FORMATION OF WORM-PASSAGES IN THE LIVER. 571 



globule, which, on closer investigation, proved to be a young Cysti- 

 cercus tcnuicollis. 



The streaks were detached without great difficulty from the sur- 

 rounding parenchyma of the liver, and proved to be somewhat firm and 

 expansible cylinders, possessing a high degree of elasticity, and consist- 

 ing largely of a tough granular substance. The length of the cylinders 

 was from about 12 mm. to 15 mm., and their diameter between 1 mm. 

 and 1'5 mm., according to the place at which it was measured. 

 Instead of being regularly rounded, the streaks appeared almost 

 knotted, for they were either thick or thin, either constricted or pro- 

 vided with dilatations, which looked like knots, or with papillary 

 protrusions. Some of these protrusions formed true lateral branches 

 of a conical shape, which, after a short course, terminated in thin 

 solid threads. 



I confess that the nature of these structures somewhat puzzled 

 me, until I discovered, while extracting one, that it was connected 

 like a twig with a large branch of the portal vein. The connection 

 was certainly not quite direct, since a short vascular process intervened 

 between the latter and the streak, but although distinctly marked off, 

 it passed continuously into the streak. Under these circumstances, 

 there could be no doubt that the streaks represented modified blood- 

 vessels, so that the Cysticerci occupied the same position as in 

 Leisering's case mentioned above. 



The histological structure of the knot-bearing streaks was also 

 in agreement with this fact, inasmuch as the cheesy substance which 

 they enclosed contained, besides numerous granules and pus-corpuscles, 

 a number of uninistakeable blood-corpuscles. The dirty white or 

 yellowish walls of the streaks had certainly hardly any resemblance 

 to those of blood-vessels. They were much thickened and of an 

 almost structureless granular nature. At the most, one could only 

 perceive here and there a slight appearance of fibres. I must, how- 

 ever, remark that, on account of its indiarubber-like elasticity, the 

 tissue could only be submitted with great difficulty to microscopic 

 examination. 



As has already been mentioned, most of the streaks were unten anted. 

 We must assume, however, that these empty streaks also had inmates 

 originally, but that, as so often happens in such experiments, the 

 worms had perished and disappeared. Only in two streaks had they 

 been preserved and developed into young bladder-worms. 



The smaller of the two worms was a delicately walled, clear 

 globule, ovoid in form, and already of considerable size (6 mm. long, 

 3'5 mm. broad). It lay in an enlargement near one end of the other- 

 wise unaltered streak, and was surrounded on all sides by its granular 



