576 GEORGE H. BISHOP 



nucleoli increase in number to this stage (beginning of pupation), 

 and the nucleus as a whole decreases in size with the formation 

 of the granules. The globules developed somewhat differently 

 in the different forms studied. 



Hufnagel, '11 (Hyponomeuta) , described an 'epuration' of 

 chromatin from the nucleus of the cell. This process was observed 

 to commence in the larva, but persisted throughout pupation to 

 the formation of the imaginal fat-body. Granules of chromatic 

 material formed within the nucleus passed into the cytoplasm and 

 became enclosed by a chromatic portion of cytoplasm. Different 

 stages of ' condensation' of the chromatic substance were observed 

 in the same cells, due to the fact that the granules were developed, 

 not all at once, but in a successive order. The globules were 

 finally expelled from the cell and engulfed by phagocytes. The 

 fat-cells persisted after this expurgation of nuclear material to 

 form the imaginal fat-body. 



Hollande, '14 (Vanessa), conducted a chemical investigation 

 of the contents, especially of the albuminoid reserve globules, of 

 the fat-cells. He found that the globules in this form developed 

 as in other larvae from granules formed close about the nucleus ; 

 that granules of sodium urate were also formed here, and he 

 concluded that the process represented an expulsion from the 

 nucleus, and consequent digestion, of nucleic acid containing 

 material, from which sodium urate was split off almost imme- 

 diately by enzyme action as waste material. This was demon- 

 strated to be formed endogenously, not acquired from without 

 in the functioning of the fat-body as an excretory organ. The 

 development of the granules from feebly basophile particles to 

 globules with acidophile margins, and finally to hj^peracidophile 

 bodies, apparently by attack of enzymes, was checked by micro- 

 chemical tests which showed a transformation from nucleo- 

 proteids to albuminoids, and finally to biurette polypeptids and 

 crystalloids. The possibiUty is considered that part of the fat is 

 transferred to albuminoid (the reverse of the process reported by 

 Weinland ('08) of transformation of albuminoid to fat by fly 

 larvae), but no evidence was offered for such a process. Crystal- 

 loids were observed in the center of fat-globules. 



