TCENIA VULGARIS AND T^ENIA DENTATA. 419 



the unarmed species, since in his description Werner said "The 

 existence of a circlet of hooks could not have been overlooked if it 

 had been present with any distinctness." Instead of it, a median 

 papilla is mentioned, lying between the suctorial cups, which 

 recalled those of T. solium, except that they were larger, and visible 

 even to the naked eye. In length, general appearance, and form of 

 the joints these specimens closely resembled the common tape- worm 

 of man, and particularly the broad form (T. saginata), but there was 

 a striking difference between them in the doubling of the marginal 

 pores. 



But since two opposite peripheral openings sometimes occur in 

 the common human Tcenice, especially in T. saginata, and since such 

 joints, like other similar malformations, often repeat themselves 

 several times in the same worm, the supposition of Eudolphi that 

 Werner's worm belongs to the so-called T. solium seems very pro- 

 bable. 1 Joints with two lateral sexual openings are, however, rare in 

 the cystic tape-worms, while Werner credits the whole chain with 

 double openings. It is just possible that the reports in question are 

 due to the observer having erroneously generalised the peculiarities 

 noted, which had never been previously observed. It strikes one as 

 strange that a worm such as Werner describes should have never been 

 rediscovered during the lapse of a century. A Saxon physician, 

 Mcolai, did indeed describe a Tcenia dentata, 2 but this worm, about 

 which Nicolai said only that it " belonged to the rare species Tcenia 

 dentata" thus identifying it, according to Batsch's nomenclature, 

 with Werner's T. vulgaris has only a single generative opening like 

 the ordinary tape-worms. It is, indeed, nothing (as the accompanying 

 description proves) but the common T. saginata, with its unarmed 

 head and characteristic body-form. 



In this Tcenia dentata we find then, for the first time, a well 

 characterised 3 second species of large-jointed Tcenia infesting man 

 a species which is expressly designated as such, and as different from 

 the ordinary Tcenia solium. This difference holds true, however, 4 

 only in regard to " the flat transparent form " (our modern T. solium), 



1 "Entoz. hist, nat.," vol. ii.,p. 76. 



2 Neue Zeitschr. f. Natur- und Heilkunde, Bd. i., p. 464 : Dresden and Leipzig, 1830. 



3 Nicolai diagnoses his species as follows: "Taenia capite inermi acuminate sessili, 

 articulis dilatatis brevioribus, marginis utriusque lateris medio elatiore, alterius osculato, 

 majoribus transverse striatis, emarginatis." 



1 Nicolai was, indeed, quite unaware of this fact, and we can therefore understand his 

 report when he says that the host of the Tcenia dentata, shortly before expelling the 

 latter, voided also "a piece of Tcmia solium with unusually large joints, and about six 

 inches long " a piece which was obviously only the terminal portion of the subsequently 

 voided worm. 



