REACTIONS OF ANIMALS. IO/ 



appear to be inhabitants of moist woods. Fontaria however 

 while living under the leaves of the beech woods is most common 

 in earlier forest stages (Shelford, '12) where the evaporation is 

 i.o c.c. or more per day greater. It is clearly less sensitive to 

 evaporation than Pterostichus. Microbembex and Geolycosa are 

 confined to open sand situations. 



3. Physiology of Water Withdrawal and Water Starvation. 

 Tiedeman ('36) described the symptoms of great thirst experi- 

 enced by travelers in the desert. The first thirst is followed by 

 dryness and smarting of the throat; next the respiratory action 

 is increased and later long deep breaths alternate with hiccoughs; 

 hoarseness occurs and is followed by loss of speech ; the pulse is 

 quickened ; the skin becomes dry ; the muscles become w^eak and 

 a feeling of great fatigue ensues with staggering and labored 

 movements. The thirst then becomes maddening and loss of 

 consciousness usually follows. Hill ('06) states that with a loss 

 of ten per cent, of his weight in water, a man usually dies. The 

 study of the phenomena of water starvation dates from the 

 beginning of modern experimental physiology. Some of the 

 early experiments in physiology w r ere water starvation experi- 

 ments on birds and mammals. Schuchardt ('47, see Noth- 

 wang, '920) found that pigeons fed on air-dry grain but deprived 

 of water died in about eleven days. Scheffer ('52, see Noth- 

 wang, '920, pp. 275-276) describes some of the symptoms of 

 death by water starvation in pigeons. During the earlier part 

 of the experiment there was great unrest and excitement accom- 

 panied by characteristic sounds. This gradually passed off and 

 the animal became quiet and did not notice the surroundings 

 or respond to stimuli. Northwang ('92) summarizes the earlier 

 literature. He studied the dry weight of fat-free tissues of 

 w r ater-starved birds and found that it was increased. He came 

 to the conclusion that death from want of water resulted from the 

 accumulation of splitting products in the cells, due to the lack of 

 sufficient fluid to remove them. The results according to this 

 view should resemble fatigue, which may account for the fatigue 

 symptoms which accompany water starvation. He states that 

 fat animals resist lack of water better than those without fat 



