COMPARATIVE STUDIES ON THE SENSE OF TASTE 



295 



regulation of pH is perhaps one of the body's most sensitive mechanisms. 

 It was reasonable to consider that the water response was in part a sen- 

 sitivity to pH. For this reason we tested the reaction of chicks (Fuerst 

 and Kare, 1962) and also calves to pH (Kare). In Fig. 10 is a summary of 

 the results with chicks. The most starthng observation is the tolerance, 

 taste-wise, for acid. The results with calves are similar, although not as 

 dramatic. Thus the pH of the water used in electrophysiological studies is 

 probably not an important factor. 



Percent intake of acids and bases at diferenl pB levels 



pH 



1.0 



2.0 



3.0 



pH 



I I 



15 

 11.0 



I I I 



59 



56 



I I 



52 



53 



W.O 



Fig. 10. Tabled values are the mean of replicate lots. The per cent intake 



volume of tested fluid 



= total fluid intake^ '' ^^^ ^^^ ^'^'^^ ^^'"^' ^^^^ averaged). The 



position of the numbers is an indication of the pH of the test solution. For 



example at pH 1.5 the average daily consumption of HCl was 19 per cent of the 



total fluid intake. Distilled water was the alternative in every instance. 



The question still remains, what is the function of taste in animals? 

 The mean number of taste buds in a variety of species are presented in 

 Table 3. We know that the cow with 25,000 taste buds does not respond 



Table 3. The mean number of taste buds described for 

 different animals are presented. 



behaviorally to chemicals that evoke strong rejection in the fowl who has 

 only a few dozen. What if any is the correlation between gross anatomy 

 of the receptors and taste behavior? This numerical enigma parallels 

 many others in taste which so far affects no pattern of function. 



