270 Influence of environment on animals 
succeeded in this, but the writer wishes to apologise to these authors 
for his inability to convince himself of the validity of their claims 
at the present moment. He thinks that only continued breeding 
of these apparent mutants through several generations can afford 
convincing evidence that we are here dealing with mutants rather 
than with merely pathological variations. 
What was said in regard to the production of new species by 
physico-chemical means may be repeated with still more justification 
in regard to the second problem of transformation, namely the 
making of living from inanimate matter. The purely morphological 
imitations of bacteria or cells which physicists have now and then 
proclaimed as artificially produced living beings; or the plays on 
words by which, eg. the regeneration of broken crystals and the 
regeneration of lost limbs by a crustacean were declared identical, 
will not appeal to the biologist. We know that growth and develop- 
ment in animals and plants are determined by definite although 
complicated series of catenary chemical reactions, which result in 
the synthesis of a definite compound or group of compounds, namely, 
nucleins. 
The nucleins have the peculiarity of acting as ferments or 
enzymes for their own synthesis. Thus a given type of nucleus will 
continue to synthesise other nuclein of its own kind. This determines 
the continuity of a species; since each species has, probably, its own 
specific nuclein or nuclear material. But it also shows us that 
whoever claims to have succeeded in making living matter from 
inanimate will have to prove that he has succeeded in producing 
nuclein material which acts as a ferment for its own synthesis and 
thus reproduces itself. Nobody has thus far succeeded in this, 
) although nothing warrants us in taking it for granted that this task 
' is beyond the power of science. 
