290 



MORLEY R. KARE AND M . S. FICKEN 



might be suggested that this is related to nutritive value. However, this is 

 unHkely since a saccharin solution is preferred equally as well as xylose and 

 fluid intake is increased as for the other sugars. The restricted fluid intake 



100 



Xylose Lactose Saccharin 

 3.2%) (i27o) (0.064) 



SUGAR PREFERENCE /WATER AND FLUID INTAKE 

 ML. SUGAR SOL. 



*PERCENT PREFERENCE 



TOTAL FLUID INTAKE 



RATS) 

 XI 00 



Fig. 5. The preference for sugar solutions and the influence on total fluid intake 

 is illustrated. While xylose is preferred by the rat to about the same degree as 

 glucose, maltose or sucrose, it fails to increase fluid intake in a similar manner. 



PREFERENCE FOR XYLOSE /WATER 

 AND TOTAL FLUID INTAKE (RATS) 



ASCENDING 



DESCENDING 



-53 



.5 4.5 75 12 18 24 



CONCENTRATION GMS./IOOML. 



5 4.5 75 12 18 24 



CONCENTRATION GMS./IOO ML 



Fig. 6. The eff"ect of prior ascending or descending concentration sequences on 

 subsequent preferences on the left and on fluid intake on the right (xylose). 



could be related to the toxicity of xylose. However, this theory requires 

 additional support. The results with lactose are interesting since preference 

 is less than that encountered with the common sugars while total fluid 

 intake is close to that of the control. 



