342 SUMMARY OF CURRENT RESEARCHES RELATING TO 



to genetic relationsliips, and suggests that these observations may 

 only be the commencement of the raising of a new set of problems. 



Entozoa confounded with Trichinae.* — P. Megnin points out that 

 Trichina spiralis is not the only worm which may become encysted 

 in the peritoneum or the muscles ; and after showing how various 

 naturalists have been led to speak of Trichinae where none exist, 

 he gives an exact account of the character of T. spiralis. It is an 

 extremely delicate, filiform worm, with a very narrow anterior 

 extremity, in the centre of which is the small round mouth ; the 

 posterior end is truncated, and has the anus in its centre. The in- 

 testinal tube is straight, and has a distinct cesophagus, stomach, and 

 rectum. The agamic encysted forms are chiefly found in the 

 muscles of animal life, but they are sometimes to be seen in the 

 adipose tissue and in the muscles of the intestinal walls. Around 

 the spherical space occupied by each coil, there is a deposit of 

 colourless granular matter, which is more abundant towards the two 

 poles, and has generally an elongated conical form. A single cyst 

 or capsule rarely contains more than one worm. Later on, the walls 

 of the cysts become incrusted with calcareous salts, within which 

 the Trichina may continue to lie. After its death fatty degenera- 

 tion occurs. 



The European mole is often in spring infested, on the external 

 surface of its stomach and intestines, with small cysts, in which a 

 worm is coiled up. The integument of this parasite is markedly 

 striated, the mouth has a papilla, and the body is more cylindrical 

 than that of Trichina ; in addition to these and other characters 

 there is a conical tail. This is the larval stage of Spiroptera strumosa. 

 In some Spanish and other lizards there may often be found a 

 number of cysts scattered throughout the body; here again the 

 anatomical characters are those of Spiroptera rather than of Trichina ; 

 and, in fact, the organism is S. ahhreviata. Other forms from other 

 animals, including the frog, are described ; one belongs to the genus 

 Dispharagus, all the rest to Spiroptera. The author justly points out 

 that a careful com]iarative study should be made on all occasions 

 when it is stated, or believed by the observer, that he has to do with 

 the genus Trichina. The paper will be very useful to all who are 

 engaged in researches of this kind. 



Life-History of the Liver Fluke. t — Professor E. Leuckart states 

 that his search for the young of Distomum hepaticum has at last 

 been rewarded ; specimens of what he regarded as Limnceus minutus 

 were obtained from Dresden, and many of these were, after a few 

 days, found to have in their respiratory cavity, and generally, near 

 the kidney, a number of the embryos .with which he had in vain 

 attempted to infect larger snails. More or less rounded bodies were 

 found more or less closely packed together, and attached by a 

 delicate cellular envelope to the operculum ; there could be no doubt 

 as to the relation of the parasite to the embryo, not only was there 



* Bull. Soc. Zool. France, v. (1881) pp. 189-98 (2 pis.). 

 t Arcli. f. NaturgcKch., xlviii. (1882) pp. 80-119 (1 i)l.). 



