43 



specimens of this entozoon ; none of them, however, 

 perfect. The parasite was obtained from a " healthy 

 infant, nineteen months old, which had been weaned 

 about six months, and had had the usual diet from 

 that time. The worm was discharged without medi- 

 cine, its presence having never been suspected." 



Owing probably to the regularity and shortness of 

 the joints, and the presence of a yellowish spot situ- 

 ated about the middle of each joint, it was catalogued 

 as a Bothriocephalus until Dr. Weinland described 

 it as a new species of Tsenia. 



I quote his description of it : " The length of the 

 whole worm is between 200 and 300 mil. ; that is, 

 from 8 to 12 inches. There were pieces of 50 mil. in 

 length, consisting of very young joints, only -J- mil. long, 

 and 1 to 1 J mil. broad ; again, other pieces, about 

 100 mil. long, consisting, in their anterior half, of 

 white, immature joints, J to J mil. long, and 1J to 2 

 mil. broad, while the mature joints of the posterior 

 half, which are of a greyish tint (produced by the 

 eggs they contain), average 1 mil. in length, and 1J 

 to 2 mil. in breadth. In the young joints, the sides 

 form straight lines, the transverse diameter being 

 equal throughout the joint ; in the riper ones, they 

 are round and bulged, and the transverse diameter is 

 the greatest in the midst of each joint. One of the 

 pieces which is especially mentioned in the Catalogue 

 of Dr. J. B. S. Jackson, shows the form of the joints 

 when fully matured, and soon to be freed as prog- 

 lottides. They are in this specimen triangular in 

 shape, being narrow in front and suddenly broadening 



