HISTOLYSIS OF FAT-BODY OF APIS 583 



ends of this elongated nuclear area, appear dark staining granules 

 identical in size and shape, at first at least, with the nuclear 

 granules^ and exhibiting certain of the staining reactions of these. 

 An interpretation may here be anticipated; that these bodies 

 are identical with the larger chromatic or basophile granules of 

 the nucleus ; that they leave the nucleus and invade the cytoplasm 

 when the nuclear wall disintegrates, or becomes permeable to 

 them; that their subsequent activity may be in part at least an 

 enzymatic one, and is certainly concerned with the further me- 

 tabolism of the stored fat of the cell. 



The detailed anatomy of this stage merits closer scrutiny 

 (pi. 1, figs. 5, 6, 7). Several facts are apparent. First, vacuoles 

 from the peripheral ring may be traced passing in toward the 

 nucleus, through the densely staining cytoplasm surrounding it; 

 and the appearance of basophile granules in the cytoplasm coin- 

 cides with the disappearance of the distinct outline of the nuclear 

 vesicle — may, in fact, shortly precede the indentation of the 

 nucleus by fat-vacuoles. This picture is so constant and so 

 characteristic of whole sections, when it occurs at all, that it 

 evidently signalizes an important crisis of the metabolic activity 

 of the larva itfeelf. The series of changes follows the cessation 

 of feeding, and precedes the transformation of larva to pupa, 

 so immediately, that their interpretation must be correlated with 

 the process of metamorphosis as a whole. If other forms which 

 have been worked upon exhibit the same phenomena, the failure 

 of the workers handling them to demonstrate this change may be 

 accounted for by the abruptness and rapidity with which the 

 cell is transformed from one relatively permanent state to another. 



The first sign of the transformation is the diffusion of the nu- 

 clear wall and the elongation of the nucleus in the long axis of 

 the oval. The line of demarcation between nucleus and cyto- 

 plasm does not at once vanish, but gradually blurs, as if the 

 substance of the membrane were partially dissolved by the 

 material on either side of it, or as if a membrane, formed by sur- 

 face tension between two non-soluble substances were obliterated 

 by their becoming soluble. This blurring is most pronounced 

 at the ends of the nucleus, and here a little later the transition 



