animal experiencing it either the more fre-
quent employment of such of its organs of which it previously
made less use, which develops and enlarges considerably, or
else the employment of new parts to which the needs insensi-
bly give rise within it through efforts of its internal sense."*

In all this Lamarck does not expressly say that these trans-
formations are perpetuated by heredity, although this is clearly
implied, otherwise they would not be permanent. But he now
proceeds to embod}^ the general principle in what he calls a
law, the first law of organic life, to which he adds a second law
in which the principle of heredity is distinctly formulated. Al-
though these two great Lamarckian laws have been frequently
quoted in biological discussions, especially within the past three
or four years, it seems essential to the completeness of the
present exposition to introduce them. They are as follows :

First Law : "In every animal which has not passed the limit
of its development the more frequent and sustained exercise
{emploi) of any organ gradually strengthens that organ, de-
velops and enlarges it, and gives it a power proportioned to the
duration of such exercise ; while the continued lack of exercise
{usage) of an organ gradually enfeebles it, deteriorates it,
progressively diminishes its power, and finally causes it to dis-
appear."

Second Law : ' 'All that nature has caused individuals to ac-
quire or to lose through the influence of the circumstances to
which their race has found itself for 'a long time exposed, and
consequently, through the predominant exercise of certain or-
gans, or through a failure to exercise certain parts, it preserves
through heredity {generation) to the new individuals that are

^ e

*Op. fit., Vol. I, pp. 234-235.

18 BIOLOGICAL SOCIETY OF WASHINGTON. .

«

produced by them, provided the changes acquired are common
to the two sexes, or to those that have produced these new
individuals." *

These laws are enforced bj' considerable iteration and all the
facts and illustrations that he could command. He condenses
his first law into the following form :

"The frequent exercise of an organ which through habit
has become permanent increases the capacity of such organ,
develops it, and causes it to acquire dimensions and power of
action which it does not possess in animals that exercise it
less."t

The second law is re-stated in the following language :

" Every change acquired in an organ by an habitual exercise
sufficient to have brought it about, is preserved thereafter
through heredity {generatioii) if it is common to the indi-
viduals which, in fecundation, unite in the reproduction of
their species." %

Such is Lamarckism pure and simple, which it seems neces-
sary to set forth at first hand before approaching those modern
phases of the problem which have grown out of it. It is obvi-
ous that it deals onh^ with the first of the two agencies in bio-
logic progress mentioned at the outset, namely the functional ;
and Lamarck, although he clearly grasped the law of compe-
tition, or the struggle for existence, the law of adaptation, or
the correspondence of the organism to the changing environ-
ment, the transmutation of species, and the genealogical de-
scent of all organic beings, the more complex from the more
simple ; he nevertheless failed to conceive the selective princi-
ple as formulated by Darwin and Wallace, which so admirably
complemented these great laws.

*Op. cit., Vol. I, pp. 235-236. top. cit.. Vol. I, p. 247.

J Op. cit., Vol. I, i)i>. 2.SS-259.

PRESIDENTIAL ADDRESS. 19-

The cogency of Lamarck's reasoning, especially when we
consider the time at which he wrote, is sufficiently apparent
to all, but it may not be without interest to note the manner
in which it struck so excellent a judge as Professor Huxlej'
as late as 1876. In contrasting it with the views of Cuvier
who maintained the fixity of species and their special crea-
tion, Professor Huxley says: "It is impossible to read the
' Discours sur les Revolutions ' of Cuvier, and the ' Principes '
of lyamarck without being struck with the superiority of the
former in sobriety of thought, precision of statement, and
coolness of judgment. But it is no less impossible to consider
the present state of biological science without being impressed
by the circumstance that it is the conception of Lamarck
which has triumphed and that of Cuvier which has been van-
quished ... It is not too much to say that the facts of
biology known at the present day are all consistent with and
in favor of the view of species entertained b}^ Lamarck, while
they are unfavorable to, if not incompatible with, that advo-
cated by Cuvier."*

DARWINISM.

Darwin was acquainted with Lamarck's views when he
wrote the Origin of Species, and notwithstanding the fact that
whenever he refers to Lamarck, as he does in several of his
lettersf he does so in a very disparaging wa3% he must have
been greatly influenced by them, or at least by views of the
same import expressed by others as well as by Lamarck, but
especially those of his grandfather Erasmus Darwdn, who
anticipated, rather from the standpoint of the poet and seer,
the truths to which Lamarck was led by a life-long study of
living things.

*Am. Cycl. , Art. Species.

t Life and Letters, Vol. I, p. 542, Vol. II, p. 19b.

20 BIOLOGICAL SOCIETY OF WASHINGTON.

But Darwin, like most other thorough naturalists, was little
satisfied with the L,amarckian theory, because it left, as all
now admit, so much still unexplained, but instead of reject-
ing it in toto, as most other naturalists did, he sought, and
happily succeeded in finding the principle on which the
remainder of the facts could be accounted for ; or, at least,
the greater part of them, for it seems that however deeply
we may probe the secrets of nature there will ever remain a
few residual phenomena that refuse to submit to our canons.

It is certainly unnecessary that I should occupy your time
with any extended exposition of the law of selection, and I
will content myself with the following bare definitions :

Natural selection is the general law that variations are con-
stantly occurring in organized beings, and that such of these
variations as prove advantageous to the species are preserved
through heredity and transmitted to posterity while those
which are not advantageous or are disadvantageous to the
species are not preserved nor transmitted ; the cause of such
selection being the fact that advantageous variations tend to
increase the chances that the individuals possessing them will
reach the reproductive age and continue longer to reproduce,
and will hence leave a larger number of offspring than those
individuals which had not varied or had varied in an equivo-
cal or unfavorable manner.

Artificial selection is the act of man in intelligently select-
ing the individuals that possess in the highest degree the
particular qualities that he desires to produce as the parents
of the animals or plants which he wishes to domesticate or
cultivate. The eminent success obtained by man in this way
is the certain proof that the qualities of the parents are trans-
mitted to their offspring, and explains the efficacy of natural
selection.

PRESIDENTIAL ADDRESS. 21

Sexual selection is the law that one sex, usually the
female, exercises a choice between the individuals of the
other, whereb}' those individuals possessing the selected qual-
ities stand a much greater chance to have the opportunit3^ of
transmitting them to their offspring. This law explains the
greater ornamentation of the males in so many species, since
most such characters are peculiar to one sex and only appear
at maturity. Sexual selection also checks the tendency of
natural selection to extreme variation in certain directions,
since the sexes are well known to prefer their opposites,
which causes the offspring to occup)- a mean between the
extremes. This effect is very marked in the human race, but
is doubtless operative among the lower animals. As I pointed
out in last year's address, sexual selection has wrought a
great revolution in the relative size, strength, and beauty of
the two sexes, and reversed in birds and mammals the normal
law of female superiority which prevails in most of the lower
departments of life.

ACQUIRED CHARACTERS.

It will be readily perceived from what has been said of the
two great principles of transformism, the functional, as set
forth by Lamarck, and the selective, as elaborated by Darwin,
that the fundamental distinction between them is that in the
former the transforming qualities which are to be cumulativelj^
transmitted through heredity to the descendants of a given
ancestral pair are acquired during the lifetime of these indi-
viduals, whereas in the latter the transforming increment is a
merely accidental modification arising from unknown causes
and hence called spontaneous. The theorj^ is that such .spon-
taneous variations are constantly taking place in all individ-

22 BIOLOaiCAL SOCIETY OF WASHINGTON.

uals, some in one direction and some in another, and that all
except the advantageous ones are immediately lost, while
such as tend to increase the chances of survival in the strug-
gle for existence are preserved. Nature has thus provided,
through this survival of the fittest, for the maintenance of the
equilibrium between the organism and the environment, and
also for the increase of structural adaptation and vital power,
independently both of the effort of the individual to conform
more exactly to its surroundings and of the reaction of the
organism upon the impinging environment.

There has never been anj- doubt of the perfect transmissi-
bility of these spontaneous modifications, or, as they have been
called, fortuitous variations. They belong to the essential na-
ture of the organism, and have, as we shall see later on, been
ingeniously explained as originating in the very germ itself.

But with regard to functional modifications, or as they are
more commonly called, acquired characters, grave doubts have
arisen in the minds of many natiiralists as to whether they are
capable of being inherited by the descendants of those in which
they have been superinduced. They are in a certain sense for-
eign to the organism, external and superficial, and the great
question has been how they can succeed in so affecting the
reproductive germs of the parents as to reappear in the off-
spring. That Darwin believed in the transmission of func-
tionally acquired characters is attested not only by many
passages in which this belief is expressly stated but by the
bringing together by him of more facts in support of it than
have been given by all other writers combined either before
or since. And although the greater part of his work was
naturally directed to the establishment of the hitherto un-
known, but as he believed, more important law of selection,
nevertheless Darwinism proper must be made broad enough

PRESIDENTIAL ADDRESS. 23

to embrace both of the great agencies of organic transforma-
tion, the functional and the selective.

It is hardl}^ necessary to add that pure Lamarckism has
nothing whatever to do with such a question as whether acci-
dental modifications produced upon an organism, such as mu-
tilations from whatever cause, are inheritable, since these are
not due to continuous interaction between organism and envi-
ronment, are not the objects of the creature's efforts, and are
not acquired by any functional or habitual activities. And yet it
is no exaggeration to say that at least one-half, probabl}' much
more, of the space devoted by the Neo-Darwinians to the sup-
posed refutation of Lamarckism has been directed to proving
that acccidental mutilations are not transmitted to offspring.

I do not deny that there is a doctrine of the transmissi-
bility of mutilations, and Darwin and others have collected a
large body of facts pointing strongly in that direction, while
Brown-Sequard is believed by many to have demonstrated
that hereditary epilepsy may be artificially superinduced in
guinea-pigs by lesions of the brain. And it may be that
Lamarck, coming upon similar facts, gave them a certain cre-
dence, but, as we have seen from typical passages quoted from
his work, these cases are not capable of being used in support
of his general philosophy, which rests entirely upon the
effects of functional activities exerted in response to secular
alterations in the surrounding conditions of existence.

Whatever of truth, therefore, there may be in the doctrine
of the transmissibility of suddenl}^ or accidentally acquired
characters, it is clearly outside the present discussion and
need not be further touched upon.

After the doctrine of natural selection had been clearly ex-
plained it was found to be so simple and at the same time so
far-reaching that it began to be questioned whether much that

24 BIOLOGICAL SOCIETY OF WASHINGTON.

had been formerly attributed to the other agency ought not to
be credited to it instead ; and it cannot be denied that this in-
quiry tended to broaden the field of the selective at the ex-
pense of that of the functional principle. So clear and certain
are the workings of the former that it is considered safe to
credit it with every fact that can be explained by it, even
though it be also explicable by the other law.

But it was not allowed to rest here. The difficulties in the
way of accounting for the transmission of qualities originating
after the birth of the parents appeared to some so great that
they began to doubt whether in fact such a thing is really
possible. Of course, there were many popular and superficial
writers on evolution who fail to distinguish the two principles
and talked as though all development was due to natural
selection, so that to the unscientific and popular mind evo-
lution and natural selection were largely synonymous and
vaguely comprehended, as is, in fact, still to a large extent,
the case. Other better informed people, including some
naturalists of note, were so dazzled by the new idea that they
lost sight of the old one, and habitually ignored the func-
tional element without criticising it or taking any account of
it. It appears to have been against this class that Mr. Her-
bert Spencer's brilliant exposition of the principle which, in
characteristic language, he calls "direct equilibration" was
directed. To this I shall have occasion to revert.

For the present I propose to confine myself to those writers
who clearly comprehend the nature of the two principles, and
who either gravely doubt for what seem to them sufficient rea-
sons, or else deny altogether the efficacy of functional modifi-
cation and the doctrine of the transmission of acquired charac-
ters. The limits of an address such as this preclude any effort
to make the discussion historically exhaustive by enumerating

PRESIDENTIAL ADDRESS. 25

all the investigators who from the first to last have taken this
view, or some modified form of it, and I shall be content to
name among Germans Du Boise Reymond, Pfliiger, His, and
Weismann, and among Englishmen Galton, Wallace, and Ray
Lankester ; while what I shall have time to say relative to
the nature of the objections raised by these authors will be
chiefly confined, for the present, to the views of Galton and
Weismann.

THEORIES OF HEREDITY.

It must, however, be premised that inasmuch as the objec-
tions raised against the doctrine of the transmission of ac-
quired characters are based upon the difficulties encountered
in attempting to explain how such characters can impress
themselves upon the germ, all those who have doubted or de-
nied such transmission have approached the subject from the
side of embryology, which makes their arguments difficult to
explain to biologists in general and still more so to the general
public. The laws and processes of heredity are still in the
stage of mystery, and their mysterious character has led to
many erroneous beliefs and popular superstitions. It is a sig-
nificant fact that all the mysteries that have been thus far
cleared up by science — astronomical, physical and chemical
mysteries — have been shown to be the expressions of previ-
ously unknown laws of matter and force, and to rest upon a
purely material and mechanical basis. The chief obstacle to
their comprehension has been the minuteness of the material
elements in action — a minuteness far beyond the capacity of
the most powerful artificial aids to the senses — so that their
secrets have had to be wrung from them by ingenious and
multiplied experiments upon their effects. Now, the ultimate

26 BIOLOGICAL SOCIETY OF WASHINGTON.

reproductive elements, though doubtless many times larger
than any chemical molecule, even the most complex, such as
those of protein and other organic compounds, are doubtless
still far too minute to be observed by the highest powers of
the microscope, and if the entire history of the formation of a
new organic being is ever to be learned it must be by a suc-
cessful study of the actions of such minute objects. But this
is infinitely more difficult than the study of the actions of
inorganic elements, since they take place within an organism
whose destruction destroys their vital character.

