THE ENTOMOLOGIST. 



Vol. XX.] FEBKUARY, 1887. [No. 285. 



ON MELANISM. 

 By N, F. Dobree. 



So much has been written on this subject that it might be 

 considered threadbare ; but as it has always been treated from a 

 purely insular point of view it is permissible to take it up once 

 more and examine it from tlie broader basis of its bearing on 

 European insects generally. British entomologists apparently 

 overlook that from such a standpoint the matter can be pre- 

 sented in a fresh light, which may tend to disprove more than 

 one of the theories which pass current amongst us. I propose to 

 do so briefly. 



Adopting as a means of comparison Dr. Staudinger's definition 

 of the range of European Lepidoptera (though perhaps it is 

 questionable how far he is justified in including Central Asia 

 within its limits), let us pass to a careful examination of any of 

 the large collections in continental museums, carefully noting the 

 habitat of the species before us. The first striking feature is the 

 generally larger size which prevails in the imago and also in the 

 larva, so far as opinion of the latter can be formed from preserved 

 specimens. We also note that the imago type is uniformly of dis- 

 tinctly lighter colouring than our own, and that where variations 

 occur they are usually in the direction of a lighter rather than a 

 darker shade. So many examples of this may be given that I 

 only note a few taken from my collection ■.—Orthosia suspecta, to 

 warm light grey in Austria. Hadena dissimilis (suasa), beautifully 

 variegated, suffused with pink in Central Germany. H. adusta, 



ENTOM. — FEB., 1887. t^ 



