288 THE EVOLUTION OF LIFE 

ing mass of such organisms in the substance of the 
still intact spine. 
How, again, are we to explain these appearances? 
The spine has a chitinous envelope which could not 
easily be penetrated by active full-grown organisms, 
much less by motionless germs, even if these existed 
in the distilled water. Thus infection from without is 
here again scarcely to be thought of. We see motion- 
less specks appear and slowly develop into motion- 
less Bacillii To assume the pre-existence in the 
protoplasm of the spine of multitudes of ultra- 
microscopic germs, for no other purpose than to 
stave off a belief in the de zovo origin of Bacteria, is 
surely neither scientific nor permissible. And yet 
my critics hint only at the existence of ‘latent 
germs,’ without attempting to offer any evidence 
of their existence, or of any previous belief in this 
direction. Truth-seekers are thus left with a simple 
choice: either (a) a belief in the existence of latent 
germs independently of all evidence; or (6) a belief in 
the de xovo origin of Bacteria on very cogent evidence. 
In my work, “The Nature and Origin of Living 
Matter,” Chapter ix., other instances of this de ovo 
origin of Bacteria by heterogenesis are cited, and 
in all such cases what can be seen is this—particles 
becoming visible in the midst of more or less homo- 
geneous protoplasm, such particles being rnvariably 
motionless, but followed soon by their development 
into definite Bacteria or their allies, recognisable as 
such by their shapes and modes of collocation. 
There is, therefore, in all such cases an appearance 
altogether different from that of adult organisms in 