In view of the history of the less complex sciences it is
natural that biologists should insist that the phenomena of
heredity are due to the activities of the ultimate material
reproductive elements, and not to any vague and occult force
or deus ex niachina. Consequently we find that the only
theories of heredity that have been put forth have been based
on this assumption.

One of the earliest, and certainly the most celebrated of such
theories is Darwin's pangenesis, published in 1867.* Accord-
ing to this theory, which is doubtless familiar to most of you,
the ultimate reproductive elements, called gem mu/es, are given
off from the cells of all parts of the body and collect in the
germ-cells and sperm-cells, so that the fertilized ova contain
literal representatives of every organ and every part of both
parents, which in the new being return to their respective
locations and cause the repetition in each of the exact qualities
possessed by the parental organs or parts, subject, of course,
to the modifications due to a conflict or cooperation between
the genimules of the two parents, equalizing a character where
they are different, and emphasizing it where they are alike.

* Variations of Animals and Plants under Domestication. Vol. II,
Chaps. XXXVII, XXXVIII.

PRESIDENTIAL ADDRESS. 27

It will be readily seen that this theory adapts itself to the
broadest conception of heredity and, if trne, accounts for the
transmission of functionally produced modifications as well as
the selection of such accidental ones as prove advantageous.
But to the ordinary mind this strictly materialistic explanation
of heredity seems crude and is to a large extent unintelligible,
and the doctrine of pangenesis has gained few adherents
among scientific men. They fail as a rule to comprehend
Mr. Darwin's gemmules and to understand how they should
behave in the manner required by the theory.

\^ery much of this difficulty, however, is cleared away by
the admirable exposition of Mr. Herbert Spencer of the na-
ture of what he calls physiological units. To the biologist the
organic unit is the cell and when he has explained the nature
and action of cells he thinks he has gone far enough. But the
facts of heredity cannot be explained by any phenomena man-
ifested b}^ cells. Between the cell or morphological unit in
biology and the molecule of a highly complex organic com-
pound, such as albumen, — the highest class of chemical units —
no intermediate element had hitherto been recognized. Mr.
Darwin's gemmule is clearly such an intermediate element,
and the question at once arose, is there any such ? Mr. Spen-
cer has, I think, shown beyond the possibility of doubt that
there is and must necessarily be such an element — a unit which
is not chemical, since it possesses life, and which is not the
morphological unit or cell, bvit is that of which the active part
of every cell consists, and is appropriately termed the physio-
logical unit. I have elsewhere* undertaken to show that life
may have resulted from a process of chemical recompounding,

*Americau Naturalist, Vol. XVI, December, 1882, p. 976. Dynamic
Sociology, New York, 1883, Vol. I, p. 311.

28 BIOLOGICAL SOCIETY OF WASHINGTON.

and may actually constitute the leading property of the high-
est organic compound protoplasm, and I venture to suggest
here that the gemmules of Darwin and the physiological
units of Spencer may be nothing more than the molecules of
protoplasm, which, as I have explained, are so immensely
complex that any required degree of difference in their essen-
tial constitution may easily exist.

The only other theory of heredity which time will warrant
my mentioning now is that of Professor Haeckel, published in
1876 and known as "the perigenesis of the plastidule." To
avoid the possibility of misstatement, I will give this theory
in the words of its author, as epitomized in the latest (8th)
edition (1889) of his Schopfungsgeschichte (pp. 200-201):
"The perigenesis-theory was founded by me in 1876 in a
memoir ' on the wave-reproduction of vital particles or the
perigenesis of plastidules,' and as a ' provisional attempt at a
mechanical explanation of the elementary processes of devel-
opment,' and especially of heredity. (In the second part of
my collection of popular lectures, Bonn, 1879, pp. 25-So). The
perigenesis-hypothesis seeks to explain heredity by a simple
mechanical principle, namely, by the well-known principle of
transmitted motion. I assume that in everj^ process of repro-
duction not only is the special chemical composition of the
plasson or plasma transmitted from the parent to the offspring,
but also the special form of molecular motion which belongs
to its physico-chemical nature. In harmony with the funda-
mental laws of modern histology and histogeny, I assinne that
this plasma (either the caryo-plasma of the cell-nucleus or the
cytoplasma of the cell-body) is alone the original bearer of
all vital activity, and hence also of heredity and reproduction.
In all plastids (as well the anucleated cytodes as the genuine
nucleated cells) this plasma or plasson is composed of plasti-

PRESIDENTIAL ADDRESS. 29

dules or plasma-molecules, and these are ' probably sur-
rounded by aqueous envelops ; the greater or less thickness
of these aqueous envelops, which at once separate and bind
the neighboring plastidules, determines the softer or harder
condition of the flowing plassou' (p. 48).

' Heredity is the transmission of plastidule motion, whereas
adaptation is change of plastidule motion' (p. 55). This
motion may in its general aspects be conceived as a ramified
wave-motion. In all protists or unicellular organisms (proto-
phytes and protozoans) this periodical movement of the mass
goes on in a correspondingl}' simple manner while in all
tissue-bearing or multicellular creatures (metaphytes and
metazoans) it is combined with a mutual generation of the
plastids and a division of labor of the plastidules."

It will be observed that although this theory of heredity
lays special stress upon the idea of motion, thereby recogniz-
ing the element of force, it is nevertheless based like all others
upon the existence of ultimate material elements different on
the one hand from the chemical molecules and on the other
from cells, and intermediate between these. The gemmule of
Darwin, the physiological unit of Spencer, and the plastidule
of Haeckel are the same in essence, and the study of the phe-
nomena of these ultimate elements of biology open up a new
and most promising field of research into which scarcely any
investigator has as yet deliberately entered.

We are now prepared to consider the objections of Galton
and Weismann to the doctrine of the transmission of function-
ally acquired characters.

VIEWS OF MR. GAtTON.

The earliest expression of Mr. Galton's views, so far as I
am aware, is contained in a paper "On Blood-Relationship "

30 BIOLOGICAL SOCIETY OF WASHINGTON.

presented by him on June 13, 1872, to the Royal Society of
lyOndon and published in its proceedings.* In this paper
stress is laid upon the distinction in embryonic development
between what he calls the "patent" and the " latent " ele-
ments, and he argues from the facts of reversion and atavism
that the greater part of the parental elements in heredity are
latent in the germ, but prepared to express themselves in
more or less remote decendants. Although he addres.ses
himself to the anthropologist rather than the biologist, and
claims only to be making a contribution to the difficult sub-
ject of kinship, he nevertheless evinces a clear grasp of the
embryonic conditions of the problem, and as we shall see,
anticipates, some of the more exact conceptions of Weismann.
He does not wholly deny the possibility of the transmission
of acquired characters, but says that " the effects of use and
disuse of limbs, and tlio.se of habit, are transmitted to pos-
terity in only a very slight degree."

In this respect Mr. Galton makes only a slight advance
toward the conclusions of Weismann in the much more elabo-
rate paper which he read before the Anthropological Institute
of Great Britain on November 9, 1S75, and which appeared in
the December number or the Contemporary Review for that
year, and also in an expanded form in the Journal of the Insti-
tute (Vol. V, p. 329). In this paper which is entitled "A
Theory of Heredit3%" he, however, approaches the main ques-
tion with much greater directness. "The facts" he says "for
which a complete theory of heredity must account' may con-
veniently be divided into two groups ; the one refers to those
inborn or congenital peculiarities that were also congenital in
one or more ancestors, the other to those that were not con-
genital in the ancestors, but were acquired for the first time by

*Vol. XX, p. 394.

PRESIDENTIAL ADDRESS. 31

one or more of them during their lifetime, owing to some change
in the condition of their life. The first of these two groups is
of predominant importance, in respect to the number of well-
ascertained facts that it contains, many of which it is possible
to explain in a broad and general way, by more than one theory
based on the hypothesis of organic units. The second group
includes much of which the evidence is questionable or difficult
of verification and which, as I shall endeavor to show, does not
for the most part, justify- the conclusion commonly derived from
it." He further says that his theory " is largely based on the
arguments and conditions brought forward by Mr. Darwin in
support of pangenesis ; nevertheless the conclusions in this
paper w^ill be seen to differ essentially from his own. Pan-
genesis appears more especially framed to account for the cases
which fall in the second of the above-mentioned groups which
are of a less striking and assured character than tho.se of the
first group, and it will be seen that I accept the theory of pan-
genesis with considerable modification, as a supplementary and
subordinate part of a complete theory of heredity, but by no
means for the primary and more important part."

• He employs the term s//rp " in a special sense — to express
the sum-total of the germs, gemmules, or whatever they niaj^
be called, which are to be found, according to every theory of
organic units, in the newly fertilized ovum — that is in its
earliest pre-embryonic stage." In defending the theory of
organic units he says : "We must bear in mind that the
alternative hypothesis of a general plastic force resembles that
of other m3'stic conceptions current in the early stages of
many branches of physical science, all of which yielded to
molecular views, as knowledge increased."

The paper is an exceedingly luminous contribution to the
subject, and the theory advanced may be designated in general

32 BIOLOGICAL SOCIETY OF WASHINGTON.

terms as the doctrine of natural selection or survival of the
fittest among the organic units constituting the stirp, to de-
termine which shall become manifest in the offspring and which
shall lie latent to reappear or not in later generations. As the
stirp contains organic units that have lain latent in previous
generations and may become patent in the generation in ques-
tion, the theor}- accounts for reversion, atavism, and the whole
train of facts in heredity that have so long puzzled the scientific
investigator. We are at present onl}- concerned with so much
of it as relates to the transmission of acquired characters. The
following passage expresses his views on this point : " We have
thus far dealt with three agents — (i) the stirp, which is an or-
ganized aggregate of a host of germs ; (2) the personal struc-
ture, developed out of a small portion of these germs ; and (3)
the sexual elements, generated by the residuum of the stirp.
The cases before us are those which are supposed to prove that
2 reacts on 3 — that is, the personal structijre upon the .sexual
elements. The first and largest class of these cases refer to
adaptivity of race. It is said that the structure of an animal
changes when he is placed under changed conditions ; that his
offspring inherit some of his change ; and that they vary still
further on their own account, in the same direction, and so on
through successive generations, until a notable change in the
congenital characteristics of the race has been effected. Hence
it is<:oncluded that a change in the personal structure has re-
acted on the .sexual elements. For my part, I object to so
general a conclusion." And he proceeds to elaborate his
reasons for such objection. Passing over these for want of
time I will conclude this exposition of Galton's views by quot-
ing the following passage :

"The conclu.sion to be drawn from the foregoing arguments
is, that we might almost reserve our belief that the structural

PKESIDENTIAI. ADDRESS. 33

cells can react on the sexual elements at all, and we may be
confident that at the most they do so in a very faint degree ;
in other words that acquired modifications are barely, if at all,
inherited, in the correct sense of that word. If they were not
heritable, then the second group of cases would vanish, and we
should be absolved from all further trouble about them ; but
if they exist, in however faint a degree, a complete theory of
heredity must account for them. I propose, as alread}^ stated,
to accept the supposition of their being faintly heritable, and
to account for them by a modification of pangenesis."

I am not aware that l\Ir. Galton has modified the views here
expressed since the date of that paper, but in all his subsequent
ones, as well as in his work on "Hereditary Genius" (iSyg)
he continues to emphasize the paramount importance of the
latent elements in heredity, and the superiority, as he forcibly
expresses it, of nature over nurture.

TEACHINGS OF PROFESSOR WEISMANN.

The vigorous onslaught which has been made upon the doc-
trine of the transmission of acquired characters, since the date
of Mr. Galton 's papers, and apparently without a knowledge
of them, by Prof. August Weismann of the University of Frei-
burg has probably aroused a greater amount of interest among
scientific men than any other event that has transpired since
the appearance of Darwin's Origin of Species. Professor Weis-
mann is an embrjologist and histologist and has conducted a
series of prolonged and successful investigations upon several
groups of lowly organisms. But he has looked beyond the
special facts which are immediately connected with his re-
searches and has thought out for himself all the deeper prob-
lems of biology. Besides making himself complete master of

34 BIOLOGICAL SOCIETY OF WASHINGTON.

the whole field of that science as generally accepted he has co-
ordinated its facts and drawn from them a nnmber of new and
brilliant conclusions which have set the world to work on
entirely new lines of investigation.

Professor Weismanu was logically led to the conclusion that
acquired characters cannot in any conceivable way be trans-
mitted. The first of the series of essays which have produced
such a sensation, that on the duration of life, was originally
read before the Association of German Naturalists and Physi-
cians at Salzburg in September, 1 88 1, and a short abstract of
it appeared in Nature for April 5. 1888 (Vol. XXXVII. p.
541). It was in this paper that he elaborated the theory that
unicellular organisms are potentially immortal. The second
of the series, that on heredity, was his inaugural agldress as
Pro-rector of the University of Freiburg, delivered June 21,
1883. It was in this that he first attacked the doctrine of the
transmission of acquired characters, and in it and the preceding
essay may be found the germs of all his later theories. The
remaining six essays appeared at intervals from 18S3 to 1S88.
Abstracts and reviews of them occured in Nature and the
English magazines, and long before the appearance in 1889 of
the admirable work containing an English translation of the
whole series with numerous additions and amendments by the
author and notes by the translators, "^ the controversy had be-
gun in which so many of the most eminent biologists of Europe
and America have taken part.

