No. 598] THEORIES OE HIBEEXA TIOX 621 



this gland contains lipase, and while it does not convert 

 starch to sugar, its extirpation diminishes the amyloptic 

 power of the serum. It also has an antitryptic power. 

 Thus he conceives that it might serve as an economizer 

 of proteins by insuring the utilization of reserve carbo- 

 hydrate and fats during the long period of winter-sleep. 



Salmon's view on the role of the hypophysis cerebri in 

 the production of sleep was soon criticized by Gemelli 32 

 (1906), who argued that if this hypothesis were correct, 

 the pituitary body would show signs of increased activity 

 during hibernation, since, as lias already been stated, hi- 

 bernation is considered by many to differ from ordinary 

 diurnal sleep only in degree and duration. But on the 

 contrary, he found that the cyanophil cells of this gland 

 in the marmot decreased during winter-sleep and that 

 they increased again simultaneously with the appearance 

 of numerous karyokinetic figures after the animal wakes 

 up in the spring. Gemelli interpreted his findings as in- 

 dicating that the anterior lobe of this organ cooperates 

 with other ductless glands in neutralizing toxins which 

 are produced in increased quantity when the animal be- 

 comes active, and hence is not to be regarded as a center 

 of sleep. A later contribution to the relationship be- 

 tween the pituitary body and hibernation is by Gushing 

 and Goetsch 82 (1913). As a result of observations on the 

 hypophysis of the woodchuck, in which they confirm in 

 general the findings of Gemelli on the decrease in size and 

 histological changes during winter-sleep, these authors 

 suggest that hibernation may be ascribed to a period of 

 physiological inactivity, possibly of the entire ductless 

 gland series, but certainly more especially of the pituitary 

 gland, because during the dormant period this structure 

 diminishes in size and shows profound histological 

 changes and because deprivation of this gland in the 

 human subject and in experimental animals causes a train 

 of symptoms comparable to those of hibernation. Mann 83 

 (1916), however, found demonstrable changes in the 

 pituitary body and other ductless glands of a large num- 



