6 Transactions of the Society. 



cells surrounding it appear to dwindle in size, and eventually they 

 disappear from its surface. The mature oocyte is surrounded by a 

 well-marked vitelline membrane. 



In'iea Vitam Examination of the Oocytes. 



When living eggs are examined microscopically two types of 

 cytoplasmic inclusions are distinguishable, large clear bodies, the 

 yolk spheres, and smaller granular ones, the mitochondria. Eggs 

 from animals wliich had been liglitly chloroformed were smeared 

 on slides and treated with various staining reagents. The large 

 yolk bodies, in common with iat compounds, were stained red by 

 alcoholic solutions of scarlet red and Sudan III, but they were not 

 coloured by the other reagents used. The mitochondria were 

 stained a pale green colour by Janus green, and methyl green, and 

 a purple colour by dahlia : the other stains were without effect. 

 A 1 p.c. solution of potassium permanganate, 1 p.c. acetic acid and 

 iodine solution produced no appreciable change; but with 90 p.c. 

 alcohol the yolk spheres underwent a slirinking, so that they 

 appeared somewhat like crenulated blood corpuscles. This was 

 evidently due to something being dissolved out. Most probably 

 this substance is a lecithin-like body, as lecithin is known to be 

 present in the yolk spheres of most animals, and is soluble in 

 alcohol. 



Although Janus green does in some cases stain the Golgi 

 apparatus (6'), it was without effect in the material examined. 



The Golgi Apparatus and its Function in 

 Oogenesis. 



In the youngest oocytes the Golgi apparatus consists of a 

 number of rods or batonettes of a semi-lunar shape arranged 

 around the archoplasm. In Plate I, fig. 2 and fig. 3, are shown 

 cells at this stage. The former is drawn from a preparation by 

 Da Fano's silver impregnation method, and the latter from a 

 Mann-Kopsch preparation. In both of these cells the large 

 nucleoli (plasinosomes) are a distinguishing feature of the nucleus. 

 As the cell grows certain of the Golgi elements begin to spread 

 out away from the archoplasm, but others appear to remain attached 

 to it for a time, and to initiate the process of yolk formation. 

 In fig. 4 is shown a cell with the Golgi batonettes just commencing 

 to disperse. This is drawn from a Mann-Kopsch preparation 

 which has been treated with turpentine to remove the blackened 

 fat. The archoplasm is therefore colourless. In fig. 8, however, 

 which has not been treated with turpentine, the whole of the compact 

 part of the Golgi apparatus appears black, showing that a fatty 

 substance has been already formed at this stage. The batonettes 



