ON A. NEW CESTODE LARVA PARASITIC IN MAN. 19 



the larger vessels divides into two, more or less clearly distinguish- 

 able lateral tracts, each of which, further anteriorly in the head, 

 runs out into a single main canal on both sides. I have no ob- 

 servation on the capillary vessels. 



On several occasions I have seen parts of the excretory 

 vessels excessively swollen for a longer or shorter extent, appa- 

 rently the result of an unnatural stowing of the fluid contents. 

 In fig. 18 is shown the head of an individual with an abnormally 

 swollen vessel, which at the extreme tip formed a loop and 

 was continuous with another of much smaller caliber. I have 

 been unable to exactly decide whether the vessels referred to 

 were the two lateral vessels communicating with each other at 

 the anterior end, or whether they represented ascending and 

 descending parts of a lateral vessel of one side. Frequently, as 

 the worms were observed under pressure between glasses, the 

 swollen parts of the excretory vessels were seen to be filled with 

 granules, apparently those of the reserve nutritive-matter that 

 must have found its way into the vessels by rupture of tissues 

 at some point. 



Of the parenchymal musculature there exists in the first 

 place a well developed system of longitudinal muscles, to the 

 action of which should be ascribed the contractility of the body 

 in length and the great retractility of the head. In them the 

 fibers form anastomosing bundles, running from the tip of the 

 head to the caudal end and present in all parts of the parenchyma 

 except in the periphery (figs. 16, 17, 21, 22). The bundles are 

 strongest and most numerous in the thick hind parts of the body. 

 Where a head bud arises from the mother-body they give off 

 branches into it as do also the excretory vessels. 



