BEHAVIOR OF VERTEBRATES 423 



a coefficient of correlation with the stimulus of .65S±.059 — a 

 correlation far too great to be due to chance alone. 



OLFACTION AND CHEMICAL SENSE 



Fish. Copeland (12) concludes after a study of the Puffer 

 that while sight plays an important part in the finding of food 

 the reactions to concealed food depend upon olfaction. The 

 experiments with concealed packages of food and cheese cloth 

 showed more visits to the one than to the other and that these 

 reactions depended upon the olfactory organs since they ceased 

 when the sense was rendered inoperative and were only resumed 

 when it again became functional. 



Shelf ord (50, 51) reports some work on the reaction of fish 

 to evaporation and to atmospheric gases. He finds that " short 

 exposure to high evaporation increases the sensibility to high 

 evaporation" and that "in survival time experiments, heightened 

 sensibility was sometimes followed by depression and apparent 

 fatigue." The fish detected differences in the character of the 

 water charged with gases as was shown by definite behavior. 

 The exact mode of detection was not studied. 



Parker (43) gives, in the paper here reported, some of the 

 results of his study of Ammocoetes and Amiurus nebulosus. 

 He is chiefly concerned with the relation of the general chemi- 

 cal sense to taste. He tested the whole body of his animals 

 with different chemicals and gives the exact details of his find- 

 ings. Like Sheldon he found no stimulating effects from sugar. 

 He thinks sensitivity to sugar is probably a recent evolutionary 

 acquisition and says that it cannot be due to osmotic pressure 

 which is relatively high, but it is a real chemical effect on the 

 nerve endings. There was a considerable diversity in the reac- 

 tions to quinine and the salt was least efficient except in the 

 mouth. Olfaction is a chemical sense, stimulated in this case 

 by substances in solution. It acts as a distance receptor and 

 is both structurally and functionally in strong contrast to taste. 

 He agrees with Sheldon and Herrick that the chemical sense is 

 the primitive sense from which olfaction and taste have differ- 

 entiated and attempts to give some of the mechanism of the 

 change. 



Amphibians. Copeland (13) from his study of the spotted 

 newt draws conclusions which differ somewhat from those 



