57 



tines of dogs, and not of the human subject, I shall 

 not dwell upon a description of it. 



The scolex is contained in a vesicle which hardly 

 exceeds the size of an apple, and, according to Esch- 

 richt, generally measures 2| to 3 inches. This vesi- 

 cle consists of two similar membranes, arranged in 

 several concentric lamellae, of which one (the outer) 

 is thick and cartilaginous ; the inner one, thin and 

 membranous. From the inner surface of this latter 

 are seen small elevations, up to 4"', which are partly 

 very young scolices in the act of development, partly 

 further developed scolices of 10'", and partly repre- 

 senting the points where such scolices formerly sat ; 

 sometimes contained in cysts, sometimes not (Esch- 

 richt, Kiichenmeister). 



Within the fluid contained within this vesicle are 

 seen free scolices (resulting from the rupture of the 

 cysts, or their detachment from the membrane), some 

 furnished with the stalk by which they were attached, 

 and, on being pressed, form flat discs. From the hinder 

 portion near the stalk is seen a circlet of 30 to 40 

 hooks, arranged in a double row ; at its anterior 

 extremity, four sucking discs ; and within these latter 

 the calcareous corpuscles, measuring O'Ol to 0-02 mil. 

 (Kiichenmeister). 



2. Echinococcus hominis (E. altricipariens of Kiich- 

 enmeister). The mature form of this scolex is as 

 yet unknown, although Kiichenmeister thinks that 

 it may probably exist -in the human intestine, and 

 has suggested that the T. nana of Von Siebold 

 has such an origin, its scolex being nothing but 



