Miscellaneous. 363 



a solid iiilostinal caual filling all the body. M. Schneider has already 

 rejected this cui-ious iuterpretation ; but he regards the perienteric 

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

 represent the medullary substance extraordinarily develoijed. 



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 Mermis ; but as regards Gordius M. Grenachcr 

 shows that the generative organs are already completely developed 

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

 the intestine terminates ccecally, 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 intestine, 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 

 Go?-t7u' present a distinct mouth leading directly into an intestinal canal 

 lined with epithelium ; but at the time of migration, or immediate!)' 

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

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

 sHght, 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. Bhin- 

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

 the Gordii, at least in the adults, the ati'ophy of the intestinal canal. 

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

 the Nematoi'des ; 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 difiPerent ages of the life of the animal." Most 

 zoologists of late years have api)roximated the Gordii to the Nema- 

 todes. Diesing has formed, under the name of Nematoda ajn-octa, 

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

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

 maintained : in the first place, the absence of an anus (true, perha])s, 

 as regards biennis and the SjiJictndaricf) wiU 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 {Ichthijonema). The 

 results obtained byM. Grenachcr seem to remove the ^owxi?, Gordius, 

 more than is generally supposed, both from the tnie 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- 



