146 ANIMAL PARASITES. 



especially of their uteri and collections of ova, at once distinguish 

 the four large species from the human intestine, and predicate 

 what species of cestode worm are to be expelled. 



The mature segment of a Bothriocephalus latus is characterised 

 by the collection of its dark-brown ova in the middle of the seg- 

 ment, and by the separate opening of the vagina and penis in 

 the middle of its ventral surface ; the ova are oval, and, when 

 pressed, open with an operculum. 



The mature segment of Taenia solium has a uterus with a tor- 

 tuous median stem, from which the lateral branches, which rarely 

 exceed 9 — 15 in number, are given off in an irregularly alter- 

 nating manner; the branches are dendritic, but often only on 

 one side ; the purus genitalis is simple and lateral, and the ova 

 are roundish, and rough externally. 



The mature segment of Taenia mediocanellata has a straight 

 median stem, from which numerous (30 — 50) regularly opposite 

 lateral branches are given off; these are undivided, or at the 

 utmost bifurcated, and run horizontally through the segment, 

 and usually parallel to each other. The poms genitalis is lateral 

 and simple, and the ova are rough externally, and rather more oval. 



The mature segment of the Taenia No. 3 — the Taenia of the 

 Hottentots — has a median stem and branches, very similar to 

 T. mediocanellata, but the lateral branches at the upper and 

 lower margins run more obliquely from above downwards, or 

 vice versd. The branches which approach most closely to the 

 upper and lower margins acquire a form which nearly resembles 

 that of the teeth of a rake ; the poms genitalis is lateral, and the 

 ova resemble those of T. mediocanellata, but the embryo is 

 armed with more distinct booklets than in the other Taeniae of 

 the human subject. The most distinctive character, however, is 

 formed by the ridge which runs through the whole body of the 

 Taenia. The rest is best explained by the figures on PI. I and II. 



The general prognosis is favorable, with the exception of 

 T. solium. Thus, as long as it is not proved that the embryos of 

 this last Taenia cannot make their escape in the intestine and 

 become converted into Cystic, cellulosae in the tissues of the same 

 man, its presence in the intestine is always a subject of fear and 

 apprehension. For this reason these animals, when they do not 

 trouble their host, may be left to themselves, with the exception 

 of T. solium, against which I always operate, on precautionary 

 grounds, whenever I meet with it. Bothriocephalus latus is the 



