264 
Negri bodies 
is produced. The neuroglial cells do not exhibit the true nucleolus, 
but numerous chromatin nucleoli are seen. These false nucleoli are of 
a different type and are generally known as “ Netz-Knoteu,” chromatin 
nucleoli or karyosomes. They are condensed portions of the chromatin 
network and exhibit all the characters of chromatin. They are generally 
multiple, irregular in shape, and can hardly be distinguished except by 
size from the nodes of the chromatin network. The exact relationship 
between these two forms—true and false nucleoli—is as yet far from 
being certain, owing to the fact that variations occur in the staining 
reactions of the true nucleolus so as to render it not improbable that 
intermediary forms may exist which may represent an actual ti’ansition 
of one to the other (Wilson 1906). 
In contrast to the nucleolus of the normal ganglion cell, the germinal 
spot (or true nucleolus) of the ovum is generally of a very large size 
{e.g. in Echinoderm eggs). It appears as a large single spherical body. 
As a rule the single nucleolus gives rise to several nucleoli with the 
growth of the ovum. In the ovum of amphibians and reptiles they may 
be counted by hundreds. Fleming (1882) has described two types of 
general nucleoli in the ovum (a) the principal nucleolus and, (h) the 
accessory nucleoli. These differ widely in staining reaction, and it is 
still sub judice whether they represent the plasmosomes or karyosomes 
of tissue cells. The principal nucleolus stains deeply like chromatin 
and yet differ.s widely from the chromatin network and does not play 
any part in the contribution to the formation of the chromosomes. It 
is vacuolated and sometimes assumes the form of a hollow v^esicle. The 
accessory nucleoli on the other hand are generally coloured by plasma 
stains and thus resemble the plasmosomes of the cytoplasm : they are 
generally multiple and appear to arise during the growth of the ovum. 
As a rule no visible relationship is evident between these two kinds of 
nucleoli, but in annelids they are closely united to form a compound 
body. During the early pro-phase and meta-phase of mitosis, the 
principal nucleolus may be cast out bodily from the dividing nucleus, 
e.g. in the parasitic annelid Myzostoma. In the copepod (Heterocope) 
during the mitosis of its ovum, the principal nucleolus degenerates as 
soon as the germinal vesicular membrane has disaj^peared. Montgomery 
(1898) in his study of the subcutaneous glands of Piscicola, found that 
their cell-nuclei at first contained a single nucleolus. During growth 
of the cell the nucleolus undergoes fragmentation and gives rise to about 
300 nucleoli one of which remains behind and the remainder migrate 
into the cytoplasm. Chubb (1906), in his paper on the growth of the 
