genera, on the remnants of previous elements of utilitarianism. The 
active utilities are more conspicuous to us, are more prominently 
brought to our notice, by the difterences existing between the species 
and its local race, between species and species, and so on through¬ 
out the whole scale, for, if we may so term it, the differences 
between two families, or classes, are only the accumulated differences 
which have existed (and in a measure persisted) between the endless 
specific forms which have been developed and died out since the 
representatives of the now distinct classes, formed but a single 
species. The problem of the utility of family, tribal, and generic 
characters is all included, then, in the consideration of the utility 
of specific characters, for, in the species, the useful differentiations 
have been completed, and are not in a state of doubt, as they are 
between a species and its local races. At the same time the con¬ 
sideration of the utility of specific characters leaves the problem shorn 
of the secondary and tertiary (and so on, ad m/in.) considerations as 
to disuse and subsequent modifications that at once accumulate when 
one commences to study the same problem when applied to genera, 
tribes, families, etc. 
CLIMATE AS PRODUCING USELESS SPECIFIC CHARACTERS. 
Romanes considered that the actual causes which lead to the 
production of useless specific characters were : Climate, Food, Sexual 
Selection, and Laws of Growth. It may be well to examine these 
points from our position as entomologists. 
The influence of climate on Lepidoptera (and I have no doubt on 
other classes of insects) is undoubted. When the same species in¬ 
habits central Europe, the Alps at high altitudes, and the Polar 
regions at high latitudes, the forms from the various localities often 
exhibit marked differences, and those from high altitudes more or less 
tend to resemble those from high latitudes. These differences may be 
produced either by climate directly, or by a difference in the nutritious 
value of the food brought about by a difference of climate. According to 
Staudinger, the variety aegidion of Plebeius argils is confined to Lapland 
and the Swiss Alps. Polyommatus eros inhabits the Alps and Pyrenees; 
a large form known as var. eroides occurs in the plains of south-east 
Germany. The var. polaris of Aglais urticae is almost confined to the 
Polar regions. Melitaea aurinia has a small undersized Alpine variety 
known as merope, whilst M. partlieniae has a similar form known as 
var. varia. Ossia7ius is a small Lapland variety of Brenthis apldrape, 
and Brenthis selene and B. euphrosyne have parallel Lapland forms 
known as hela and jxngal respectively; Coenonympha arcania has an 
Alpine form known as danviniana, and so on. We have the bright 
red form of Chrysophanns j)hlaeas from northern Europe, the almost 
black form of the same species appearing in the summer, in those 
countries washed by the Mediterranean. Yet, in neither race, 
is the character a very fixed one, nor the physiological change 
accompanying the change of colour one that is hereditary, for the 
breeding of the species from the dark form in more northern 
latitudes results at once in the production of specimens scarcely dis¬ 
tinguishable from the normal form of the species occurring in our 
latitude. The difference, then, may be due to the rapidity of feeding 
up, so that the larvae do not get sufficient material for use; this, 
however, is unlikely. It may be due to the rapid metabolism of the 
