NEMATOID EXTOZOA. 628 



study of the structure and actions of their Generative apparatus 

 has yielded many very interesting results, especially in regard to 

 the first formation of the Ova, the mode of their fertilization, and 

 the history of their subsequent development. — Some of the Worms 

 belonging to this group are not parasitic in the bodies of other 

 Animals, but live in the midst of dead or decomposing Vegetable 

 matter. The Gordius or 'Hair-Worm,' which is peculiar in not 

 having any perceptible anal orifice, seems to be properly a para- 

 site in the intestines of Water-Insects ; but it is frequently found 

 in large knot-like masses (whence its name) in the water or mud 

 of the pools inhabited by such insects, and may apparently be 

 developed in these situations. The AnguillulcE are Little Eel-like 

 Worms, of which one species, A. fluviatilis, is very often found in 

 Fresh-water amongst Desmidiece, Confcrvce, &c, also in wet Moss 

 and moist Earth, and sometimes also in the Alimentary canal of 

 Snails, Frogs, Fishes, Insects, and larger Worms ; whilst another 

 species, A. tritici, is met- with in the ears of Wheat affected with 

 the blight termed the 'Cockle ;' another, the A. glutinis, is found 

 in sour Paste ; and another, the A . aceti, was often found in stale 

 Vinegar, until the more complete removal of mucilage and the addi- 

 tion of sulphuric acid, in the course of the manufacture, rendered 

 this liquid a less favourable 'habitat' for these little creatures. A 

 writhing mass of any of these species of 'Eels,' is one of the most 

 curious spectacles which the Microscopist can exhibit to the un- 

 scientific observer ; and the capability which they all possess (in 

 common with the Rotifera and Tardigrada) of revival after desic- 

 cation, at however remote an interval, enables him to command 

 this spectacle at any time. A grain of Wheat within which these 

 Worms (often erroneously called Vibriones) are being developed, 

 gradually assumes the appearance of a black Pepper-corn ; and if 

 it be divided in two, the interior will be found almost completely 

 filled with a dense white cottony mass, occupying the place of the 

 flour, and leaving merely a small place for a little glutinous matter. 

 The cottony substance seems to the eye to consist of bundles of 

 fine fibres closely packed-together ; but on taking-out a small por- 

 tion, and putting it under the Microscope with a little water under 

 a thin glass-cover, it will be found after a short time (if not imme- 

 diately) to be a wriggling mass of life, the apparent fibres being 

 really Anguillulce, or the 'Eels' of the Microscopist. If the seeds 

 be soaked in water for a couple of hours before they are laid open, 

 the eels will be found in a state of activity from the first ; their 

 movements, however, are by no means so energetic as those of the 

 A. glutinis or ' Paste-Eel.' This last frequently makes its appear- 

 ance spontaneously in the midst of Paste that is turning sour ; but 

 the best means of securing a supply for any occasion, consists in 

 allowing any portion of a mass of paste in which they may present 

 themselves to dry up, and then, laying this by so long as it may 

 not be wanted, to introduce it into a mass of fresh paste, which, if 



