THE TJESIJE OF LINNE AND PALLAS. 415 



Besides this Tcenia lata, however, there figured among the human 

 tape- worms a second species with short joints and median openings. 

 This form was first advanced by Linne as Tcenia vulgaris, 1 and was 

 said to be distinguished from Tcenia lata by its less broad body, and 

 by its exhibiting two openings, one behind another, on the more ex- 

 tended joints, while Tcenia lata had only one. Pallas, who, notwith- 

 standing his knowledge of Bonnet's second treatise, firmly believed 

 that Tcenia lata was provided with four suctorial pits, thought that 

 this T. vulgaris alone was furnished with the Bothriocephalus-liQa.d, 

 and expressed the doubt whether what Bonnet had described as " a 

 somewhat inflated delicate point, cleft longitudinally, but without 

 papillae or circlet of hooks," was really the head, and whether it might 

 not be simply " the snapped end of the chain." Eudolphi, however, 

 recognised neither this second short-jointed species, nor T. tenella, 

 another form distinguished by Pallas, but classed them both with T. 

 lata a proceeding which was afterwards followed by the majority of 

 investigators, and especially by Bremser. 



These short-jointed human tape- worms with median pores were 

 thus contrasted with the long-jointed forms, with laterally situated 

 " osculum," which from this time were, after the example of Linne, 

 generally (and always in our century) called Tcenia solium. Pallas 

 indeed departed from this rule by exchanging Linne's name for that 

 of T. cucurbitina, a name which seemed in some measure justified, 

 since he (Pallas) comprehended under it not only the long-jointed 

 human tape-worms, but, further, the related forms in dogs and cats, 

 which we now rightly regard as separate species. Among other 

 characters, they were all credited with a cephalic armature, as had 

 had meanwhile been repeatedly demonstrated by Tyson on the apex 

 of tape-worms infesting mammals. 



Linne had, moreover, already noted the circumstance that Tcenia 

 solium did not always exhibit exactly the same appearance in man. 

 After having described the typical form (Tcenia saginata), with refer- 

 ences to Andry, Vallisnieri, and others, he continues 2 as follows : 

 " In hominibus ssepius hie ipse vermis maxime planus, macilentus et 

 fere membranaceus ejicitur, instar vittae, quod ex eo forte est, quum 

 raro nisi mortuus ex homine expulsus obtineatur, et sic mortuus 

 spiritu vini committitur, ut fibras suas ab irritatione spiritus contra- 

 here nequeat, quemadmodum fit in vivo verme spiritui indito." It is 

 further added that specimens in this condition somewhat resemble 

 Tcenia vulgaris. 



The same fact was also noted by several of the later investigators, 



1 " Amcenitates academics," vol. ii., p. 69 : Holmiae, 1762. 



2 Loc. cit., p. 69. 



