18H6.] MR. H. J. ELW'ES ON THE GENUS FARNASSIUS. H 



in the allied genus Euryades proved Von Siebold's ideas to be in the 

 main correct. 



Burmeister, in his 'Atlas de la Republiqne Argentine,' Livr. ], 

 p. 10, pi. 3, figures and describes the structure of the abdomen in 

 Euryades diiponcheli and E. corethrus, which is analogous to that 

 in Parnassius. 



He says that the copulation in Euryades is very protracted, and 

 though he gives no details of the manner in which the af)pendages 

 of the female are formed, yet he states that the secretion forming 

 them proceeds from the male, in the same manner as in Pitrnassius. 

 He does not, however, suggest any use for the appendages nor state 

 whether there is any variation in them. From the figures it is clear 

 that they are almost identical in the two species comprising the 

 genus. 



Dr. Hagen, in the'Comptes Rendus Ent. Soc. Belgique,' vol. J 8, 

 p. Ivi, savs that he is convinced that the appendage of Euryades is 

 an analogous structure with the pouch of Parnassius, and that the 

 only difference is one of form, which may be easily understood if one 

 allows that the fluid which composes it is emitted on the two sides 

 during copulation. 



Burmeister, in Stett. ent. Zeif. I87-J, p. 427, says of Euryades, 

 that he is convinced that the female appendages of this genus are 

 not developed before copulation, and that the substance of which 

 the apparatus is composed is completely homogeneous with that of 

 Parnassius. He suggests that the secretion flows from the male 

 during the act of copulation, and hardens afterwards in the form 

 which it took during its exudation from the male's body. 



Though there was every reason to believe that Reutti's observa- 

 tions, as far as they went, were accurate, yet wishing not only to un- 

 derstand more fully the manner in which the pouch was formed, but 

 also its function in the life of the insect, I went in 1884 and 1885 

 to the Alps to study the question, where the insects are abundant; 

 but owing to various difficulties, which are detailed in my account 

 of the life-history of P. ajmllo, delius, and mnemosyne, I failed in 

 observing for myself the necessary details. I was, however, fortunate 

 in procuring through Herr Heine, of Leipzig, a numberof pupaeof P. 

 apollo, which were sent to the Insectarium of the Zoological Gardens, 

 and have afforded ample details as to this species. Mr. Thomson's 

 notes are here printed verbatim, but I was able to gather some further 

 details which are worthy of note. 



He found that Parnassius apollo requires about an hour after 

 emerging from the pupa, in order to perfect and harden the wings, 

 and that the colour of these is at first of a yellowish tinge, but soon 

 fades to white when exposed to the sun. This yellowish tinge I 

 may add is found in some very fresh examples of almost all the 

 species, and may be taken as an indication that the insect is only 

 just out of the pupa. 



He found that the copulation of the sexes takes place immediately 

 after the complete development of the insects, provided that the 

 sun is bright and warm, but that on dull days the insects remain 



