42 



somewhat larger, thereby leading principally to the creation of the so-called 

 species Cyllo Zithenius Herbst, while others again have regarded it merely $ of 

 Cyllo Suyudana Moore. The other process, that of colour evolution, manifests 

 itself at first in the fading of the original red pigment to orange and yellow, 

 after which this pigment — whether or not first fading to white, of which there 

 is no evidence — appears to be broken up but in such a manner that the 

 scales, which contained the pigment, or some of them, become filled with air 

 and thus acquire an intense white colour. Side by side with this, as usual, the 

 black pigment at first strongly suffuses itself over the original colour, covering 

 it completely or nearl}' so but subsequently decreases again sothat either the 

 black investment becomes lighter in colour or the original colour — mean- 

 while having faded to yellow — reappears, even though still suffused with some 

 black. The upper and the under sides of the wings independently pursue their 

 course in this process so that any specific pattern of marking on the under surface 

 goes side by side, now with one then with another pattern on the upper surface. 

 Thus the following combinations may be met with : 



upper side, A (PI. XV, fig. 30c) under side, A', E, D, F, H, G, I, K' (PI. V, 



fig. 30 d, i, h, k, I, m, 71, p). 



„ „ B (PI. XV, „ 30.') „ „ C, E, D, F, H (PI. V, fig. 30 .c. 



/, //, k, I). 



„ „ C (PI. XV, „ 30/-) „ „ C F, H, K' (PI. V, fig. 30-, k. 



It is only in the very pale specimens, mostly V, figured on pl. XV, fig. 30 f, g, 

 that some connection appears to exist, at least as regards the general tint, 

 between the upper and under sides which, however, simply indicates an equally 

 advanced stage in the process of colour evolution. In most cases that is to 

 say, since there are also specimens with such an upper side, but whose under 

 side have nothing in common with the latter. 



Now first as regards the upper side, it is covered by the black pigments, 

 either completely or with the exception of a small portion near the apex, to 

 such an extent that of the original red colour nothing remains or only a spot 

 faded to orange or yellow, while subsequently this black colour again has 

 commenced to recede and in many specimens in this manner has become a 

 light grey. This process is met with especially, but not exclusively, in 9 (PI- XV, 

 fig. 30/), since I possess also f? in which it occurs, the former, therefore, 

 having reached apparently a more advanced stage than the majority of 

 the latter. The reddish, orange, or yellow spot referred to, which in its turn 

 is margined by intense black containing two clear white dots, varies consider- 

 ably as to size and shade in individuals, according as to whether the process 



