336 Dr Eschricht's Inquiries conceminj 



rudimentary parts, on a diminutive scale. If, on the contrary, 

 the Entozoa be propagated like other animals, as extreme dif- 

 ficulty exists in their getting to their appropriate habitat, their 

 efforts must often be abortive and but rarely successful, and 

 hence their reproductive faculty should be great. In this lat- 

 ter alternative, we should expect to find the reproductive sys- 

 tem developed in the highest possible degree ; whilst in the 

 former, we should conclude, it would be reduced nearly to in- 

 significancy. How then stands the fact ? Concerning this 

 there can be no doubt. Not only is it known that the whole 

 generative system is immensely developed, but, moreover, its 

 very redundancy is so characteristic of the anatomy of intes- 

 tinal worms, that sometimes all their other organs have been 

 overlooked ; and it has happened to those engaged with the 

 anatomy pf these animals, that for a time they doubted whether 

 the common explanation of the organization were really the 

 true one, although eventually all such doubts were dispelled. 

 I shall adduce a few instances of what is here advanced, and 

 from my own observations. 



Sect. 2. Example from the Ascaris lumbricoides. — In the 

 Ascaris lumbricoides the external organs of generation have 

 been well represented by Mr H. Cioquet ; but their internal 

 structure seems not hitherto to have been accurately explored. 

 Each of the horns of the female organs consists of several 

 parts, of which the one next to the smaller extremity is the 

 ovary; the middle part is an oviduct, and the thicker extremity, 

 which unites with that of the second horn to form the com- 

 mon vagina, is the uterus. In the axis of the ovary is a cord, 

 which we may call the rachis, from its relation to the ova, 

 these lying around it in wreaths as in the flowers of the plantago 

 (Plate VII. fig. 1). But the ova in the ovary (figs. 1, 2,3, 4) have 

 a very different form from those in the uterus (figs. 5, 6), viz., 

 that of cones, the point being attached to the rachis, the basis 

 turning towards the external parietes. M. Cloquet's draw- 

 ings of these parts are but very imperfect in his beautiful mo- 

 nography. Dr Henle of Berlin observed and described them 

 in his treatise upon the Branchiobdella (Mliiler's Archiv 1835); 

 but although he had observed their beautiful vesicle (the 

 Purkingian), still he did not recognise them as ova, as was 



