S2 BulUtin of Laboratories of Denison University. [Voi. xii 



plied with a pipette, etc. The operated fish would locate 

 a concealed bait by means of the pelvic fins exactly as the nor- 

 mal fish does and he would similarly root it out and eat it. In 

 short, the gustatory reflexes, so far as I have observed them, 

 were absolutely unmodified by the operation. That the 

 olfactory apparatus was totally destroyed was verified by 

 autopsy dissections made after the close of the observations. 



(3) Other Fishes. 



The sea robin {Prionotus catolinus). The three finger-like 

 rays of the pectoral fins ol the gurnards have long attracted the 

 attention of zoologists, and the American species of P}ionotus 

 have been made the subject of a careful research by Morrill 

 ('95). He finds that, as in the European Trigla, the free rays 

 are totally devoid of terminal buds or other specialized sense 

 organs and that the sensory nerves with which these free rays 

 are so abundantly supplied end free, like tactile nerves in gen- 

 eral. 



He also made some interesting physiological experiments. 

 The normal food of these species so far as known is small fish, 

 young clams, shrimps, amphipods and other small Crustacea, 

 squid, lamellibranch mollusks, annelids and seaweeds (Lin- 

 ton, 1 90 1, p. 470). They are constantly feeling about the 

 sand, turning over stones and feeling under them, etc., with 

 these free rays and undoubtedly find their food largely in this 

 way, especially the annelids, mollusks and Crustacea. But in 

 captivity the eyes are used chiefly in securing the food. Mor- 

 rill writes further, "In order to test the use of the free rays in- 

 dependently of sight the crystaline lense and cornea were re- 

 moved from some fish and in other cases the cornea was cov- 

 ered with varnish, balsam or tar. The repeated experiments 

 were negative in their result, as the fish paid no attention to 

 the food, even when it was placed in contact with the free 

 rays." Morrill concludes "that the free rays have been modi- 

 fied for tactile purposes, and that they are mainly if not alto- 

 gether used in searching for food." 



Morrill's dissections leave it uncertain whether the free rays 



