ZOOLOGICAL SOCIETY BULLETIN 



ZOOLOGICAL 

 SOCIETY BULLETIN 



EDITED BY THE DIRECTOR 



Elwin R. Sanborn, Asst. Editor. 



Published at tlie Office of ilie Society, II IVall St., New York City. 



Cojtyright, IQO^, by the New York Zoological Society. 



No. 17. APRIL, 1905. 



Subscription price, 50 cents for four numbers. 



Single numbers, I 5 cents. 



MAILED FREE TO MEMBERS. 



©ffirrre of tbr ^otirtp. 

 ptcsiticnt : 



III IN. I.H\I P. MOKTOX. 



<Efccutil)c »!Eommittee : 



Charles T. Barnev, Chairman, 

 Henry Fairfield Osborn, Madison Grant, 



John S. Barnes, William White Niles, 



Philip Schuyler, Samuel Thorne, 



Levi P. Morton, ex-affiiio. 



i&tnsxaX (©fficEtj : 



Secretary, Madison Grant, 11 Wall Street. 



Treasurer, Percy R. Pvne, 52 Wall Street. 



Director, William T. Hornadav, Zoological Park. 



Director o/ the Aquarium, Charles H. Townsend, Battery Park. 



•JBoarb of jnaanagcrfi : 



EX-OFFICIO, 

 The Mayor of ihe City of New York, Hon. George B. McClellan, 

 The President of the Dep't of Parks, Hon, John J, Pallas. 

 <na«|9 of 1905. <a:iag« of 1906. CiaiSjS of 1907. 



Henry F. Osborn, Levi [>. Morton, F. Augustus Schernierhorn 



Henry W. Poor. Andrew Ctriieijie, A. Newbold Morns, 



Charles T. Barney, Morris K. Jesup, Percy K. Pyne, 



William C. Church, John L. Cadwalader, George B. Grtnnell, 



Lispenard Stewart, Philip Schuyler, lacob H. Schiff, 



Ma 



1 S. Barnes, 



Hugh D. Aiichir 



Charles F. Dieb 



tames J. Hill. Henry A. C. Taylo 



George F. Baker. Hujjh I. Chisholm, 



Grant B. Schley. Win. D. Sloane. 



Kdward .1. 

 George C. Clark, 

 White Niles, Cleveland H. Dodge, 



C. Ledyard Bla 

 Cornelius N'anderbilt, 

 Nels..n Robinson, 

 Frederick G. Bourne. 



SCIENTIFIC WORK AT THE AQUARIUM. 



The subject of water density and its effect on 

 fishes, is one in which the management of the 

 Aquarium is deeply interested. The Director in- 

 vited Dr. Francis B. Sumner, of the College of the 

 City of New York, to continue at the Aquarium 

 the experiments with killifishes, begun by him at 

 Woods Hole last summer. These very small salt- 

 water fishes are always kept in abundance as food 

 for the larger species on exhibition, and certain 

 tanks in the service gallery have been placed at 

 Dr. Sumner's disposal. At the present time all 

 fishes dying in the Aquarium are being subjected 

 to careful pathological examinations in the hope 

 that it may lead to a better understanding of their 

 condition in captivity. 



The experiments conducted by Dr. Field in the 

 laboratory of the Aquarium in 1903, relative to 



the infection of oysters with typhoid bacilli, pre- 

 sented in the Eighth Annual Report of the Society, 

 were interesting and valuable. 



Dr. Sumner has consented to make the following 

 preliminary remarks respecting the character of 

 his studies: 



EXPERIMENTAL STUDIES OF FITNESS 

 IN FISHES. 



It is a commonplace among zoologists, that all 

 animals are not equally adapted to particular con- 

 ditions of hfe or equally fitted to withstand un- 

 favorable circumstances in their environment. 

 Not only do species differ from one another in their 

 degree of adaptation to given conditions, but, within 

 the limits of a species, the individuals present a 

 wide range of variation in this respect. 



If, for example, specimens of the three commoner 

 kinds of Fiindulus ("kilhfish") be placed together 

 in a pail of water, in numbers sufficient to quickly 

 exhaust the oxygen, we note that all three do not 

 succumb at the same rate, but that F. heleroditus 

 is much more hardy than is F. majalis or F. diaph- 

 anus. Similarly, if we take any one of these 

 species alone, we find that all individuals do not 

 die at once, but that some die long before others, 

 i. e., they vary in their power to resist asphyxiation. 



In the case of two different species, we find, of 

 course, obvious structural differences, in addition 

 to those functional differences which make one 

 more "hardy" than another. They may differ 

 in shape, color, fin and scale characters, etc. Are 

 any such structural differences to be discovered 

 between the more and the less resistant lots within 

 the limits of a species? If present, they can only 

 be revealed by making accurate measurements of 

 particular features in great numbers of individuals. 



Studies begun in the laboratory of the Bureau of 

 Fisheries at Woods Hole, Mass., and continued at 

 the New York Aquarium, have in view a deter- 

 mination of the measurable differences between 

 the more and the less ''fit" members of particular 

 species of fish in the presence of various conditions. 

 Is the "fitter" type, with respect to asphyxiation, 

 the same as the "fitter" type with respect to the 

 attacks of fungus or to sudden changes in the sur- 

 rounding medium ? Do the more fit and the less 

 fit individuals of Fundidus hctcrocUtus differ in 

 the same traits as do the more and the less fit of 



