VITAL LIMIT OF EXSICCATION. 



45 



vitality ; and chameleons were exsiccated to 46.3 per cent, of their 

 body weight without loss of vitality. (2) Horned "toads" and 

 desert lizards were exsiccated to 33.8 per cent, and 47.8 per cent, 

 of their body weight, respectively, before death occurred. (3) 

 Horned " toads " and desert lizards endured exsiccation and 

 starvation for 119 and 86 days, respectively, before death oc- 

 curred. (4) Reptiles are apparently better fitted to resist exsic- 

 cation than any other group of animals experimented upon. 



Mammalia. 



As representatives of the mammals, three rodents were used : 

 the house mouse, Mus musculus (Linn.) ; the wood mouse, Pcro- 

 nivscus leitcopus noveboraccnsis (Fischer) ; and the meadow 

 mouse, Microtus pennsylvanicus (Ord.). The mice were caught 

 in traps and kept in cages in a vivarium with food and water be- 

 fore them constantly. During exsiccation corn and oats were fed 

 and the amount eaten determined by subsequent weighing. Mice 

 remained active until the vital limit of exsiccation was apparently 

 reached and then died quickly if not removed to a suitable en- 

 vironment. The mice became very nervous after subjection to 

 the dry air for a few days but became drowsy as the vital limit 

 was approached. 



TABLE IX. 



WOOD MOUSE, Peromyscus leucopus noveboraceusis (Fischer). 



The results of the experiments with mice, summarized in 

 Tables IX.-XI., show: (i) The house mouse was exsiccated to 



