INTERNAL ANATOMY OF INSECTS. 153 



small orbicular vesicle, connected by a short tubular foot- 

 stalk with the main reservoir a . A similar organ was dis- 

 covered by Malpighi in the imago of the silkworm, who 

 denominates it the uterus ; to which indeed it seems ana- 

 logous, and which he also regards as a reservoir for the 

 sperm for the gradual fecundation of the eggs b . But in 

 that fly the organ is of a rather different shape, and the 

 interior vessel terminates in several spherical vesicles c . 

 John Hunter by the most decisive experiments, such as 

 covering the eggs of the unimpregnated moth, after ex- 

 clusion, with the liquor taken from the spermatheca in 

 those which had been impregnated, and rendering them 

 fertile, he demonstrated that this organ was a reservoir for 

 the spermatic fluid, to impregnate the eggs as they were 

 ready for exclusion, and that coition and impregnation 

 were not simultaneous d . It is not improbable that in 

 all insects whose eggs are gradually laid, this provision 

 for their gradual fecundation, if carefully sought for, 

 might be detected e . Rifferschweils is of opinion, that 



a Herold Schmetterl. t. iv./. 1. x. &c. PLATE XXX. FIG. 12. d. 



b De Bombyc. 36. c Ibid. t. xii./. 1. I. and/. 2. O. M. 



A Philos. Trans. 1792. 186. 



Swammerdam, in dissecting the female of Oryctes nasicornis, dis- 

 covered a blind vessel opening into the vagina, and at the other or 

 inner extremity not terminated by any secretory tube, containing 

 a yellowish matter, that seems analogous to the organ mentioned 

 in the text ; and in the hive-bee he found a similar organ covered 

 with air-vessels, which he supposes to be connected with the Colle- 

 terium (see above, p. 132.), and which he states to contain a slimy 

 matter. Bibl. Nat. i. 151. b. t. xxx./. 10. g. 204. b. /. xxix./. 3. t. 

 Perhaps likewise the organ discovered by M. L. Dufour in Scolia, 

 which he imagines to belong to the poison-secretor, and which he 

 describes as a sac consisting of a double tunic, the exterior one mus- 

 cular and the interior membranous, and filled with a blueish-green 

 gelatinous matter (A 7 . Diet. (THist. Nat. xxx. 388.) may be a spcr- 

 mathcca. 



