﻿254 THE ENTOMOLOGIST. 



before my machaon began to put in an appearance, and I did not 

 notice any pairings between the two species. It is a curious fact, 

 however, that for three or four years after a certain proportion 

 of my machaon larvas exhibited the blue-green ground-colour of 

 zolicaon when full-grown, though the pupae and imagines seemed 

 in all respects normal machaon. This state of things continued 

 until three years ago, when an irruption of field-mice into my 

 butterfly-house, and an exceptionally cold and wet August, 

 obliged me to replenish my stock of machaon. From my small 

 experience with zolicaon I should say that it is habitually double- 

 brooded, but though in the year in which I bred it unfavourable 

 weather conditions prevented me from obtaining pupge of the 

 second generation, its early date of emergence, and the fact that 

 April is usually a fine and dry month with us, should give it 

 some chance of establishing itself, if introduced into Southern 

 England. 



(7) Iphiclides ajax. — This beautiful insect is the principal 

 North American representative of the great branch of the 

 PapilioninsB known as the kite swallow-tails, and is said to 

 be common everywhere in the United States of America, where 

 its food-plant, Asiinina triloba, papaw (natural order Anonaceae, 

 i.e. custard apples) is found. Though it is a near relative of the 

 European Iphiclides jJodalirius, to which species it bears a 

 striking general resemblance in all its stages, unlike the latter, 

 which is the most refractory species in captivity with which I 

 have ever had to deal, it takes very kindly to the conditions 

 in my butterfly-house, feeding, pairing, and ovipositing freely 

 there. Apart from the objection that it is seasonably poly- 

 morphic in its native country, where the four varieties of its two 

 broods used to be mistaken for as many separate species, the 

 fact that the food-plant to which it would seem to be confined, 

 Asimina triloba, is only half hardy, and is grown but seldom in 

 England, would seem an insuperable objection to its ever 

 succeeding here. It has been suggested, I think by Edwards, 

 that as it has been observed in parts of the United States of 

 America where the papaw is not found, it must have some other 

 means of sustenance ; and with the view of discovering what 

 this may be I have tried to induce the imagines to lay their 

 eggs, and the larvse to feed on plants belonging to the families 

 represented here which are most nearly related to the Anonaceae. 

 In this I have been quite unsuccessful, the butterflies generally 

 choosing to die with their ova unlaid and the larvse to starve, 

 rather than exchange the usual pabulum of the species for 

 Cocculiis or Berberis or any other allied plants. In one instance, 

 in the absence of Asimina, one of my I. ajax oviposited on a 

 plant of Aristolochia sipho growing in my butterfly-house, but the 

 larvse died at once after feeding on it. On another occasion, 

 also in the absence of Asimina, 1 saw a female of the spring 



