204 



Wm. S. Marshall, 



directly around the nucleus and vacuoles appear in any part (Fig. 87). 

 The nuclear structure lias changed but little, the achromatin is more 

 irregulär and less net-like, the nucleoli are still present but more 

 broken up. 



In older stages one can see that there is a gradual absorption 

 of the Contents of the nurse Chambers and that those cells lying 

 nearest the oöcyte are the first to go. In younger nurse Chambers 

 the cells lying nearest the oöcyte are the largest, but now we notice 

 that, in this region, they become much smaller, due to their partial 

 absorption into the oöcyte. The cells in the other part of the Chamber 

 have nearly all lost their boundaries, and the cytoplasm of most ot 

 them lies entirely distal to the nucleus, giving the appearance as if 

 they were passing down towards the oöcyte to be absorbed (Fig. 88). 

 When the more proximal nurse-cells have disappeared and, although 

 all the remaining cells are broken up, the structure of the nuclei is 

 but little changed. A mass of many small and a few large bodies, 

 nucleoli, are scattered through it, of these, the large ones especially, 

 stain darkly (Fig. 89). This is all opposed to the view of Paulcke (25) 

 and Gross (10) who hold that the nurse cells pass into the oöcyte, 

 swaliowed as it were. Such I have not found to be the case. 



The nurse Chamber grows smaller and smaller as its cells dis- 

 appear, and, by the growth of the oöcytes, they are pushed to one 

 side, so that two neighboring egg Chambers lie with their ends nearly 

 touching. The nurse cell boundaries disappear and the cytoplasm also 

 goes; just before the Chamber is finally emptied we find in it some 

 epithelial cells, two or three nurse-cell nuclei, and a small amount 

 of cytoplasm (Fig. 90). 



We would record an irregularity in the finding of two nurse 

 Chambers without any egg Chamber between them (Fig. 91). Whether 

 or not there ever was an oöcyte in the Chamber, we do not know, 

 but most probably it died and disappeared and its Chamber was 

 crushed between those of the nurse cells. 



We have seen how the oöcytes, after their Chambers are formed, 

 change their shape, becoming elongated and lying with their long axis 

 parallel to that of the tubule (Fig. 57); the large spherical nucleus looses 

 its regulär shape and a nucleolus appears in it, the beaded threads 

 become broken up (Figs. 75, 76 and 77), and one or more irregulär 

 masses appear which contain darkly staining chromatin granules, 

 achromatin Strands are present in which are lightly staining granules. 

 We have also seen how around the oöcyte nucleus a number of 



