mplies no structural
differences, but presents the same structure combined under certain
minor differences of size, proportion, and habits. All the specific
characters stand in direct reference to the generic structure, the
family form, the ordinal complication of structure, the mode of
execution of the Class, and the plan of structure of the Branch, all of
which are embodied in the frame of each individual in each Species, even
though all these individuals are constantly dying away and reproducing
others; so that the specific characters have no more permanency in the
individuals than those which characterize the Genus, the Family, the
Order, the Class, and the Branch. I believe, therefore, that naturalists
have been entirely wrong in considering the more comprehensive groups
to be theoretical and in a measure arbitrary, an attempt, that is, of
certain men to classify the Animal Kingdom according to their individual
views, while they have ascribed to Species, as contrasted with the other
divisions, a more positive existence in Nature. No further argument
is needed to show that it is not only the Species that lives in the
individual, but that every individual, though belonging to a distinct
Species, is built upon a precise and definite plan which characterizes
its Branch,--that that plan is executed in each individual in a
particular way which characterizes its Class,--that every individual
with its kindred occupies a definite position in a series of structural
complications which characterizes its Order,--that in every individual
all these structural features are combined under a definite pattern of
form which characterizes its Family,--that every individual exhibits
structural details in the finish of its parts which characterize its
Genus,--and finally that every individual presents certain peculiarities
in the proportion of its parts, in its color, in its size, in its
relations to its fellow-beings and surrounding things, which constitute
its specific characters; and all this is repeated in the same kind of
combination, generation after generation, while the individuals die.
If we accept these propositions, which seem to me self-evident, it is
impossible to avoid the conclusion that Species do not exist in Nature
in any other sense than the more comprehensive groups of the zoological
systems.

There is one question respecting Species that gives rise to very earnest
discussions in our day, not only among naturalists,