rwise, as I said before, the work of social preparation cannot go
on. On this count, then, I claim acquittal, being for the moment on
the side of Virchow.

Besides the duties of the chair, which I have been privileged to
occupy in London for more than a quarter of a century, and which never
involved a word on my part, pro or con, in reference to the theory of
evolution, I have had the honour of addressing audiences in Liverpool,
Belfast, and Birmingham; and in these addresses the theory of
evolution, and the connected doctrine of spontaneous generation, have
been more or less touched upon. Let us now examine whether in my
references I have departed from the views of Virchow or not.

In the Liverpool discourse, after speaking of the theory of evolution
when applied to the primitive condition of matter, as belonging to
'the dim twilight of conjecture,' and affirming that 'the certainty
of experimental enquiry is here shut out,' I sketch the nebular theory
as enunciated by Kant and Laplace, and afterwards proceed thus:
'Accepting some such view of the construction of our system _as
probable_, a desire immediately arises to connect the present life of
our planet with the past. We wish to know something of our remotest
ancestry. On its first detachment from the sun, life, as we
understand it, could not have been present on the earth. How, then,
did it come there? The thing to be encouraged here is a reverent
freedom--a freedom preceded by the hard discipline which checks
licentiousness in speculation--while the thing to be repressed, both
in science and out of it, is dogmatism. And here I am in the hands of
the meeting, willing to end but ready to go on. _I have no right to
intrude upon you unasked the unformed notions which are floating like
clouds, or gathering to more solid consistency in the modern
speculative mind_.'

I then notice more especially the basis of the theory. Those who hold
the doctrine of evolution _are by no means ignorant of the uncertainty
of their data, and they only yield to it a provisional assent_. They
regard the nebular hypothesis as probable; and, in the utter absence
of any proof of the illegality of the act, they prolong the method of
nature from the present into the past. Here the observed uniformity of
nature is their only guide. Having determined the elements of their
curve in a world of observation and experiment, they prolong that
curve into an antecedent world, and accept as