governed by corresponding conditions everywhere. The doctrine of "_similia
similibus gignuntur_"--similar conditions producing similar forms--obtains
universally. The _Graptolites_, occurring in the bituminous shales of the
Silurian sandstone period, afford only another instance of the same law to
which we have called the attention of our readers. In fact, the annals of
natural history abound in the most conclusive proofs, as well in the
fossilized as the living world, of what the paramount text of the Bible
teaches us.

When Professor Ehrenberg, one of the most distinguished classifiers of
minute forms of life in the world, declared, as he recently did before the
Royal Geographical Society of London, that there was "a great invisible
rock-and earth-forming life in nature," he came pretty near enunciating a
great truth in science; and had he connected his language with the
induction of "environing conditions" and the sequence of life therefrom,
he would have accomplished what we undertook to do in our work begun
several years ago, but not completed and published until 1880. For it will
be seen that we had been gathering the material for "Life: Its True
Genesis" for many years before we sat down to the task of writing it.

When we said to one of our most intimate college friends that we were less
than six months preparing it for the press, we stated what was literally
true; but we had no intention of giving him to understand that we had
spent only that time in gathering the vast amount of material at our
command--twenty times as much as we could possibly use in the preparation
of such a volume for the press. The long months and even years of toil and
study spent by us in the needful preparation, were a part of the labor, as
every author, writing intelligently on any subject, knows. The immense
amount of care and labor that enabled Hermann von Meyer to prepare his
paper on the _ArchA|opterix_, rescued from the lithographic slate, is a