756 SUMMARY OF CUE RENT RESEARCHES RELATING TO 



tube until they are mature, and this passage is the natural Gonsequence 

 of their development, increase in size, reciprocal pressure, and the 

 elasticity of the wall of the ovigerous diverticula. 



The fatty degenerat'on of the embryonic cells of the parenchyma 

 which furnish the necessary fond for the generative products is much 

 more extensive in the female than in the male. In addition to the 

 circumintestinal cavity, a cavity appears in the dorsal midrlle line ; the 

 complete degeneration at the time when the ova are deposited is very 

 marked. The parenchyma does not become regenerated, and does not, 

 as Vejdovsky supposes, form fresh gonads. Gordius rejproduces only 

 once in its life, and the females, shattere 1 by oogenesis, die soon after 

 they have deposited their eggs. 



Life-history of a Free Nematode.* — M. E. Moniez has made a 

 study of the metamorphosis and migration of Bhabditis oxyuris. After 

 the young have acquired a certain size, they fix themselves to various 

 Acari, and particularly to Holostaspis marginatus, in considerable 

 numbers ; sometimes, indeed, there are as many as sixty worms on one 

 Acarid. The young JRhahditis secretes a large chitinous plate, to which 

 it is suspended by a short pedicel ; the tissues and organs are detached 

 from the skin, which becomes altered in character, though remaining 

 perfectly transparent ; its e^.ements fuse, and the refractive granules 

 which mark the rudiments of the reproductive organs disappear. There 

 is thus formed an ovoid body which is much smaller than the larvae 

 at the expense of which it was formed, is completely detached from, 

 its old skin, and has the digestive tube in the form of a narrow longi- 

 tudinal cleft. 



From the commencement of metamorphosis a long tail begins to 

 appear ; in time the new larval form breaks away from the old one. 

 The author has not yet been able to trace the further history of the 

 second larva. 



Filaria medinensis in Animals.f — Prof. A. Eaillet points out that, 

 although Filaria medinensis is generally considered a human parasite 

 it is found in other Mammals, such as the Dog, Horse, Cow, and Jackal. 

 Though the pathological conditions which it determines are much the 

 same, it does not produce the painful complications seen in Man. 



Pseudalius alatus.| — Dr. 0. v. Linstow gives a description of the 

 form which, in 1848, Leuckart called Strongylus alatus ; the new account 

 differs considerably from the original, which was drawn up when our 

 methods of research were less perfect. The author remarks that the 

 six known species of the genus appear to flourish where there is an 

 abundant supply of oxygen, since they live in air-containing organs or 

 in the blood-vascular system ; thus P. alatus is found in the pharyngeal 

 cavities, mouth, and Eustachian tube of Monodon monoceros ; four species 

 are found in the air-cavities and blood-vessels of the Porpoise, and 

 P. ovis pulmonalis in the bronchi of sheep. 



Spiroptera alata, a new Nematode found in Rhea americana.§— 

 Dr. F. Zschokke found in the crop of a Bhea americana a male specimen 

 of Spiroptera. Apart from the size, it is distinguished from S. uncipenis, 



» Coniptes Rendus, cix. (1889) pp. 506-7. 



t Bull. Soc, Zool. France, xiv. (1889) pp. 73-6. 



X Proc. R. Soc. Ediub., xvi. (1888-9) pp. 15-7 (1 pi.). 



f, Centralbl. f. Bakteriol. u. Parabitenk., v. (1889) pp. 792-4. 



