INTERNAL ANATOMY OF INSECTS. 127 
passage*. A similar organ is found in Phryganea gran- 
dis®, 
iv. Jelly-secretor (Corysterium). ‘This is a remarkable 
organ, related to the preceding, which secretes the jelly 
of Trichoptera, some Diptera, &c.; this organ in the for- 
mer, at least in Phryganea grandis, is of an irregular 
shape, with four horns or processes ¢. 
Poison-secretor (Ioterium). 'Vhis organ, which is most 
conspicuous in the Hymenoptera Order, has not received 
much notice, except in the case of the Hive-bee and the 
Scolia: in the former, it is an elliptical membranous 
vesicle or reservoir, furnished at its lower extremity with 
a tube which renders to the sting, and at the other by a 
blind, long, filiform, secretory, vessel, which according ta 
Swammerdam divides into fwo terminal blind branches 4, 
though Reaumur could detect but one*; in this vessel the 
poison is secreted and stored up. In Scolia there are 
two secretory vessels, which enter the reservoir in the 
middle on each side‘. In the Scorpion, we learn from 
Marcel de Serres that the poison-secretor is clothed ex- 
ternally with a horny thickish membrane, containing 
two yellowish glands, composed of an infinity of spheri- 
cal glandules, terminating in a canal, enlarged towards 
its base so as to form a reservoir, and leading to the ex- 
tremity of the sting’. Connected by a slender tube with 
each mandible in spiders is a vessel with spiral folds, 
which seems properly to belong to this head—though 
* Herold Jbid. x. t.iv. f.1. p, u, y. Marcel de Serres Mem. du 
Mus. 1819. 141. > Gaede Anat. t. i. f. 3. d. 
Pe Tbids Wed. tf A 4 Bibl, Nat. t. xix. f. 3. 6. 
“(Reaumiy. 3/7. 6. XXIX. 7. (« $: f N. Dict. d’ Hist. Nat. xxx. 
388, & [bid. 427—, 
