Protoplasm, cell, oogenesis, etc. Oen. Sub. 49 
Critical review of our knowledge as to the periodic reduction of 
Chromosomes ; Strasburger (522, 523). 
Nature of central spindle : A supporting framework, which not only 
fixes the poles against one another, but by its growth determines their 
distance. It changes with the strain on the fibres at different moments ; 
Druner (131). 
“ Mechanism” of mitosis, &c.; Reinke (444). — Amitosis in Mammals : 
In placental neo-formation in guinea-pig ; Paladino (404). 
Mitoses, pathological ; ELecker (213). 
Contrast of generative and non-generative mitoses ; HaeckeR (213). 
The phenomena of karyokinesis are dominated by the attractive- 
spheres. The chromosomes divide longitudinally by their proper activity, 
but are passively drawn to the poles by the contractility of the achro- 
matin ; Herla (233). — Variations in the mitoses of A scar is megalo- 
caphala ; Herla (233). 
Role of nucleoli in mitosis ; Reinke (444). 
Study of karyokinesis in embryo cat ; Aby (1). 
Cell-division in Noctiluca ; Isiiikawa (257). 
Indirect cell-division in Selachians ; Mitrophanow (363). 
A new type of nuclear multiplication ; Sciiaudinn (490). 
Nuclear division ; Rompel (458). — Nuclear division in relation to 
granula theory ; Metzner (347). 
6. Oogenesis, Spermatogenesis, Maturation, Fertilisation. 
a. The Ovum. 
Oogenesis : in rabbit, a cell in the germinal epithelium divides by 
indirect divisiou, gives rise to two cells, of which the one next the stroma, 
becomes an ovum, is enveloped by epithelial cells and pushed by their 
growth into the stroma. When the stroma and epithelium have not time 
to surround the ovum before new ova are formed, balls of cellsf arise ; in 
these, at a later stage, the epithelial cells are arranged around the ova, 
and the developing follicle is embedded in the stroma ; Buhler (72). 
In Micronereis variegata ; Racovitza (432). 
Peculiar oogenesis, &c., in Ophryotrocha ; Korschelt (282). 
Origin of sex-cells iu Hydractinia , &c.; Bunting (73). 
Development of genital cells in composite Ascidians ; Pizon (421). 
Degeneration of genital products in Polyclinidce ; Caullery (84). 
Degeneration of Graafian follicle ; Henneguy (229). 
Experimental degeneration of frog’s ova ; Mingazzini (353-355). 
History of yolk-nuclei ; Ziegler (589). 
Yolk-nuclei in meroblastic ova. These are elements left behind in the 
development of the embryo, take no part in forming the germinal layers, 
and illustrate nuclear degeneration ; Ziegler (589). 
The term vitelline body has been applied to the attractive-sphere and 
