218 THE ENTOATOLOGIST 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 E?iio7nologisfs Record, he has discussed at considerable 

 length one aspect of it. The chief feature of The British Noctucz 

 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 Nocture, 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 the 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 exampl s of the same species; and specimens from 

 South Britain differ from Noith 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 vice 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 artaxei xes, F. of LyccEiia astrarche, Bgstr. ; var. subochracea, B. 

 White of Zygcena exulatis, H. (^ R. ; var. borealis, Stdgr. of Spilosoma 

 ficliginosa, L. ; var. ochracea, B. White of 6". menthastri, Esp. ; var. scotica, 

 B. White of Thera juniperata, L. etc. ; and amongst the Nocture 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 

 difTused 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, 



