Entomological, is its tendency to raise Zoology to the rank of a demonstrative
science. By proving that natural affinities were circular, it
established at the same time the existence of definite groups ; from
which, of course, if any part was taken away, and placed in another,
group, a violation of natural affinities would inevitably follow, and both
groups be rendered artificial. Now this principle, as it appears to me,
has been either completely overlooked or essentially violated by the
disciples of this school. They express their opinion that a genus,
which seems allied to two different families, “ may be placed in either,
according to its external characters* and if these two families are
in juxtaposition, “ it is immaterial to which of them it may eventually
be referred.” Now, if an arrangement be artificial, that is, framed
merely to assist the memory, this mode of proceeding would be very
well; but if such a principle be admitted in the theory of Mr. Mac-
leay, it completely destroys all his idea of definite groups, and leaves
every one to describe their circles at their own good will and pleasure.
Again another most important definition, contained in the same
volume, relates to the nature and value of those groups which are
there denominated genera, and which are shown to contain certain
types of form, termed sub-genera. It is, moreover, proved that every
zoological genus thus characterized returns into itself, and forms a
circle. It matters not whether this definition of a zoological genus
agrees with that which has been given to the word by logicians; yet
one of the most zealous disciples of Mr. Macleay has rejected his
application of this word, which is definite, and has advocated another,
confessedly founded upon metaphysical reasoningf and mere opinion
It is owing to these and to similar misconceptions, which the disciples
of Mr. Macleay have fallen into, that the theory itself has been of
late so severely attacked, and has even lost some of its supporters.
Certain, however, it is, that these inconsistencies are nowhere to be
found in the writings of this distinguished master. He has repeatedly
warned his disciples on the facility of making circles and
quinary divisions, when unsupported by those tests which he has him-
* Vigors, Zool. Journ., i„ p. 397. t Zool. Joarn., iii., p. 97. J Ibid., i., p. 341.
self applied to the only two groups he has thoroughly analysed;
namely, Scarabams and Phan tens; while, so far from presuming that
he has discovered the natural system, he states upon every occasion,
most prominently and distinctly, that we have as yet obtained but a
glimpse of that system ; while, at the same time, he has pointed out
the only path by which, as he truly conceives, it can be further developed
*.
It will be readily perceived, from the tenor of these observations,
that my own researches have led to the adoption of the two great
principles of natural arrangement already adverted to. I speak of the
circular theory alone, since MM. Macleay and Fries differ in the
number of their divisions ; Mr. Macleay’s being Jive, while Mr.
Fries insists upon fourf. Neither of these agree with the details now
laid before the public. Fortunately, however, each party is desirous
that his theory should be tried by one and the same test. We agree
that no group, or division of a group, can be natural, if its affinities
are not circular, or decidedly tending thereto: this must be the test
of all. And here I may observe, that the opponents of Mr. Macleay
have adopted a line of argument, which, in every other branch of
science, is totally inadmissible. Instead of combatting his theory by
general or abstract reasoning, or, what is even more inconclusive, by
mere opinion, they should have either disproved the facts upon which
it is founded, or have explained them in some other way, more calculated
to show the harmonious combinations of Nature. If this had
been done, the foundation would have been sapped, and the theoretical
superstructure destroyed. But the singularity of the controversy has
been this, that the facts have been suffered to remain unquestioned,
while the inferences have been vehemently denied; denied, also,
without an attempt to substitute others in their place. It seems to
* The only probability, I conceive, of our ever understanding the great scheme of the creation,
must depend on studying the method in which the organs and properties of natural beings vary. All
true knowledge of Natural History hinges on this,—“ Ordinis hcec virtus erit et venus.”—Horae Exit.,
p. 458.
t Mr. Macleay, with every appearance of reason, views this difference as rather nominal than
real.—See Linn. Trans., xiv., p. 46.