Nucleus 
THE ORGANIC CELL 
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epithelia, or of a solid mass as in the head of the spermatozoon, 
and between these two every possible variation exists. 
In the stages before cell-division the chromatin network 
breaks up into a definite number of rod-like bodies called 
chromosomes, and these split longitudinally into exact halves 
as the cell divides. The chromosomes originate as collections 
of rounded bodies called chromomeres, which are identical 
with Weismann’s ids. 
Attraction- sphere, enclosing 
Diagram of a cell. The basis consists of a network containing minute 
granules (microsomes) and traversing a transparent ground -substance. 
The Centrosome 
A very minute single body or pair of bodies, surrounded by 
a rounded mass called the attraction-sphere, is usually situated 
near the nucleus ; it may, however, lie inside the nucleus. 
Two great authorities, Van Beneden and Th. Boveri, regard 
the centrosome as a persistent cell-organ, which is handed on 
from one generation to another by division. It has been looked 
upon as the active organ of cell- division ; in fact, as the ‘dynamic 
centre ’ of the cell. Boveri looked upon the centrosome as the 
active fertilizing element in the spermatozoon, which gave to 
the egg its power of division. This fascinating hypothesis 
of Van Beneden and Boveri doubtless has some truth in it, 
