414 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, 1891. 



the latter had in the course of a longer existence departed more than 

 the former from the type of a perfect insect with six fully-developed 

 legs. 



Considering the size and streugth of most species of the genus 

 Pamlio, their quick high flight, and their generally restless habits, 

 it may seem strange that they should require any additional 

 protection in a resemblance to members of another species. Yet the 

 species I have mentioned are by no means the only ones that enjoy 

 it. There is a common but very curious butterfly of the same 

 genus, Papilio polytes, the females of which occur in three different 

 forms. The first, black, with a row of cream-coloured spots round 

 the posterior margin of its hindwings, resembles its own male ; 

 but the females of this type appear to be barren, never, so far as 

 has been ascertained, laying any eggs. The fertile females imitate 

 two other species, not, as in the instances I have yet mentioned, of 

 another genus, but the same, viz., P. hector, which has the body and 

 hindwings marked with red, and the tips of the forewings with 

 white ; and P. aristolocluce, also red and black, but with a large distinc- 

 tive blotch of white of irregular shape about the middle of each 

 hindwing. Indeed, the whole life of that remarkable insect, 

 P. polytes, would seem to be one long course of deception. When 

 first hatched, the larva, which is of sluggish habits and feeds on 

 the upper side of the leaves of the sweet lime, where it would 

 naturally be conspicuous to passing birds, so exactly resembles 

 both in colour and shape the droppings of some small bird, that 

 it may well deceive any except the most careful eye. As it grows 

 too large to avail itself of this resemblance, the larva gradually 

 changes in colour from its first dirty white and gray to the exact 

 shade of green of the leaf on which it feeds. When it assumes 

 the pupa form, it is of a bright green colour and is in shape exactly 

 like a bent leaf with its edo;es curled inwards. It then attaches 

 itself by the tail end to the stem of the food plant with its head 

 upwards, and inclines its body outwards at a angle of about 45 

 degrees. In this position its resemblance to a leaf is so complete 

 that it can with difficulty be distinguished on the spray even by 

 those who know it to be there. Then when the imago emerges, 

 if it bo a fertile female, on whom the perpetuation of the species 



