VITAL LIMIT OF EXSICCATION. 



47 



weight without loss of vitality. (3) The meadow mouse was 

 exsiccated to 32.1 per cent, of its body weight without loss of vi- 

 tality. 



Graphs. 



The graphs shown in Fig. 2 represent the loss of water during 

 exsiccation for intervals of time. It will be noted that in the 

 graphs,, with the exception of the house mouse, the water lost for 

 intervals of time is constant. In the case of the house mouse, 

 however (graphs V., VI.), the downward curve indicates a rapid 



\\ 



UoA 



\\ow=e 



Ho. 4 



NoA 



loss of water for the first few days, it then straightens and is 

 nearly horizontal until death of the mouse occurs. 1 These facts 

 indicate a resistance in the house mouse to evaporation a resist- 



i The irregularities in Graph VI. for the ninth to the twelfth days are due 

 to the absence of food the ninth day and the excess eaten the following day. 



