FRAGRANT BUTTERFLIES—CLARK 423 
DELAYED APPEARANCE OF THE PERFUME 
Various observations giving negative results have been recorded 
on butterflies remarkable for their strong fragrance. It some cases 
it is stated than the examination was made on males recently 
emerged from the chrysalis. Very fresh butterflies appear always 
to be nearly, often indeed quite, odorless, while very ragged indi- 
viduals sometimes are very fragrant. It appears to take some time 
after the wings are fully formed and functional for the odoriferous 
secretion to become diffused sufficiently to give the characteristic 
perfume. 
OTHER ODORS EXHALED BY BUTTERFLIES 
Besides these pleasant odors arising from the hairs and scent scales 
and confined, or almost entirely confined, to males, there are also 
other sorts of odors possessed by butterflies. 
If you take a living female of any of our common fritillaries 
(Argynnis cybele, A. aphrodite, A. atlantis [figs. 57, 58, pl. 13] or 
Brenthis myrina) ‘and gently squeeze the abdomen there will appear 
from between the last two segments on the upper side a double patch 
of soft dull light orange tissue. On further pressure there suddenly 
pops out just in front of this a pair of thick blunt processes like short 
thick horns which give off a strong and nauseating smell resembling 
that of the forked red or orange organ which the caterpillars of all of 
our swallowtails protrude from the first thoracic segment when they 
are disturbed. 
Among the heliconians of the American tropics, close relatives of 
the fritillaries, the females have similar organs, though not quite so 
large, which also give off a disgusting smell. 
The males in both these groups have a single unpaired organ of 
the same nature which is very small and situated between the upper 
ends of the terminal valves where in our fritillaries it is very notice- 
able because of its bright orange color. 
In the females of some pierids, as Catopsilia (fig. 14, pl. 2) and 
Melete, there are organs like those of female fritillaries which give 
off a peculiar odor. 
In one of the nymphaline butterflies (Didonis) both sexes from 
the upper side of the abdomen between segments four and five 
extrude hemispherical protuberances which have a strong and rather 
disagreeable smell. The male has in addition a pair of similar pro- 
tuberances, white in color, which are extruded between segments 
five and six and give off an agreeable odor comparable to that of 
heliotrope. 
In various forms the insects of both sexes give off a rank, mouldy, 
cockroachlike, or similarly disagreeable, in rare cases pleasant, odor, 
