NEMATODA 237 



lule dans la diarrhee de Cochinchine," in 'Archives de Mede- 

 cine Navale' for September, 1878, pp. 214-224. 



Ascaris mystax, Rudolphi. This well-known helminth pos- 

 sesses aliform appendages, one on either side of the head. It 

 is of a medium size, the male measuring 2J" and the female 

 usually 3i" to 4" in length. Both as regards the size of the 

 alae and the length of the body it varies in different hosts. 

 Thus the variety infesting the dog has long been regarded as a 

 distinct species (A. marginata), partly from the circumstance 

 that the alao are less conspicuous, and partly because the indi- 

 viduals are often longer and thicker. I possess one specimen 

 from the dog measuring more than six inches in length. From 

 like causes the Ascaris leptoptera and other varieties infesting 

 the carnivora have been regarded as distinct species, but the 

 worm also varies in one and the same host. 



As remarked in my elementary treatise, the late Dr 

 Bellingham, of St Vincent's Hospital, Dublin, published in the 

 13th vol. of the ' Annals of Natural History/ an extended 

 catalogue of Irish entozoa, and in this list he recorded the 

 existence of a new round worm in man. He says of it : "From 

 the distinctness of the lateral membranes of the head I have 

 given it the name of Ascaris alata. 33 The catalogue was con- 

 stantly referred to by Dujardin, Diesing, and other systematists ; 

 but some of the continental helminthologists do not appear to 

 have had access to Dr Bellingham's more extended account of 

 this parasite as given in the first volume of the ' Dublin Medical 

 Press/ No. 7, Feb. 20th, 1839. I am led to this inference from 

 the doubt which some have cast upon the very existence of the 

 worm, although others, with more candour, supposed that Belling- 

 ham had only mistaken the species. Thus, Kiichenmeister (' Para- 

 siten/ s. 464, and in Lancaster's edit., vol. ii, p. 100) says : 

 11 The Ascaris alata, found in the small intestines of a man, is 

 probably only a young individual of one of the long-known 

 nematoda, if, indeed, it be a worm at all !" (The italics are 

 mine.) This statement was reproduced by Hulme in his 

 English edition of Moquin-Tandon's ' Elements of Medical 

 Zoology/ p. 341 and the French author himself evidently 

 shared the doubt expressed by other people. Dujardin (' Hel- 

 rninthes/ p. 156) admitted the species, as also did Diesing 

 (' Systema Helminthum/ p. 175), but the latter unluckily added 

 the following very significant suggestion : " An Ascaris lum- 

 bricoides capitis epidermide emphysematice inflata V 



