230 SECRETS OF ANIMAL LIFE 
the offspring, undergoing in a most puzzling way 
differentiation into nerve and muscle, blood and 
bone, a residue is kept intact and unspecialized to 
form the primordium of the reproductive organs of 
the offspring, whence will be launched in due time 
another similar vessel on the adventurous voyage 
of life. So it comes to be that the parent is rather 
the trustee of the germ-plasm than the producer 
of the child. In a new sense the child is a chip 
of the old block. Or, as Bergson puts it in less 
static metaphor, “life is like a current passing 
from germ to germ through the medium of a 
developed organism.” Though it is now clear 
that Weismann exaggerated the contrast and 
apartness of body-cells and germ-cells, the general 
idea of the continuity of the germ-plasm remains 
as one of the most important contributions to post- 
Darwinian biology. It is the explanation of the 
inertia of the main mass of the inheritance, which 
is carried on with little change from generation to 
generation. For men do not gather grapes off 
thorns or figs off thistles. Similar material to 
start with; similar conditions in which to develop; 
therefore like begets like. 
While the epoch-making experimental work of 
Mendel, which would have so much delighted 
Darwin’s heart, lay buried in the records of the 
naturalists’ society at Briinn, there was developed 
in Britain a statistical study of inheritance, especi- 
ally associated with Sir Francis Galton and Profes- 
sor Karl Pearson. It was Galton who began to study 
