EARLY DEVELOPMENT OF GRANTIA COMPRESSA. 289 



prolonged osmication ; the collar-cell is often drawn out into two regions, an 

 outer "neck" and an inner "base," containing all the granules and the 

 nucleus (PI. 19. fig. 4) ; the Golgi apparatus and centrosome generally lie 

 in the " neck,"'' other granules in the " base." 



4. Collar-cells contain three cell-elements other than the nucleus: the 

 Golgi apparatus (and centrosome), the mitochondria, and metaplasmic store- 

 granules. 



5. The mitochondria are irregular, but fine, and lie around the nucleus 

 (PL 19. fig. 1, M, fig. 3, M.) 



6. The metaplasmic or yolky store granules are much larger than the 

 mitochondria, but lie in the same region. (PI. 19. tigs. 1 and 4, Y). 



7. The Golgi apparatus lies in the "neck" of the bottle-shaped cell, 

 either upon the nucleus (PL 19. fig. 1, A) or separately (PL 19. fig. 1, B). 



8. In certain definite cases the centrosome is seen to lie inside the Golgi 

 apparatus (PL 19. fig. 1, A) and the flagellum originates from the centrosome. 

 In other cases the centrosome appeared separate (PL 19. fig. 4, C ?). 



Oogenesis. 



1. The young oocyte contains the three cytoplasmic inclusions : yolk 

 granules, Golgi apparatus, and mitochondria (PL 19. figs. 2 and 9). 



2. The oocyte consists of two well-marked regions : a peripheral smooth 

 ectoplasm and an internal froth)- endoplasm, in which all the cytoplasmic 

 granules lie (PL 19. fig. 9). 



3. The Golgi apparatus consists of isolated multiple elements formed of 

 several rods arranged in angular formation, much resembling that of the 

 mollusc oocyte (PL 19. fig. 2, GAO). 



4. The mitochondria are fairly large, often irregular bodies, lying in the 

 endoplasm (PI. 19. fig. 9, M). In the ripe oocyte they are often abnormally 

 large, and are never very numerous. The mitochondria constitute the 

 " chromidia " of Jorgensen and Dendy. In their histocbemieal reactions 

 they differ from chromatin. 



5. Yolk-spheres are very fine and delicate, entirely filling the endoplasm 

 and lying in the trabecule between the endoplasmic vacuoles. The yolk is 

 only properly preserved by Kopsch's method. Yolk-granules are formed 

 in and by the ground-cytoplasm, and have no connection with the mito- 

 chondria "(PL 19. fig. 9 etc., Y). 



6. The egg is amoeboid and ectoplasmic pseudopodia are common (PL 19. 

 fig. 9, EOT). 



7. The full-grown oocyte is oval or elliptical in shape, as is the nucleus, 

 but the granule? and yolk are evenly disposed, and there is no sign of a 

 definite vegetative or animal pole. 



8. No organ-forming areas, or visible aggregations of cytoplasmic materials, 

 was made out. 



