218 Dr. Fritz Muller's Notes on 



The only thing which he could not perceive, whilst chasing 

 after the female, is that part of her sexual organs which 

 is now for the first time exhibited to him. Now, these 

 copulating parts of the female, when protruded, emit a 

 peculiar odour, and it is probably the individual odour of 

 the several females which determined the decision of the 

 male. In Dajjtonoura Lycimnia this odour is rather 

 faint, though quite distinct. It is very different from that 

 emitted by the wings of the male. 



The male of Daptonoura llaire is also provided 

 with " plumules " on the upper side of the wings, but no 

 odour was here j)erceived. At the same time he has a 

 tuft or pencil of broAvn hairs at the end of the abdomen, 

 on the ventral side. This tuft is not retractile, but applied 

 to the ventral margin of, and partially hidden between, 

 the anal valves ; it may be made to radiate in every direc- 

 tion and then emits a rather strong odour. This tuft of 

 hairs exists in the female also, but it is much shorter, and 

 I could not perceive any odour produced by it. 



The males of most species of CaUidryas have a chalky 

 spot on the upper side of the hind wings, near the base 

 and the anterior margin ; sometimes it is covei'ed by a 

 mane of long hairs, and sometimes the front wings also 

 have a similar spot opposite to that of the hind wings. 

 I perceived a musk-like odour issuing from this spot and 

 mane in CaUidryas Cipris, C. Arya7ife,au([ C. Trite. It is 

 unusually strong in Cipris, very distinct in Argante, 

 rather faint in Trite. In several males of this last species 

 which I caught two years ago I could not perceive any 

 odour, while I find it to be quite distinct in all those 

 Avhich I have lately examined. Are those butterflies pro- 

 ducing a more powerful perfume in 1878 than they did in 

 1876, or have my olfactory organs, by continual exer- 

 cise, become more acute in the meantime? According 

 to Boisduval, the chalky spot is wanting in the male 

 CaUidryas Euhule, and, indeed, it may easily be over- 

 looked through hardly differing in colour from the rest of 

 the Aving ; but it exists, and is easily discovered by its 

 opacity after denuding the wing. It emits a faint musk- 

 like odour. 



The females of CaUidryas Argante, Euhule, and pro- 

 bablj^ also of other species, show on either side of the 

 jirotruded copulating organs a small, shining, circular spot, 

 from which a very strong peculiar odour issues, in which 

 some volatile acid seems to predominate. 



