TiENIA SOLIUM. 215 



verse branclies are given off. Tliis I have recently ascertained from 

 tlie careftil injection of a perfectly fresh tapeworm. In the neigh- 

 bourhood of the head the two channels divide to form four distinct 

 vessels, which, according to Kiichenmeister, " are united quite at. 

 the front of the head by a common transverse branch, as thick as, 

 or thicker than, themselves." Kiichenmeister also thought he re- 

 cognized the existence of cilia vdthin these canals, such as have 

 undoubtedly been shown by Yan Beneden, Yirchow, Wagoner, and 

 others, to occur in allied cestodes. 



The eggs of Tcenia solium in their mature condition present a 

 globular figure, and are easily recognized by their remarkably thick 



Fia. 47. — Eepresentation of the mode of union of the latei-al and transverse vascular trunks in 

 Tcenia solium; outlined with the aid of a camera (x 40 diam.)— Original. 



shell, which surrounds the contained six-hooked embryo, leaving a 

 brief interspace between the surface of the latter and the inner 

 layer of the shell. They present an average diameter of -^^ of an inch, 

 the shell itself measuring about i^q' in thickness. As early as the 

 year 1856 I observed that many of the eggs, whilst still within the 

 uterine branches, displayed an outer envelope, very delicate in 

 structure, and totally dissimilar from the egg-shell proper. This 

 has since been more accurately described by Weinland, and espe- 

 cially, also, by Leuckart, who has, moreover, given a minute account 



