PSLCIL. 
Mulachius consist of ai pair of reddish, 
trilobed organs, one on each. side,. be- 
tween :the head and _ the. first. thoracie 
segment, and a similar, but. somewhat 
larger! pair of .bilobed: organs, one- on 
each side, between the metathorax. and 
first abdominal segment. 
are protruded by:the fluids of the body- 
cavity, but have muscles. for.their retrac- 
tion. ‘These organs were mentioned by 
Schiffer in 1754, by Sulzer” in 1761, 
and since that. time. more or less dis- 
cussed by Kirby and Spence®® (in whose 
work may be found mueh that is impor- 
tant and interesting on the glands .and 
odors of insects), by- Westwood,* La-’ 
boulbéne,®” Liegel,®® Klemensiewicz,* 
and by others whose papers IL.cannot at 
present cite, as I have not. collected the 
literature of this part of my subject with 
much thoroughness. ‘The function of 
these organs of .Maluchius is. not :deter- 
minediwith certainty. 
The larvae of certain: species of DLy- 
caena have: been found to attract ants; 
on account of: an opening upon the dor- 
sun of the: eleventh segment, which 
gives out a liquid apparently: containing 
sugar.- Upon the: twelfth segment, and 
evidently connected in function with the 
opening above mentioned, are two pro- 
trusile’ organs ‘covered. with. fine hairs. 
The fact of ants being attracted to these 
larvaeiwas first. observed, so far as I can 
learn, ‘by Esper; Petzhold;® in 1793, 
figured, and described with considerable 
minuteness; the appearance of: the pro- 
trusileiorgins on the twelfth segment of 
Lycaena biton, and mentions their occur- 
rence on .the larvae of ..other species. 
‘These organs. 
Gerstaecker,®™ in 1861. 
395 
Guenée,” in 1867, describes and figures: 
Wi.k: 
Edwards, in 1878, described and fig- 
these organs in Lycaena boetica. 
sured similar organs on Lycaena pseu- 
dargiolus and LL. comyntas, American 
Scudder,®. in 1881, 
Edwards’ figures, referring lLowever. to 
Guenée as the discoverer of. these organs. 
The function and structure of the evagin- 
able organs of the larva of Lycaena are 
not yet settled. 
Kvaginable. organs 
species. repeats 
were described 
from a: blattid, Corydia carunculigera, by 
The organs of 
Corydia, are . yellowish white, covered 
with hairs, and there are two of.them on 
each side of the insect, evaginable, from 
between the dorsal and ventral plates of 
the first and second abdominal segments.. 
These organs are .present in. both. male 
and female, but. are.not found in .the 
larva of Corydia.. Gerstaecker suspected 
them tobe of glandular.natuve. . Brunner: 
von Wattenwyl,® in 1879, deseribed an. 
3 - 
evaginable organ on the femora of acii- 
didae ; Burgess gives an abstract of shis 
paper in, Psycur, v. 3, p. 32... These 
‘organs in. acrididae and those of Corydia 
are the only evaginable organs of which 
_I have found mention in orthoptera.. 
-- The larvae of European species of Or- 
gyia (e.g., of O. auriflua) have long been 
known. to: have evaginable. warts upon 
their dorsum. Brief notice of these warts 
will be found «in works of. Schwarz, 
.Jérdens,*: Klemensiewiez,*. and other 
writers, but. I have found only the slight- 
est allusions to them in American species. 
Fitch”.in describing the larva of O. nova, 
mentions them; Coleman,®..in describ- 
