212 Dr. Fritz Miiller's Notes on 



Secondly, those odours which do not serve as a guide, 

 but as an excitement to the opposite sex. They appear to 

 be by far more frequent in the males, though occurring 

 also in some females. Odom^s of both classes" will of 

 course be agreeable to the attracted or allured sex : but in 

 the first class the odour of the female is agreeable to the 

 male because it is the odour of his female ; while in the 

 second class the odour emitted by the male is agreeable 

 to the female, males with that peculiar odour having been 

 preferred. The two classes may, of course, graduate into 

 each other. 



Colours, whether acquired as an attraction by the males 

 or for the sake of protection by the females, are often 

 transmitted to the opposite sex ; with sexual odours of 

 butterflies this seems but very seldom to be the case. 



I shall not enter into minute descriptions of the 

 odoriferous organs,* nor mention those very numerous 

 species, Avhich, though evidently possessing such organs, 

 emit odours too faint for human noses ; the only object of 

 this paper being to state that there are a large number 

 of male butterflies provided with special organs for the 

 production and emission of peculiar odours. 



BUTTERFLIES. 

 Family 1. NYMPH ALIDiE. 



Subfamily 1. Danain^. 



A. Dana'is yrowp. 

 Dana'is Erippus, Dana'is Gilippus,'\ Lycorea [sp. ?] 

 and Ituna llione have a pair of finger-like hollow pro- 

 cesses at the end of the abdomen, into which they can be 

 retracted ; they bear a tuft of black hairs, radiating in 

 every direction and emitting a rather disagreeable odour, 

 Avhen the processes are fully protruded. This odour is 

 extremely strong in Lycorea and Ituna, less so in D. Gil- 

 ippus, and rather faint in Z>. Erippus, differences exactly 



* A series of papers describing odoriferous oi'gans of various butterflies 

 and moths have been sent for publication to the " Archivos do Museu 

 Naeional do Kio de Janeiro." 



f Kirhij (Synon. Catal. of Diurn. Lepid. 1871, p. 7) doubts whether 

 D. OiUppus may not be a variety of D. Erippus^. But the caterpillars 

 are quite dilfereut ; those of Eilppiis have two, those of G'dippnx three, 

 pairs of " tentacles." The microscopical structure of the " sexual spot" of 

 the male also shows considerable differences. 



