122 Mr. O. H. Latter on the Prothoracie Gland of 
Thorax. 2. Perophora melsheimeri, Schiiffer (19), 
Lacosoma, 5 species of Nolide. 
Many Hemiptera. 
3. P. melsheimeri, Lacosoma, 5 species of 
Nolide. Imago of Bed-bug. 
Abdomen. 1. Hyperchiria varia, Dimmock (4). H. io, 
Packard (11). Hemileuca maia (id.). 
. H. mara. 
. H. varia ; H. io. 
» Ho maia. 
In Campodea staphylinus similar glands have been de- 
scrited by Packard (10) in abdominal segments 1 to 8, 
and in | to 7 in Madulis.* 
It is thus seen that in all the segments of the body, 
with the exception of the difficult segments of the head, 
glands of this nature are present within the limits of the 
Insecta. A closer examination of the accounts given by 
various authors affords very striking support to Bernard’s 
view alluded to above. 
Packard (11) describes the larva of Perophora mel- 
sheimeri as possessing small sternal tubercles on the 2nd 
and 3rd thoracic segments. There are four of these 
structures on each segment, two on each side of the 
middle line. The square area enclosed by these four has 
in its centre the mouth of an eversible gland. The same 
author describes similar structures on all the thoracic 
segments of Lacosoma, and mentions further the interest- 
ing fact that, according to C. D. Ash, the posterior pair 
on the 3rd segment are “ armed at the end with several 
crowded spine-like granulations.” The correspondence 
of the above structures with the prothoracic sternal 
gland of D. vinula is very obvious, especially when the 
lateral tubes of the latter are in the everted condition. 
Other species present a most striking series of tran- 
sitions towards the actual conditions found in D. vinwla. 
On the 6th and 8th abdominal segments of Heimileuca 
maia, according to Packard (10), are “indications of 
aborted glands (which are well developed in segments 1 
and 7 of the abdomen) encroached upon by two or three 
pale flattened minute spiniferous warts, which are wanting 
(invaginated ? O. H. L.) in segments | and 7.” 
The larva of Astyanaz archippus possesses in the Ist 
CO NI OD 
* Vide Carriére, Arch. f. mikr, Anatomie, xxxv., 1890. 
