STRUCTURE OF CYSTICERCUS TENUICOLLIS. 



573 



slender bottle-shaped appendage of insignificant length (1*3 mm.), 

 which hung clapper-like and in a longitudinal direction in the interior 

 of the bladder. The interior of the clapper was of considerable width, 

 especially at the posterior end, but otherwise it had ne very distinctive 

 feature. The receptacle appeared in the form of a thin layer, which 

 was in marked contrast to the rest of the head. 



In a second pig, which had been fed a month before, the exit 

 from the liver, for which the first case was evidently a preparatory 

 stage, had just taken place. The Cysticerci, of which there were 

 four, were found free in the body-cavity. The former streaks had 

 disappeared, but in their place there were seen on the surface of the 

 liver four funnel-shaped pits, of appreciable width and more or less 

 considerable depth, out of which the bladder-worms had issued. The 

 borders of the place of exit were tolerably smooth and not much 

 injected, but deeper down there was to be observed a more or less 

 thick layer of a cheesy substance, evidently the remains of that 

 exuded mass which was found in the tubular streaks, and also in the 

 cysts formed by enlargements of the latter. 



The length of the Cysticerci was 11 or 12 mm., and the breadth 

 5 mm. In this case also the anterior end was markedly narrowed, 

 but to different degrees in the different specimens. 

 The head-process had still the same slender form, 

 although its length was now 2 '4 mm., and the first 

 rudiments of the suckers and of the circlet of hooks 

 were already distinctly visible on its under end. It 

 is true that both these structures were as yet very 

 far removed from their ultimate form. The suckers 

 appeared simply as hemispherical protrusions on 

 the inferior flask-shaped enlargement of the cavity 

 of the head, and were for the most part still with- 

 out the subsequent muscular layer, which was 

 differentiated from the surrounding wall only in 

 one specimen. Similarly, the hooks were some- 

 times represented only by the claws, which, with 

 blunt base, were situated as little cones upon the 

 floor of the cavity of the head ; yet, in spite of their softness and the 

 thinness of their walls, they had already attained their subsequent 

 size and form. The calcareous corpuscles within the head were few 

 in number and of insignificant size. 



It is hardly necessary to notice specially the differences between 

 the young Cysticerci and the muscle bladder-worms, especially of T. 

 solium. Apart from the actual history, the differences are indeed 

 marked enough, not only in the size and form of the bladder, but in 



FIG. 310. ^, Young 

 Cysticercus tenuicollis 

 (nat. size) ; , the 

 head-process ( x 15). 



