394 DAVID E. FINK. 



Whether it is ordinary adipose tissue or a special gland that 

 functions in the mammal as a storage for nutrient material, 

 with the potato beetle, and perhaps with insects in general, it 

 seems quite certain that adipose tissue serves that purpose. 

 To determine some of the morphological changes that take place 

 during hibernation sections were made of the adipose tissues of 

 the potato beetle. During prehibernation (Fig. 5) the sections 

 show it to be composed of regular cells, oval in general outline 

 and filled with conspicuous fat vacuoles of more or less uniform 

 shape and size which extensively overlap and partly mask the 

 actual contour of the large nucleus. Barely distinguishable 

 are diminutive albuminoid granules dispersed among the 

 vacuoles. The sections of beetles in hibernation for one 

 month (Fig. 6) are strikingly different in appearance from 

 those of non-hibernating ones. In the former we find that 

 the fat vacuoles have become much smaller and that the nucleus 

 has undergone disintegration and diminution in size. The most 

 striking objects are the albuminoid granules aggregated along 

 the periphery of the cells of the fat body, or clustered around 

 the nucleus. The sections of adipose tissues of animals in 

 hibernation for the longest period (six months) show clearly the 

 prominently large albuminoid granules clustered in groups, 

 exhibiting many open spaces (Fig. 7). Indications of a 

 dissolution of the cells of the fat bodies and a dispersal of the 

 albuminoid granules are quite evident. 



The author compared Figs. 5-7, with those published by 

 Rasmussen and Sheldon of sections taken from the hibernating 

 gland in mammals, and the similarity is indeed very striking. 



The existence of albuminoid granules or uric acid concretions 

 indicates an active metabolism in the fat body. According to 

 Lang (15) the fat body of larvae of insects is rich in fat and poor 

 in concretions of uric acid before metamorphosis, while in the 

 adult the opposite is true. Fabre (n) thinks that the adipose 

 tissue serves the purpose of a urinary organ, since urates are 

 formed within the cells. Both Graber (13) and Landois (14) 

 regard it as a single many lobed lung (owing to the many fine 

 branched tracheal endings in the fat body). Similarly Roubaud's 

 view of the necessity of a physiological purification during 



