INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 445 



cessation of the functions of the scolex, which at that moment cease to 

 produce segments. It is then absorbed gradually, losing first its 

 booklets, then its suckers ; it diminishes insensibly in bulk, and 

 finally disappears. The Tcenia is then literally acephalic, but its 

 segments continue to grow, to sexualize, to fill with ova, and to detach 

 themselves successively down to the last. 



Thus, naturally, the parasite ends. 



The duration of life in the Tcenice. is doubtless very variable, 

 according to the species, and especially the medium in which it lives. 

 These phases are relatively short among the Tcenice of certain birds, in 

 two of which (^Tcenia infimdibuliformis and T. lanceolata), the author 

 was best able to follow them out. 



The specific determination of Tcenice by the presence or absence of 

 the booklets is therefore entirely insufficient, and a revision of the 

 nomenclature of these parasites has become necessary. 



New Taenia.* — M. Megniu has discovered ths vesicular stage of 

 a Tcenia in a jerboa, which he is not able to group under any of the 

 three old heads of Cysticercus, Ccenurus, or Ecldnococcus. Found in a 

 tumour it resembled a mass of fibrinous concretions, each part of 

 which was multitubercular ; it resembled a very tortuous root, 

 covered with distinct nodes, which again were charged with nodules ; 

 the smallest of these were of an elongated cordiform shape. The 

 interior was filled with a clear liquid which communicated with all 

 the parts, and so showed the vesic'e to be single; tlie internal surface 

 was provided with large cylindrical papillae, each of which proved to 

 be an invagiuated scolex, with four suckers and the characteristic 

 double crown of hooks. As the scolices belonged to the external 

 surface the cyst most resembled the Coenurus-stage, from which it 

 differs, however, by its remarkable form, and by the fact that the 

 buds remain attached to the parent vesicle. The author is unable to 

 say whether this " polytubercular Ccenurus " belongs to a new species, 

 or whether it owes its form to the special region of the body (face) 

 which it inhabits. 



In a more elaborate communication,! M. Mcgnin discusses the 

 view of Kuhn that there are two modes of proliferation among 

 Echinococci, one exogenous and one endogenous, and describes a 

 remarkable case of the fcu'mer mode, which he observed in an entozoon 

 in a horse ; in one of the muscles of the thigh there was found an 

 immense multilocular cyst, or rather a large number of contiguous 

 cysts differing in size, and separated hy tissue from one another ; 

 the contained hydutiils varied in size from a pea to a pigeon's egg. 



M. Megnin then details some examples of Cffinuri and Cysticerci 

 presenting the jthenomena of proliferation during the hydatid stage, 

 and conchides by briefly criticising the account given by Villot as to 

 that author's new form Stdjihifloci/stis ; he shows that as Staphylo- 

 cystis is " monocej^halous " and not " polycephalous " it ouglit ratlier 

 to bo allied to the Cysticerci than to the Echinococci, and that 

 M. ViHot is not the first to describe the phenomena of exogenous 

 proliferation. 



* 'Compten RtniUifl,' Ixxxix. (1S70) p. 1045. 



t • Journ. Aniit. ct i'hysiol.' (Robin), xvi. (1S8U) \k 181. 



