THE ORGANIC CELL 
49 
which still carry in their bodies a supply of the germ plasm. 
The generations or buds attached along this continuous chain 
are mortal ; the germ plasm itself, however, only ends when the 
individual containing it dies without issue. We must therefore 
look upon the body as a new formation which soon ceases to 
live, but which passes on to its offspring a portion of the 
original germ plasm ; the germ plasm itself having existed far 
back through the ages that have been to the very commence- 
ment of all life. 
As we have already seen, during the maturation of the germ- 
cells half of the chromosomes or germ plasms will be removed, 
and the next generation will receive a fresh mixture. It is 
therefore evident that the chromosomes of any single individual 
contain germ plasms descended from various ancestors. In 
fact, the chromosomes must be looked upon as containing a 
mosaic of ancestral germ plasms. Different individuals will 
contain different mixtures, and this explains Weismann’s 
hypothesis of the origin of variations. Varying combinations 
of ancestral plasms will bring about differences in individuals, 
new combinations will occur in every fertilised ovum, and as a 
result there must be variations between individuals. 
Any influence which acted directly as a stimulus on the germ 
plasm may so modify it that the effects of this stimulation may 
be transmitted. The chromosome is a battlefield in which the 
units of the germ plasm are carrying on a desperate struggle 
among themselves for nourishment ; some will acquire more 
nourishment than others, and should this line of increase be 
carried on in the chromosomes of successive generations, 
certain characters (corresponding to the glutted units) would 
become accentuated, while others (corresponding to the attenu- 
ated ones) would diminish. These variations, arising as they 
do in the germ plasm, will of necessity be inherited, and will 
differ in the most radical manner from any changes brought 
about in the body during life as a result of environment ; these 
latter changes coming from without cannot reach or affect the 
germ-cells, and therefore cannot be transmitted. 
‘ The distinction between these characters of an organism 
which it acquires by use or disuse during its life, or which are 
impressed upon it by its environment, and those characters, 
Vol. V.— No. 9. E 
