64 EVOLUTION AND THE 
and present more consistency with observed facts 
than that which it seeks to supersede? if so, the 
philosopher will adopt it, and the world will follow 
the philosopher—after many days.” 
But if, even when looked at merely as hypotheses, 
that of Archebiosis with Heterogenesis seems so 
likely to drive the old doctrine out of the field, we 
instinctively look around us for one of those “crucial 
instances” which may serve, as has been so often 
the case in the history of science, finally to decide 
between the contending claims of old and new views. 
Now a crucial instance of this kind (or oppor- 
tunity of employing the all-decisive experimental 
“Method of Difference”), does very fortunately lie 
within our reach, and has already been referred to, 
Its true value, however, may be now more clearly 
seized by the reader; so that for this reason, and 
because all past discussions on the question of the 
Origin of Life have shown that this is the part of the 
subject whose scientific basis is least understood or 
most persistently disregarded, I venture, even though 
with some slight reiteration to make a few con- 
cluding remarks on this crucial test—whose decision 
the opponents of Archebiosis attempt to set aside by 
a mixture of what appears to me to be, illogical 
arguments and groundless assumptions, 
