274 'Journal of Comparative Neurology and Psychology. 



used as stimuli were those known to affect the gustatory, and to a less 

 extent the olfactory sense, in higher forms. 



The work was carried out at the laboratory of the U. S. Bureau 

 of Fisheries at Woods Hole. I wish to express to the Director, Dr. 

 F. B. Sumner, my appreciation of his assistance in furnishing me 

 with every facility necessary for the successful prosecution of the 

 work. The subject was originally taken up in 1907 under the direc- 

 tion of Dr. G. H. Parker in the Zoological Laboratory at Harvard 

 University. I desire to tender to him my thanks for many helpful 

 suggestions made both at that time and at the Woods Hole laboratory. 



During the last few years much has been done, particularly among 

 the invertebrates, on the reactions of animals to different kinds of 

 stimuli. Part of this work has been concerned with chemical stimula- 

 tion, the character of which is shown by the work of Pearl ('03), Bell 

 ('06) and Jennings ('04 and '06). So far as the vertebrates are con- 

 cerned, work on chemical stimulation has dealt almost exclusively with 

 their two chief organs of chemical sense, smell and taste. A serious 

 attempt has been made, however, to determine for the organs and their 

 functions a physico-chemical basis. Haycraft ('87) was one of the 

 first to attempt seriously to deal with taste from a strictly chemical 

 standpoint. He was followed shortly by Corin ('88). The most im- 

 portant work of this character appeared about a decade ago from sev- 

 eral sources simultaneously. Overton ('97) considered osmosis, while 

 Kahlenberg ('98, '00), Kichards ('98, '00), Kastle ('98) and 

 Hober and Kiesow ('98) have taken up critically the physical and 

 chemical characters of substances which stimulate the gustatory ap- 

 paratus in man, together with the chemistry of taste itself. Still more 

 recently Herlitzka ('07) and particularly Sternberg, in a series of 

 papers published from 1898 to 1906, have made a detailed study of 

 the chemical basis of sweet, sour, salty, bitter, metallic, electrical and 

 alkaline tastes. 



Many other writers have made a physiological study of the action 

 of this same series of chemical substances on the gustatory apparatus 

 of man. This includes the work of Kiesow ('94b), Haycroft ('00a), 

 Hanig ('01), ISTagel ('05) and Lemberger ('08), together with nu- 

 merous others, practically all of whom, however, consider in this con- 



