EXTOZOA — NEMATOIDEA. 
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has formerly done (v. Arch. 1840, ii. p. 189, and 1841, ii. p. 342). He 
also found, like Valentin, the coverings of the pupae, or cysts, in the 
cavity of the body of the same frogs : many of these cysts contained 
Filaria similar to those in the blood. If the cysts in the intestine were 
whitish-coloured, they contained small Filaria, and no worms were found 
in the blood; but if the cysts were brown, they were then without 
Filaria, and the blood was full of them. Their head was truncated, the 
tail-end pointed, and in their interior, Vogt could distinguish an intes- 
tinal canal and ovary. This ovary, in the opinion of the reporter, could 
have been nothing else than the remains of the yolk, which remains for 
a longer while, as a cellular mass, in the already escaped embryos of 
the Nematoidea. Vogt found, in the abdominal cavity of a frog, two 
gross of female Filaria more than an inch long, with developed sexual 
organs, swollen with eggs and embryos. As the latter resembled the 
little worms observed in the blood, Vogt thought that the presence of 
these Filaria in the blood of frogs might be explained as follows : — The 
pregnant females deposit their brood in the abdominal cavity; the 
young perforate into the great vessels, circulate for a while with the 
blood, and at last become fixed to a particular spot ; they now become 
surrounded by fibrous layers, and, after attaining to maturity in their 
cysts, break through into the abdominal cavity, in order there to deposit 
their young. Whether these Filaria do attain to maturity in the cysts 
the reporter very much doubts, as neither he nor Creplin have found 
encysted Nematoidea with the sexual parts developed. 
Miescher has seen the small Nematoidea described by Vogt almost 
uniformly in the blood of frogs (ibid. p. 191). 
The reporter may add, from a treatise by Charles Lee, which he has 
just seen, that a Filaria papillosa was observed in the anterior cham- 
ber of the eye of a horse at New York, which seemed to occasion no 
uneasiness to the animal, and only rendered the aqueous humour muddy. 
(Sniim. Amer. Journ. vol. xxxix. 1840, p. 278.) 
Barkow (Ubers. der Arbeit, and Verand. der schles. Gesellsch. fur 
vaterl. Kult. 1839. Breslau, 1840, p. 93) has hazarded the conjecture, 
that the Entozoa of those warm-blooded animals which hybernate, do 
also fall into the dormant state when the lower temperature of their 
habitation renders them less inclined to motion. He found, in the 
stomach of a hedgehog, killed during its winter sleep, several specimens 
of Physaloptera clausa, without any signs of life, but which became 
lively so soon as they were placed in warm water. 
Steenstrup has hinted (Op. ant. cit. p. 110) that Sphcerularia homhi 
(v. Arch. 1838, ii. p. 297) may perhaps be the nurses (keimschlaiiche, 
germ-bags) of certain Nematoidea, an opinion which the reporter finds 
improbable, since Sphcerularia possesses distinct sexual parts with real 
eggs, Avhich had entered on the process of evolution. 
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