Professor Weismann's general course of reasoning is some-
what as follows : It is universally admitted that all the higher
organisms consist of tissues made up of cells and that these

* Essays upon Heredit}' and kindred biological problems. By August
Weismann. Authorized translation edited by Edward B. Poulton, Selmar
Schonland, and Arthur E- Shipley. Oxford, Clarendon Press, 1889.

PRESIDENTIAL ADDRESS. 35

cells do not differ essentially from those which are found lead-
ing an independent existence and are termed unicellular or-
ganisms. Many of these unicellular organisms reproduce by
the process known as fission or division ; that is, they split or
divide into two equal parts each of which becomes a new or-
ganism exactl}- like the original. These halves exist for an
appointed time, increase in size until they are each equal to the
original cell before division, and then divide again, so that
what was formerly one now becomes four. Each of these four
repeats the process, and so on, thus multiplying in a geometri-
cal ratio. But if we follow any one of these lines of descent we
observe that the last of the line contains some of the same mat-
ter that was in the first, and none of the matter has ceased to
live. Unless destroyed by some external cause all of the sub-
stance of the original cell will continue to live for any conceiv-
able length of time. It is " potentially immortal." Now, the
theory of descent as a universal organic principle, which Weis-
mann fully accepts, explains all the life of the globe as result-
ing from previous life through some form of reproduction. Fis-
sion is the simplest form of reproduction, and it is found that
it is the common form of cell-reproduction within the tissues of
the higher animals. All growth is brought about by it or some
modification of it. A study of the phenomena of reproduction
in the lower organisms shows that it takes place ultimately
through some similar process, which, however greatly modi-
fied in its details, consists essentially in the actual transmission
of the reproductive cell-substance from parent to offspring, and
Weismann maintains that the reproductive cells, like those of
unicellular organisms, are immortal or perpetual, and that
nothing can get into the body of the offspring except through
that of one or other of its parents. This is his fundamental
doctrine of the continuity of the germ-plasm. The impregnated

36 BIOLOGICAL SOCIETY OF WASHINGTON.

ovum contains the germ-plasms of the two parents, and out of
it the embryo is formed. The embryo develops independently
of the mother by a circulation of its own, and no external in-
fluences can b}' any conceivable method affect or change the
characters of the offspring.

But it is well known that variation takes place, that the off-
spring does not always resemble either parent, and that changes
go on so great as to result in the creation of new species, new
genera, and entirely new types of life. All this Weismann ad-
mits. How does he explain it ? Primarily by natural selec-
tion, but he does not stop with that. It has always been ad-
mitted that natural selection did not explain the cause of varia-
tion. Weismann attempts to do this, and his reasoning is
exceedingly ingenious.

The original reproductive cells are assumed by him to con-
sist of an indefinite number of units which he calls germ-plasms,
and their presence is explained on the assumption of their pre-
servation from ancestral organisms. Asexual reproduction is
of course incapable of producing variation, and he maintains
that sexual reproduction has been developed and exists solely
for the purpose of insuring variation.

Relative to the constitution of the germ-plasm he says :
" Every detail in the whole organism must be represented in the
germ-plasm by its own special and peculiar arrangement of the
groups of molecules (micellae of Nageli) and the germ-plasm
not only contains the whole of the quantitative and qualitative
characters of the species, but also all individual variations as
far as these are hereditary : for example the small depression
in the center of the chin noticed in some families. The physi-
cal causes of all apparently unimportant hereditary habits or
structures, of hereditary talents, and other mental peculiarities,
must all be contained in the minute quantity of germ-plasm

PRESIDENTIAL ADDRESS. 37

which is possessed by the nucleus of a germ-cell ; not indeed,
as the preformed germs of structure (the gemmules of pangene-
sis), but as variations in its molecular constitution ; if this be
impossible, such characters could not be inherited " (pp. loo,

lOl).

The union of two germ-cells from entirel)^ different indi-
viduals always multiplies the number of ancestral germ-plasms
by two. The excess is kept down by the removal of the second
polar body, as he supposed was proved by its not taking place
in parthenogenesis. But the part removed as w^ell as the part
retained contains germ-plasms from both parents alike and
hence the offspring must partake of the nature of both.

These ancestral germ-plasms exist in the reprod'uctive cells
in vast numbers, and in the removal of half of them at each
union of the sexes, there must remain not merely those of the
immediate parents, but those of previous generations. If we
were theoretically to conceive that at the outset only a single
germ-plasm existed from each parent, then the second genera-
tion would transmit four, the third eight, and so on in a
geometrical ratio, until they would become so numerous as
to require the removal of a portion and ultimately always of
half the ancestral germ-plasms at each act of reproduction.
Says Professor Weismann : " These different qualities are
what I have called the ancestral germ-plasms, i. e., the germ-
plasms of the different ancestors, which must be contained in
vast numbers, but in a very minute quantities, in the nuclear
thread. The supposition of a vast number is not only required
by the phenomena of heredity but also results from the com-
paratively great length of the nuclear thread ; furthermore it
implies that each of them is present in very small quantity.
The vast number together with the minute quantity of the
ancestral germ-plasms permit us to conclude that they are.

38 BIOLOGICAL SOCIETY OF WASHINGTON.

upon the whole, arranged in a linear manner in the thin thread-
like loops ; in fact the longitudinal splitting of these loops
appears to me to be almost a proof of the existence of such an
arrangement, for without this supposition the process would
cease to have any meaning" (pp. 359-360).

His general view of the origin of variation is thus given by
him: "It is well known that this process [sexual or amphi-
gonic reproduction] consists in the coalescence of two distinct
germ-cells, or perhaps onh' of their nuclei. These germ-cells
contain the germ-substance, the germ-plasm, and this again,
owing to its specific molecular structure, is the bearer of the
hereditary tendencies of the organism from which the germ-
cell has been derived. Thus in amphigonic reproduction two
groups of hereditarj- tendencies are as it were combined. I
regard this combination as the cause of hereditary individual
(Characters, and I believe that the production of such characters
is the true significance of amphigonic reproduction. The
object of this process is to create those individual differences
which form the material out of which natural selection
produces new species " (p. 272). " I do not know what meaning
can be attributed to sexual reproduction other than the creation
of hereditary individual characters to form the material upon
which natural selection may work" (p. 281). "The most
important dut}^ of sexual reproduction is to preserve and
continually call forth individual variability, the foundation
upon which the transformation of species is built" (p. 373).
" Sexual reproduction is to be explained as an arrangement
which ensures an ever-varying supply of individual differ-
ences" (p. 384).

Weismann's classification of cells into somatic and reproduc-
tive is fundamental to his whole philosophy. On this point he
says : ' ' The first multicellular organism was probably a clus-

PRESIDENTIAL ADDRESS. 39

ter of similar cells, but these units soon lost their original
homogeneity. As the result of mere relative position, some of
the cells were especially fitted to provide for the nutrition of
the colony, while others undertook the work of reproduction.
Hence the single group would come to be divided into two
groups of cells, which may be called somatic and reproductive —
the cells of the body as opposed to those which are concerned
with reproduction (p. 27) , . . As the complexit}- of the
metazoan body increased, the two groups of cells became more
sharply separated from each other. Very soon the somatic
cells surpassed the reproductive in number, and during the in-
crease they became more and more broken up by the principle
of the division of labor into sharply separated systems of tis-
sues. As these changes took place the powxr of reproducing
large parts of the organism was lost, while the power of repro-
ducing the whole individual became concentrated in the repro-
ductive cells alone " (p. 28). His theory further assumes that
the germ-cells contain two kinds of plasm, which he calls re-
spectiveh' the ovogenetic and the somatogenic, i. e., the first
capable onh- of producing germ-cells, the latter capable only
of producing somatic cells. These exist together in the fertil-
ized ovum, and if allowed to remain there would go on repro-
ducing themselves in something like equal numbers. But the
bod}^ consisting almost entirely of somatic cells, it is evident
that such a multiplication of germ-cells would be onh- a hin-
drance to development. This, he claims, explains the myste-
rious phenomena so long observed by embryologists and called
the removal of polar bodies. The polar body first removed is
nothing more nor less than the ovogenetic nucleo-plasm, which
is now in the way, and whose removal is necessary to the
formation of the embryo. This is the work alone of the somatic
cells, and these, consisting as they do of the germ-plasms of an

40 IJIOLOUICAL SOCIETY OF WASHINGTON.

indefinite series of ancestors, and containing representatives of
every part of the parent organism, proceed to reproduce a new
creature on the hereditary type of the parents with the modifi-
cations due to the commingling of many ancestral types.

Without dwelling longer upon these ultimate processes
which constitute the premises of Weismann's argument, I will
now proceed to state his conclusion. It is simply that he is
utterl}^ unable to see how the somatic cells of an adult indi-
vidual can react upon or in any waj^ affect its reproductive
cells. If it cannot, the transmission through either parent to
its offspring of any peculiarity acquired since the embryo of the
parent began to form is impossible. Firmly believing in the
truth of his theory he stoutly insists that no such thing can
take place. Of course it needs to be clearly understood what
he means by acquired characters, and here, it is claimed lies
the chief point in dispute between the Neo-Darwinians and the
Neo-Lamarckians. The former contend that the latter class as
acquired characters those which are simply due to natural
selection. It will therefore be profitable to dwell a moment
upon this point.

" The tendencies of heredity ", says Weismann, " of which
the germ-plasm is the bearer, depend upon this very molecular
structure, and hence only those characters can be transmitted
through successive generations which have been previously in-
herited, viz. , those characters which were potentially contained
in the structure of the germ-plasm. It also follows that those
other characters which have been acquired by the influence of
special external conditions, during the lifetime of the parent,
cannot be transmitted at all " (p. 267). " It is only by suppos-
ing that these changes arose from molecular alterations in the
reproductive cell that we can understand how the reproductive
cells of the next generation can originate the same changes in

RESIDENTIAL ADDRESS. 41

the cells which are developed from them ; and it is impossi-
ble to imagine any way in which the transmission of changes
produced by the direct action of external forces upon the somatic
cells, can be brought about . . . To this class of phenomena
of course belong those acts of will which call forth the func-
tional activity of certain groups of cells " (p. 80). " Only those
new characters can be called ' acquired ' which owe their origin
to external influences, and the term ' acquired ' must be denied
to those which whollj^ depend upon the mysterious relationship
between the different hereditary tendencies which meet in the
fertilized ovum. These latter are not ' acquired ' but inherited,
although the ancestors did not possess them as such, but only,
as it were, the elements of which they are composed " (p. 252).
"If acquired characters are brought forward in connexion
with the question of the transformation of species, the term
' acquired ' must only be applied to those characters which do
not arise from within the organism, but which arise as the re-
action of the organism under some external stimulus, most
commonly as the consequence of the increased or diminished
use of an organ or part " (p. 322).

That such characters cannot be inherited he asserts with the
strongest emphasis and frequent iteration. His treatment of
this point often borders on the dogmatic, as a few extracts will
show.

" It has never been proved " he says, " that acquired char-
acters are transmitted, and it has never been demonstrated,
that, without the aid of such transmission, the evolution of the
organic world becomes unintelligible. The inheritance of ac-
quired characters has never been proved, either by means of
direct observation or by experiment " (p. 81). "No single
fact is known that really proves that acquired characters can
be transmitted" (p. 267). " If acquired characters cannot be

42 BIOLOGICAL SOCIETY OF WASHINGTON.

transmitted the Lamarckian theory completely collapses, and
we must entirely abandon the principle on which alone Lamarck
sought to explain the transformation of species, — a principle
of which the application has been greatly restricted by Darwin
in the discovery of natural selection, but which was still to a
large extent retained by him. Even the apparently powerful
factors in transformation — the use and disuse of organs, the re-
sults of practice or neglect — cannot now be regarded as pos-
sessing any direct transforming influence upon a species, and
the same is true of all the other direct influences, such as nutri-
tion,light, moisture, and that combination of different influences
which we call climate. All these, with use and disuse, may
perhaps produce great effects upon the body (soma) of the in-
dividual, but cannot produce any effect in the transformation
of the species, simply because they can never reach the germ-
cells from which the succeeding generation arises" (pp. 387-
388). And much more in the same strain.

Weismann fully admits the influence of the environment
upon the individual in producing marked changes. He also
fully admits the facts of adaptation to environment and the
transformation of species and development of organic beings.
But he insists that natural selection is competent to explain all
this, that it takes place through the selection of such accidental
variations in the germ as prove advantageous, or, as he puts it,
the selection from among an infinite number of ancestral germ-
plasms in the fertilized ovum of such as will produce an indi-
vidual most in harmony with its environment, leaving all others
in the latent state. This, as we have seen, is pure Galtonism.

But this incapacity for the inheritance of acquired characters
is confined to metazoans or multicellular organisms — organisms
whose reproductive and somatic cells are differentiated. It
does not apply to protozoans or unicellular organisms. These

PKESIDKNTIAL ADDRESS. 43

are greatly influenced by the environment, and, consisting en-
tirely as it were of reproductive cells, naturally transmit their
variations to their descendants directly. Only thus can vari-
abilit}^ be perpetuated, and whatever is true of them is true
of all germ-cells. "The origin of hereditary individual vari-
ability," says Weismann, "cannot indeed be found in the
higher organisms — the Metazoa and Metaphj-ta ; but is to be
sought for in the lowest — the unicellular organisms. In these
latter the distinction between body-cell and gerra-cell does not
exist. Such organisms are reproduced b}- division, and if,
therefore, any one of them becomes changed in the course of
its life by some external influence, and thus receives an indi-
vidual character, the method of reproduction ensures that the
acquired peculiarity will be transmitted to its descendants ' '
(pp. 277-278).

