CtAmetogenesis of saccocirrus 16 



spherical condition, in other examples this condition is retained, 

 as in PI. 3, fig. 19, which was a remarkably clear example ; 

 the neighbouring cell in fig. 21 showed this condition less well, 

 while in fig. 33, most of the smaller fragments were of no special 

 shape. In PI. 4, figs. 28 and 29, the Golgi elements form 

 a fine dust at the periphery of the cell. In all the cases, however, 

 the ultimate result is the same — the apparatus breaks up into 

 hundreds of irregular grains, as in PI. 4, fig. 32, at ga. 



If the Saccocirrus is prepared by the Mann-Kopsch method, 

 and the sections mounted in balsam without any previous 

 treatment, the cell-granules of the oocyte appear as in PI. 4, 

 fig. 31 ; here we find a confused mass of granules which have 

 become either blackened or browned to different degrees. 

 But if the sections on the slide be treated for several hours 

 in turpentine all but the Golgi granules become decolourized 

 or a light yellow in colour. In PI. 4, fig. 33, the egg-granules 

 were throughout the colour of those in fig. 31, but the slide 

 was treated in turpentine and the colour extracted from 

 everything except the apparatus, which is here seen to be 

 fragmenting and spreading through the cytoplasm. 



(d) The Formation of Patty Yolk. 



In the egg of Saccocirrus which has been centrifuged, a layer 

 of fatty yolk of an oily type collects on the upper pole of 

 the egg (see Text-fig. 1). The characteristics of this yolk are 

 that it goes greenish or brown only after prolonged osmication 

 and is rapidly destroyed by fixatives containing lipoid solvents. 



Such fatty yolk is quite distinct from both nucleolar deuto- 

 plasm and mitochondria, but it is best shown by Kopsch 

 techniques which demonstrate the Golgi elements so well. 

 In PI. 4, fig. 30, the fatty yolk is shown black and the nucleolar 

 deutoplasm yellowish grey, after prolonged immersion in 

 formol-Flemming. 



From the method and time of appearance of the fatty yolk 

 I believe it is formed from the Golgi bodies, but I admit it 

 is impossible to make a trustworthy statement in such un- 

 favourable material. 



