by an example, not by a precept; in short, instead
of Definition we have a _Type_ for our director. A type is an example of
any class, for instance, a species of a genus, which is considered as
eminently possessing the characters of the class. All the species which
have a greater affinity with this type-species than with any others,
form the genus, and are ranged about it, deviating from it in various
directions and different degrees."--WHEWELL, _The Philosophy of the
Inductive Sciences_, vol. i. pp. 476, 477.

[8] Save for the pleasure of doing so, I need hardly point out my
obligations to Mr. J.S. Mill's "System of Logic," in this view of
scientific method.

VI.

ON THE STUDY OF ZOOLOGY.

Natural history is the name familiarly applied to the study of the
properties of such natural bodies as minerals, plants, and animals; the
sciences which embody the knowledge man has acquired upon these subjects
are commonly termed Natural Sciences, in contradistinction to other,
so-called "physical," sciences; and those who devote themselves
especially to the pursuit of such sciences have been, and are, commonly
termed "Naturalists."

Linnaeus was a naturalist in this wide sense, and his "Systema Naturae"
was a work upon natural history, in the broadest acceptation of the
term; in it, that great methodizing spirit embodied all that was known
in his time of the distinctive characters of minerals, animals, and
plants. But the enormous stimulus which Linnaeus gave to the
investigation of nature soon rendered it impossible that any one man
should write another "Systema Naturae," and extremely difficult for any
one to become a naturalist such as Linnaeus was.

Great as have been the advances made by all the three branches of
science, of old included under the title of natural history, there can
be no doubt that zoology and botany have grown in an enormously greater
ratio than mineralogy; and hence, as I suppose, the name of "natural
history" has gradually become more and more definitely attached to these
prominent divisions of the subject, and by "naturalist" people have
meant more and more distinctly to imply a student of the structure and
functions of living beings.

However this may be, it is certain that the advance of knowledge has
gradually widened the distance between mineralogy and its old
associates, while it has drawn zoology and botany closer together; so
that of late years it has been found convenient (and in