1877.] 215 



nearly a perfect chevron pointing forwards ; the dorsal lino can scarcely be traced on 

 the thoracic segments, bat thence backwards it continues as a violet-white line to the 

 anal extremity ; on the dark marking the shining black tubercular warts project con- 

 spicuously from white rings, on the green portions they are also green, small in size, 

 and escape notice ; the spiracles are also inconspicuous, being small, and of the same 

 colour as the segments, on which they happen to come ; all the legs are yellow-green. 



The cocoon is placed just on the surface of the soil, and formed of small particles 

 of earth, leaves, &c., fastened together with a tough, although not hard, lining of pale 

 silk ; the pupa is five-sixteenths of an inch in length, rather stout in proportion, the 

 abdomen tapering off rapidly fi'om the end of the wing-cases, and ending in four or 

 five curled-topped spines of unequal lengths, but twisted together so as to look like 

 a spike ; the eye- cases rather prominent ; in colour the wing-cases are tinged with 

 greenish, all the rest mahogany-brown and shining. 



I have now made acquaintance with the eai'lier stages of three species of Astliena, 

 namely : candidata, sylvata, and Blomeraria, and find them exhibiting as close a 

 resemblance in these, as in the perfect state ; of luteata I do not know so much, and 

 am anxious to know more, and shall be extremely obliged to any one who, during the 

 coming season, will kindly forward me a few eggs. — John Hellins, Exeter : 

 January \Oth, 1877. 



Melanism in Lepidoptera. — It seems somewhat absurd for me to enter an arena 

 of controversy where Mr. Edwin Birchall and Dr. F. Buchanan White are to be found ; 

 truly the circle is one " where angels might fear to tread," but it does appear to my 

 humble judgment that both have to some extent overshot the mark in trying to 

 account for varieties of coloration in Lepidojytera ; first, Mr. Birchall quotes from 

 learned writers who assert in fact that darker coloured animals, from the lower 

 orders up to the superior animal man, have advantages in freedom from disease, less 

 liability to parasites, superior acuteness of the senses, &c., which their paler coloured 

 fellows do not possess ; I must say I do not see any foundation for this doctrine ; 

 in the races of men it certainly does not appear to hold good, as the fair-haired 

 Saxon is able to hold Ids own physically and intellectually against the darker races, 

 the single instance in which the rule holds being the albino in all animals, but this 

 is, after all, a diseased type. If Mr. Birchall's theory of survival of the fittest be 

 true, and that the darker races in insects, animals, and the superior animal man are 

 the fittest, the inevitable conclusion to which it points is that the darker forms in 

 insect and animal life, and the Negro in man, would, after so many ages of natural 

 selection, largely predominate in the world, the contrary being, however, the fact. 



Secondly, Dr. White, adopting the natural selection theory, appears to reject 

 Mr. Birchall's notion that cold, damp climates, with the absence of sunshine, may 

 be the cause of the origin of variations of colour, and suggests meteorological causes. 



May we not then very easily suppose that variations of colour in insects may 

 be, BO to speak, accidentally produced by external objects, present to their acute vision 

 during the process of generation, and this may occur again and again ; it seems to 

 me a less far-fetched theory than to assert dogmatically that dark coloured insects 

 are endowed with stronger constitutions, and are therefore perpetuated by natural 

 selection. — S. Radcliff FETiiERSTONnAroit, 17, Eccles Street, Dublin : December 

 20th, 1876. 



