ORGANIZATION OF T^NIA SOLIUM. 519 



"We will afterwards consider the malformations of the bladder- 

 worms which are specially seen in those specimens found in the brain 

 of man. 



Organization of Tsenia solium. 



Sommer, " Ueber den Bau und die Entwickelung der Geschlechtsorgane von Taenia 

 mediocanellata und T. solium," Zeitschr. /. wiu. ZooL, Bd. xxiv., p. 499, 1874. 



The worm is distinguished not only by the size and general form 

 of its jointed body, but also by the shape and structure of its com- 

 ponent parts. Whether one examine a head or a proglottis, there can 

 be no possibility of confusing it with T. saginata. 



The Eipe Proglottides, which, in contrast to those of the last species, 

 are very seldom liberated singly, present characters even more striking 

 than the head, which requires for diagnostic purposes to be examined 

 with the microscope, or at least with a lens. The flat form and the 

 small quantity of parenchyma are at once evident when we press the 

 proglottides between two glass slides and hold them against the light, 

 or when we dry them on an even surface. 



It is, however, the structure of the uterus which in reality deter- 

 mines our decision, for although we have also the shortness of the 

 joints and their delicate transparent nature to help us, these charac- 

 ters are too deceptive to be implicitly relied upon. 



In general, the ripe uterus of Tcenia solium, with its few lateral 

 branches, and the loose nature of its ramification, gives one the 

 impression of being somewhat reduced and spare. This is specially 

 evident on comparison with T. saginata. On the whole, the general 

 appearance is the same, in so far as we have to deal with a median 

 stem and with lateral branches. But the median stem is shorter, 

 corresponding with the shorter joint, and the lateral branches 

 are further separate, amounting hardly ever to more than nine on 

 either side, and usually only to seven. I have not observed that they 

 alternate irregularly as Sommer says. In fact they seem to me to be 

 very symmetrical, except when neighbouring branches interlace, and 

 when a lateral branch sometimes indeed every alternate one 

 becomes abortive. The interlacing of these lateral twigs is on 

 the whole much more abundant than in. T. saginata, and more 

 tree-like, so that the main branch is often turned from its trans- 

 verse direction, and the secondary branches often corne to have a 

 somewhat longitudinal course, with exception of those at the ends, 

 which are spread out like a fan. This is always the case with the 

 anteriorly directed ramifications of the principal branches, which 

 from their large size, regular distribution and shortness, exhibit 



