PERIPLANETA ORIENTALIS. 
229 
Note on a New Organ, and on the Structure of 
the Hypodermis, in Periplaneta Orientalis. 
By 
Edward A. Mincliin, 
Keble College, Oxford. 
With Plate XXII. 
The organ which I have to describe, and of which I have 
been unable to find an account in the latest works on the 
anatomy of the Cockroach, consists of two pouch-like invagi- 
nations of the cuticle lying close on each side of the middle 
line, between the fifth and sixth terga of the dorsal surface of 
the abdomen. In the normal condition these are covered by 
the fifth tergum, but when this is removed they are seen as 
two shallow pouches lying beneath the transparent intertergal 
membrane and opening to the exterior by two slit-shaped 
openings, which face backwards (fig. 1). They are lined by 
a continuation of the chitinous cuticle, which forms within 
the pouches numerous stiff, branched, finely-pointed hairs, 
beneath which, i. e. on the side towards the body- cavity, are 
numerous glandular epithelial cells. Fig. 2 shows a section 
longitudinal to the body of the animal passing through one of 
the pouches. The figs, v and vi are placed above the fifth and 
sixth terga respectively ; d. denotes the upper dark layer, and 
t. the lower transparent layer of the chitinous cuticle, and h. 
the hypodermis of at least two layers, and resting on the 
basement membrane (6. m.). At p., the most posterior point 
of the fifth tergum, the transparent layer of the cuticle and the 
uppermost layer of the cells of the hypodermis are continued 
VOL. XXIX, PART 3. NEW SER. Q 
