21 
means of reasoning only, should be of any value for the discovery of 
new results, because the subtlety of nature far exceeds the subtlety of 
the reasoning power; but axioms duly and orderly abstracted: from 
particulars, in their turn easily point out and mark off new particulars, 
and so render the sciences active.” It is necessary to keep this well 
in mind, lest, trusting to theory only, and neglecting the facts which 
alone can be derived from a wide, comprehensive, and direct 
observation, we pervert the latter (facts), by trying to make them 
fit into our preconceived notions of what ought to be, and entirely 
overlook what is. 
It is very necessary to point out these general ideas before 
entering upon the detailed consideration of the arrangement of the 
creatures we study, z.e. their orderly and natural classification, for 
from our infancy we are indirectly suckled on erroneous notions of 
the facts relating to organic existence, so that when we commence 
our work independently, we have, often unwittingly, very strong 
preconceived notions of what ought to be, and which have to be 
rooted out completely before we can bring our mind to the proper 
consideration of the facts, and deduce our conclusions solely from 
the facts before us. 
Among the various names adopted for the definition of the 
different subsidiary zoological assemblages, none is more likely to be 
misunderstood than that of the “genus.” Our most conservative 
naturalists have at any rate a general idea and perception of what is 
meant in an abstract sense by the term “species ;” but the nature 
of a genus 1s often entirely misunderstood, more especially by those 
men who give their attention particularly to synonymy and nomen- 
clature. But until this has been really grasped, the claims for the 
annihilation or retention of genera will be based on no sound 
principle, and will, on the other hand, add to the general confusion, 
and prevent the advance towards the model and ideal system we 
desire. 
Probably the most difficult erroneous notion to uproot is that in 
which the ‘‘genus” and ‘ species,” through having been so long 
associated with the same things in our minds, are regarded as of 
equal importance, and hence both are often looked upon as of equal 
(or even of the same) value, and the true idea of the “genus ” is then 
altogether lost, being, as it were, blended entirely with the specific. 
This curious result is followed out to its logical conclusion by those 
who would, on specific characters alone, give two names to every 
species, or by those who, on a specific character, are ready to sepa- 
rate a species from its natural associates, and find a new generic title 
for it. Such do not comprehend that genera represent certain 
natural groupings of units (species), which units, although differing in 
certain particulars z7¢er se (which, indeed, makes them recognisable 
as units), yet possess characters that unite them into a more or less 
homogeneous whole, z.e. the genus. The application of this general 
principle can be further applied to tribes, sub-families, and families ; 
