424 STELLA B. VINCENT 



of Reese in 1912. He used the method Parker, Sheldon and others 

 have used and as controls had animals in which the external 

 nares were covered and others in which the olfactory nerves 

 were severed. He thinks there is first a visual response to the 

 object which is then tested as to its food properties by olfaction 

 and that any snapping at an edible object depends upon olfac- 

 tory stimulation by substances in solution. 



Sound as a directing influence in the movement of fishes is 

 the subject of a paper by G. H. Parker (42). The experimenter 

 set up a tank 50 x 6 x 100 cm. made of wood 3.5 cm. thick, with 

 a controllable inlet and outlet for water. The tank was screened 

 and illuminated by reflected light from the ceiling, or from an 

 incandescent light hung directly over it. The stimulus was an 

 iron ball pendulum which struck the exact middle of one end 

 of the tank with a momentum of 361200 C.G.S. units. The 

 ball weighed 4300 gr. The contact produced a low booming 

 noise. Fishes were put in five at a time and tested 50 times. 

 The positions of the fishes in the tank were noted before and 

 after each stimulation. Then the pendulum was shifted to the 

 other end of the tank and the experiment was repeated. The 

 first group of fish was followed by another group of five. Tau- 

 toga, Stenotomus, young kingfish and swellfish, he says, showed 

 unmistakable tendencies to avoid the sound center. Sea robins 

 tended to move toward this center. The killifishes ceased move- 

 ment but neither moved toward or away from it. He asserts: 

 ' It is obvious that fishes are stimulated by sound but most 

 sounds are generated in air and either fail to enter the water 

 or enter it to so slight a degree that they are of little significance 

 for fishes. The surface between the air and the water is an 

 extremely difficult one for sound to penetrate in either direction 

 so that most sounds generated in the water or in the air stay 

 in the medium of their origin. Such sounds as reach fishes, 

 however, not only influence their movements but also the direc- 

 tion of their movements." No doubt all who read Parker's 

 paper will be willing to admit the possibility of the truth of this 

 last statement but few, the reviewer fears, would be willing to 

 admit that he has proved that sound did reach these fish or that 

 their movements were caused by sound. 