It is here that comes in his fundamental doctrine of the con-
tinuit}' of the germ-plasm. If not the germ-cells, at least the
germ-plasm of either parent passes intact to the offspring. It
is perpetual, or as he calls it, immortal. It gives to the new
being its special character, but receives nothing from it. It
remains in the offspring until it in turn becomes a parent, and
again passes to the third generation without ever having ceased
to live. Ever}' living being on the globe to-day contains in
its germ-plasm something that has never ceased to live since
the original life-breath was breathed into organic nature.
Through all the ancestral t3'pes of the phyletic chain it has
persisted, passing from parent to offspring through the trans-
forming series, so that in the loins of the highest types of man
there is something which was still living in the lowest primor-
dial worm and even in the bathybian ooze of those primeval
waters which in the earliest Cambrian times succeeded the
formation of the original crust of the globe.

44 BIOLOGICAL SOCIETY OF WASHINGTON.

Upon this series of brilliant speculations and startling asser-
tions, including much that it has been impossible for me to
bring forward, has been founded the school of Neo-Darwinism.
In Germany they attracted comparatively little attention, in
France none, but in England they have become almost a shib-
boleth in the mouths of a large class of leading biologists.

It unfortunately requires something more than mere truth to
arouse enthusiasm in many minds, and however much it may
be di.sclaimed, it cannot probably be justly denied that the
peculiar position of prominence and honor which this theory
gives to the doctrine of natural selection, conceived and elab-
orated by Englishmen, had much to do with its especial charm
for English ears. It is not to be supposed that Weismann de-
liberately bid for applause from England, but he could clearly
see the tendency of his doctrines to exalt natural selection.
He does not allude to this in any of his earlier essays, nor
until he had begun to observe the effect his writings were pro-
ducing in England. In the preface to liis nfth essay, dated
Nov. 22, 1885, however, he says : " The transmission or non-
transmission of acquired characters must be of the highest im-
portance for a theory of heredity, and therefore for the true
appreciation of the causes which lead to the transformation of
species. Any one who believes, as I do, that acquired charac-
ters are not transmitted, will be compelled to assume that the
process of natural selection has had a far larger share in the
transformation of species than has been as yet accorded to it ;
for if such characters are not transmitted the modifying in-
fluence of external circumstances in many cases remains re-
stricted to the individual, and cannot have any part in produc-
ing transformation" (pp. 252-253). And in the last essay of
this series, originally delivered in September, 1888, he further
remarks : ' ' But if the transmission of acquired characters is

PRESIDENTIAL ADDRESS. 45

truly impossible our theory of evolution must undergo material
changes. We must completely abandon the Lamarckian prin-
ciple, while the principle of Darwin and Wallace, viz. , natural
selection, will gain an immensely increased importance " (p.

423)-

A CRITIQUE OF WEISMANN.

I have now, as I believe, fairly if not fully stated, chiefly in
the language of its founder, the Neo-Darwinian theory, and
before passing to consider what has been said on the other side,
and the position of the Neo-L,amarckians in general, I would
like to pause a moment in order to offer a few reflections of my
own upon Weismann's teachings. I am emboldened to do this
the more not only because I have not seen the exact point of
view from which they especially strike me touched upon by
others in the voluminous discussion which has grown out of
them, but also because what I shall say will be based entirely
upon his own statement of the facts, and therefore the objec-
tion that, not being an embryologist, I am not competent to
weigh the considerations from that side (which I would freely
admit), cannot properly be raised.

The question is whether, accepting the continuit}- of the
germ-plasm, accepting the nature which he ascribes to the fer-
tilized ovum with its multitudes of ancestral plasms out of
which selections are made, accepting his explanation of the
meaning of the first and second polar bodies, accepting his
differentiation into reproductive and somatic cells, and all the
other details which he brings forward, many of which are, of
course, only hypotheses, there do not still remain grounds on
which to base a theorj^ of the transmission of certain kinds of
acquired characters, and especially those of a strictly functional
nature. In fact, the question seems to me rather to be whether

46 BIOLOGICAL SOCIETY OF WASHINGTON.

his line of argument carried to its extreme logical conclusion
would not preclude the possibility of any variation whatever
even in the germ-plasms themselves. It is not sufficient to say
that all variation is due to the varied character of multitudin-
ous germ-plasms in the fertilized ovum, brought there from
many often remote ancestors possessing ver}- different charac-
ters. This is a pctitio principii, since it assumes these differ-
ences in those ancestors, and the primary question must be
answered ; whence these ancestral differences ? How does he
account for any differences at all ?

We have already seen that Weismann restricts his denial
to multicellular organisms and admits as a necessary part of
his theory, that unicellular organisms are easily affected by
the nature of their surroundings and activities, and that the
changes thus produced are directly transmitted. "If for in-
stance," he says, "a protozoan, by constantly struggling
against the mechanical influence of currents in water, were to
gain a somewhat denser and more resistent protoplasm, or were
to acquire the power of adhering more strongly than the other
individuals of its species, the peculiarity in question would be
directly continued on into its two descendants, for the latter
are at first nothing more than the two halves of the former.
It therefore follows that every modification which appears in
the course of its life, every individual character, however it
may have arisen, must necessarily be directly transmitted to
the two offspring of a unicellular organism (p. 278). . . . We
are thus driven to the conclusion that the ultimate origin of
hereditar}^ individual differences lies in the direct action of ex-
ternal influences upon the organism " (p. 279). But he even
goes further and asserts that there is no other waj^ b}' which
the germ can be affected. " I have never doubted" he says,
' ' about the transmission of changes which depend upon an

PRESIDENTIAL ADDRESS. 47

alteration in the gerni-plasni of the reproductive cells, for I have
ahA'a5^s asserted that these changes, and these alone must be
transmitted (p. 410) . . . In what other way could the trans-
formation of species be produced, if changes in the germ-plasm
cannot be transmitted ? And how could the germ-plasm be
changed except by th& operation of external influences, using
the words in their widest sense?" (p. 411).

Now if, as he insists, external influences cannot possibh' af-
fect the germs of metazoans, and if, as he here maintains, it is
external influence alone that can influence any germs, it must
follow that the onh^ variation that could have taken place in
the germ-plasms of the highest animals are those which oc-
curred in the protozoan stage of their development.

This is clearl}- a reductio ad absiirdiwi^ derived entirelj^ from
his own statements, some of them among his latest utterances.
The difficulty is to see why he should adhere so tenaciously to
the idea that the germ-cells cannot be influenced by functional
changes in the organism containing them. The mere fact that
they are lodged within the body of an animal does not affect
the question unless it can be shown that they are so lodged that
no change is possible in the nature of their immediate surround-
ings. To assume this is gratuitous and contrary to what would
be naturally supposed. In reading certain passages in his own
book one is strongly tempted to doubt whether he believes it
himself. For example, he says in one place speaking of hered-
itary variations : "I believe however that thej^ can be referred
to the various external influences to which the germ is exposed
before the commencement of embryonic development. Hence
we ma}' fairly attribute to the adult organism influences which
determine the phjdetic development of its descendants. For
the germ-cells are contained in the organism, and the external
influences which affect them are intimatel}^ connected with the

48 BIOLOGICAL SOCIETY OF WASHINGTON.

state of the organism in which they lie hid. . . It is even pos-
sible that the effects of these influences may be more special-
ized ; that is to say, that they may act only upon certain parts
of the germ-cells " (pp. 103-104). But he seems to see a great
difference between this and the transmission of characters ac-
quired in certain special organs to the sa'me organs of the off-
spring. This would probably be clear only to an embryologist.
One of the most suggestive thoughts in his whole philosophy is
that of the total dissimilarit}^ between the germ and the devel-
oped organism which is to result from it. He maintains with
every semblance of truth that there can be nothing in common
l^etween them except the fact that the molecular structure of
the germ is such that if allowed to develop it will produce a
being similar to the one from which it sprung. This principle
seems to be peculiarly applicable to the subtle influences which
effect heredity, and without appealing to anything occult or
abandoning the strictly casual and mechanical theory of hered-
ity, it may be submitted whether we know enough about it as
yet to assert that influences affecting the parental organism,
even any of its organs, may not react specifically and in kind
upon the germ and set up molecular tendencies in the same
direction. This may be said quite independently of any at-
tempt to explain precisely how it can do so, as the theory of
pangenesis claims to do.

If the germ-plasms vary within the body of either parent be-
fore they are brought together that variation must be due to
influences acting upon them in the animal body. All this
Weismann admits, but he denies that the changes which he
admits to take place in the individual as the result of changes
in the environment and subsequent changes in the habits and
activities of the creature can be regarded as among the causes
which produce changes in the germ-plasm. Is this logical or

PRESIDENTIAL ADDRESS. 49

even reasonable ? If not due to such changes to what causes
are they due ? Without pretending to explain how such a thing
could happen, I claim that the indications are that it does hap-
pen. To say without proof that it cannot happen adds nothing
to the argument. We have an antecedent and we have a con-
sequent. Both are facts. There is no possibility in the present
state of our knowledge of either proving or disproving the casual
connection between these facts. Variation takes place in the
direction of adaption to changed conditions and activities. So
far the inference is confirmed by a third fact. If the inference
had not been challenged in the interest of another principle
this would be regarded as proof. I do not agree with.Weis-
mann that the burden of proof rests on those who draw this
natural inference. It rests on him and the Neo-Darwinians to
show that the assumed cause is not a cause. This they have
thus far failed to do.

You will understand that I am speaking of variations which
take place in the germ-cells and sperm-cells of parental organ-
isms before they blend in the fertilized ovum. Most of Weis-
mann's argument is directed to show that the fertilized ovum
itself cannot be affected by any transforming influence acting
upon the mother during the growth of the embryo. This may
be true but it is unimportant. The time required to^ develop
the embryo is too short for the environment to produce any
material change however strongly the tendenc}^ might be at
the time in the direction of such change. It is chiefly the un-
combined sexual elements which are admitted by all to be un-
dergoing specific transformation. The Neo-Darwinians deny
that this is due to admittedly parallel transformations going on
in the individual, the result of external and internal influences
upon the developed body ; the Neo-I^amarckians consider the
latter as in great part the cause of the former, while admitting

50 BIOLOGICAL SOCIETY OF WASHINGTON.

that Other variations are taking place clue to unknown causes
and that these are seized upon by natural selection to the
advantage of the species.

The difficulty, on Weismann's theory, of accounting for any
variation at all above the protozoans still confronts us. If ex-
ternal influences can only act on unicellular organisms in such
a way as to be transmitted, it must follow that so soon as the
multicellular stage is reached a rigid fixity must result. One
of these lower metazoans may undergo important modifications
during its lifetime, but its offspring are always set back to pre-
cisely the same place where the parent was when it set out.
All these functionally produced changes are, according to him,
utterly lost because they cannot react upon the germ-plasm.
Where is the room for the action of natural selection ? He has
not dwelt upon this point, but he would probably say, though
contrary to statements above quoted, that the germ-plasms are
constantly undergoing spontaneous variation and that natural
selection works on these. We would then be brought back to
where we were a moment ago, with the question still before
us, how spontaneous variations differ from functional ones (for
he would not maintain that they were wholly uncaused effects),
and why it is not logical and rational to assume that functional
changes are impressed upon the germ-cells in ways which,
though unknown to us, are no more unknown than is the cause
of spontaneous variations. This seems to be far more reason-
able than the far-fetched, and, as it seems to me, childish view
recently expressed by Prof. E. Ray Lankester, that the envi-
ronment does indeed influence the germ-cells but only by
kaleidoscopically shaking up their contents, thus causing what
are called "sports " in the progeny, and that natural selection
seizes upon the.se, thereby securing advantageous tran.sfor-
mations.

TTvESIDENTIAL ADDRESS. 51

NEO-DARWINISM.-^

We will next briefly pass iu review the extraordinar}^ dis-
cussion which has followed chiefly from the publication of
Weismann's essays. As already remarked, they produced very
little influence upon the German mind, and most German in-
vestigators who noticed them at all, either saw little in them,
or else attacked them with greater or less violence. It is
almost exclusively in England that thej^ have found favor, and
here a veritable school of biologists has sprung into existence
prepared to defend even the most extreme of Weismann's
theories. It is due to the German investigator to say that,
with the exception of the slight tendency above pointed out to
dogmatize on the subject of the non-transmissibility of acquired
characters, his essays are dignified and courteous and often
evince an almost Darwinian modesty wdth regard to his own
theories. Far different was the case with most of his English
disciples. What he states as probable they assert as forever
settled, and his working hypotheses become for them the funda-
mental truths of science. His papers were translated and re-
viewed, usually in an aggressive manner before au}^ one had
ventured to criticise them. Being usually beyond the reach of
an}' but the embryological specialist all except ardent disciples
reserved their judgment and declined to enter the field. At
first there was an attempt to make it appear that Weismann's
views reflected only those of Darwin himself and that all out-
side of them consisted in deviations and wanderings from his
doctrines. It was sought to stamp them with the name of

* The expression Neo-Darwinian was first used, so far as I am aware,
by Dr. G. J. Romanes in a letter to Nature for Aug. 30, 1888 (Vol.
XXVIII, p. 413), and occurs frequently iu subsequent discussions. The
substantive form Neo-Darwinism was a natural outgrowth from it.

