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Wm. S. Marshall, 



bodies (nucleoli), an irregulär reticulum, in the Strands of which are 

 fonnd a number of small, slightly staining bodies (chromatin granules). 

 At first tbese nuclear-like bodies lie in a Single layer around the 

 nucleus but, as their number increases, this layer changes to an 

 irregulär mass. In older oöcytes one notices (Fig. 57, position 68, 

 that some of these bodies leave the mass and wander to other parts 

 of the oöcyte where they always take a peripheral position. Bloch- 

 MANN (3) and Stühlmann (27) have studied these bodies more thoroughly 

 than any one eise but, as I have already given the views of each 

 one and what they found, in the historical part, there is no use of 

 repeating them here. In the two oldest oöcytes we notice that the 

 nucleus has changed greatly, the regulär beaded threads which cau 

 be found any place between Syn. and position 61 in figure 57, have 

 disappeared, the entire nucleus being filled with a fine irregulär, 

 net-like reticulum in which lie a number of small, lightly staining 

 bodies. Gathered near the center of the nucleus, are a few irregulär 

 achromatin masses in which lie imbedded the chromatin granules we 

 earlier saw in the threads; these stain darker and are much more 

 distinct than those in the reticulum (Figs. 67 and 68). In the oldest 

 oöcyte we find that the nucleus is of about the same size as that of 

 the next youngest one, but, in proportion to the size of the oöcyte. 

 it is very much smaller. The oöcyte has increased in size but not 

 the nucleus. In these oldest stages, we notice for the first time since 

 the very early ones, that a nucleolus is present, it is generally round, 

 but may be irregulär; it contains a number of vacuoles (Fig. 681 

 We have already noted the fact that in Polistes, when the 

 epithelial celis arrange themselves as a follicular layer around the 

 oöcyte, there is left a passage way between it and its accompaning 

 nurse-cells. In this stage the oldest oöcyte shows that towards this 

 opening it has sent out a process (Fig. 57). This, which has been 

 observed in many other insects, is found more often in older ovaries 

 where there are more oöcytes of this and later stages, and we shall 

 refer to it again. 



Ovary J. The ovary which we next study, if viewed externally, 

 does not appear much older than the last; we find however that it is, 

 and that, a much greater number of Chambers being formed, we cau 

 more easily follow the changes which take place in the oöcyte nuclei. 

 The tubules as a whole deserve but little attention, the Chamber 

 formation is externally much more marked and the oviduct further 



