170 



ZOOLOGICAL SOCIETY BULLETIN 



old) still has the white egg tooth on the tip of his 

 upper mandible. Bill measures 13 mm. in height 

 and the under mandible is 2 mm. longer than the 

 ujjper. 



CONCLUSIONS. 



A. — The call, food and alarm notes of conmion 

 terns, black skimmers and laughing gulls arc in- 

 stinctive; not taught by the parents nor learned 

 by imitation. The one positive proof of this would 

 warrant the assertion. 



B. — Thr ri'iii:iik;d)le disparity in the length of 



such conditions the terns (which we remember 

 are not so protectively colored as the skimmer), 

 take time to run to the darkest corner or shadow 

 before squatting, while the skimmer crouches in- 

 stantly, and with two or three instinctive flicks of 

 feet and legs, almost buries himself. 



E. — The sight of small but entire fish e.xcites a 

 newly-hatched skimmer much more than does 

 macerated fish. Terns are not so excited until 

 after the first week. 



F. — The act of pecking is instinctive to a certain 

 extent, Jbut}[isjacquired ^very slowly in this wav. 



PHOTOGRAPH 



FEMALE EUROPEAN BISON. 



the mandibles in the adult black skimmer is fore- 

 shadowed even in the embryo and in the newly- 

 hatched bird. 



C. — My experience with a dozen terns and gulls 

 showed that these individuals prefer fresh water to 

 sah. 



D. — There is absolutely no "instinctive" fear 

 of man or other objects which enter quietly into 

 the environment of the young birds, but a sudden 

 shadow or loud noise causes them to perform cer- 

 tain acts — wholly instinctive — which have for their 

 object an escape from supposed danger. Under 



By imitation it is learned quickly, and is performed 

 successfully within a few minutes. 



G. — The art of flying is wholly instinctive, the 

 terns learning the use of their wings as soon as the 

 primaries are large enough to support them. 



EUROPEAN BISON. 



For a century or more, the survivors of Bos bonasus 

 have existed solely through the iron-clad protection atTorded 

 them by the Czar of Russia. For many years it has been 

 only by imperial favor that a zoological garden or museum 

 could procure a specimen. Excepting the few small 



