ABERRATIONS OF ABRAXAS SYLVATA (uLMATA). 307 



shading on the wings, for, in the less deeply suffused specimens, these 

 markings stand out distinctly, although in the darkest they are very 

 inconspicuous or entirely lost in the ground colour. The intermediate 

 stages also show that the darkening of the ground colour does not develop 

 by the spread of the already existing slaty-grey blotches, but that it is a 

 general modification of the scale structure which results in suffusion, 

 the fact that the suffusion is of the same hue as the normal shading- 

 being quite fortuitous. It appears to be, in this respect, exactly 

 parallel with the suffused aberrations of Arctia rillica, Nemeop/iila 

 pla)ita(/inu; etc., in which the normal ground colour is changed to a 

 suffused black, through which the normal black spots show quite 

 distinctly. 



The poor physique of these aberrations suggests that, whether the 

 crippling was the result of the larva being ill-supplied with food, or of 

 some unfavourable condition to which the pupa was subjected, the 

 prime factor in the production of these aberrations is one that spells 

 " death " to the race, and hence this particular form of aberration is 

 not likely to occur continuously in any great numbers. It may occur 

 from time to time, even in abundance, if it be a species so easily and 

 rapidly affected by external circumstances, as this extensive appearance 

 suggests. If so, it is certainly a species for Mr. Merrifield's special 

 attention. 



On the other hand, in a district such as that where these specimens 

 were captured, in which melanism would probably be useful to such a 

 species as this, there might be sufficient cumulative force for heredity 

 to produce such a race, but as this could only be done by means of the 

 more vigorous specimens of the suffused form, the process would 

 necessarily be a slow one. 



I only know of one fact that makes me hesitate to accept the mal- 

 nutrition of the larva as the direct cause for this sudden appearance 

 of suffusion in so many specimens of this species, and it is, that I 

 have on two or three occasions received larvae from this locality and 

 Edlington Wood, starved them most systematically, and never got a 

 suffused variety, although the specimens only emerged about two- 

 thirds the normal size. If it is not the food-supply that reduces the 

 energy, and results in producing cripples and suffusion, what is it ? 

 Experiment is needed. 



To make these aberrations recognisable without a separate diagnosis 

 each time one is recorded, the following varietal nomenclature is 

 suggested : — 



1. — With the whole of the wings and body suffused with paler or 

 darker slaty-grey = ab. siifusa, n. ab. 



2. — With the wings, or some part of the wings, irregularly or 

 unequally suffused with slaty-grey patches = ab. intermedia, n. ab. 



3. — With the wings, or part of the wings, suffused with dirty 

 ochreous or cream-colour = ab. obscura, n. ab. 



4.— With the discoidal and central slaty-grey shades forming a 

 central transverse band across the fore-wings = ab. transversa, n. ab. 



Coleoptera in the winter. 



By CLAUDE MORLEY, F.E.S. 

 By the end of October, the ivy blossom is over, and we have taken 

 our Xanthias and our Thorns, and searched in vain (as usual) for our 