52 BIOLOGICAL SOCIETY OF WASHINGTON.

"pure Darwinism,"* and the reader was frequently informed
what Darwin reall}- intended to say in certain passages which
could not otherwise be made to harmonize with the new doc-
trine, and even in some still more refractor}^ passages we are
told what we would have said "if it had occurred to him." f

In default of any real opponent the Duke of Argyll, with his
strong theological bias, his medieval spirit of logomachy, and
his total lack of scientific ideas, was called out and set up as a
sort of man of straw to be repeatedly demolished. But like
the shadows in the valley of Walhalla, he emerged each time
unscathed and renewed the deathless struggle. His presence
in the arena had the further advantage for the new school of
affording them an opportunitj^ to point to him as a sample of
the opponents of Weismann.

Against all this a few protests were raised from time to time
and after the appearance of the English edition of the essays
a few able and critical analyses were made. But the general
character of the discussion as it has gone on in the columns of
Nature and in the British magazines is such as I have de-
scribed. The only other prominent or frequent contributor in
answer to the disciples of Weismann is Dr. G. J. Romanes,
and he has been more especially concerned with defending his
priority to the idea which he has elaborated under the name
of Physiological Selection, and to the discussion of certain
phases of the law of panmixia which he claims to have dis-
covered. It would, however, be unjust to deny that the dis-
cussion has been of value to science, since, had it done no
more than to attract wide attention to so momentous a question
it could not have been without its uses.

'^Nature, Vol. XXXVIII, Aug. i6, 1888, p. 364 ; Aug. 23, 1888, p. 388 ;
Vol. XL, pp. 567, 619.

t See Nature, VoL XLI, March 27, 1890, pp. 487, 48S.

PRESIDENTIAL ADDRESS. > 53

NEO-LAMARCKISM.*

Let us inquire what has really been done from first to last
toward the demonstration, or scientific establishment of the law
of transmission of functionally acquired characters and the
preservation through heredity of the modifications produced
by changes in the environment. It will not be necessary to
go back to Lamarck as his presentation of the subject has been
sufficiently dwelt upon. But I cannot agree with some recent
writers that Lamarck was defending a totally different prin-
ciple from that which is being defended to-day. It is true that
Neo-Lamarckians recognize natural selection as an equalh\
and in some respects far more potent law, although, as has
been justlj^ insisted upon, it does not explain the cause of the
variations of which it makes use. The Lamarckian principle
does this, so far as it goes, and affords a true mechanical, <hat
is, scientific explanation of the origin of species.

After Darwin himself, whose methods were always those of
the true naturalist, unquestionably the most successful defender
of this view is Mr. Herbert Spencer, whose methods are alwaj-s
those of the true philosopher. A man of such originalit}' would
be incapable of approaching the subject from the same stand-
point as any of his predecessors, and we find him evolving this
law from his great general scheme of mechanical cosmolog}',
in which it appears as one of the equilibrating forces of the
organic world. It is his law of " direct equilibration," natural
selection forming a second law of "indirect equilibration."

* Prof. A. S. Packard is believed to be the first to use the term Neo-
LaniarckiaJi. This he did in the introduction to the vStandard Natural
Histor}- (Vol. I, Boston, p. iii) in 1885, and on page iv he adopts the sub-
stantive form Neo-Lamarckianism. As the word Lauiarckis})i had
already been long in use the shorter form A^co- Lainarckisni should be
preferred.

54 BIOLOGICAL SOCIETY OF WASHINGTON.

Through the operation of these two principles the phenomena
of adaptation are explained. Adaptation is placed by him in
what seems to be a new light, as the tendenc}' of the organism
to respond through modification of form and structure to an
ever-changing environment. The introduction of this form of
words by Mr. Spencer has been of the utmost value to science
in affording it a clear and precise terminology for the most
important of all phenomena. Lamarck floundered about in
straining after such a terminology. As I have shown he gen-
erally used the word circumstances for vSpencer's cnviro7inient,
but in many cases he employed the word medium {inilieti)
and he occasionally approached the Spencerian expres.sion so
nearly as to speak of the environing medium {inilieii environ-
7iant).''^ His idea was undoubtedly the same, but he lacked
both the literary training and the philosophic power to present
it in its best light.

Mr. Spencer showed that the general proposition that the
organism must be permanently, constantly, and profoundly
influenced by the environment is one that cannot be logically
escaped. It is not a mere a priori deduction, but rests upon
all the facts and phenomena of the organic world which he
marshaled in a most masterly manner in its support. But
the Neo-Darwinians who deny this because it conflicts with
their new hypothesis, never cease to demand facts. Haeckel's
reply to this was eminently just, that this new hypothesis is
itself wholly unsupported by facts, in the sense in which they
use the term. It is an inference from the study of embryology,
and an opposite inference is as legitimate as the one they
draw. The truth is that the real phenomena of heredity are
too recondite for direct observation. We are dealing with the

* Philosophic Zoologique, Vol. II, pp. 5, 304.

PRESIDENTIAL ADDRESS. 55

ultimate units of organic being and are compelled to judge of
their actions by the general results. But Mr. Spencer went
further than au}- one had done before him and brought together
an immense array of the most convincing facts upon his side
of the question. Although he wrote before the new hypothesis
had been proposed he seems to have fairly anticipated it, and
one is surprised to find the objections of the Neo-Darwinians
clearl}- stated and squarel}' met. It would l)e needless to re-
peat his arguments here, even if there were time, but I may
call attention especially to that which relates to the origin
^ of those correlated structures which are necessary to render
effective the modifications which natural selection or sexual
selection has produced. He shows that unless these are due
to inherited functional variations a series of violent assump-
tions must be made which put one's credulity to the severest
test — not a pre-established harnion}', but a multitude of pre-
established harmonies, all of which must co-operate with
unerring exactness. Under the hypothesis of the hereditary
preservation of the functionally produced modifications neces-
sary to secure these correlations the explanation is perfectly
simple and rational. This argument, so far as I know, has
never been answered, nor has any attempt been made to
answer it.

Early in the discussion of Weismann's theory and three
years before the appearance of the English edition of his
essaj^s, Mr. Spencer seems to have foreseen their probable effect
in England, and he turned aside from his systematic labors to
reargue this question in the light of fresh facts and evidence.
This he did in two articles in the Nineteenth Century for April
and May 1886, which are characterized by an unfailing vigor
of treatment and all the philosophic power which he is wont to
display in the discussion of biological questions. I would

5() BIOLOGICAL SOCIETY OF WASHINGTON.

especially commend the second of these articles as an alto-
gether fresh presentation of the case, replete with facts from
the lowest forms of organized life. Many of these taken from
the vegetable kingdom come home to me with great force, and
it seems difficult to see how another interpretation can be put
upon them.

Prof. Karl Semper published in 1881 as one of the Interna-
tional Scientific series his Natural Conditions of Existence as
they effect Animal Life, in which he supports the same class
of views by many observations from his own profound studies.
Prof. Sidney H. Vines in his Lectures on the Physiology of
Plants (1886) offered some direct and telling .strictures upon
Weismann's teachings (Chap. XXIII), and after the English
edition of the essays appeared he repeated these and answered
categorically a large number of points in a communication to
Nature ^^' Professor Weismann replied to this review, defend-
ing himself satisfactorily at some points, but was compelled to
recede from several of his most important positions.

Mr. Patrick Geddes advanced in the Encyclopedia Britan-
nica (Art. Variation and Selection) a somewhat novel theory
of variation in plants, substantially in the same line, but prob-
ably with some vulnerable points, and ProfeSvSor Henslow's
recent work on the Origin of floral structures, seeks to show
that " the responsive actions of the protoplasm in consequence
of the irritations set up by weights, pressures, thrusts, ten-
sions, etc., of insect visitors," have played the principal role
in determining the forms of irregular flowers. In much of all
this there is a tendency to extremism, and harm is often done
by neglecting to recognize the action of natural selection where
it is clearly present, but there always remains a residuum of
facts which cannot be explained by that hypothesis.

Vol. XL, Oct. 24, 1S89, p. 621.

PRESIDENTIAL ADDKESS. 57

Among those Germans who have so ably and systematically
opposed the views of Weismann should doubtless first be men-
tioned Dr. G. H. Theodor Eimer. The work * in which he
has most effectively undertaken this has been translated into
English by Mr. J. T. Cunningham,! who is one of those who
early took part in the discussion. The title of this work as
well as the heads of some of the chapters (such as : " the in-
fluence of adaptation in the formation of species," "mental
faculties as acquired and inherited characters, " " evolution of
the living world as the result of function," etc.) shows how
directly Eimer antagonizes Weismann, and one of the leading
merits of the book is the great number of new illustrations that
it contains in support of his position.

Perhaps I should not pass over, in this imperfect survey, the
able and very temperate paper of Mr. J. Arthur Thompson, J
who, of all the writers here noted, comes the nearest to having
anticipated the point of view of my own criticisms. The bibli-
ography of the general subject which this writer gives at the
end of his paper w'ill enable any one who desires to pursue it
further to supplement this brief enumeration to any extent,
and also to take a retrospective view into its history and
progress.

It would be easy to select from these and other works any
required number of illustrations of the transmission of acquired
characters, but there w^ould not probably be one that Weis-
mann would not find means of explaining away. He has

*Die Entstehung der Arteii auf Gruiid vou Vererbung erworbener
Eigenschaften nach den Gesetzen organischer Wachseiis, Jena, iS88.

t Organic Evolution as the Result of the Inheritance of Acquired Char-
acters, London, 1890.

j The Histor}' and Theory of Heredity. Proc. Roy. Soc. Edinburgh,
Vol. XVI, i888-'89, pp. 91-116. (Read Jan. 21, 18S9).

58 BIOLOGICAL SOCIETY OF WASHINGTON.

taken up a nunil)er of such in his essays, stated them with
sufficient fairness, and then proceeded to show that they are
also capable of another interpretation. In some cases this is
doubtless true, but in most cases his explanations seem strained
and unnatural. In many they amount to an admission that
the quality transmitted was functionalh^ acquired and that the
changed environment has actually influenced the germ. But
he alwa3\s insists that this does not constitute an acquired
character. I do not see why it does not. For example, he
says : " It is difficult to say whether the changed climate may
not have first changed the germ, and if this were the case the
accumulation of effects through the action of heredity would
present no difficulty" (p. 98). I cannot see why this is not
conceding the whole issue. Of course all modifications must
first affect the germ, otherwise there could be no hereditary
transmission. The only question is : Can the climate or the
environment impress changes upon the germ ? If yes, the
Neo-Lamarckian asks no more. All that he contends for is
conceded.

The quotation just made is from one of his earlier essays
and he has objected to its being urged against him on the
ground that it does not represent his latest conclusions. But
what has he to say to the following from his eighth and last
essay originally delivered in vSeptember, 1888 ?

" It is therefore possible to imagine that the modifying effects
of external influences upon the germ-plasm may be gradual
and may increase in the course of generations, so that visible
changes in the body {soiiia) are not produced until the effects
have reached a certain intensity " (p. 433).

It matters nothing to the Neo-Lamarckian whether the effects
of external influences become visible in the first or the hun-
dredth generation. The whole question is : Are they the

PRESIDEXTlAr, ADDKESS. oO

cause of the modifications that actually take place ? Weis-
niann's English followers deny this and say that such modifi-
cations are due to the selection of accidental variations in the
germ, and so in all cases. If the term "acquired" is to be
au}' further refined away, then discussion is useless, for it is
not a mere dispute about a word that interests us, but the
fundamental question whether external conditions do or do not
permanently and progressively influence the development of
organic beings.

THE AMERICAN "SCHOOL."

Probably the strongest arguments that have been brought
forward upon the affirmative side of this question are those
derived from paleontology, and singularly enough, hitherto, so
far as I am aware, this view of the question has been presented,
with the single exception of Kowalevsky, entirely by Ameri-
cans. This work was not done under the stimulus of Weis-
mann's writings, because most of it was already accomplished
before his essays appeared.

As far back as iS66 Prof. Alpheus Hyatt read a paper " On
the Parallelism between the different stages of life in the
Individual and those of the entire Group of the Molluscan
order Tetrabranchiata," -^ in which were foreshadowed the
views more definitely expressed in 1880 in his papers " Upon
the Effects of Gravity on the forms of shells and animals," f
and "The Genesis of the Tertiary Species of Planorbis at
Steinheim." :{; In these papers Professor Hj-att showed the
moulding influence of what in this case happened to be an

*Mem. Rost. Soc. Nat. Hist., Vol. I, p. 193. (Read Feb. 21, 1866).
tProc. A, A. A. vS., 1880, p. 527.

I Mem. Bost. Soc. Nat. Hist., Fiftieth Anniversary, 18S0. vSecond
Memoir.

GO BIOLOGICAL SOCIETY OF WASHINGTON.

environment growing gradually less and less favorable, but not
the less adapted to display in a very clear light some of the
most important laws of transformation.

In 1877 Mr. John A. Ryder read a paper "On the laws of
digital reduction,"* showing the obvious adaptations to the
changing environment which had taken place in vertebrates
in this respect, and a year later he pursued the same line of
argument for modifications of the teeth. f

Mr. Ryder has for many years past been engaged in enibry-
ological researches, but there is no evidence that they have
led him to abandon the views expressed in these earlier papers
in favor of those of Weismann. On the contrary, several
comparatively recent papers of his X consist in great part of
direct attacks upon Weismann' s teachings and criticisms of his
embryological theories.

