( 324 ) 



i'. (?, postdiscal tawny interspace R^ — E' of forewing smaller than the 

 black patch at its proximal side, or absent ; ? , discal bar R' — R' of 

 forewing above mnch heavier than posterior discal bars, about 

 midway between outer margin and median bar R' — R', or nearer 

 the latter. Poli/.tena group. 



The forms of Ckaraxes we are now going to deal with are more perplexing than 

 any others. We can roughly divide them into two groups, according as the males 

 have a white discal band on forewing, or not. On the islands of Palawan, Borneo 

 and Sumatra, in the Malay Peninsula, and in China, there occur both a banded and 

 a not-banded form without there being found any intergraduate s])ecimens between 

 the two. We must, therefore, conclude, for want of evidence showing the reverse to 

 be true, that in those localities the two forms are j)erfectly independent of one 

 another, or, in other words, belong to two distinct species. But if we examine the 

 material from Burma and North India, we find no longer two well-separated forms, 

 but meet with a great number of different-looking insects which entomologists have 

 been at pains to describe as distinct species, but which are all connected with one 

 another by intergradations. However, if we group the individuals again according 

 to the presence or absence of a white discal band on the forewing of the males, we 

 observe that the number of specimens which have the band more or less vestigial 

 and connect the two groups of individuals comjiletely is much smaller than the 

 number of specimens of either grouji. We have vainly endeavoured to find 

 characters in the sexual organs by which the forms could be constantly separated. 



Have we then to deal with one, two or more " species " in North India and 

 Burma ? It might be suggested that the intergraduate specimens were hybrids. 

 But that explanation is not admissible, (1) because the number of " hybrids " would 

 be much too large, hybrids being rare, if not produced in confinement ; (2) because 

 the fact that no intergraduates between the banded and not-banded forms of Sumatra 

 and Borneo, whence large material has come to Europe, are known, speaks entirely 

 against the Burmese and North Indian " species " hybridizing so freely. Hence we 

 disregard this assumption of general interbreeding of " two species " altogether, and 

 consider all the numerous forms known from Burma and N. India as specifically 

 identical. Some authors have avoided the difficulty presented by the insects in 

 question by 2)ickiug out certain specimens as specifically distinct and including the 

 intermediate examples arbitrarily into one or the other of those "species" ; others 

 preferred enumerating the insects as a dozen or more " species," but lea\Tng it 

 doubtful whether the " species " were all distinct. We agree with those who 

 suggested, like Watson and Elwes, that the insects in question belonged all to one 

 and the same very variable species. To clear up the matter entirely as regards 

 the specific identity of the various Burmese and North Indian forms, it is necessary 

 to rear the insects from the eggs of ? ? which have copulated with S <S that are 

 similar to them in colour. It would be a long stej) forward if one of the officers 

 in Burma who takes an interest in Natural Science would try to obtain eggs from 

 one ? , rear the insects, and send the ? , together with the oftspring, carefully 

 marked, to a public collection or to an expert. 



There is one other point to be noted. The individuals which are intermediate 

 between the banded and not-banded forms are mostly small specimens, being not 

 only rarer, but on an average also decidedly less robust than the forms which 

 approach the extremes in colour. Therefore, if it is true that we have to do only 



