8 THE ENTOMOLOGIST. 



have observed, a larger proportion will do so more successfully in 

 the artificial cocoon thus made than in the earth or other material 

 provided for them in captivity. Of course, if biological data are 

 desired it is the obvious thing to do, but does not seem to have 

 been hitherto regarded as a simple alternative to the usual and 

 more natural method. 



I first noticed that larvae would so pupate in the autumn of 

 1910, when an attempt at transferring external parasites to 

 other hosts (Noctuid caterpillars) failed, partly perhaps through 

 the intended victims too rapidly turning to chrysalids in the 

 tubes. Since then, by way of a test, I have placed all my larvse 

 under the same conditions, and they have all, without exception, 

 turned to healthy chrysalids : and in thus managing them I 

 have found several advantages, among which may be mentioned 

 the elimination of earth, &c., a decreased mortality w^hen 

 changing, being able to feed several species in the same cage 

 without an eventual mixing of chrysalids, and keeping in touch 

 with individual larvse through to the imago ; also, when travelling, 

 to have the difficulties of dealing with larvae then obtained, which 

 desire to pupate, removed is an advantage, as they can be 

 accommodated en route by carrying a supply of tubes and wool. 



I must add, though, that I have had nothing like a sufiicient 

 number of caterpillars to make a really comprehensive test of 

 the usefulness of this method. But perhaps some collector with 

 greater opportunities, and to whom large boxes of earth and 

 other impedimenta are cumbersome, may think it worth while 

 to experiment. 



St. Edward's, St. Mary Church, Torquay, Devon. 



AN ATTEMPT TO COLONIZE PAPILIO MACHAON 



IN ESSEX. 



By Professor Eaphael Meldola, D.Sc, LL.D., F.E.S., &c. 



In the November issue of the ' Entomologist ' (vol. xliv. 

 p. 365) there are three records of captures of this butterfly, one 

 at Bishop's Stortford, one near Kelvedon, and a third at Enfield. 

 The tendency to attribute the occurrence of the insect in districts 

 so far removed from its native habitat to the exceptionally warm 

 summer is quite justifiable, and may be the correct explanation. 

 I remember in 1895, when at Sheringham, in Norfolk, seeing a 

 boy sweep a specimen of P. machaon off a flower-head with his 

 net, but this locality is not very remote from fenny districts. 

 With respect to the recent captures in Hertfordshire, Essex, and 

 Middlesex, however, I think it only right to offer a suggestion. 

 In 1909, in the course of a conversation with the Earl of War- 



