ORIGIN OF CYSTICA AND CESTOIDEA. 63 



was fed with twenty-one cystic worms. On the 12th May, he 

 had five, and on the 14th, three more, so that this dog altogether 

 swallowed twenty-nine Cysticerci without their caudal vesicles. 

 On examining the dog on the 17th May, seventeen scolices were 

 found in his small intestine, of which the smallest was from three 

 quarters to one line in length, and the largest two lines. 



Third experiment. A young poodle swallowed, ou the 18th 

 June, twelve Cysticerci, of which, on the 23d of June, eleven 

 were found as scolices, from one to two and a half lines in length, 

 in the small intestine of the dead animal. 



It was then the body of the Cysticercus that had perished by 

 digestion, for the short thick body of these scolices was no other 

 than the neck of the Cysticercus. It showed no trace of trans- 

 verse wrinkles, and at its posterior end appeared to be cut off 

 transversely or obliquely, with a sort of hollow scar in the 

 middle, denoting the place where the hollow cylindrical body of 

 the Cysticercus had been detached in the dog's stomach. 



In uninjured individuals of Cysticercus tenuicollis one can 

 easily recognise that portion of the body which, in the small 

 intestine of the dog, becomes the scolex, by putting the uninjured 

 worms into lukewarm water. The worms seem to like the 

 warmth, which corresponds with that of the mammals they infest, 

 moving about in the most lively manner, and stretching out their 

 tubular body (previously contracted into a short, transversely 

 wrinkled, milk-white knot), with the head seated at its extremity 

 on a short, slender, and solid neck, for a long distance. This thin 

 neck appears to be sharply separated from the body of the worm, 

 and easily permits the line of demarcation to be seen, where, at 

 a later period, the head and neck become detached as the scolex. 1 



Fourth experiment. A young mongrel pug-dog received, at 

 various intervals, two- and-twenty cystic worms ; namely, on the 

 llth July, six; on the 14th July, fourteen; and on the 17th, 

 two. The examination of this dog when killed, on the 5th 

 August, proved that out of these two-and-twenty worms nineteen 

 individuals had passed as scolices out of the stomach into the 

 small intestine, and that their seventeen to three-and-twenty 

 days' sojourn had caused a remarkable growth in their abdominal 



1 Amongst the various figures of the Cysticercus tenuicollis, that given by Pallas, 

 (see his 'Miscellanea Zoologica,' 1766, p. 167, Tab. xii, fig. 10; or * Stralsundisches 

 Magazin/ Bd. i, 1767, p. 69, Taf. ii, fig. 10), exhibits the head and neck marked off 

 from the body of the worm as the future scolex, very distinctly. 



