408 



HISTORICAL ACCOUNT OF T^NIA SAGINATA. 



The bladder-worm generally inhabits singly the muscles of the ox, but 

 is occasionally found in the internal organs. It contains only a small 

 quantity of fluid, is of a roundish form, and hardly ever attains the size 

 of 1 cm. 



FIG. 238. Fio. 239. 



B 



FIG. 238. Head of Tcenia taginata in 

 contracted (A) and extended condition 

 (B). (x 8.) 



Fio. 239. Ripe segment of T. saginata. ( x 2.) 



Historical Development of our knowledge of Ttenia saginata and 

 the related Forms. 



We give Tcenia saginata (T. mcdiocanellata, Klichenmeister) the 

 first place in our description, partly because it is the only cystic tape- 

 worm with unarmed head which occurs in man, and partly also from 

 historic reasons ; for, in opposition to the widely spread belief that 

 the so-called Tcenia mediocanellata was only discovered a few 

 decades ago, a critical analysis of the existing information regarding 

 the human tape-worms shows it to be the very species that has been 

 longest known. For not only does the oldest complete picture of a 

 human Tcenia (that of Andry) unmistakeably represent Tcenia 

 saginata, but it is further quite indubitable that the e\//,iV#e? 

 TrXaretat, and also the identical rawiai, (or Krjptai) of the Greeks the 

 Lumbrici lati and Tcenice of the translators and commentators refer 

 especially to this species, and by no means to the T. solium of Kudolphi. 



The descriptions of the ancients, it is true, do not supply any direct 

 foundation for specific diagnosis. They are so unsatisfactory that in 

 their time they did not even suffice to establish the animal nature of 



