1876.] Spontaneous Generation. 421 
teria only develop in sterilized infusions when the air around 
them is laden with motes of incalculable multitude and exquisite 
minuteness. Given the presence of these, and the development 
of bacteria is inevitable. The inference is that the motes are 
germs. The above experiments show, that in closely allied 
septic organisms, the germs of which have been demonstrated 
and their developments watched, if the dry débris of a mace- 
tation in which these forms are found be scattered in the air 
around a prepared fluid, and demonstrated by similar optical 
means, that the said organisms develop; but if the minute dust 
from the débris be optically proved to be absent, none of the 
monad forms appear. Here we do not hypothecate a germ, but 
we know that it exists ; and its deportment in similar conditions 
ìs identical with that of the assumed bacterial germ. Do we 
need more irresistible evidence that the bacteria develop, not de 
novo, but from genetic products ? 
Now, until Dr. Bastian’s promised “ new results”! have ap- 
peared, I believe I am justified in affirming that the strongest 
cases on which even he relies for “ spontaneous generation ” are 
recorded on pages 175, 180, of his Evolution and the Origin of 
Life. They are thus introduced: “ After this I may, perhaps, 
be deemed fully justified in quoting two very typical experiments 
for the further consideration of those who stave off the belief in 
Spontaneous generation — either by relying on the insufficient 
reasons for doubting the influence of boiling water, or because of 
their following Pasteur, Cohn, and others in supposing that cer- 
m peculiar bacteria germs are not killed except by a brief 
“Xposure to a heat of 227° or 230° F. For even if we could 
stant them these limits, of what avail would the concession be 
"+++ in the face of the following experiments?” The details 
of the €xperiments follow. They are alike in method, and we 
will concern ourselves only with the second. A strong infusion 
oL common cress, with a few of the leaves and stalks of the 
Plants, were inclosed in a flask, which was hermetically sealed 
While the fluid within was boiling. It was then introduced into 
à digester and gradually heated, and afterwards kept at a tem- 
Perature of 270-275° F. for twenty minutes, and was retained 
Sa temperature, if the time of heating and cooling be consid- 
“G 230° F, for one hour. This flask was opened after 
? Weeks, The reaction was acid; the odor was not striking. 
a microscopical examination with a yy inch objective “there 
es Peared more than a dozen very active monads.” 
1 Times, January 29, 1876. 
