122 H. CHARLTON BASTIAN ON THE STRUCTURE AND 
they may be the rudiments of the water-vascular system ; but the protrusions from them 
are difficult to reconcile with this view. At all events, they appear hitherto to have 
escaped observation, as the only writer who has noticed anything different from the 
ordinary kind of worm with the single central body is M. Jacobson*, who mentions and 
figures young with “deux petits mamelons” in this situation, and, curiously enough, 
alludes to no other form t, and apparently did not recognize the internal sacculi at all. 
The young, in this stage of their development, are asexual, though the rudiments of 
some organ appear to exist just above the sacculi, which may ultimately develope into a 
genital apparatus (Pl. XXII. figs. 57, 58, 59, 60, f). 
'The description 1 have given of the mode of termination of the alimentary canal does 
not agree either with that of Mr. Carter} or of M. Charles Robin$; but I have noticed 
the cæcal termination so plainly, and in such a large number of specimens, that I have 
the less hesitation in advancing anything in opposition to such skilful observers. 
According to Carter, the central body at the root of the tail is a gland, and the, very 
narrow termination of the intestinal tube opens near it. Robin, on the contrary, says 
the intestinal canal terminates at the central spot of the cellular body, which he regards 
as à prominent anus. 
The aecounts given by different writers of the vitality of the young worms are rather 
contradictory: Carter regards them as very delicate, and but slightly tenacious of life, 
whereas the positive observations of Busk, Robin, Deville, and others go to prove that 
they may remain in a torpid state, when not perfectly dry, for even twelve or more 
hours, and then be restored to their usual life and activity by the addition of a little 
fresh water. They seldom live more than five or six days in pure fresh water; but then, 
as has been very reasonably suggested, it is scarcely to be expected that they should, 
seeing that pure water is not the natural habitat of the microscopic Filaridze, which they 
so closely resemble. Forbes|| has found that they lived longest (about twenty days) in 
fine impalpable clay but slightly covered with water and exposed to the sun's rays. 
General Observations on the Nature and History of the Guineaworm. 
Having investigated the anatomy of Filaria medinensis, several interesting questions 
have to be considered as to the real nature of the parasite, its early history, and the 
mode of production and ultimate fate of its young; and on these several points I will 
now make a few brief observations. 
Several years ago, before so much was known of its anatomy, Mr. Busk, in the very 
interesting paper before alluded to, suggested that the Guineaworm was an intermediate 
stage in the development of a nematoid worm, and analogous to one of the so-called 
2 nurses" of Cercarie, described by Steenstrup and other anatomists as a transition form 
in the development of the Trematoda. This opinion he based upon the facts, that no 
well-authenticated case of a male parasitic Guineaworm existed—all that had hitherto 
* Loc. eit. T In the figures which he gives, the young are also represented as being straight. 
+ Ann. of Nat. Hist. 1859, vol. iv i 
t Aun. of N i , vol. iv. p. 32. $ Gaz. Méd. de Paris, 1855, p. 363. 
|| Madras Quart. Journ. of Med. Science, 1837. T 
