DESICCATION AND CARBOX DIOXIDE PRODUCTION. 269 



had been kept in the laboratory for several day- \\ere used. To 

 quiet the animals proved rather difficult. A dark chamber with 

 a small opening in the paper covering caused the animals to orient 

 themselves towards the light. After being handled the respira- 

 tory rates of the animals returned to normal very slowly, that is, 

 a number of consecutive readings showed a decrease in rate 

 before they l>ecame constant. This suggested the possibility of 

 oxygen depletion within the closed system. Kn^li (1916) in 

 summari/iii;,' the \\ork of several authors concluded: "In cold 

 blooded .mimals oxygen consumption is practically independent 

 of tin -sure down to about 2 per cent, pressure." 



I resh air \\.i- admitted to the animal chamber?- without di>- 

 turbinK the animal, by the removal of the indicator tube. This 

 hail no etie. t upon the rate of carbon dioxide production, so it 

 aed that the animal had obtained -m'licient oxygen. 

 The rate of < arbon dioxide production in the d< ted frogs of 



the four Berii Fi cperiments increased \\ith lo in \\eiuht until 

 the ! >8fl aim 'tinted to from 15 to 20 per cent . < >f t heir 1 n >< ly weight. 

 The late diminished subsequently to the completion of the 

 experiment. The total time of a single experiment \\a- less than 

 14 hours and hardly permitted of starvation a- : tor in the 

 dei rease in re-pirat i- -n rate. The control animals Io>t \ cry little 

 \\ater. fiom O._M> to 1.47 per cent. The re>pirator\ rates of the 

 control fn>i;s \\ere fairly constant throughout the \\ork. 



V. Piscussi' 



The>e in\ e~t i-ation> show that de-iccation -limulates the 



ph\ -.-iolo-i( al at ti\ it\ ot certain animals and that tin- increase in 

 irritability is followed by marked depre-.-ioii. \\ hile there is no 

 literature on the eliects of desiccation on the i arbon dioxide 

 output of animals, it i< interesting to note that Bodine (1922) 

 obtained >..me\\ hat similar resalts from the a( lion of ether, xylol 

 and acetone upon ^i a Imppers, and concluded th. -thetics 



ha\e ph\>ioloyical effects other than on re.-piration. Shelford 

 (1913), with beha\ ior methods, found that animal> subjected to 

 air of low humidity were more active than normal ones, and if 

 kept under such conditions, the period of activity was followed by 

 a period of depnion, and suggested that the increased irrita- 

 bility was probably due to the concentration of the blood and 