Professor Cope commenced publishing on this subject at
about the same time and has continued to study the vertebrate
fauna of America without interruption to the present time.
It appeared to him from the first that paleontology affords
proof of the causes of variation, as revealed in the wonder-
fully complete transition series that are found in the teeth,
toes, and various parts of the skeleton of extinct animals,
adapting them to a changing environment and higher struc-
tural perfection. The study of living animals cannot, in the
nature of things afford any such series of forms, and the evi-

* American Naturalist, Vol. XI, October, 1877, pp. 603-607.

t On the mechanical genesis of tooth forms, by John A. Ryder.
Proc. Nat. Sci. Phil., Vol. XXX, 1878, p. 45 ; Vol. XXXI, 1S79, p. 47.

i The Origin of vSex through Cunmlative Integration and the Relation
of Sexuality to the Genesis of »Species. Proc. Am. Phil. Soc, Vol.
XXVIII, May 29, 1S90, pp. 109-159.

A Physiological Hypothesis of Heredity and Variation. Am. Nat.,
Vol. XXIV, January, 1890, pp. 85-92.

PRESIDENTIAL ADDRESS. . 01

dence from paleontology is particularly striking- in this respect.
A volume of Professor Cope's memoirs was published in 1887
inider the title of "The Origin of the Fittest," by which title
he aimed to express the idea of the cause or origin of modifi-
cations that have taken place, as distinguished from Darwin's
explanation of the laws of transformation based on the assump-
tion of such modifications taken as simple facts of observa-
tion. Both methods are scientific, but the former carries us
one step nearer to the true origin of things.

More recentl)' Prof. H. F, Osborn of Princeton College has
taken up this line of argument and presented it in several
memoirs in which he has attempted a direct answer to Weis-
mann's charge that no facts have been furnished in support of
the transmission of acquired characters.*

In the latest of these papers, that read before the Society of
Naturalists in Boston December 31, 1890, not yet published,
but of which an advance copy was kindly sent me by him, he
has stated the whole problem with a judicial fairness which all
must admire, and with a keenness of analysis which places
him in the front rank of modern biological thinkers.

Perhaps the most important contribution which he has made
to the subject is that in which he shows that " the main trend
of variation is determined not l)y the transmission of the full
adaptive modifications themselves, as Lamarck supposed, but
of the disposition to adaptive atrophy or hypertrophy at cer-
tain points."

This principle goes farther than any other that has Ijeen
brought forward to differentiate Neo-Lamarckism from Lam-

* Proceedings of the American Association for the Advancement of
Science, Vol. XXXVIII, 1SS9 (Toronto), pp. 273-276.

Britisli Association Report, 1889 (Newcastle-upon-Tyne), p. 621 ;
Nature, Vol. XLI, Jan. 9, 1890, p. 227.

Atnerican Naturalist, Vol. XXIII, July, 1889, pp. 561-566.

62 BIOLOGICAL SOCIETY OF WASHINGTON.

arckism proper, while at the same time it is an effective
answer to a large part of the argument directed against the
transmission of functionally acquired characters.

Professor Osliorn has probably made the most of the argu-
ment from paleontology, and it must be left to the candid
judgment of scientific men to sa}' whether the case is made
out. It is of course always possible to saj- that the initial
variations which inaugurated each new adaptation were
merely accidental and were seized upon b}' natural selection,
and it is to a large extent a question of faith in the universal
efficacy of that theory ; or rather a question in candid minds
of the relative reasonableness of that view and of the view
which ascribes a considerable part of this initial variation to
functionall}^ produced modifications transmitted by heredity.

It would be unjust to this Societ^^ to omit in an enumera-
tion, however imperfect, of the American defenders of the
transmissibility of acquired modifications, your former presi-
dent Prof. W. H. Dall, whose protracted studies in inverte-
brate paleontolog}-, conchology, and especially the molluscan
life of the deep sea have led him to a full accord with other
American workers as regards questions of this class. In his
presidential addresses, not to speak of earlier papers, he has
emphasized the molding influence of the environment upon
the plastic organisms with which he is most familiar, and
during the past year he has contributed to the Society one
paper-' dealing directly with the Neo-Darwinian claims, in
which the case is as clearly presented as it has been by an}-
other writer, and in man}- respects in an entirely new light.

For myself, I cannot claim to have made any direct contri-
bution to this specific subject. I have been deeply interested

*Oii Dynamic Influences in PA'olulion, l)y W. H. Dall. Proc. Biol.
Soc. Wash., Vol. VI, pp. i-io.

PRESIDENTIAL ADDRESS. 63

in the development of plant life and have from time to time
within the past fifteen j-ears presented this theme from every
point of view that I have been able to see it. I recognize the
law of natural selection as probabh^ the most potent of all or-
ganic laws, but I have never doubted that a great part of the
variations upon which its action depends are due to reactions
of the organism upon the environment, and after reading Weis-
mann's essays and ever}- scrap of discussion that I ha\e been
able to find arising from them, I am still so dull as to remain
unconvinced that such modifications are incapable of hered-
itar}' transmission. To sa}- that the environment may and
must influence the germ, but that it can onh* influence it in
a hap-hazard wa}- analogous to that in which a jar aflects
the figures of a kaleidoscope, is to my mind a begging of the
question, and I prefer to assume that there is a causal con-
nection between the nature of the influence on the germ and
the alterations that result, especially as the latter are admit-
ted to be in harmony with the former.

If I have succeeded in showing in one of my papers before
this Society* that considerable variation is constantl}- taking
place irrespective of any advantage to the species, this much
at least has been withdrawn from the domain of natural
selection, and if these changes are not produced b}- that law
there seems no escape from the conclusion that they are caused
by some unknown external influences.

In the foregoing review of the work that has been done
toward the scientific demonstration of the transmissibility of
functionally acquired characters I do not pretend to have
given the arguments themselves. I have onl}- pointed out the
fact that they have been presented, by whom, from what

* Fortuitous Variation as illustrated b}' the genus Eupatorium. Ab-
stract in Nature (London) Vol. XLI, July 25, 18S9, p. 310.

()4 BIOLOGICAL SOCIETY OF WASHINGTON.

branch of science, and under what circumstances, and I must
leave it to each of you, if sufficiently interested, to stvidy them
for yourselyes from the original sources.

APPLICATION TO THE HUMAN RACE.

The wide-spread agitation of a problem of this nature,
however technical or recondite it may be, lying as it does on
the very ocean bed of science, cannot help sooner or later
making itself felt at the surface and producing its normal
influence upon the great practical questions of the moral and
social world. And the nature of this influence, fortunately
for us, is some indication of the truth or falsity of the views
defended. Just as the mathematician knows, when his cal-
culations lead him to just and rational results that his
assumption was a true one, and when they lead to a series
of negations and absurdities, that it was a false one, so we
may expect that if the assumption of the non-transmissibility
of acquired characters is a sound one the practical conclusions
that flow from it bearing upon the affairs of life will harmo-
nize with the best thought on the development of the human
race ; and conversely, if its application to practical life con-
flicts with such best thought and with the facts of history and
of social progress we are justified in the inference that it is an
unwarranted assumption. What do we find ?

The highl}' artificial character of what we call civilization
is a fact which I have for many years sought to enforce by a
variety of illustrations. That nothing like it could ever result
from the natural flow of the forces that have combined to pro-
duce it is too obvious to require explanation, and that human
advancement in general is exclusively the result of the exer-
cise of man's intellectual power in the artificial direction of
the raw forces of nature into channels of human advantage,

TKESIDENTIAL ADDRESS. ()'")

is a proposition which only needs to be understood to be uni-
versally admitted. The tendency of the scientific mind to
apply to social phenomena the canons that prevail in the non-
intelligent world, is at least as ancient as the French physio-
crats, Adam Smith, Ricardo, and Malthus, and it has been
strengthened since Darwin by the writings of some of the
ablest social philosophers. It rests on the seductive idea that
what nature does must be well done, and that nature's methods
must be the best methods for man to adopt. I have hitherto
designated this kind of philosophy as a sort of nature-w^orship,
and shown that the entire fabric of reasoning crumbles away
at the first touch of critical analysis. But it is a fascinating
habit of thought and difficult to dislodge from a certain tN'pe
of mind.

Now on examining the practical applications which the Neo-
Darwinians make of their underlj-ing conception, I find them
to be strikingly in line with those last described. If nothing
that the individual gains b}- the most heroic or the most assid-
uous effort can by any possibility be handed on to posterity,
the incentive to effort is in great part removed. If all the
labor bestowed upon the youth of the race to secure a perfect
physical and intellectual development dies with the individual
to whom it is imparted why this labor ? If, as Mr. Galton puts
it, nurture is nothing and nature is everj-thing, wh}- not aban-
don nurture and leave the race wholly to nature ? In fact the
whole burden of the Neo-Darwinian song is : Cease to educate,
it is mere temporizing with the deeper and unchangeable
forces of nature. And we are thrown back upon the theories
of Rousseau, who would abandon the race entirely to the feral
influences of nature.

The great men who talk this way, trained in the methods
of the university, their minds stored with the fundamental,

66 BIOLOGICAL SOCIETY OF WASHINGTON.

comprehensive, and organized materials for thinking and
working which modern methods of education could alone
have given them, use these materials, and take advantage
of this training to spin out a sulitle thread of reasoning
which results in condemning tlie only means l)y which
they were enabled to comprehend questions of this nature.
Professor Weismann could never have prosecuted those pro-
longed investigations which have given him such a grasp of
the intricate problem of heredity had he not been trained in
the rigid methods of the German universities. Nay, those
rigid methods themselves have been the product of a series of
generations of such training, transmitted in small increments
and diffused in increasing effectiveness to the whole German
people. It has not been brought about by natural selection
which only selects such ancestral germ-plasms as increase the
certainty of reproduction. vSuch habits of mind could have
no such tendency. They secure no advantage in the struggle
for existence. And the fact that out of the barbaric German
hordes of the Middle Ages there has been developed the great
modern race of German specialists is one of the most convinc-
ing proofs of the transmission of acquired characters, as well
a^ of the far-reaching value to the future development of the
race of such an educational system as that which Germany
has had for the last two or three centuries.

It was said of Mr. Darwin that he was himself a good illus-
tration of the law of atavism which he fornuilated since his
habit of mind lay latent in his father and came to him from his
grandfather Erasmus. Similarly it might be said that Professor
Weismann is as good an example as need be asked of the trans-
mission of acquired characters and of the hereditary embodiment
of that wide-spread German characteristic which has been the
increasing product of the German educational system and of
German institutions.

PRESIDENTIAL ADDRESS. H7

Mr. Herbert Spencer has followed out this same line of rea-
soning as applied to the great development of the musical facult}'
in Germany, and shown that the Haydns, Mozarts, Beetho-
vens, the Liszts, Rubensteins, and Wagners, have formed, as
it were, the several peaks of a great hereditary musical uplift
in the German nation. The same is true of Itah-, not only in
music, but especially in sculpture, and we have there, so to
speak, a race of sculptors. Those who, without any patriotic
bias, compared the Italian and American pieces at the Cen-
tennial Exhibition could not help being impressed with this.
There could be seen the most exquisite pieces of statuary, in
which not only features of rare perfection and beauty, but
every form of draper}- were represented in marble with a true-
ness to life that almost deceived the looker on. And to such
pieces were attached, not one or two celebrated names, but a
great number of names of artists unknown to the public out-
side of tho.se who make sculpture a special study. Contrast-
ing these perfect productions with the lifeless ones that repre-
sented the highest reaches of American sculpture, even those
produced b}' Americans who had spent many years at Rome
and worked in an atmosphere of Italian .sculpture, I was im-
pressed with the little that a single generation can accomplish
in such things, and with the fact that in Italy we have a race
of born sculptors wdio inherit their deftness from anqestors as
remote as Michel Angelo.

Weismann has not ignored the arguments from this side, but
his attempts to meet them are among the weakest of all his
reasonings. Here are some samples of them : ' ' The children,"
he says, "of accomplished pianists do not inherit the art of
playing the piano ; they have to learn it in the same laborious
manner as that by which their parents acquired it ; the}' do
not inherit anything except that which their parents also pos-

OS r,I()[.0(i]('AL SOCIETY OF WASHIX(iTON.

sessed when children, viz., manual dexterity and a good ear"
(p. 269). "The pianist . . . may by practice develop the
muscles of his fingers so as to ensure the highest dexterity and
power ; but such an effort would be entirely transient, for it
depends upon a modification of local nutrition which would
be luiable to cause an}^ change in the molecular structure of
the germ-cells, and could not therefore produce any effect
upon the offspring" (p. 278). If this were true nothing is
more certain than that the talent for piano execution could be
no higher in the ten thousandth generation than that attained
during the first, and that the curve representing the progress
of music, sculpture, the talent for special scientific research,
or any other form of genius, would be an irregular line with
absolute average horizontality instead of what we know it to
be in every case, an irregular, but progressively ascending
curve marking a great forward movement.

It is universally conceded that the evidence for the trans-
mission of acquired mental qualities is much stronger than for
those of any other class, chiefly because they are entirely with-
drawn from the action of natural selection, not tending in the
least to the survival of the fittest. It has therefore been nee-
essary for Weismann to deny their transmission at all. This
is so palpabl}^ contrary to the facts of human history that few
have been willing to follow him to this length. It is well
known that Mr. Wallace has always excepted the human race
from the action of natural selection, but in so doing he has
seen fit to abandon the scientific method entirely, and in his
last work he makes a complete break in the continuity of
development with the advent of the higher psychic facul-
ties, calling in an independent spiritual attribute to account
for this class of phenomena. Prof. E. Ray L,ankester, the
foremost of Neo-Darwinians, in reviewing this work of Mr.

