294 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XV. 



THE CLASSIFICATION OF THE LEPIDOPTERA 



PAPILIOMNA. 

 By 



L. C. H. Young, Entomological Hony. Secy, to the 

 Bombay Natural History Society. 



Partly owing to the fact that most Indian Lepidopterists have 

 confined their attention to one group only and partly because most of 

 the prophets of the cult have been too busy multiplying and dividing 

 each other species to pay attention to anything else, the classification 

 of the Indian PAPILIONINA is in a particularly chaotic condition. 



In most of the handbooks in use it would appear that the authors were 

 ignorant that Darwin had ever lived and written or at any rate that 

 they had not grasped the particular application of his discovery to their 

 own subject. 



Now it should be an axiom that classification should have for its 

 object the grouping of genera and families in their natural order of 

 descent and relationship to each other and a system which does not 

 satisfy this criterion cannot be worth maintaining. 



A true classification can therefore only be formed by tracing the deve- 

 lopment of the various organs and characters of the insect throughout 

 the order and discovering which are the important and constant features 

 which can be relied on. 



Certain general principles, however, must be a guide to any system : 

 (1) A lost character cannot be reproduced though it may be com- 

 pensated in some other way in cases where there has been a reversion 

 to primitive habits or surroundings ; (2) a rudimentary organ is 

 rarely re-developed ; (3) no new organ can be produced except as a 

 modification of some previously existing structure. 



And in applying these it should be borne in mind (i) that characters 

 which are adaptive that is liable to have been effected or affected by 

 external influences through natural selection are, as a rule, very untrust- 

 worthy. For instance colour and outline, hairs or spines on the larvse, 

 genital organs of imagos, can be of but slight importance in defining 

 groups ; (ii) secondary sexual characters should rarely be used to define 

 genera — if for no other reason on account of the difficulties they 

 place in the way of the student — but in cases where a large number 

 of allied species fall naturally into two groups and are yet not 

 easily separated by any other characters there is no scientific reason 

 why they should not be used ; (iii) characters distinguished by degrees 



