HISTOLYSIS OF FAT-BODY OF APIS 589 



give evidence of the membrane after the nuclear membrane m 

 their interstices had become pervious to the basophile granules. 

 But microscopically this condition cannot be demonstrated, 

 except by inference from the presence of granules immediately 

 outside the layer of fat-vacuoles. 



Conditions in the metabolic activity of the cell may be pictured, 

 e.g., cutting off of the nutrient supply to the cell with cessation 

 of larval nutrition, or possibly some regulatory mechanism in 

 the cell itself, which would at this specific stage of development 

 cause the constituents of nucleus and cytoplasm to approach 

 such a degree of acidity, say, as would cause them to approach 

 each other in fluidity. A membrane formed due to their previous 

 difference in consistency would then be destroyed, and the two 

 colloids might diffuse in the region of this surface.-^ The same 

 force which in the intact condition of the nuclear wall prevents 

 the nuclear granules from fusing or agglutinating — apparently 

 some repellent force, such as like electrical charge — would upon 

 equalization of the physical conditions within and without the 

 nucleus cause a dispersal of the granules throughout the cell. 

 This dispersal would go only so far as to render the granules 

 equally numerous per volume within and without the nuclear 

 area; that is, not all the granules would pass into the cytoplasm, 

 but the process would cease when the granules were about equally 

 dispersed throughout the cell. It is worth noting that 

 this is approximately the case; moreover, that the granules tend 

 to remain for a time within the more central densely staining 

 cytoplasm — although the immediate change in the character 

 of the granules as they leave the nuclear area and commence 

 to absorb cytoplasmic substances renders precarious too strict 

 an interpretation of the appearances. 



d. Variations from type. The above description of the fat- 

 body-cell development is based upon a study of, and applies most 

 accurately to, the cells of the abdominal region of the worker 



may be thought of as taking place between nucleus and cytoplasm. In the case 

 of the fat vacuoles this explanation does not call for a destruction of their surface 

 membranes, for the fat does not become more soluble in the cell protoplasm than 

 it was before. A condensation of material at the surface of the fat-vacuole might 

 account for its heavj- staining capacity. 



