form similar to that under which
all the others commence their existence. We have found the whole of the
vast array of living forms, with which we are surrounded, constantly
growing, increasing, decaying and disappearing; the animal constantly
attracting, modifying, and applying to its sustenance the matter of the
vegetable kingdom, which derived its support from the absorption and
conversion of inorganic matter. And so constant and universal is this
absorption, waste, and reproduction, that it may be said with perfect
certainty that there is left in no one of our bodies at the present
moment a millionth part of the matter of which they were originally
formed! We have seen, again, that not only is the living matter derived
from the inorganic world, but that the forces of that matter are all of
them correlative with and convertible into those of inorganic nature.

This, for our present purposes, is the best view of the present
condition of organic nature which I can lay before you: it gives you
the great outlines of a vast picture, which you must fill up by your own
study.

In the next lecture I shall endeavour in the same way to go back into
the past, and to sketch in the same broad manner the history of life in
epochs preceding our own.

End of The Present Condition of Organic Nature.

THE PAST CONDITION OF ORGANIC NATURE.

In the lecture which I delivered last Monday evening, I endeavoured to
sketch in a very brief manner, but as well as the time at my disposal
would permit, the present condition of organic nature, meaning by
that large title simply an indication of the great, broad, and general
principles which are to be discovered by those who look attentively at
the phenomena of organic nature as at present displayed. The general
result of our investigations might be summed up thus: we found that the
multiplicity of the forms of animal life, great as that may be, may be
reduced to a comparatively few primitive plans or types of construction;
that a further study of the development of those different forms
revealed to us that they were again reducible, until we at last brought
the infinite diversity of animal, and even vegetable life, down to the
primordial form of a single cell.

We found that our analysis of the organic world, whether animals or
plants, showed, in the long run, that they might both be reduced into,
and were, in fact, composed of, the same constituents. And we saw
that the plant obt