PRESIDENTIAL ADDRESS. 69

Wallace-'- makes the following remarks on this point: "Mr.
Wallace's contention that the mathematical and artistic fac-
ulties of man have not been developed under the law of
natural selection must in large part be conceded .... their
sudden and rapid development to a very much higher level in
civilized communities cannot be traced to the struggle between
man and man. It does not however follow that, because
natural selection will not account for these extraordinary
developments of the human brain, therefore we must have
recourse to the assumption of supernatural agencies. Mr.
Wallace seems so much convinced of the capability of the
principle of natural selection, that when it breaks down as an
explanation he loses faith in all natural cause, and has recourse
to a metaphysical assumption.'' But Prof. Ray I^ankester,
estopped by his consistent defense of Weismann's views, is
obliged to ignore the obvious explanation that the intense
exercise of these faculties, impressing itself profoundly upon
the plastic brain substance and reacting upon the germs of
posterity has been transmitted to descendants through centu-
ries of developing civilization, and he has recourse to his
doctrine of "sports" and to Gulick's law of "divergent
evolution" which is nearly the same as what I have called
"fortuitous variation."

But we need not confine ourselves exclusively to the mental
qualities. A favorite illustration of the efficacy of selection is
the progress which has been secured in the fleetness and other
desired qualities in horses, and Mr. Wallace, in the Fortnightly
Review for September 1890, has instituted a contrast between
what would result in this direction from a system of intelligent
breeding and one of mere feeding and exercise. His illustra-
tion is thoroughly unfair, even ridiculous, since he does not

* Nature, Vol. XL,, Oct. 10, 1S89, pp. 569-570.

70 BIOLOGICAL SOCIETY OP WASHINGTON.

attempt to transmit the acquired superiority but allows it to be
diluted and lost In- promiscuous breeding with stock that has
not been subjected to any training. As a matter of fact train-
ing enters largely into the development of superior breeds of
horses, and great care is taken that educated strains be bred
together. And breeders as a rule would ridicule the idea that
all their training goes for nothing, and that it is only accidental
variations that can be bred into the new race of horses.

But let us take another case in which natural selection is
wholly excluded. It is well known that a steady and uniform
progress has been going on for a century or more in all forms
of gymnastic skill and feats of bodily suppleness by men con-
stantly in training for the purpose, which is comparable to that
which has taken place in the trotting power of horses. Every
year new wonders are brought before the public and the feats
of the previous year are exceeded by some fresh virtuoso. This
is accomplished, I am told, by lifelong training of the children
of acrobats and of their children, thus producing, as it were, a
little race of acrobats. What care is taken to prevent the loss
of much of this through marriage outside of the trained stock,
I do not know, but certain it is that great progress in physical
development has taken place and is taking place, and there is
no doubt whatever that it is largely due to the transmission of
the qualities directly acquired by training.

In fact, Mr. Galton's conclusions, notwithstanding his doubts
about the transmission of acquired talents, are not only not
opposed to that view but in great part confirmatory of it. He
is led by a carefully conducted series of inquiries and investi-
gations to believe that genius is in the main hereditary ; that
the exceptionally talented and highly endowed are descended
from talented and highly endowed parents, etc. But this only
throws the question back one generation farther, and it remains

PRESIDENTIAL ADDRESS. 71

to be shown that such talent and endowment in their ancestors
was not the result of education, personal effort, or some other
form of acquirement and not of mere accident.

But the great debate on heridity seems destined to secure
still other and more far-reaching advantages. Not only has it
assured us that we may hand our good works down to posterity
through the law of the transmi.ssibility of acquired qualities,
but it may and should teach us that the all-powerful law of se-
lection is also an instrument in the hands of intelligence for the
working out of human destiny. It is the right and the dut}'
of an energetic and x'irile race of men to seize upon every great
principle that can be made subservient to its true advancement,
and undeterred by any false ideas of its sanctit}^ or inviola-
bility, fearlessly to apply it. Natural .selection is the chief
agent in the tran.sformation of species and the evolution of life.
Artificial .selection has given to man the mo.st that he possesses
of value in the organic products of the earth. Ma}^ not men
and women be selected as well as sheep and horses ? From the
great stirp of humanity with all its multiplied ancestral plasms
— some very poor, some mediocre, some merely indifferent, a
goodlj' number ranging from middling to fair, only a compara-
tive few very good, with an occasional crystal of the first water
— from all this, why may we not learn to select on some broad
and comprehensive plan with a view to a general building up
and rounding out of the race of human beings ? At least we
should by a rigid .selection stamp out of the future all the
wholly unworthy elements. Public sentiment should be created
in this direction, and when the day comes that societ}- shall be as
profoundly shocked at the crime of perpetuating the least taint
of hereditary di.sea.se, insanity, or other serious defect as it now
is at the comparatively harmless crime of insect, the way to prac-
tical and successful stirpiculture will have already been found.

ALPHABETICAL INDEX.

A.

PAGE

Acquired characters 3, 7, 21

Acquired characters, Alphonse DeCau-

dolle on the transmission of xix

Address, eleventh presidential xii

Affinities of the Xorth American squirrels,

etc., remarks on the xix

American school of Neo-Lamarckians ... 59
Anatomy of //('i/i<?ror«z'.r, a point in the . xiv
Apple disease caused by Gymnosporan-

giitm macinpHS vi

Argyll, Duke of 52

Arrow weed and jumping bean, the Mex-
ican xvi

Artificial selection 20

Aspects, the winter, of the Mohave Desert

region xviii

Aster, a new, from Southern California . xiii

B.

Bacillus, hog cholera, production of im-
munity in guinea pigs with sterilized ,

cultures of xv

Bacteria, some illustrations of ferments

and fermentation among vii

Bacteria, on species among xi

Bacteriological progress in the prevention
and cure of disease, remarks on recent . xv

Baker, A. B., election of ... xi

Baker Frank — An undescribed muscle
from the infraclavicular region of man . v

Notes on dwarfs xvi

Banks, Nathan, election of ix

Barrows, W. B.— Cuckoo stomachs and

their contents xvii

Bean, jumping xvi

Bean, T. H. -Notes on some fishes from

British Columbia vi

The death of salmon after spawning . . .x

Fishes of Great South Bay xiii

Kenuerly's salmon xv

Some fishes new to New England

waters xvii

Beds, bone, age of the Peace Creek, in

Florida xiv

Bil)liography of Economic Entomology,
authorship of the ix

PAGE

Biology in the public schools, the place of viii

Birds, captive, foot disease of x

Birds, distribution of, on the Pribj-lov

Islands . . xvi

Birds, fossil, a collection of, from the

Equus beds of Oregon xiv

Bison latifvous, specimen of, from Peace

Creek, Florida xiii

Boring mollusks 8, 9

Bone beds in Florida, age of the Peace

Creek .- xiv

Botanical Division of the Department of

Agriculture, notes on the recent field

work of the xvi

Boyle, C. B., election of xiv

Bread-fruit tree, a fossil, from the Sierras

of California xix

British Columbia, notes on some fishes

from vi

Brown-S^quard 23

c.

Cambrian, Lower, a new genus and spe-
cies of ostracod crustacean from . ... V
Carboniferous Flora, upland, peculiar

forms in an xviii

Challenger expedition, Haeckel's Radio-

laria of the xviii

Characters, acquired 3, 7, 21

Characters, acquired, Alphonse DeCau-

dolle on the transmission of xix

Characters, transmission of, defined .... 3
Chick, embryo of, with two protoverte-

br£e xiv

Chipmunks, North American, remarks

on affinities of xix

Circumcision 8

Classification of the apodal fishes xv

Classification of the Tetraodo>itoidea . . . xvii

Coccidiiim bigetniimm xviii

Color of flowers in attracting insects . . . xiv

Color of human hair, change in vi

Color of plumage of birds, change in . . . vi

Colors of fishes vii

Colors of insects vii

Columellar plaits, development of, in

Gastropods g

Committees iji

74

ETOr.OdlCAL SOCIETY OF WASHINGTON.

PAGE

Cotnmittees for 1S91, announcement

of xii-xiii

Conscious effort, relations of 3

Cope, K. D 60, 61

C(3;<//<'><'//a, a new genus of Compositse . . ix

Council iii

Co%'ille, F. v.— The new arrangement of
genera in the Herbarium of the De-
partment of Agriculture v

Fruiting of the Ginkgo at the Depart-
ment of Agriculture x

Food plants of the Indians of the Death

Valley region xvii

A review of Kuutze's Revisio Generum

Plantaruni xix

Cretaceous mammals, review of the dis-
covery of xiii

Crustacean, ostracod, new genus and

species of, from Lower Cambrian . . . . v
Cuckoo, Asiatic, occurrence of the, on the

Pribylov Islands xi

Cuckoo stomachs and their contents . xvii

Cunningham, J. T 57

Curtice, Cooper. — The moultiugs of the

cattle tick (Ixodes bovis) v

A preliminary study of ticks in the

United States • • . . . . xi

Some little known worms in cattle . . . xiii
Practical value of investigating parasites

of live stock xv

Cuvier 19

Cyclopteroidea ix

Cypress knees, what are xiv

D.

Dall, W. H 62

Dall, W. H. — On dynamic influences in

evolution vi, i

Original drawings of the fur seal and

Steller's sea cow vii

Paleontological notes from the north-
west coast X

On the topography of Florida with
reference to its bearing on fossil

faunas xi

Age of the Peace Creek hone beds in

Florida xiv

Darwin, Charles

12, 13, 18, 20, 22, 23, 26. 31, 45, 53, 61, 65, 66

Darwin, Erasmus 13, 19, 66

Darwinism 12, 19

Date palms, recent introduction of .... xv
DeCandolle, Alphonse, on the transmis-
sion of acquired characters . ... .xix

De Maillet 13

DenWWon oi Desmognathus, notes on . . xvi
Desmognathus, notes on dentition of . . . xvi

PAGE

Dewey, L A., election of xv

Dicentta ciicullaria, vegetative propaga-
tion of ... X

Dichromatism, remarks on xix

Direct equilibration . 24,53

Discovery of cretaceous mammals, review

of xiii

Discovery of vertebrate life in Lower

Silurian (Ordovician) strata xiii

Discoveries, recent, of Potomac fossil

plants near Washington xix

Disease, foot, of captive birds x

Disease, recent bacteriological progress

in prevention and cure of xv

Diseases, plant, recent progress in the

study of xvi

Distribution of animal and vegetable life xiv
Distribution of certain mammals, birds

and plants on the Pribylov Islands . . . xvi
Distribution of fishes by underground

water courses xvi

Distribution of species, geographical,

some early views of viii

Drawings, original, of the fur seal and

Steller's sea cow vii

Du IJois, Raymond 25

Dwarfs, notes on xvi

Dynamic evolutionists 2

Dynamic influences in evolution, Dall on vi. i
Dynamic variations limited 4,5

E.

Echinococcus in swine xviii

EchiHorhynrliiis gigas. development of . xvii

Edson, J. R., election of viii

Effort, conscious, relations of .3

Egleston, N. H.— The temperature of

trees xvii

Eimer, Theodor 57

Election of Officers xii

Embrj'oofchick with two protovertebrae . xiv
Entomology, economic, authorship of

bibliography of ix

Environment .... 54

Environment, its relation to the organism . 2
Environment, selection limited hydjiiain-

ics of 6, 9

Equilibration, direct 24, 53

Equilibration, iii<iirect 53

Equus beds of Oregon, collection of fossil

birds from xiv

Evermann, B. W., election of xvii

Evolution, on dynamic influences in . . vi, i
Evolution, relation of life history of

micro-organisms to viii

Evolutionists, dynamic 2

ALPHABETICAL INDEX.

75

F.

PAGE

Fauna and flora of Gulf States, evidences

of Sonorau origin of vi

Faunal and floral divisions proposed for

North America, historical review of . . vii
Faunas, fossil, bearing of topography of

Florida on xi

Ferments and fermentation among Bac-
teria, illustrations of vii

Ferns, fruiting, from the Laramie group xviii

Figgius, J. D., election of. xviii

Filaria gasterostei . . xviii

Fishes, apodal, classification of xv

Fishes from British Columbia, notes on

some \-i

Fishes, colors of . / vii

Fishes, distribution of. by underground

water courses xvi

Fishes of Great South Bay xiii

Fishes, Halosauroid. characteristics of . . ix
Fishes new to New England waters . . . xvii

Flora, American Triassic ix

Flora of Gulf States, evidences of Sonoran

origin of \A

Flora, upland Carboniferous, some pecu-
liar forms in xviii

Florida, topography of, with reference to

its bearing on fossil faunas xi

Flowers, color and odor of, in attracting

insects xiv

Flowers that bloom in winter v

Fortuitous variation 22, 63

Fossil birds, a collection of, from Equus

beds of Oregon xiv

Fos.sil bread-fruit tree from the Sierras . . xix
Fossil plants, Potomac, recent discoveries

of, near Washington xix

Fruits, cultivated, in the mountains of

North Carolina ix

Fucoids X

Fur of mammals, change in color of the . . vi

G.

Galloway. B. T.— Observations on an
apple disease caused bj- the fungus

Gyinnosporangium macropus vi

Recent progress in the study of plant

disea.ses xvi

Galton, Francis ... 25, 29, 30. 32, 33, 65, 70
Gastropods, development of columellar

plaits in 9

Geddes. Patrick . • 56

Gemmules 26

Genera, arrangement of, in the Herba-
rium of the Department of Agriculture . v
Geographical distribution of species, some

early views of viii

Geoff"ro3-, St. Hilaire 13

PAGE

Germ-plasm, continuity of the 35

Gill, T. N. — Characteristics of the Halo-
sauroid fishes ix

The super family Cyclopteroidea ix

Classification of the Apodal fishes . . . xv
Cla.ssification of the Tetraodontoidea . xvii
Ginkgo, fruiting of the, at the Depart-
ment of Agriculture x

Glands, poison, of Lathrodectus x

Goethe 13

Goode, G. Brown — Colors of fishes .... vii

Graptolites, American vii

Grass genus, a new \nii

Guinea pigs, production of immunity in,
with sterilized cultures of hog cholera

bacillus XV

Gulick 69

Gurley, R. R. — American graptolites . . . vii
Gymnosporangium macropus vi

H.

