ination of the more or less similar species would only lead to a 
useless slaughter of the innocents. The point is obvious. And what 
is true in the case of the practical branches of our science, is no less 
true also in regard to the philosophical treatment of biology in 
general. Although we admit that it may be utterly indifferent at the 
time to know whether some certain form of Insect is specificallv 
distinct, it would be equally rash for the scientist to point to this 
or that group ot Animals as a negligible quantity, or to this and 
that line of research as being futile. Science must not prejudge 
anything and must not be negligent anywhere. We can never 
know beforehand to what prominence in practical life or in philoso- 
phical theories any creature may attain. 
The aim of the systematist as such is the establishment, on 
reasoned evidence, of the degree of relationship between the 
forms with which he is concerned, the evidence being furnished by 
the specimens and the bionomics of the species and varieties to 
which the specimens belong. He has to weigh similarities which 
may mean relationship or may not, and differences which may be 
only recent modifications or may point to the Insect having 
branched off at an early period. If a classifier tries to accomplish 
this difficult task, if he marches along this road so studded with 
obstacles, he is nothing less than a speculative philosopher who 
constructs a cosmogony in parvo. 
The philosophic aspect of systematics is unfortunately much 
obscured, and it cannot be denied — no thoughtful systematist, at 
any rate, will do so I think — that this is due in a large measure to 
an unduly great importance being attributed to the mere giving of 
names. Nomenclature is the servant of science, but has in many 
houses the position of master. However, that is a subject which 
another Section of the present or a future Congress will have to 
consider. 
My object in taking up your time is to demonstrate by a few 
selected instances that there is more in classification than lies at 
the surface, by proving to you, with the help of slides, that there 
exists a very intimate connection between, on the one hand, the 
vexed question of specific distinctness, and, on the other, the elucid- 
ation of the factors of evolution to which is due the great divers- 
ity of the animal world. The very title of the book which is the 
basis of modern biology, the Origin of Species, renders it evident 
even to those who do not claim a special knowledge in any branch 
