460 CYSTIC STAGE OF MNIA SAGINATA. 



servant brought me word that it had died during the night. The 

 day before it had been ill and unable to stand, though it had taken 

 its milk as usual. 



An immediate post-mortem examination showed at once that the 

 feeding had been followed by a rich result. All the muscles, and 

 especially those of the breast and neck, and the psoas, were penetrated 

 by cysts, which had a breadth of T5-3 mm., and a length of about 

 2-4 mm. They were whitish, as if filled with chalky or tubercular 

 masses, such as had never been seen in the young cysts of Cysticercus 

 ccllulosce. Inside the exudation layer, which was surrounded by a 

 firm connective-tissue envelope, they contained a clear vesicle of 

 about 0-4-1-7 mm. in diameter. On cutting into the cyst this pro- 

 truded, and was recognisable as a young Cysticercus. 



These bladder-worms were round, sometimes pointed at one pole. 

 The internal cavity was small, and mostly confined by the conical 



vesicle to the distended end of the body. 

 Below the cuticle, which looked as if it 

 were continually shedding off scales, 

 could be distinguished first a thin layer 

 of delicate transverse and longitudinal 

 fibres (the first at intervals of 0*03, the 

 others of 0'05 mm.), whose muscular 

 nature was already evidenced by the 

 Fm. 264.-Young bladder-worms pow erful contractions of the little worm. 



of Tcenia sagmata, with rudimentary *_ . . 



head, (x 30.) Below this there was a thick layer of 



small cells difficult to isolate, and finally, 



clothing the internal cavity, large clear vesicles measuring 0'05-0'07 

 mm. in diameter. Between these there lay yellow balls of irregular 

 and partly ramified appearance. Vessels could not be detected even 

 in the largest bladder-worms, but the latter exhibited already the 

 rudiment of a head, which intruded for about 0*3 mm. into the 

 interior of the very wide bladder cavity, and which seemed to be 

 attached not to the equatorial zone, but to one end of the body. 

 There was as yet no trace of suckers. The interior of the head 

 showed hardly any terminal enlargement, but was in some of the 

 smaller bladder-worms still of a simple conical form. 



Although these cysts were extremely numerous, and in many 

 places lay so thickly together that their total number must have been 

 many thousands, yet it seemed at first as if the death of the animal 

 under experiment could hardly have been caused by them. It was, 

 however, indeed the Cysticerci which had killed the calf. Further 

 examination showed that the distribution of the parasites was in no 

 way confined to the peripheral muscles of the body. The internal 



