136 SIXTH ANNUAL REPORT 



H A C K B E RR Y BUTTERFLIES. 



One of the most beautiful of European butterflies, much coveted 

 and prized by the collector, especially in England, where it is ex- 

 tremely rare, is that known as the Purple Emperor {Apatura Iris 

 Eabr). The wings in the male of this magnificent species exhibit 

 now the deep brown which alone the female, as a rule, possesses, now 

 a beautiful deep violet-blue, according to the direction from which we 

 view them. This changeability of color is owing to the peculiar form, 

 shape and arrangement of the wing-scales. If, by the aid of a good 

 microscope, we examine these scales, we shall see that, besides the 

 longitudinal imbrications so generally characteristic of the wing- 

 coverings of the Lepidoptera, they are furnished, on the parts natur- 

 ally exposed, with innumerable minute, transverse, angular ridges, 

 •each having a brown and each a blue surface exposed — a fact which, 

 by means of his excellent magnifier, Rosel von Rosenhof demon- 

 strated a century and a quarter ago, and which at once explains the 

 peculiarity which renders the butterfly so conspicuous among its 

 scaly-winged companions. The adolescent life of this butterfly is 

 quite interesting, and there are amusing accounts of the zeal with 

 which the larva and chrysalis have been sought by some of the earlier 

 entomologists, and of the pleasure which their discovery has aflbrded. 

 The larva feeds on Salix. 



In this country there are two butterflies belonging to the genus 

 Apatura^ as heretofore understood: viz., Lycaun Fabr. and Herse 

 Fabr. The complete natural history of these has so far remained 

 untold ; and from any figures or descriptions extant they could not 

 be distinguished from each other in their earlier stages. In Boisduval 

 et LeConte's Iconographie^^ to which we naturally look for something 

 respectable, the figures are, to speak in their own language, affreuses. 

 ^o characteristics are given by which the larvse could be separated 

 with any certainty, while the chrysalides are wrongly represented 

 hanging by the tip of the body, at right angles from the point of 

 attachment (which they never do), rounded and entire dorsally (they 

 are notched and angular), and without a single generic character that 

 belongs to them. Nor authors nor draughtsmen, if they ever saw the 



* Hist. Gen. et Icon, des Lepid., et dcs Chenilles de I' Am. Sept., 1833. 



