Miscellaneous. 363 



a solid intestinal canal filling all the body. M. Sclineider has already 

 rejected this curious interpretation ; but he regards the perienteric 

 tissue as a dependence of the muscular tissue, of which it would 

 represent the meduUary substance extraordinarily developed. 



It is generally admitted that the Gordiacea are without internal 

 organs of reproduction so long as they lead the life of parasites. 

 This may be true of Ilermis ; but as regards Gordius M. Grenacher 

 shows that the generative organs are already completely developed 

 during the phase of parasitism. It is not true that in these animals 

 the intestine terminates csecaUy, and that there does not exist any 

 opening playing the part of an anus. In the females the intestine 

 opens into the uterus immediately in front of the sexual pore, so that 

 this last is in reality the opening of a cloaca. The uterus, however, 

 soon divides into three canals, of which the two lateral are the ovi- 

 ducts, and the middle one is the direct continuation of the uterus, but 

 performs the part of a seminal receptacle. In the males there also 

 exists a cloaca in the form of a sac, presenting three orifices — one, 

 superior and median, leading into the intesdne, the other two, smaller 

 and lateral, corresponding to the deferent canals. 



The variable statements of authors with regard to the digestive 

 system of the Gordiacea are explained by the following facts, ascer- 

 tained by the author. So long as they are in the state of parasites, the 

 G'orrfn present a distinct mouth leading directly into an intestinal canal 

 lined with epithelium ; but at the time of migration, or immediately 

 before it, the mouth appears to be obliterated in the greater number 

 of species. It disappears then entirely, or there only remains a 

 slight, scarcely perceptible, trace of it. The anterior part of the in- 

 testinal canal seems also to become atrophied, and the place that it 

 occupied before is henceforth filled with the perienteric tissue. These 

 remarkable modifications had already been foreseen by M. Blan- 

 chard. In 1849, he expressed himself as follows : — ""We remark in 

 the Gordii, at least in the adults, the atrophy of the intestinal canal. 

 This sufiices, up to a certain point, to separate the Gordiacea from 

 the Nematoides ; and yet we are not in a position to describe clearly 

 the digestive tube of a single Gordius, for it would be necessary to 

 have observed it at difierent ages of the life of the animal." Most 

 zoologists of late years have approximated the Gordii to the Nema- 

 todes. Diesing has formed, under the name of N"matoda aproda, 

 a group including Mermis, Gordius, and the SpJicendarue. The 

 name proposed by the Viennese naturalist, at all events, cannot be 

 maintained : in the first place, the absence of an anus (tiiie, perhaps, 

 as regards Mermis and the Sj^licertdarice) will not hold good in Gor- 

 dius ; in the second place, we know now of true Nematodes appear- 

 ing to be without any anal opening whatever (Ichthyonema). The 

 results obtained by M. Grenacher seem to remove the genus Gordius, 

 more than is generally supposed, both from the true Nematodes and 

 from Mermis. M, Schneider has already pointed out a certain num- 

 ber of differential characters. To these we must now add the exist- 

 ence of a cloaca in both sexes of Gordius, in the male sex only 

 of the Nematodes ; then the existence in Gordius of that con- 



