40 ENTOMOLOGICAL SOCIETY 
the statement that the odor is thus retained until the insect desires to dis- 
perse it. It is claimed that the insects have the power to open the various 
sacs or folds containing the scales, and, where the scales are protected only 
by their compact massing, they can be erected, so as to expose their entire 
surface. Thus it is calculated that Pamphila comma can expose a surface 
of 160 square mm. from a spot less than one millimeter square! The au- 
thor cites Weismann for the statement that the wings of the Lepidoptera 
contain connected and living cells, capable of secreting the odor-giving 
substance, and claims the presence of minute glands at the base of these 
scales. 
As a separate group of odor-giving organs, the tufts on the feet and body 
of many species are instanced. A number of these are described ; but they 
all take the form of a pencil of hair capable of expansion and ordinarily 
concealed in a cavity of the leg. In Hepialus hecta, in which the arrange- 
ments for protecting the tuftings are very abnormal, Dr. Bertkau has found 
the cells secreting the odor-giving substance. In many species a distinct 
odor is perceptible when the leg containing the tuft is crushed. Another 
group of organs is found in the abdomen, also usually so concealed and 
protected as to be invisible. 
In Danais gilippus, erippus, and arckippus there is between the eighth 
and ninth segments on each side a closed sac, which, opening on pressure, 
exposes a ball of fine hair that gives out a distinct odor. 
Many of the Glaucopidce have the power of protruding from the abdo- 
men odor-giving filaments, while many Zygcenidce have within the side 
pieces (After-klappen) glands filled with a sweetly-scented fluid. Didonis 
biblis is especially favored with odor-giving glands. Not only have both 
sexes a sac between segments four and five of the abdomen, which exhales 
a very unpleasant (protective) odor, but the males have, in addition, a pair 
of glands or sacs between segments five and six, from which proceeds a very 
agreeable, heliotrope-like smell. That the Sphingids, or many of them, ex- 
haled a very distinct odor has been long known, and Fritz Miiller, in 1876, 
located it in a tuft of hair at the base of the abdomen, which fits into a 
groove in the first segment, so as to be ordinarily invisible. Reichenau, 
in 1880, described at length the structure in Sphinx ligustri, and our author 
summarizes his discoveries. 
Mr. Smith added the following remarks : 
Prof. Dalla Torre offers little or nothing that is actually new; but he 
brings together and collates the almost unknown and inaccessible notes 
of other authors, and produces a decidedly interesting and valuable paper. 
Within the last year or two a number of structures similar to those cited, 
have been observed by American authors, and one very remarkable struc- 
ture in Cosmosoma omphale was discussed at the late meeting of the Ento- 
mological Club of the A. A. A. S., where none of the gentlemen present 
were able to give any satisfactory explanation of the structure. Attention 
was also drawn to a structure in Lygranthwcia marginata, which, in some 
