COMPARATIVE STUDIES ON THE SENSE OF TASTE 



287 



is obvious that the rat is different from the fowl in these responses. Care- 

 ful observation also reveals fundamental differences from the calf. A good 

 example of this is the reaction to maltose. The calf was apparently in- 

 different to this sugar at concentrations up to 4 per cent while it was the 

 most preferred sugar by the rat. 



SUGAR PREFERENCES / WATER (CHICKS) 

 ^^.^^' ''""^^'^**.^ DEXTROSE 



XYLOSE 



* SUGAR SOLUTION ML. 

 TOTAL FLUID INTAKE 



X 100 



75 10 125 15 20 



CONCENTRATION GMS./IOO ML. 



25 



Fig. 1. The response of the chick to various sugar solutions in a two-choice 

 preference test is illustrated. The response to dextrose, sucrose and maltose 

 at all concentrations was one of indifference, i.e., close to 50 percent. Xylose was 



actively rejected. 



lOOr 



a" 50 



40 



SUGAR PREFERENCES/ WATER (CALVES) 



XYLOSE 



y , FRUCTOSE 



^LUCOSE 



SUGAR SOLUTION ML 

 TOTAL FLUID INTAKE 



20 3D 4.0 5.0 6.0 



CONCENTRATION GMS./IOO ML 



Fig. 2. The response of the calf to various sugar solutions in a two-choice 

 preference test is illustrated. With the exception of maltose and lactose marked 

 preference for the sugars are indicated. 



These animals are not closely related phylogenetically and the physio- 

 logical differences between them can be exemphfied by the diversity in 

 digestive systems with correlated differences in diet. 



In the dog, a carnivore, data on a wide range of concentrations have not 



