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XX. Notes on Brazilian Entomology. By Dr. Fritz 



MiJLLEK. 



[Read June 5th, 1S78.] 



Odours emitted hy Butterjiies and Motlis. 



Two years ago I ventured to suggest* that all tliose 

 various pencils, tufts or manes of hairs, all those chalky, 

 silky or velvety spots of peculiar scales, as well as the 

 recurved margins or other pouches enclosing pale buff or 

 white down, which distinguish the wings of the male sex 

 in many butterflies, might be odoriferous organs. This 

 suggestion might then have been justly censured as too 

 rash, being founded on the actual observation of odours in 

 four species only, and I felt, of course, the necessity of 

 testing this view by examining as to their odours all living 

 butterflies I might be able, to procure. I will here give 

 the results hitherto obtained, enumerating those spcciesf 

 in which distinct odours could be perceived, and I hope 

 the facts to be given will fidly justify my suggestion. 



Odours, as well as colours, may have been acquired by 

 butterflies either for protection or as an attraction between 

 the sexes. Protective odours appear to be in most cases 

 equally strong in both sexes, or sometimes stronger in the 

 females ; they may exist in the caterpillar as well as in 

 the perfect insect. When capable of voluntary emission, 

 they are emitted as soon as tho animal fears some danger, 

 e.g., when it is seized, and this may in some cases serve 

 to distinguish them from sexual odours. 



Sexual odours may be divided into two classes. 



Firstly, those which give notice to the opposite sex of 

 the existence of, and lead it the way to, the odoriferous 

 animal. Such odours must exist in many female moths 

 which atti-act the males from great distances. Among 

 butterflies the males appear to be guided more by the 

 colour than by the odour of their females. 



* Jenaische Zeitschrift fiir Naturwissenschaft, xi. p. 09. 

 •f I am much' indebted for the names of the butterflies mentioned in this 

 paper to Prof. A. Gerstaccker and Dr. O. Staudinger. 



TRANS. ENT. SOC. 1877. — PART III. (oCT.) 



