270 abstracts: physiology 



(Macrorhinusleoninus). It now breeds only at Guadalupe Island, and 

 there are about 150 of the animals in existance. The trunk, or proboscis, 

 of the adult male is not capable of inflation, but is retracted into heavy- 

 folds on top of the head by muscular action. The breeding season begins 

 a few days before March 1 and the period of gestation is 12 months. The 

 color of the young at birth is black. The yearling utters a call or scream 

 unlike the voice of any other seal. In captivity its favorite food is fish. 

 The yearling and two-year-old have a peculiar habit of lifting the head 

 and hind flippers above the back until they nearly meet. 



One important statement is to the effect that the Mexican authorities 

 have already taken steps to prevent further killing of this species. 



W. E. Safford. 



PHYSIOLOGY. — Sound as a directing influence in the movements of 

 fishes. G. H. Parker. Bulletin of the Bureau of Fisheries, 30: 

 97-104. 1910. Issued April 27, 1912. 



Pursuing his researches upon the sense of hearing in fishes, Dr. Parker 

 has found that different species of fish differ not only in sensitiveness 

 to sound but respond by movements of different directive character. 

 With a tank of special construction which concealed from the fish all 

 outside surroundings, and a pendulun which delivered regular blows 

 upon one end of the tank, eight species were tested in numbers of five 

 individuals each, their movements being carefully noted for fifty blows 

 upon each end of the tank. 



The fishes fell into three classes as follows: (1) Those which tended 

 to retreat from the region of sound production; illustrated by the tautog 

 (Tautog onitis), the scup (Stenotomus chrysops), young kingfish (Men- 

 ticirrhus saxatilis), and young swellfish (Spheroides maculatus). (2) 

 Those which were attracted by the sound, as the sea robins (Prionotus 

 carolinus and P. strigatus). (3) Those which, though agitated, moved 

 neither toward nor away from the sound; illustrated by the killifishes 

 (Fundulus heteroclitus and F. majalis). Of all three classes it was ob- 

 served that the influence of the sound was almost as short in duration 

 as the stimulus. It is therefore improbable that sounds of brief dura- 

 tion can have much effect on the temporary distribution of fishes within 

 their reach. That fishes should be attracted over any considerable 

 area or repelled from that area by sound would seem to demand some 

 more or less continuous source of sound production. 



Ethel M. Smith. 



