xxr 



species, the consequence is that not only do all the species resemble each 

 other very closely in general, but in particular there may be a strong resemblance 

 between forms of one species and those of another, when these happen to be 

 in the same stage of colour-evolution: When the evolutionary process has 

 reached its end, all these species will have become quite white, and therefore, 

 as regards colour, will be indistinguishable. 



In eight of the Cyaniris species found in Java, this process can be 

 followed pretty clearly by means of the accompanying illustrations. 



According to the general rule of colour-evolution which we have already 

 noticed above, the original colour must have been red, which later, on the 

 upperside at any rate, has been completely covered by a dark pigment, after 

 which a structural blue has been superimposed upon this. This procedure 

 can be observed in Poritia Erycinoides Felder, in which the blue structural 

 colour, still surviving in the cf (Plate XX, 23^), has disappeared in the 9 

 (Plate XX, 2^b), while the original red, although considerably faded, has 

 re-appeared. After the darkening and the accompanying structural blue had 

 proceeded for a longer or shorter period, the fading process must have begun, 

 with female preponderance, first with the female, so that in this sex it is 

 conspicuously further advanced than in the male, and also earlier on the 

 underside than on the upperside, and upon the secondaries than upon the 

 primaries. Thus the original colour was little by little destroyed. Of this 

 darkening there are now the following remains : Upon the upperside of the 

 primaries a broad black band along the costal margin, the outer margin 

 and the apex in both sexes of L. Marginata de Nic. (Plate XXII, 73^.(5.) 

 L. Ouadriplaga Sn. (PlateXXII, 72«.(5.)andL.CossAEAdeNic. (Plate XXII, 75^.^.); 

 in the 9 of L. Ceyx de Nic. (Plate XXII, 79/^), L. Coalita de Nic. (Plate XXII, 77^) 

 and L. Puspa Horsf. (Plate XXII, T^b) ; while in the 9 of L Catreus de Nic. 

 (Plate XXII, 78i5) this band extends along the inner margin as well. In the cT 

 of L. Cyanicornis Sn. (Plate XXII, ^6a) and of L. Puspa Horsf. (Plate XXII, 74^) 

 the band is considerably broadened; along the outer margin only, while in 

 the cf of L. Coalita de Nic. (Plate XXII, 77^) it has shrunk to a thin stripe. 

 Amongst the ^ of L. Ceyx de Nic. (Plate XXII, 79^) some still have the 

 broadened band, while in others it has become a narrow stripe. 



The same bands are strongly developed upon the upperside of the secon- 

 daries in the cf of L. Ouadriplaga Sn. (Plate XXII, 72a) and the 9 of L. Cossaea 

 de Nic. (Plate XXII, 75a), while in the 9 of L. Catreus de Nic. (Plate XXII, 

 78(5) it extends along the inner margin also, but in other species it is only 

 seen along the costal margin or the outer margin, and sometimes then only faintly. 



As regards the underside, the dark pigment appears along the outer 



