14 J. BRONTE GATENBY 



oocyto ; it will be noted that there are now enormous numbers 

 of granules formed, and the majority of these are nucleolar 

 deutoplasm derived from the original nucleolus of the oogonium. 



(b) The Mitochondria. 



In the young oogonia I did not find it possible to demonstrate 

 mitochondria, but in all the oocytes just at or after the last 

 stages of the prophases of the heterotypic division, mitochondria 

 are easily identified, especially after proper staining in iron 

 alum haematoxylin. In PI. 8, fig. 22, are two oocytes showing 

 the fine grey-staining bodies which I have identified as mito- 

 chondria. These show more clearly in PI. 3, figs. 24 and 25 : 

 the mitochondria do not appear to have anything to do with 

 the nucleolus. 



(c) The Golgi Apparatus. 



The Golgi apparatus (Golgi body or element) was studied by 

 the Cajal, the Da Fano, and the Mann-Kopsch techniques ; 

 of these the Mann-Kopsch technique was the most suitable. 

 In young oocytes the Golgi apparatus consists of an excentric 

 juxta-nuclear mass, as at ga in PI. 3, fig. 20. This mass really 

 hes around an archoplasm, as in PI. 3, fig. 24, at ar. In PI. 4, 

 fig. 33, is an oocyte showing the Golgi apparatus on the right 

 of the nucleus. Now in the youngest oogonia the Golgi body 

 is isolated at one side of the cell, but quite early in the history 

 of the progerminative oogonium it grows rapidly and begins 

 to fragment ; the additional pieces so derived move out into 

 the other regions of the cytoplasm, as has already happened in 

 all the three cells drawn in fig. 20 of PI. 8. In fig. 88 on the 

 same plate (though the oocyte is drawn much older in so far 

 as the extrusion of nucleolar deutoplasm is concerned) the 

 Golgi body is still fairly isolated, being just in process of 

 fragmentation. In some cases, as pieces break off from the 

 original body, they pass away into the free parts of the cyto- 

 plasm and form remarkable nests or areas of proliferation, 

 as in the cell in PI. 4, fig. 28, at ga. While in certain cases 

 the fragments of Golgi body scarcely retain their semi-lunar 



