special characters of living beings--_i.e._,
what the phrase "animals and plants" _connotes_; so the present Essay is
intended to explain what that phrase _denotes_. It is not by any means
intended at present to place before the reader a definitive and complete
system of classification--that task must be reserved for the conclusion
of the series, as it will be the expression of all the facts and
inferences which will have been in the meantime brought forward.

For the purpose now in view it will be well, perhaps, to follow the
suggestion of the great naturalist, Buffon, and begin with creatures
which are amongst the best known and most familiar, and thence proceed
to speak of less and less familiar forms.

In this Essay assertions will be freely made as to the natural
affinities which the author believes to exist between the creatures to
be enumerated, but no attempt will be made to give the reasons for such
assertions. The justification of such affirmations will, it is believed,
become apparent later, when the organization of living beings shall have
been portrayed as far as the space and the ability at the command of the
writer may enable him to portray them.

As before said the object now in view is to endeavour to present a
general view of living beings--of animals and plants--in the hope of
fixing in the reader's memory the names of species, and of groups of
species, to which names reference will have to be more or less
frequently hereinafter made. At the least, such a catalogue may serve
for reference whenever the reader may come upon the names of animals or
plants, or of groups of animals or plants, the meanings of which names
may have escaped his recollection.

The animals most familiar to us, our domestic cattle and our dogs and
cats, all belong to a group of animals technically termed _mammals_,
from the circumstance that the females have milk-glands (or _mammae_), by
which they nourish their young. The name "beasts" may be set apart for
the brute animals belonging to this group; but they do not altogether
form it, since man himself--the most individually numerous of all the
large animals--is, structurally considered, also a mammal.

For various reasons, which will appear later, the domestic cat (which is
a member of the genus _Felis_) may serve as an instructive, as it is a
familiar, example of a highly-organized mammal. Allied to the cat, and
formed on so completely the same model as hardly to differ, s