•218 
THE entomologist’s RECORD. 
of the varieties, but in the introduction he refers briefly to some theories 
thereon ; and, in a series of articles on “ Melanism and Melanochroism ” 
in The EiitomologisV s Record^ he has discussed at considerable 
length one aspect of it. The chief feature of The British Noctuce 
and their Varieties is the careful manner in which all marked 
variations from the type of each species are described. There seem 
to be a few species — but a very few — in which there is scarcely any 
variation. On the other hand there are some which are quite protean 
in their inconstancy of coloration and markings. Taking, however, the 
majority of the species, the rule seems to be that each has several well 
marked varieties. Although the main object of the book is merely the 
discrimination of the varieties which exist, and not a discussion of their 
distribution (though localities are often mentioned) or origin, yet a study 
of it will show that in the Noctu^, just as in animals and also in 
plants, some variations have intimate connection with the localities they 
inhabit, and hence — it may be supposed — have tb.e cause of their 
origin in the conditions which surround them — in other words, their 
environment. In many cases British specimens are somewhat different 
from Continental exampks of the same species; and specimens from 
South Britain differ from North British ones. As a rule, though by 
no means invariably, there is a tendency in the latter to melanochroism 
or melanism, but in some species the very opposite is the case. 
Amongst the Noctu^, there are, according to Mr. Tutt, three modes of 
variation : — (i). in general coloration, (2). in the markings of the wings, 
and (3). in the size and shape of the insect. All these may be combined 
in one specimen. 
Although Mr. Tutt calls all forms which differ distinctly from the 
type “ varieties,” it is evident that all the forms so designated are not 
of equal value or rank. Staudinger’s division of forms into “varieties” 
and “aberrations,” seems to be a preferable mode of classification, but 
doubtless Mr. Tutt has reasons for the plan he has adopted. An 
“aberration” is a varietal form which occurs along with the type. It 
may occur only once, or very rarely, or it may be not unfrequent. 
A “ variety,” on the other hand, is a form, which in some locality or 
country, has supplanted the type, and which, though only a “local 
race,” might readily be taken (as indeed has happened in some cases) 
for a distinct species. Whilst the difference between an aberration 
and a variety thus seems to be sufficiently great, it must not be 
forgotten that gradations between them sometimes occur ; and, more- 
over, that what is an aberration in one country may attain the rank of 
a variety in another, or ince versa^ and that even the type of the 
species might have to be considered in some circumstances as no more 
than an aberration. ^ In other families of the Lepidoptera, we have in 
Scotland several well marked examples or varieties or local races, e.g. 
the var artaxe> xes, F. of Lyccena astrarehe, Bgstr. ; var. subochracea, B. 
White of Zygoena exulans^ H. (ic R. ; var. borealis^ Stdgr. of Spiloso 7 na 
fuiiginosa, L. ; var. ochracea, B. White of S. ??ienthastri, Esp. ; var. scotica, 
B. White of Thera ju?iiperata^ L. etc. ; and amongst the Noctu^ there 
are also some forms which are recognised as local races, as, for example, 
^ For example, if in a country where a local race had supplanted the more widely 
diffused typical form, the latter occurred occasionally, it must be regarded — strictly 
speaking — as an aberration only, so far as that country is concerned. — F.B.W. 
