6 
ON THE CETONIIDjE OF SOUTH AFRICA. 
appear sometimes to be consonant with what we observe in nature. If we divide all animals 
into sub-kingdoms, classes, orders, tribes, stirpes, families, genera, sub-genera, sections, sub- 
sections, &c. &c. or any other names, we must not confound all these groupes together, but 
during our investigations, preserve each of them in that proper subordination which may 
have been agreed upon by naturalists. But here some one may observe that all groupes are 
arbitrary and artificial, since after all they must depend on the selection and good pleasure 
of man. To this I answer that affinities are natural ; and if all these affinities are expressed 
by any mode of grouping, it follows also that the groupes must be natural ; although, 
certainly, these last must in some degree have depended on our selection. But in fact, 
these groupes are only chosen because they coincide with the affinities which exist in nature. 
Our grand object, when we are trying to find out a natural arrangement, is not to give 
an arbitrary value to particular characters ; but to express all the relations, whether of affinity 
or analogy, which may exist in the branch of natural history we study. If these relations are 
all indicated by the arrangement, our object is gained ; and it can be no objection whatever 
to the system, that in our pursuance of an eclectic plan, a character which at one time we 
set a value upon, is at another time esteemed of little worth. Indeed, it is obvious in every 
part of natural history, that the most important characters break down in certain species, 
and become at times perfectly worthless. Comparatively constant as is the structuie of the 
teeth in the genera of Mammalia generally, we find in some groupes, such as the Edentata , 
or the genus Rhinoceros, that the dentition varies extensively in almost every species. Again, 
in Botany, how steady is the dicotyledonous character of Exogenous plants ; yet we have even 
this most important distinction breaking down in certain families. One naturalist arranges 
animals according to their brain and nervous system ; another tells us, he prefers their 
osteology, and so on. Each point of structure, being of the utmost consequence to animal 
economy, is concluded by its peculiar partisan to be therefore infallible as a ground of arrange- 
ment. Very little experience, however, is sufficient to shew that each of these favorite hobbies 
is unsafe to ride upon ; and we are in our search for an accurate way of expressing the relations 
which connect various beings, obliged to adopt another plan of calculating the value of 
principles of arrangement. 
My plan, as is well known, has ever been not to estimate the value of any arrangement 
by the value in animal economy of the structure upon which this arrangement is founded, but 
to make the importance of every organ or structure for purposes of arrangement, rise in inverse 
proportion to its degree of variation. The consequence of this rule of procedure, has been 
the birth of an arrangement which is universally applicable. And yet, even this rule is 
nothing more than an abstract measure of the importance of some individual character in the 
arrangement of that particular groupe, where we may happen to make use of it. It is a 
rule, moreover, that we cannot always with safety put in practice ; for although with respect 
to arrangement, it is ever an admirable instrument of correction, it is sometimes also a 
dangerous one of discovery. Indeed, in discovering natural arrangement, we can never safely 
swerve from the Linnean axiom, which although it alludes more immediately to “ genera, 
holds good equally of all groupes ; “Scias characterem non constituere genus sed genus 
characterem, et characterem non esse ut genus fiat sod ut genus noscatur.” V e truly make 
use of a process of tatonnement. We do not argue that such must be the groupe, because 
such and such are, in our opinion, good and distinct characters ; but we say, such happens to 
be the character, of no matter what importance, which prevails throughout the groupe, and 
