Cees [liv, lv 
still retained their distinctive qualities. During the present 
year I have had the opportunity of testing many of the 
African butterflies in the same way, and I now propose to 
give details of some of the facts that I have been able to 
observe in relation to their property of scent-production. In 
this investigation I have had the great advantage of the co- 
operation of Dr. Longstaff, who had already, at my suggestion, 
made a careful examination of the odours of many Asiatic 
butterflies, as recorded in the volume of our Transactions for 
1905, pp. 61-144. Iam further indebted to him for permission 
to include his own impressions of these perfumes. 
“The scents now dealt with are of two kinds; these 
may be roughly distinguished, in reference to their probable 
functional significance, as attractive and repulsive. 
“The first class is, I think, of importance in courtship as a 
means of sexual attraction and possibly of recognition. The 
odours belonging to this class, in all the species with which I 
am here concerned, are confined tothe male sex. They have 
a general family likeness, recalling in most cases the perfumes of 
flowers, or of various aromatic vegetable products such as lemon- 
peel, spices, vanillaand chocolate. They are, I think, in nearly 
every instance agreeable to the average human perception. 
“The scents included in the second class are probably made 
use of for defensive purposes. They occur, as a rule, in 
species which we have grounds for believing to be dis- 
tasteful to some at least of the usual enemies of butterflies. 
They are found, as would be expected on this supposition, 
in both sexes; and they are for the most part disagreeable 
or even disgusting to the human observer. It is perhaps 
conceivable that both kinds of odours may occur in the 
same individual; though such instances, if they exist at all, 
would appear to be rare. 
“The Pierine scents that have been examined belong to 
the first class—probably serving the purpose of sexual 
attraction and perhaps also of recognition. I subjoin a list 
of the African species in which they have been noted. 
“Catopsilia florella, Fabr. When the tufts of hair-like 
scales present in the male are exposed by separating the 
fore- from the hind-wing, they emit a very strong, sweet 
