740 SUMMARY OF CURRENT RESEARCHES RELATING TO 



for the four families — Tricliotraclielides, Strongylicles, Filarides, Asca- 

 rides ; (b) EhabditiformsB for the Rhabditidae, and (c) the Anguillulidje 

 for the PlectidcB, Dorylahnidce, Monh/steridce, Leptolaimidce, and 

 Tylenchidce ; and he concludes with a description of the following 

 new species : Plectus de Mani, P. triplogaster, Cephalohus gracilis, 

 JRliabditis heterurus, and Diplogaster macrodon. 



Formation of the Cyst in Muscular Trichinosis* — M, J, Chatin 

 finds that when the entozoon has made its way into the muscles it 

 soon becomes adherent to the interfascicular tissue, the connective- 

 tissue elements of which rapidly undergo hypertrophy, and there 

 appears an amorphous mass. In this there are to be recognized 

 products of differentiation, such as fine protein granules, and, later 

 on, glycogenous granulations ; the appearance of which ought not, as 

 the author thinks, to cause any surprise, as they are always to be found 

 in very actively forming parts. Soon after their appearance consider- 

 able changes take place in the j)eriphery of the granular mass ; the 

 new formation becomes indurated externally, and the elements form 

 a parietal zone which becomes notably thicker. He finds that 

 the sarcolemma takes no jjart in the formation of the cyst ; when, 

 indeed, the Nematoid first adheres to the sarcolemma instead of to 

 the intermediate tissue it rapidly dies, and there is no new formation 

 of any kind, excepting only a fibrinous exudation. 



Development of the Liver-Fluke.f — Mr. A. P. Thomas here 

 gives an account of his experiments on this subject, in which he 

 was, we believe, assisted by the late Professor RoUeston. He 

 describes the eggs of the parasite as giving a dark brown colour and 

 sandy appearance to the bile, and in some of the smaller ducts forming 

 a mass which completely plugs uj) the lumen. These eggs are oval in 

 form, and have a yellowish-brown chitinous shell ; the length varies 

 from '105 to '145 mm., and the breadth from '066 to "09 mm. As 

 to the number of eggs produced by a single fluke, Mr. Thomas thinks 

 that they " may be safely estimated at several hundred thousands." 

 In one case he obtained 7,400,000 eggs from the gall-bladder of a 

 single sheej), in the liver of which there were about 200 flukes ; this 

 gives an average of 37,000 eggs to each ; but these were found in the 

 gall-bladder alone ; " the liver must have contained as many more, 

 and eggs had been passed copiously by the sheep for some months 

 past." 



The embryo can only develope at a temperature lower than that of 

 the mammalian body, as was proved by experiment. But the temijera- 

 ture must not be too low. In the winter, for example, there is no 

 further development. Light appears to have no influence, but 

 moisture is an important factor. Further, it is curious and important 

 to observe that " all the eggs under the same conditions do not produce 

 embryos in the same time ; " no explanation of this difference can yet 

 be offered, but its importance on the question of the dangerous con- 

 dition of any given field is sufficiently obvious. 



* Comptes Kendus, xcii. (1881) pp. 1528-30. 

 t Jouru. R. Agric. Soc, xvii. (1881) pp. 31. 



