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204 EVOLUTION IN BIOLOGY v1 
from the female parent ; and that, regarded as a 
mass of molecules, the entire organism may be com- 
pared to a web of which the warp is derived from the 
female and the woof from the male. And each of 
these may constitute one individuality, in the same 
sense as the whole organism is one individual, al- 
though the matter of the organism has been con- 
stantly changing. The primitive male and female 
molecules may play the part of Buffon’s “moules 
organiques,’ and mould the assimilated nutriment, 
each according to its own type, into innumerable 
new molecules. From this point of view the process, 
which, in its superficial aspect, is epigenesis, appears 
in essence, to be evolution, in the modified sense 
adopted in Bonnet’s later writings; and develop- 
ment is merely the expansion of a potential organ- 
ism or “ original preformation” according to fixed 
laws. 
Il. Lhe Evolution of the Sum of Living Bewngs. 
The notion that all the kinds of animals and 
plants may have come into existence by the growth 
and modification of primordial germs is as old as 
speculative thought; but the modern scientific 
form of the doctrine can be traced historically to 
the influence of several converging lines of philo-— 
sophical speculation and of physical observation, — 
none of which go farther back than the seven-— 
teenth century. These are :— 
