to Ye EB. 
FRAGMENTS OF THE COARSER ANATOMY OF DIURNAL 
LEPIDOPTERA. 
BY SAMUEL H. 
SCUDDER, 
CAMBRIDGE, MASS. 
6. THE LARVA OF HAMADRYAS IO, OF EUROPE. 
(Continued from p. 275.) 
Nervous system. The cephalic lobes 
are vertically subpyriform, the apex 
downward. The third and fourth body- 
ganglia are almost as near each other 
as the third is to the origin of the nerves 
‘which spring from the cord in advance 
‘ 
of the third ganglion, and the two rib- 
bons which connect them are a very little 
parted. 
Glandular system. Each of the silk- 
vessels is formed of an initial thread, 
0.05 mm. in diameter, which is about 
one-seventh of the entire length, and a 
cylindrical tube, of four times the size of 
the thread; this terminates abruptly in 
a pointed tip, from which a delicate 
thread trails, and this thread is attached 
to the under part of the sides of the front 
of the intestine ; the whole has a slightly 
wavy course, running at first near its 
mate on the under side of the body, as 
far as the second abdominal segment ; 
then, turning abruptly and a little upward 
to above the middle of the body, it con- 
tinues its former direction. 
Male generative organs. ‘The testes 
are situated in the middle of the dorsum 
of the fifth abdominal segment, as in 
Danais; they have only a slight rosy 
tinge across the middle, are 1.5 mm. 
long by half that width, and are subreni- 
form in shape. 
Female The 
ovaries in the female are situated in the 
same place as the testes in the male, 
and consist of a pair of long obovate sacs, 
2mm. long and about 0.5 mm. broad, 
bluntly rounded at each end, vertically 
disposed, approximated, but with the 
lower end curved outward; they are 
white, and each consists of a bundle of 
similar tubes. 
Rudiments of wings. Fach of the 
wing-pads in the full-grown larva is 
formed of a_ pellucid, compressed, 
rounded, nearly hemispherical sac, fully 
2 mm. long and a little longer than 
broad, abundantly permeated by white 
branching threads which do not seem to 
extend into the very base of the wing- 
pads; they are situated, base downward 
and convexity outward, just above and 
scarcely in advance of the base of the 
tracheae of the third thoracic segment, 
and at a corresponding position on the 
second segment ; the membrane is slightly 
opaque and granulated ; the permeating 
vessels are composed of bunches of 
numerous, minute and perfectly equal 
threads, varying in length and in num- 
ber; they appear to be hollow and are 
0.0025 mm. in diameter. A figure will 
be found in my work on _ Butterflies, 
already cited, p. 95. 
generative organs. 
