182 THE DESTRUCTIVE INFLUENCE OF 
genesis and Archebiosis. With regard to Hetero- 
genesis, this is merely the opposite of Homogenesis ; 
and the latter is the name for that mode of gene- 
ration or reproduction amongst living things which 
is looked upon with most respect and which is most 
generally known. It is the process by which “like 
produces like ”—that is, where the offspring grow into 
beings similar to their parents. In Heterogenesis, 
on the other hand, we have the birth of dissimilar 
products, the beginning of a new branch from a 
“‘life-tree,” in which the offspring have no tendency 
to assume the parental type. This occurs, for 
instance, where the protoplasmic matter of an animal 
or of a vegetal cell becomes modified and resolved 
into Bacteria. Here we have to do with the mere 
transformation of living matter. It is therefore a 
truism to say that it can only take place where 
living matter pre-exists. And seeing that many 
investigators, amongst whom I may especially 
mention, Needham,* Pouchet, and Trécul, have, both 
now and formerly, understood by the phrase ‘ spon- 
taneous generation, merely such a process of meta- 
morphosis of living matter as is implied by the 
term Heterogenesis, it is, to say the least, very mis- 
leading to assert without qualification that, “the 
absolute proof of spontaneous generation must come 
* See ‘‘ The Beginnings of Life,” vol. i., pp. 246-252, and vol. ii., p. 181. 
