protoplasm ANt> the cell. Gen. Sub. 48 
with the microsome. The cell-plate consists of equatorial microsomes. 
When equatorial microsomes fuse the result is the zwischenkorper ; 
Watase (529). 
Origin of the Centrosomata : The contrast between centrosome and 
nucleus has been exaggerated. In spermatocyte of Ascaris megalocephala, 
var. univalens, it is clear that the centrosome belongs to the nucleus. The 
chromatin elements are the bearers of hereditary qualities, the centro- 
some is an organ of division. The whole of the spindle seems to be 
nuclear ; Brauer (59). 
Centrosome and Yolk-nucleus : Yolk-nucleus (studied in spiders) is 
homologous with the centrosome, or Nebenkern, of seminal cells, and 
the centrosome of somatic cells. It has a nuclear origin, and an influence 
on the cytoplasm like that of the centrosome. It may occasionally be 
double. In spiders this “ female centrosome ” is degenerate, and without 
physiological significance ; it is a “ phylogenetic reminiscence Balbiani 
(15). 
Centrosomata : attraction spheres, achromatin figures, zwischenkOrper- 
chen, in pathological states ; Lustig & Galeotti (325). — Behaviour of 
chromatin, centrosomata, &c., in carcinoma; Galeotti (176). 
Nucleoli : The accessory nucleoli, as seen in germinal vesicles of many 
Vertebrates, are said to contain the products of metabolism in the chro- 
matin. The single chief nucleolus, as seen, e.g ., iu Echinoderm ova, is a 
“ rhythmically pulsating organ of excretory and probably also of secretory 
or secretion-storing import ” ; ILecker (210, 211). 
“Nucleoli,” so-called ; Rhumbler (420). 
Micro-nucleus (?) in Amceba ; Moore (360). 
Import of paranucleus ; Eismond (145). 
d. Cell Division. 
Present state of knowledge in regard to nuclear and cell-division. 
Astrosphere proposed as term for attraction spheres. Probability that 
nuclear segments move actively, under chemotactic influence from centro- 
spheres. Spindle-fibres in plants not nuclear, but cytoplasmic, formed of 
“kinoplasm”; Strasburger (493). 
Cell-multiplication and cell-replacement : On the one hand there is 
cell-multiplication by mitosis with growth as its result; on the other hand 
there is cell-replacement by amitosis, with repair as its result ; Frenzel 
(170). 
Cell-division : Selachii ; Mitrophanow (351). 
The form of the protoplasmic masses within the cell has a directive 
influence on the nuclear spindle, and differentiation of cytoplasm is also 
dependent on nucleus ; Roux (437). 
Division of nucleoli ; Eismond (145). 
In early stages of the dace the blastoderm-cells show no individual- 
ised chromatin, the karyokinetic figures are entirely of achromatin. This 
