68 SUMMARY OF CURRENT RESEARCHES RELATING TO 



young transparent forms, there is a dark body, whence two trunks 

 proceed forwards to the eyes, and two, which may be considered as the 

 roots of the longitudinal trunks, pass backwards ; elongated ciliated 

 clefts, sometimes observable behind the second ciliated ring, probably 

 correspond to the ciliated pits which have been noted in other species 

 of this genus by Schmidt and Hallez. 



With a high power cilia in action may be detected at various 

 points of the body, and here and there we may see a plexus of clear, 

 extremely fine canals, which, after some continued pressure on the 

 cover-glass, may be made out over the whole body ; the primary 

 canals appear to be represented by wider ducts, which were most 

 often detected in the hinder parts of the body, and near the ovary an 

 orifice was seen on the ventral surface. 



After describing the generative organs, and pointing out the lower 

 organization of the male, and its shorter existence, which would seem 

 to be in correlation with this, Korschelt passes to the developmental 

 history ; in the ova there were two polar globules ; cleavage does not 

 commence for some time after deposition, and is unequal ; the smaller 

 sphere then divides equally, and then a smaller sphere is separated 

 off from the larger one. The large one then divides equally, and 

 one of these breaks up again. Later on, the large sphere again 

 divides, and the two are gradually overgrown by the smaller cells. 

 The two endoblastic, as well as the ectoblastic cells present pseudo- 

 podial processes, and it is not for some time that cilia become 

 developed. Later on, the eggs become very opaque. 



As to its systematic position, the author fi.nds that Dinophilus has 

 most resemblance to the Turbellaria, but it is remarkable for the 

 indications of segmentation, the arrangement of the cilia, the proc- 

 tuchous enteron, the position of the proboscis behind the mouth, and 

 the structure of the generative organs ; a new family must at least, 

 be formed for it. 



Life-History of the Liver Fluke.* — Prof. A. P. Thomas under- 

 took an investigation of this subject at the request of the late 

 Professor EoUeston on behalf of the Eoyal Agricultural Society. 

 The ravages made by the liver fluke have been very great (as many 

 as 3,000,000 sheep being lost by it in this country in the year 1879- 

 80), and the search for the intermediate host had previously been 

 futile. Mr. Thomas thoroughly searched meadows for every species 

 of mollusc likely to be an intermediary host, dissecting them without 

 success, until at length he succeeded in finding in the small Limnceus 

 triincatulus, a cylindrical Eedia, containing cercarise. The cercaria is 

 of tadpole shape, and has the peculiar habit of encysting itself 

 directly it is brought into contact with any solid object, the material 

 fur encystation being exuded from some lateral masses in the body of 

 the larva. For some time the inquiry was arrested because of the 

 author's inability to find any more specimens of the Limnceus, even 

 where they had abounded in the previous year. In July last, how- 

 ever, after floods, he found an ample supply. The snail in question 

 is more truly amphibious than a water-snail, is very small — about 

 * Quart. Joum. Micr. Sci., xxiii. (1883) pp. 99-133 (2 pis.). 



