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When the Doctor returned to London he performed a 
number of experiments under similar conditions^ and in every 
case with similar results. 
When speaking of these experiments^ and supposing they 
had been investigated by a careful observer, he says, Such 
faithful scrutiny fully carried out would infallibly lead him to 
the conclusion that, as in all other cases, so in this, the 
evidence in favour of spontaneous generation crumbles in the 
grasp of the competent inquirer .’’^ — Fragments of Science, 
vol. ii., p. 319. 1879. 
So much, then, for the hypothesis and the experiment. We 
go a step further, and assert that it is contrary to the analogy 
of nature to suppose that spontaneous generation did ever 
take place. Let us test the question by geology. It is gene- 
rally admitted that the formation of the various strata of 
rocks which form the earth^s crust was due to precisely the 
same physical forces that now exist. If spontaneous genera- 
tion did once take place, it must have been at a time when the 
physical forces of nature were at work which resulted in the 
formation of our rocks and earths. Now, as the same forces 
are in operation at the present day as were in past ages, what 
they were able to accomplish then they are able to accomplish 
now. If mere physical forces were able to produce life twenty 
thousand or twenty millions of years ago, they are equally 
able to produce life at the present time. But there is, as we 
have shown, no well-authenticated instance of spontaneous 
generation at the present time, although the physical forces of 
nature remain the same as at the period when it is assumed 
they did produce life. We must, therefore, insist that if spon- 
taneous generation does not occur at the present day we have 
a right to assume that it never did. 
Now, as all the conclusions of Professor Haeckel are drawn 
from the assumption that at some time in the unknown past 
life was introduced on our globe by spontaneous generation, 
which has never been established as occurring, and which, on 
the parity of reason, we have a right to conclude never did 
occur, we hold that the doctrine of evolution is unscientific, 
being grounded on a mere hypothesis unsupported by proof. 
Science is truth — truth ascertained by observation. But the 
origin of life by spontaneous generation, and the origin of 
species — species we say, not varieties — are not ascertained 
facts, but are mere assumptions. The conclusions which are 
drawn from these assumptions are the fruit of mere scientific 
imagination, and we are bold enough to say that imagination 
has no authority in such a question as this. As life is every- 
