256 REPORT— 1851. 



ging from the ova, and in process of final extrusion through the external 

 orifice. The hatched young in the Leech have never yet been seen actually 

 by the author in this situation, although the parts are accurately corre- 

 spondent in the two worms. He cannot yet therefore state of the Leech what 

 he can from actual observation of the Earth-worm, that it is viviparous : the 

 superior duct (rf, d, &c.) of each ovarian uterus passes underneath the com- 

 mon longitudinal chord (//) and opens into the true testicular duct (c, c, 

 &c.), the two channels becoming united into one just before entering the 

 substance of the gland. It is desirable here to warn the anatomist, that in 

 practice the demonstration of this fact demands great patience and minute- 

 ness of dissection. At B, fig. 65, the ovarian uterus is seen still further 

 magnified. 



The author now desires to solicit special attention while he attempts to 

 explain the nature of the connexion which, according to his view, subsists 

 between the male organ or testis (fig. (iS, «, a) on the one hand, and the egg- 

 producing and egg-incubating organ (fig. 65, h, b, &c.) or ovarian uterus on 

 the other. It will, he trusts, suffice to elucidate satisfactorily the mechanism 

 of self-impregnation. The testicular bodies (a, a) secrete a true sperm fluid, 

 the cells of which can readily be detected by the eye both in the duct (c, c) 

 which leads to the great longitudinal chord, and in that (rf, d) which conducts 

 (as seen at g, g and B, g) into the ovarian uterus. The male seminal fluid 

 travels from the testes into the ovarian uterus along the superior of these 

 ducts. It may be actually detected in the cavity of this latter organ, where 

 it comes into immediate contact with the ova, whereby impregnation results. 

 The ova thus fertilized travel gradually onwards and reach the inferior half 

 (B, m) of the ovarian uterus. As in the Leech, these ova may be discovered 

 as ova at a point in the oviduct very near the outlet, it is probable that this 

 Annelid is oviparous. This fact, vvhich is little material, may be readily 

 determined by examination instituted at the right season. The curved 

 ovario-uterine membranous organ is really the part to which Duges applied 

 the name of " the cardiac vasiform heart," and which M. Quatrefages has 

 denominated " la poche secretrice ! ! " Duges made a near approach to a 

 correct descriptive anatomy of this organ. Quatrefages' delineations are 

 extravagantly erroneous. To each ovarian uterus a beautifully delicate 

 vesicle (e, e, e and B, o) is attached. It is connected with the superior duct, 

 or that which leads directly from the testis into the ovario-uterine saccule by 

 means of a very slender tubule (B, ii) rising from the vesicle (B, o). This 

 vesicle is the far-famed " respiratory sacculus" of the Leech; the duct («) 

 communicating between it and the superior half (B) of the ovarian uterus 

 is the wondrous respiratory heart-vessel, which for half a century has chal- 

 lenged the admiration of anatomists ! 



Let it now be seen what rational and probable physiological explanation 

 these parts will bear. In the first place, it is obvious that there exists in this 

 Annelid a direct communication by means of an open duct between the male 

 and female elements of the reproductive system ; that this system opens ex- 

 ternally only at the orifice of the oviduct (/, / and B, q) ; that these orifices 

 are designed for the extrusion of the ova or young from the body of the 

 parent, and not for the reception of the sperm-fluid into the ovario-uterine 

 tract ; that the male fertilizing secretion passes directly along the duct (d, d 

 and B,g) into the ovarian uterus (b, b) ; and that thus the process of self-im- 

 pregnation is literally accomplished, for it is not the sperm-fluid of another 

 individual that, fecundates the ova, but that of the same individual. 



This conclusion may be affirmed with confidence, since the median copu- 

 lative saccule (/, fig. Q5) into which the intromittent organ (k) of another 



