+20 



FRESH WATER 



10 15 20 



Figure 3. 



Weight changes in adult kangaroo rats kept for 19 days on a diet of soy beans, given fresh 

 water, sea water, or no water for drinking. The weight changes are given in percentage of the 



initial weight. 



mg HgO/ 5 rug 



/liter air 



10 mg 15 mg 



Figure 4. 



20 mg 



Kangaroo rats; Total water intake and total water output at various atmospheric humidities at 



25°C. 



Ordinate: Water intake and output in grams per 100 kilocalories of pearled barley metabolized. 

 Abscissa: Humidity in the environmental air. 



179 



