BOTHRIOCEPHALUS LATUS. 97 



in the human body, and therefore especially interests the medical 

 man. 



Colour of the living worm bluish-white. Specimens preserved 

 in spirits change greatly in colour. Thus I possess Bothriocephali 

 which appear quite white on the sides of the ovarian organs, and 

 others of a dingy brownish-yellow colour. Eschricht proved that 

 the colour arises from the pigment which colours the egg-capsules 

 being dissolved in alcohol, and it is at the same time very pos- 

 sible that the browner or whiter colour may in part be owing to 

 the degree of concentration of the alcohol employed in their pre- 

 servation. 



Active scolex, or head. — The five heads hitherto examined by 

 me, of which I could only obtain one tolerably fresh, at the end 

 of March, 1855, were obtusely conical. The two lateral pits 

 (the analogues of the sucking discs of the Tcenia) are fissuriform ; 

 they appear, like the sucking discs on the feet of flies and mites, 

 on leeches, &c, rather to effect the adhesion in accordance with the 

 well-known laws of partial or total vacua, than to have anything 

 to do with the nourishment, which is probably introduced through 

 the entire skin. An actual opening on the head of Bothrio- 

 cephalus could not be detected any more than in other Cestoidea. 

 As a matter of course, the head must acquire many various forms 

 during life, and in spirit, specimens will retain the form which 

 the worm possessed at the moment of its death ; on which account 

 I must call such figures as Clerc's, and their copies (as for instance, 

 in ' Seeger-Wundt,' pi. ii, figs. 5 and 6), mere playthings. 



The neck is more distinct in young than in old individuals, 

 in which transverse wrinkling, i. e., segmentation, commences 

 immediately behind the head. 



The strobila, or jointed body. — The name of ventral surface is 

 given to the side on which the sexual apparatus opens ■ the oppo- 

 site one is called the dorsal surface. Each segment has four 

 margins — two slightly undulated, free lateral margins, and an 

 anterior and posterior margin, by which the segment is articu- 

 lated to its upper and lower neighbours in the colony. Although 

 the breadth preponderates over the length (in the proportion of 

 3 : 1), the form is nevertheless very variable, according to the 

 predominating contraction of the longitudinal or transverse 

 muscles. In the central line the segments are more or less 

 thick (up to 1"') and darker brown, according to their various 

 degrees of maturity and the charging of the ovaries and uteri 



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