l82 



H. L. WIEMAN. 



and pass back from the proximal end of the egg (which represents 

 the anterior end of the future embryo) to the nurse cells. 



When the egg is at the stage of development shown at e, the 

 food material passes in a broad stream toward the nucleus beyond 

 which it extends for a short distance. A little later (Fig. 2) the 



form of the nutritive stream 

 changes so that now it encloses 

 a central area of newly formed 

 yolk. The nucleus has shifted 

 its position to the distal (pos- 

 terior) end of the &^%, where it 

 appears as a rounded body 

 composed of an acid staining 

 ground substance in which a 

 number of basic staining nu- 

 cleoli are embedded. 



When a portion of the cy- 

 toplasm containing the food 

 stream is examined at a high 

 magnification, granules of dif- 

 ferent sizes are seen distrib- 

 uted on an irregular reticulum 

 (I^ig- 3)- T^^ granules at 

 their point of entrance into 

 the ^^% as well as those found 

 in the cytoplasm of the nurse 

 cells are of a uniformly small 

 size ; while inside of the &^'g 

 they are of various sizes, due 

 either to coalescence of the 



T? T •. J- 1 .• f v. If small gfranules or to an actual 



Fig. 2. Longitudinal section of a half-ma- ^^^■"•^^ &'" 



tureovocyte. ,?.^., egg string ;/., egg follicle, growth of individual granules, 

 formed by the cells of the ovariole stalk ; i., Jhgse granules now pasS 

 Keimhaut; «., nucleus; ?z.^., nutritive stream. , , . , . , 



through an mterestmg cycle 



of stages. When they have attained their full size they stand 

 out from the reticulum and project into the interreticular spaces 

 (Fig. 4, a). They now divide (Fig. 4, b). This division is very 

 exact and divides each spherule into two bean-shaped halves. 



I 



