HELMTNTHOLOGY UELMINTHES CESTODES. 475 



Fowl, the Pike, arid Roach ; the Reporter, however, is unable 

 to extract any proper generic character, from Dujardin's 

 description, by which Proc/lottis can be said to be distin- 

 guished from Tfenia. In the ova, provided with three 

 simple oval egg-cases, of Proglottis pistellum, from Sorex 

 araneus, Dujardin found the well-known embryos, charac- 

 terized by six booklets. The head of this Tapeworm 

 possesses a proboscis with hooks. The first seven to four- 

 teen joints are asexual, and constitute the neck of the animal, 

 the five or six succeeding ones contain only the male organs, 

 for at the anterior end of each of these joints there is 

 placed an oblong transversely-lying testis, and a lemniscus 

 opening laterally. The next one or tw r o joints appear to be 

 hermaphrodite, and the five last exclusively female. This 

 view of the genital apparatus of the individual joints of the 

 Proglottis may easily give rise to misconceptions. The 

 gradual development of the joints from the neck backwards 

 takes place in this instance in the same way as in the other 

 Cestoid worms ; only the development of the male organs in 

 the invariably hermaphrodite joints commences earlier and 

 proceeds more rapidly anteriorly than that of the female ; 

 in the most posterior, so-termed, female joints, the oviducts 

 are so crammed with ova that the male organs, which are 

 never wanting in these joints but have already performed 

 their function and become collapsed, are driven altogether 

 into the background by the female propagative organs. 



Respecting the history of the Bothriocephahis latus, 

 Castelli (Isis, 1843, p. 618) has communicated the notice 

 that he has met with this Tapeworm, which does not occur 

 in Italy, in two Swiss soldiers serving in that country. 



A Bothriocephahis from the duodenum of Salmo umbla, 

 and which is probably new, has been discovered by H. 

 Kolliker (Miiller's Archiv, 1843, p. 91), and employed for 

 the investigation of the history of the development of the 

 Cestoid worms. He found the youngest ova of this Bo- 

 fhriocephahts globular, and constituted of a vitelline mem- 

 brane, germinal vesicle, and probably a germinal spot ; 



