186 Mr. H. E. Strickland on the Natural System 
erroneous must be all those methods which commence by as- 
suming an @ priori system, and then attempt to classify all 
created organisms in conformity with that system. ‘This, 
nevertheless, is a defect which exists more or less in many 
modern methods of classification. The greater part of these 
arrangements are based on an assumption that organic beings 
have been created on a regular and symmetrical plan, to 
which all true classifications must conform. Some natural- 
ists have attempted to place all animal species in a straight 
line, descending from man to a monad. This theory assumes 
that each species (excepting the two extremes) has two and 
only two direct affinities; one, namely, with the species which 
precedes, and the other with that whichfollows it. Others, per- 
ceiving the existence in many cases of more than two direct 
affinities, have compared the natural system to a series of 
circles, or to the reticulations of network. Many authors 
have assigned the most mathematical symmetry to the dif- 
ferent parts of the system by maintaining the prevalence 
throughout of a constant number, such as 2, 3, 4, 5, or 7. In 
applying these views to facts, they have of course found nu- 
merous exceptions to the regularity of their assumed formule; 
but by adducing the extermination of some species, and our 
ignorance of the existence of others, and by applying a Pro- 
crustean process to those groups which were either larger or 
‘smaller than the regulation standard, they have removed the 
most glaring objections to their theory, and have with won- 
derful ingenuity given their systems an appearance of truth*. 
But when the unprejudiced naturalist attempts to apply any 
one of these systems to Nature, he soon perceives their inef- 
ficiency in expressing the real order of affinities. The fact 
is, that they all labour under the vital error of assuming that 
to be symmetrical, which is in an eminent degree irregular 
and devoid of symmetry. I will now proceed to give my 
reasons for taking this view of the subject. 
1. A priori considerations, so far from leading us to assume 
a regular geometrical pattern, or numerical property in the 
* As these remarks may appear somewhat severe, it is right to substan- ~ 
tiate them by a few examples. So long as these systems are admitted by 
their authors to bé artificial, it would be as unjust to object to them, as to 
complain of the alphabetical arrangement of an encyclopzedia, that it broke 
the connection of the subjects. The reply would of course be, that an en- 
cyclopeedia does not profess to arrange subjects in their natural order, but 
merely aims at convenience of reference. ‘The remarks in the text, there- 
fore, merely apply to those symmetrical methods which profess to exhibit 
The Natural System. The examples are seleected from Mr. Swainson’s 
‘Classification of Birds,’ in which work the reality of the quinary system is 
insisted on throughout. See Appendix. 
