1046 General Notes. [October, 
a white web with minute meshes; the cocoon not being a loose 
one; and on the oth it assumed the pupa state. The chrysalis is 
brown, sometimes green on the head and thorax, including the 
limbs: and wings; with an obscure dorsal row of irregular spots, 
forming a nearly continuous line or band; and a lateral row of 
large obscure spots. On the second segment from the end of the 
legs are two warts. The spiracles are unusually distinct. Length 
15™". The moths issued in May in the breeding boxes.—d, 5. 
Packard. 
Tue Limes oF Insecrs—In his inaugural dissertation Dr. F, 
Dahl considers the structure and function of the limbs of insects. 
After the usual historical preface the author considers, withouten- 
tering into anatomical details, the external structure of the leg, but 
devotes more space to the mechanism of the muscles. The insect 
limbs are then regarded from the point of view of their special func- 
tions, 7. e. the limb as an organ of motion, whether on the ground, 
in water, or in the air. Under this head are given histological de- 
tails, with figures filling three plates and showing the fine anatomy 
of the tarsal joints, claws and pulvilli as well as hairs, as well i 
the external appearance of the last tarsal joints of insects of d 
ferent orders. ; i 
he limbs are then treated of as organs of prehension, includ: 
ing reproductive purposes as well as their uses in ceon oe 
combing the head, antennze and mouth parts, with sketches bees 
different kinds of combs growing on the fore-legs of beetles, 
and wasps, etc. 
Poison GLANDS IN THE SKIN OF THE CECROPIA Ca 
Dr. Dimmock, in the course of a valuable article cn “ Some § 
which open externally on insects,” in Psyche, for fate 
October, 1882 (published in February, 1884), states that, 2 i 
cropia caterpillar “be examined carefully, the black spines Up 
its red, blue, and yellow knobs, or tubercles, will be seen to able 
easily from the tubercle, and a clear yellow fluid of agg ati 
odor to ooze from each opening left by the injury. By o very 
the tubercle with a pair of forceps, the same strong odor ae in 
noticeable, and by this mode of treatment one has no i , 
proving that each tubercle, small or large, blue, y ehon a sec- 
contains the odorous fluid. The red tubercles are seen, x 
tions cut with the microtome, to be divided into com chase 
the cavities of each spine opening into a compartment at vile, $0 
end. The spines themselves are quite rigid and very in the 
that they break away at a slight touch, and leave a boe 
tubercle, out of which the odorous fluid pours, pushed bY refilly, 
Pressure. This fluid, which I have not examined CW ig 
but which I hope later to study chemically, is stro ne ine 
o litmus r, but causes a purple precipitate suggests a 
utions.”” ‘The y : 
t 
sol odor given out by these glands § 
