THE ORGANIC CELL 
87 
trated that if Stentor be violently shaken it breaks up into 
fragments of every possible size, and that a portion as small as 
1-27 th of the original animal, provided it contained the nucleus 
underwent complete regeneration. All the portions without 
nuclear material die. 
Verworn has shown that in the foraminifer Polystomella 
nucleated portions possess the power of repairing the shell ; 
portions without nuclear material cannot do this. It has 
been shown that non-nucleated fragments of Amoeba may 
live as long as fourteen days. The movements gradually 
cease, the function of digestion is arrested, and it is in- 
capable of secreting the slime by which it adheres to the 
substratum. 
Verworn has further shown that both in infusoria and 
rhizopods non-nucleated portions live for a considerable 
length of time, perform normal movements, respond to various 
stimuli, and are also able to take up food material. They 
have lost, however, the power of digestion and secretion, and 
therefore must of a necessity die prematurely. In connection 
with this exceedingly interesting subject students of physiology 
will at once recall to mind the Wallerian law of degeneration. 
Waller’s law may be included in the statement that ‘ a nerve 
degenerates when removed from its trophic centre.’ The 
motor nerves, whose function it is to carry impulses to the 
muscles of the body, arise from large branched cells situated 
in the grey surface matter of two adjacent and parallel con- 
volutions of the brain, and passing along a well-defined course 
enter the spinal cord, down which they travel, leaving it at 
different levels according to their final destination. It is 
important to note, however, that before emerging from the 
cord (it matters not at what level) they communicate with 
another set of branched nerve-cells situated in the anterior or 
frontal aspect of the cord, and known as the anterior vesicular 
column. Having established this communication they proceed 
to their final termination, viz. the voluntary muscles of the body 
and limbs. 
Should a number of the cells on the cortex cerebri, from 
which these nerves arise, be damaged, those nerve fibres coming 
from the affected cells will degenerate downwards as far as 
