THE REACTIONS OF CRAYFISH TO CHEMICAL 



STIMULI/ 



JAMES CARLETON BELL. 



contents. 



Historical 299 



1. Reactions to Chemical Stimuli 299 



2. Organs for the Reception of Chemical Stimuli 304 



Experimental 310 



1 . Meat Juice 310 



2. Lavender Water 314 



3. Acetic Acid 315 



4. Hydrochloric Acid 317 



5. Saturated Salt Solution 319 



6. Sugar 320 



7. Hydrochlorate of £>uinine 321 



8. Feeding 322 



(1) Reactions to Meat 322 



(2) Reactions to Vegetables 3 24 



Summary 325 



HISTORICAL. 



I. Reactions to Chemical Stimuli. — HuxLEY, in his work on 

 the crayfish, states that they seek calcareous waters, and are not 

 found in streams flowing through granite regions. As to food, 

 he says, they are not particular, eating almost any kind of animal 

 or vegetable matter that they can get hold of, and perhaps giv- 

 ing preference to that which is tainted and decaying. They are fre- 

 quently caught by hanging a piece of meat over a net and pulling 



' The following observations on the reactions of the crayfish to chemical stimuli were made in the 

 Harvard Psychological Laboratory and are abridged in part from a thesis presented in fulfillment of 

 the requirement for the degree of Doctor of Philosophy at Harvard University. Grateful acknowledgment 

 is made to Dr. Robert M. Yerkes for kindly criticism and helpful suggestions throughout the course 

 of the work. 



