46 A. T. RASMUSSEN 



It further appears certain that there is no appreciable modifi- 

 cation in the number of mitochondria as a result of the altera- 

 tions attending hibernation, awakening, and subsequent inani- 

 tion, thus testifying to the stability of these bodies under greatly 

 modified functional conditions. 



In the first place, during winter-sleep there is a great reduction 

 in the metabolic processes. From the excellent summary of the 

 literature on respiratory exchange during hibernation by Krogh 

 ('16), it would appear that in mammals with a normal body tem- 

 perature of about 36°C. when awake and whose body tempera- 

 ture approaches 10°C. or less during hibernation, the oxygen 

 consumption falls to one-twentieth or less of the amount used 

 before dormancy occurred. The C0 2 eliminated decreases rela- 

 tively much more. This great reduction in oxidation processes 

 in the body does not apparently affect the mitochondrial content 

 of nerve cells, although in all probability the nervous system 

 shares at least to some extent in the reduced oxygen consump- 

 tion. There is, then, from this source no evidence in favor of 

 the theory that mitochondria are associated with oxidation proc- 

 esses. The possibility exists, however, that they may be in- 

 volved in such processes without showing any morphological or 

 numerical changes with degrees of activity. N. H. Cowdry 

 ('18) found in myxomycetes that the mitochondria were found 

 in all stages of the organism, even in fully formed spores with 

 a thick horny capsule and supposedly in a state where the physi- 

 ological processes are nearly at a standstill. 



What other tissues in the woodchuck will show remains to be 

 determined. The glands are now under investigation. 



During hibernation the absorbing power of the blood for C0 2 

 decreases and there is a distinct increase in the amount of C0 2 

 actually found in the blood (Rasmussen, '16 b). These changes 

 as found in the venous blood reflect an increase in the H-ion con- 

 centration of the tissues. This tendency toward acidosis does 

 not seem to have any effect on the mitochondria in nerve cells, 

 although there must be readjustments in the nervous system to 

 this altered condition of its blood supply. 