Haeckel, Ernst 13, 28, 54

Haeckel's Radiolaria of the Challenger

expedition xviii

Hair, human, change of color of vi

Hallock, Chas. — Distribution of fishes by

underground water courses xvi

Hasbrouck, E. M. — Monograph of the
Carolina Parrakeet xv

Remarks on Dichromatism xix

Henslow 56

Herbarium of the Department of Agricul-
ture, arrangement of genera in the . . . . v

Heredity, theories of 25

Hespeinriiis. a point in the anatomy of . . xiv

His • • • .25

Hoatzins. exhibition of young xiii

Holm, Theodor — Vegetative propagation

oi Dicentra cucullaria x

Holzinger, J. M., election of xi

Holziuger. J. M — Incentives to natural

hi.story study xvi

Hopkins, C. L. — Notes on the animal life

above the snow line on Mt. Shasta . . . . vi

Huxley • ... 19

Hyatt, Alpheus 59

I.

Immunity in guinea pigs, production of,
with sterilized cultures of hog cholera

bacillus XV

Incentives to natural history study . . . xvi
Indians of the Death Valley region, food

plants of the xvii

Indirect equilibration 53

Insects, colors of vii

Intelligence, selection limited by 6

Ixodes bovts, moultiugs of v

76

JUOLO(;iCAL SOCIETY OF WASHINGTON.

PAGE

James, J. F. — Variatiou with special refer-
ence to certain Paleozoic genera . . . vii
Organisms in St. Peter's sandstone . . . ix
Fucoids and other problematic organ-
isms X

Joint Commission, delegates to xii

K.

Knees, cypress, what are xiv

Knowlton, F. H.— What are cypress

knees xiv

Fruiting ferns from the Laramie

group xvui

A fossil bread-fruit tree from the Sierras

of California xix

Kowalevskj' 59

Kuntze's Revisio Generum Plantarum,
review of x'x

Lamarck, Jean-Baptiste-Pierre-Antoine
de Monet, Chevalier de

12, 13, 14, 16, 19, 21, 53, 61

Lamarckism 12, 14, 18, 23, 53, 54

Laukester, E. Ray i, :o, 25, 50, 68, 69

Laramie group, fruiting ferns from . . . xviii

Lathrodecius, poison glands of x

Lava beds and caiions of Snake River,

Idaho, life in x

Lepns idahoemis xi

Life, animal, above snow line on Mt.

Shasta, notes on the vi

Life, animal and vegetable, distribution

of. xiv

Life, vertebrate, discoverj' of, in Lower

Silurian strata xiii

Lophiomys imhansii viii

Lucas, F. A. — A foot disease of captive

birds X

The wing of Metopidiiis xi

Exhibition of young Hoatzins .... xiii
Specimen oi Bison laiifroiis from Peace

Creek, Florida xiii

A point in the anatomy oi Hcspenirnis . xiv
Remarks on a new tortoise from the
Galapagos Islands xvi

M.

PAGE

Main t, De 13

Malthus 65

Mammals, cretaceous, review of discovery

of xiii

Mammals, distribution of, on Pribylov

Islands xvi

Mammals, North American, new species

of viii

Man, acquired mental qualities of .... 64
Man, an undescribed muscle from the

infraclavicular region of v

Maun, B. P. — Authorship of the bibli-
ography of economic entomology . . . . ix
Marmots, North American, remark- on

affinities of xix

Marx, George — Investigations of the

poison glands of Z,(7//;ro(i'd'i;7/(5' x

The structure and construction of the

geometric spider web xviii

Masius, A. G., election of xvii

Meeting, eleventh annual, 1891 xii

Meeting, eleventh anniversary xii

Merriam, C. Hart — Evidences of Sonoran
origin of the flora and fauna of the

Gulf States vi

Historical review of the fannal and
floral divisions that have been pro-
posed for North America vii

Exhibition of new species of North

American mammals viii

Life in the lava beds and caiions of

Snake river, Idaho, in October x

A new rabbit from the Snake Plains of

Idaho — Lepus idahoonis xi

Distribution of animal and vegetable

life xiv

Remarks on the affinities of the North
American squirrels, chipmunks,
spermophiles, prairie dogs and mar-
mots xix

Metopidius, wing of xi

Micro-organisms, life history of, with rela-
tion to evolution viii

Mohave desert region, winter aspects of xviii

Mollusks, boring 8, 9

Monet, Jean-Baptiste-Pierre-Antoine de . . 14
Moore, V. A. — Production of immunity in
guinea pigs with sterilized cultures of

hog cholera bacillus xv

Echinococcns in swine xviii

Morsell, W. F., election of xvii

Muscle, an undescribed, from the infra-
clavicular region of man V

Muskrat, teeth of xi

Mutilations, effect of 7, 8

Mutilations, transmissibility of 23

ALPHABETICAL INDEX.

t I

N.

PAGE

Natural selection 20

Neo-Darwiuism xii, 11,51

Neo-Darwiuismand Neo-Lamarckisni . xii, n

Neo-Ivamarckism xii, 11, 53

Nomenclature, notes on xi

North America, historical review of
faunal and floral divisions proposed for . vii

Notes on nomenclature xi

Notes on the genus Phylloxera, new . . . xi

Notes on parasites xvii, x\nii

Notes, paleontological. from the north-
west coast X

Nurture vs. Nature 33

o.

odor of flowers in attracting insects . . xiv

Officers for 1891 xii

Orban, Alexis, election of x

Ordovician strata, discovery of vertebrate

life in xiii

Organisms in St, Peter's sandstone . . . . ix

Organisms, problematic x

Origin of variation . . . . : 1,4

Osborn, H. F 2,61,62

Osborn, H. F. — Review of the discovery
of cretaceous mammals xiii

P.

Packard, A. S 53

Paleontological notes from the northwest

coast x

Paleopathology, notes on xvii

Paleozoic genera, variation in vii

Palmer, T. S. — Some early views of the
geographical distribution of species . viii
The winter aspects of the Mohave Des-
ert region xviii

Palmer, Wm. — The occurrence of the
Asiatic cuckoo on the Pribylov

Islands xi

The distribution of certain mammals,
birds and plants on the Pribylov

Islands xvi

The fate of the fur seal in .\merican

waters xvii

Palms, date, recent introduction of ... . xv

Pangenesis 26 |

Panmixia 52 !

Parasites, notes on .xvii, xviii

Parasites of live stock, practical value of

investigating xv

Parrakeet, Carolina, monograph of . . . . xv

P.\GE

Peace Creek bone beds in P'lorida. age of xiv
Pelecypods, development of hinge in . . . 8. 9

Perigenesis of the plastidule 29

Pfliiger . 25

Phylloxera, new notes on xi

Physiological selection . . 52

Physiological units 26

Plant diseases, recent progress in the

study of xvi

Plants, distribution of, on the Pribylov

Islands xvi

Plants, food, of the Indians of the Death

Vallej- region xvii

Plants, Potomac fossil, recent discoveries

of xix

Plants, some F'lorida xv

Plastidule, perigenesis of the 29

Possibility of variation not equal in every

direction ." 5

Poulton, Edward B 34

Prairie dogs, remarks on the affinities of xix
Prentiss, D. W. — Change in the color of
human hair ; change in the color of
plumage of birds, and in the fur of

mammals vi

Pribylov Islands, the distribution of cer-
tain mammals, birds and plants on the xvi
Pribylov Islands, the occurrence of the

Asiatic cuckoo on the xi

Propagation, vegetative, of Dicentra
cuciiUaria x

R,

Rabbit, a new, from Snake Plains, Idaho,

Lfpus idahoensis xi

Radiolario, Haeckel's, of the Challenger

expedition xviii

Relations of conscious eflfort 3

Review, historical, of faunal and floral

divisions proposed for North America . vii
Re%nsio Generum Plantarum, review of

Kuntze's xix

Reyburn, Robert.— The life history of
micro-organisirs with its relation to

the theory of evolution viii

Ricardo 65

Richardson, C. \V., election of vii

Riley, C. V. — Colors of insects vii

New notes on the genus Phylloxera . . . xi
The Mexican arrow weed and jumping

bean xvi

Romanes. G. J 10, 51, 52

Roome, E., election of v

Rose, J N. — Coulterella. a new genus of
Compo-sitje ix

7S

BIOLOGICAL SOCIETY oK WASHINGTON'.

PAGE

Rousseau 65

Ryder, John A 60

s.

Salmon, death of, after spawning x

Salmon. Kennerly's xv

Sandstone, St. Peter's, organisms in . . . . ix

Schonlaud. Selmar M

Schools, public, place of biology in ... . viii
Sea cow, Steller's, original drawings of . . vii
Seal, fur, fate of, in American waters . . xvii

Seal, fur, original drawings of vii

Seaman, W. H.— The place of biology in

the public schools viii

Selection limited by dynamics of environ-
ment , 6, 9

Selection limited by intelligence 6

Semper, Karl 56

Sexual selection 21

Shasta,- Mount, notes on the animal life

above the snow line on vi

Shipley, Arthur E 34

Shufeldt, R. W.— A collection of fossil

birds from the Equus beds of Oregon xiv

Notes on paleopathology xvii

Silurian strata, discovery of vertebrate

life in Lower xiii

Smith, Adam 65

Smith, Theobald.— Some illustrations of
ferments and fermentations among

bacteria vii

On species among bacteria xi

Remarks on recent bacteriological pro-
gress in the prevention and cure of

disease xv

Snake River, Idaho, life in the lava beds

and canons of x

Suell, Merwiu M.. election of x

Species among bacteria xi

Spencer, Herbert 24, 26, 53. 54, 55, 67

Spermophiles, North American, remarks

on the affinities of xix

Spider web, geometric, structure and con-
struction xviii

Squirrels, North American, remarks on

the affinities of xix

Stanton, T. W., election of v

Stedman, J. M., election of x

Stedman, J. M. — Embryo of a chick with

two protovertebnc xiv

Stiles, C. W., election of xvii

Stiles, C. W.— Notes on Parasites — the de-
velopment of /•'c/unoi/iync/tH.': giMOs . xvii
Notes on Farasites—Coccidiii 111 bii:r»ii-
nuni and Filar la i^as/erostei .... xviii

P.\GE

Stirp 31

Stirpiculture 71

Stomachs, cuckoo, and their contents . . xvii

Stowell, C. H., election of vi

Sudworth, G. B —Notes on nomenclature . xi
Color and odor of flowers in attracting

insects xiv

Swine, Echinococcus in xviii

Swingle, W. T,, election of xvi

T.

Taylor, W. A., election of xiv

Teeth of the muskrat xi

Temperature of trees xvii

Test, F. C, election of . . xi

Test, F. C, notes on the dentition of

Des)nogna/liiis xvi

Tetraodontoidi-a. classification of the . . xvii

Thonip,son, J. Arthur 57

Tick, cattle, moultings of v

Ticks, a preliminary study of. in the

United States xi

Todd, W. E. C, election of xviii

Tortoise, a new, from the Galapagos

Islands xvi

Transmission of acquired characters,

Alphonse de CandoIIe 011 xix

Transmission of characters defined .... 3
Tree, fossil bread-fruit, from the Sierras . xix

Trees, temperature of xvii

Treviranus 13

Tropics, three days in the xviii

True, K W., exhibition of specimen of
Lophio»ivs i»i/iausii viii

The teeth of the muskrat xi

V.

Van Deman, H. f;., cultivated fruits in
tlie mountains of North Carolina . . . ix
The recent introduction of date palms . xv

Variation, origin of 1,4

Variation, possibility of, not equal in

every direction 5

Variation, with especial reference to

Paleozoic genera vii

Variations, dynamic, limited 4, 5

Vasey, George, a new grass genus .... viii
Notes on the recent field work of the
botanical division of the Department

of Agriculture xvi

Ve.stiges of creation 13

Vines, Sidney H 56

ALPHABETICAL INDEX.

7!)

PAGE

w.

Walcott, C. D.. a new genus and species
of ostracod crustacean from the Lower

Cambrian v

Discovery of vertebrate life in Lower
Silurian (Ordovician) strata . . . . xiii
Wallace, Alfred Russel . . 13, 18, 25, 45, 68, 69
Ward. Lester F., presidential address,
Neo-Darwinism and Xeo-Lamarck-

ism xii, 11

Flowers that bloom in the winter time . . v

American Triassic flora ix

Some Florida plants . xv

Haeckel's radiolaria of the Challenger
Expedition xviii

PAGE

Three days in the tropics xviii

Recent discoveries of Potomac fossil

plants near Washington xix

Alphonse de Caudolle on the transmis-
sion of acquired characters xix

Web. geometric spider, structure and

construction of xviii

Weismann. August 25, 29, 30

33. 34. 35, 36, 37. 38. 40, 43. 44. 45. 4b. 48, 49
50, 51, 52, 55, 56, 57, 59, 60, 61, 65, 66, 67, 69

Weismann hypothesis 1, 7

White, David, some peculiar forms in an

upland Carboniferous flora xviii

Wing of Me fop id ins xi

Worms in cattle, some little known . . . xiii