190 ANATOMY. 



to the spermatheca, yet in the instances named above not, but into the 

 spermatheca itself. It is somewhat similar in Psocus, for here the 

 gluten vessel does not merely discharge itself into the spermatheca, but 

 lies entirely in it. For thus I interpret the purse-shaped appendage 

 found by Nitzsch * in Ps.pulsatorius, in which from one to four pedi- 

 culated knobs are enclosed which unite into one duct, which runs into 

 the excretory duct of the spermatheca. 



If TWO appendages are found at the duct it must be carefully 

 observed whether they are symmetrical in situation and form or not. 

 Two dissimilar appendages are found in most insects, (namely, the 

 genera Carabus, Harpalus, Melolontha, Lucanus, Meloe, Spondyla, 

 Sirex, Apis, Xylocopa, Tinea, Pterophorus, and Cercopis}. The one 

 is larger and broader than the other, purse-shaped, and corresponds 

 both in situation and function with the just described spermatheca. 

 In Melolontha (PI. XXVII. f. 16. ), Lucanus, Spondyla, and Cer- 

 copis it is a short-necked pear-shaped bladder; in Pterophorus the 

 same, but a short blind bag springs from it laterally ; in Xylocopa (PI. 

 XXVII. f. 17- ). Apis, and Tinea it has a longer very narrow neck ; 

 in Trichius a superior vascular appendage; in Sirex (PI. XXVII. f. 

 18. a), in which it is very large, at the part where the bladder con- 

 tracts into a neck, two tolerably long, pointed appendages are found ; 

 in Meloe it is constricted near the middle, and the lower smaller half 

 has a round auxiliary bladder, which discharges itself into it by a nar- 

 row canal. 



The second appendage (PL XXVII. f. 16 18. &.) is in general 

 much longer, but also thinner and vascular. This form itself, which 

 is common to all the secreting organs of insects, bespeaks its glandular 

 function. Observation has also taught us that a white glutinous liquid 

 is secreted in this organ, which, after the eggs are laid, disappears. 

 This gluten likewise covers the impregnated eggs, and it is very pro- 

 bably what fastens them together, as well as to other objects ; conse- 

 quently all appendages which are not spermathecae are called gluten 

 glands or vessels. With respect to their form, besides the simple, 

 tubular, and vascular form which are found in Trichius, Tinea, and 

 Cercopis, there is a clavate one found in Melolontha, and a vesi- 

 cular one furnished with a short neck in Meloe. In Xylocopa it is a 

 long gradually decreasing bag, which discharges itself by a very 



Compare Otrmar's Magaz. vol. iv. p. 281. PL II. f. 3. e. f. fig. 4 and 5. 



