COMPARATIVE STUDIES ON THE 

 SENSE OF TASTE 



MORLEY R. Kare and M. S. Ficken 

 University of North Carolina, Raleigh 



How does the loss of the sense of taste affect an animal? Would the loss 

 be more critical in one species than in another? There are no adequate 

 answers to these questions because the function of taste in the physiological 

 economy of the vertebrate animal body has not been established. We can 

 only suggest possible roles for taste. The intricate relationship of taste, 

 behavior diet and metabolism are, for the most part, still undefined. The 

 objective of this paper is to present some comparative data on taste for 

 species that differ in their natural diet, digestion and to some degree in their 

 metabolism. 



Although studies in taste have a long history (Boring, 1942), truly com- 

 parative studies have only been undertaken quite recently. Parker (1922) 

 studying the chemical senses in a variety of invertebrates and fish was a 

 pioneer in comparative studies. Behavioral responses of various domestic 

 birds to taste stimuli were reviewed in a book by Engelmann (1957). 

 Carpenter (1956) reported on a number of mammals and Kare (1962) 

 described taste responses of various species of domestic animals. A com- 

 parative approach to electrophysiological studies has been used by Pfaff- 

 mann (1953), Beidler et al. (1955), Tamar (1956) and Zotterman (1961). 

 The behavioral work with animals largely measures preference thresholds 

 and the electrophysiological recordings are more likely to be related to 

 discrimination thresholds. Therefore, it is difficult to correlate these two 

 phases of taste research. 



Comparative studies, when carried out with a sufficient number of species, 

 can lead to generalizations about taste responses in animals. This may 

 permit the separation of the unique from the fundamental. Of course, 

 comparative research could be an end in itself, leading to an understanding 

 of the evolution of taste. 



The comparative approach in taste research has received limited use for 

 several reasons. One was the rather prevalent belief of early sensory 

 physiologists that the stimulus was all important and the kind of animal 

 used was rather secondary. This led to the inference that all animals 

 would react similarly to a given chemical. This concept has been demon- 



285 



