Dr. G. B. Longstaff's Bionomic Notes on Biitterjiies. 609 



tion to the scents of certain common British butterflies.* 

 Since then, dealing with South African material, he has 

 confirmed Fritz Miiller's important generalisation,-]- that 

 these scents maybe divided into two classes: — (1) those 

 which are presumably attractive, and are found (with few 

 exceptions) in the male insect only ; and (2) those which 

 are presumably repulsive, or protective, and are (with very 

 few exceptions) common to both sexes, often strongest in 

 the female. Further, Dr. Dixey has called attention to 

 the fact that the scents of the first class are agreeable 

 to the average human perception, while those of the 

 second class are for the most part disagreeable, or even 

 disgusting. J 



The additional facts that I am now able to supply 

 appear to confirm previous generalisations, though there 

 are a few apparent exceptions which require further 

 elucidation. 



One point may here be mentioned. In addition to the 

 scents hereafter dealt with, a " mousy odour" is in several 

 cases recorded ; this is not confined to one sex and is met^ 

 with in butterflies belonging to various families, but only 

 aff,&r death. This I believe to be a product of decomposi- 

 tion of either the animal juices or the fseces. The odour 

 resembles that of acetamide, and not improbably may be 

 due to that substance, or some compound ammonia. 



It will be noticed that in but very few cases have I 

 concerned myself with the special organs which are 

 involved in elaborating or distributing the scents. More- 

 over, the subject is now so familiar and the number of 

 species known to produce scents perceptible to man is now 

 so large, that it does not seem necessary to give the new 

 evidence in great detail, nor (as a rule) to deal with 

 species in which positive results have not yet been clearly 

 established. 



In the present state of our knowledge it seems most 

 convenient to deal with the various species observed in the 

 order of their systematic arrangement in our cabinets. 



* Dixev, Proc. Ent. Soc. Lond., 1904, pp. Ivi-lx. 



t Fritz Miiller, Trans. Ent. Soc. Lond., 1878, pp. 211-221. 



I Dixey, Proc. Ent. Soc. Lond., 1905, pp. liv-lix ; ibid. 1906, pp. 

 ii-vii. See also Wood-Mason and De Nice'ville, Joiirn. Asiatic Soc. 

 Bengal, 1886, vol. xv, Part II, No. 4, pp. 343-393. See also Long- 

 siaff, Ent. Month. Mag. 1905, pp. 112-115 ; do. Proc. Ent. Soc. Lond. 

 1905, pp. xxxv-xxxvi ; do. Trans. Ent. Soc. Lond., 1905, pp. 137-8. 



