"216 Caroline McGiij.. . 



the only structures in this material which can be regarded as 

 food-cells. 



Although amitosis may occur in the follicles of the adult, in the 

 larva the follicle-cells multiplj' by mitosis, and mitotic figures occur 

 abundantly. 



b) T h e G e r m - c e 1 1 s. 



When the cells of the end-filament become differentiated into 

 :germ-cells. taking on the character of typical oogonia, the cell- 

 membrane becomes very distinct, the nuclei are very large, the 

 chromatin increases rapidly in amount, the cytoplasm stains more 

 deeply and a delicate linin-reticulum is seen in the nucleus. The 

 chromatin is either in a coarse reticulum (h in Fig. 1 and 39) or 

 in a heavy spireme (« in Fig. 2 and 46). 



As it is in the germinal-area that the formation of the double 

 nucleoli so characteristic of these two forms takes place, it will be 

 necessary to describe this process more in detail. Since in the 

 ■earliest cells of the end-filament studied an oxyphile nucleolus 

 is present, it is impossible to determine the origin of this body 

 from the material at hand, but the formation of the basi- 

 phile portion of the double nucleolus is very easily traced. 

 In the primitive filament-cell the chromatin is arranged in a fine 

 reticulum (Fig. 1 and 39). As the germ-cells begin to difierentiate. 

 the reticulum becomes coarser, and later forms a heavy spireme 

 (Fig. 2, 5, 6 and 41—48). During this time the amount of chromatin 

 in the cell is increasing rapidly, and along wdth the growth of the 

 chromatin a marked increase in the size of the oxyphile nucleolus 

 takes place. Sometimes two or even more of these nucleoli are 

 present (Fig. 43), but they invariably soon fuse to form a single 

 body. The spireme of chromatin now begins to condense around 

 the nucleolus (Fig. 5, 6, 42, 44, 47 and 48 ), until finally there is 

 formed a double nucleolus with an inner oxyphile mass surrounded 

 by a deep homogeneous layer of basiphile substance (Fig. 4—11, 44 

 ■and 49). All the chromatin in the cell, except a very small amount 

 closely adherent to the nuclear wall, is now in the nucleolus. A 

 glance at Fig. 1, 2, 9, 39, 41 and 44 will show how^ similar this 

 process of wrapping up of the chromatin spireme around the nucleolus 

 is to the synapsis stage characteristic of spermatogenesis, and I 

 think, as has alreadj^ been suggested by Guekthek (1904). that the 

 name synapsis should be applied to this stage in oogenesis. 



