o be clear that a similar
intelligence was needed to account for the _living machine_. The blind
action of physical forces seemed inadequate. Thus the phenomena of life,
which had been studied longer than any other phase of nature, continued
to stand aloof from the rest and refused to fall into line with the
general drift of thought. The living world seemed to give no promise of
being included among natural phenomena, but still persisted in retaining
its supernatural aspect.

It is the attempt to explain the phenomena of the living world by the
same kind of natural forces that have been adequate to account for other
phenomena, that has created modern Biology. So long as students simply
studied animals and plants as objects for classification, as museum
objects, or as objects which had been stationary in the history of
nature, so long were they simply following along the same lines in which
their predecessors had been travelling. But when once they began to ask
if living nature were not perhaps subject to an intelligent explanation,
to study living things as part of a general history and to look upon
them as active moving objects whose motion and whose history might
perhaps be accounted for, then at once was created a new department of
thought and a new science inaugurated.

==Historical Geology==.--Preparation had been made for this new method of
studying life by the formulation of a number of important scientific
discoveries. Prominent among these stood historical geology. That the
earth had left a record of her history in the rocks in language plain
enough to be read appears to have been impressed upon scientists in the
last of the century. That the earth has had a history and that man could
read it became more and more thoroughly understood as the first decades
of this century passed. The reading of that history proved a somewhat
difficult task. It was written in a strange language, and it required
many years to discover the key to the record. But under the influence of
the writings of Lyell, just before the middle of the century, it began
to appear that the key to this language is to be found by simply opening
the eyes and observing what is going on around us to-day. A more
extraordinary and more important discovery has hardly ever been made,
for it contained the foundation of nearly all scientific discoveries
which have been made since. This discovery proclaimed that an
application of the forces still at work to-d