PREFACE vii 

with views opposed to mine. There is, however, 
in reality no such irreconcilability between my views 
and modern bacteriological work. My views, in fact, 
serve merely to give a broader outlook to ztio- 
logical and sanitary problems. 
This being the state of things, it may well be 
imagined that if I had not been imbued with the 
strongest feeling of the truth, in the main, of the 
views which | had previously published concerning 
Heterogenesis, I should never again have taken up 
this very unpopular subject and have worked hard at 
it for five years, till I had completed in 1903 my larger 
work entitled ‘Studies in Heterogenesis.” During 
these years the subject was worked at, partly over 
new and partly over old ground, and this time with 
the aid of photomicrographs rather than with 
drawings, so as to avoid the bias more or less 
inseparable therefrom. 
During the past year, in my leisure time, I 
have again been at work on the subject of Arche- 
biosis, and have, I trust, done something at last 
which will carry conviction to very many as to the 
reality of the present de zovo origin of living matter. 
The penultimate chapters of this book will show that 
in my new attempt to solve this old and fascinating 
problem, the experiments have in some respects been 
conducted in a new way, though by methods as 
notable for their simplicity as for their stringency in 
reference to all possible precautions. 
LONDON 
January 1907 
