25 
been so, but such authors have actually attempted to depreciate the 
work that has been done, on the plea that the retention of names is 
of greater value scientifically than the truths the names represent. 
I read recently, “Classification is largely a matter of opinion... . It 
is only possible to take group after group in as natural a succession as 
seems to commend itself to the individual writer, with the knowledge 
on his part that the arrangement is partly the outcome of his own 
particular views, and that, in all probability, those of other authors 
are equally substantial.” This is worthy of study, as it represents, 
with slight modifications, the characteristic apology of those whose 
field work is at a maximum, whose knowledge of previous original 
work is practically 72/7, and whose powers of generalisation, based on 
work other than their own, is at a minimum. Such a man represents 
the antithesis of the individual against whom Mr. Vernon Wollaston 
inveighs, and whom he describes as “attempting the establishment of 
propositions and principles from simple dialectics, without a previous 
training in the practical bearing of the subject;” for these men are 
not wanting for facts, except such as can only be learned from close 
and prolonged study, but they are deficient in the logical conception 
which is required to correlate these facts according to their various 
values. Classification may be “largely a matter of opinion” to such 
men. ‘To naturalists it is something very different. 
To return to the consideration of the “genus.” Let us attempt to 
understand what the term really includes. We have seen how various 
species branch off in different directions from a common stem, and 
how such branches at last may take on special characters, and 
become more or less indefinitely separated, and form what we call 
species. Let A represent such a centre, and give off as branches a B, 
AC, AD, AE, AF, and let the distance that they are from each other 
represent the amount of separate development that each has under- 
gone. The nearer B, C, D, E, and F are to A, the greater will be the 
resemblance between the species; but as they get farther from the 
centre there will be considerable difference between them. ‘They will 
all vary zz¢/er se ; some on each line, perhaps, resemble more or less 
those on others, but they will be a natural group of individuals and 
constitute a genus. 
Let us now assume that c and E in their turn develop new branches 
and characters, whilst F, Db, and B remain moderately fixed and un- 
changed. Then the subsidiary branches, a, 4, ¢ d, e, will form a 
genus, f, g g, 4, 7, another genus ; whilst the original group, B, CG; DE, F, 
with its subsidiary branches, becomes a tribe. Now there can be no 
doubt that we often include under the same generic title species 
which have been developed far away from each other; sometimes, 
indeed, species of which we have not as yet a clue to their develop- 
ment, and, until the real relationships of: our species have been 
worked out, the term ‘‘ genus” must be more or less a useful conven- 
tion, always in a state of flux, liable to change with every new 
discovery, and as far removed from the ideal “genus” as can very 
