more perfectly organized, which came to take
their places in the improving condition of things. This continuous
agency of the life-producing causes, effecting still higher results by
each successive effort, seems to point directly to the gradual expansion
and development of the qualities with which matter was first endowed.

We actually see natural agents now at work around us, producing results
which counterfeit life, if they do not constitute it. Many substances
crystallize into shapes bearing a strong resemblance to vegetable forms,
as in the well known chemical experiment producing the _arbor Dianae_.
The passage of the electric fluid leaves marks that are like the
branches and foliage of a tree, and the same fluid exerts a direct
influence on the germination of plants. Some of the proximate principles
of vegetable and animal bodies, such as urea and alantoin, are said to
have been produced artificially by the chemist; and in the combination
of the simple elements, such as carbon and oxygen, into these proximate
principles, it is now acknowledged that there is no violation of the
ordinary laws of chemical affinity. The origin of all vegetable and
animal life, so far as it can be traced, is in germinal vesicles, or
little cells containing granules. Such are the ova of all animals; and
both vegetable and animal tissues are entirely formed from them. When
the parent cells come to maturity, they burst and liberate the granules,
which immediately develope themselves into new cells, thus repeating the
life of their original. Now, it has been asserted, that globules can be
produced in albumen by electricity; and _if these globules are true
germinal vesicles_, the difficult problem of producing life by
artificial means is entirely solved.

But the burden of this part of the theory rests on the evidence that has
been produced of late years to favor the doctrine of equivocal
generation, or the production of living beings without the agency,
either direct or indirect, of parents of the same species. Can such
beings, _orphans_ in the strictest sense, now be produced or discovered?
We have not space to repeat our author's argument on this difficult
mooted question in science, nor is it necessary; he sums up the evidence
on his own side, and of course finds it satisfactory, though the weight
of authority is against him. He adduces the experiments of Mr. Crosse,
repeated by Mr. Weekes, who claim to have produced animalcules in
c