2:u 



ZOOLOGY 



SECT. 



slender nerves passing from these to the sucki -rs. and of two 

 longitudinal nerves which run backwards through all the proglot- 

 tides to the posterior end of the body. The ganglia obviously 

 correspond to the ganglia on the nerve-ring of th< Li\ er-Fluke. 



The excretory organs consist of a richly bra) id- d system of 

 excretory vessels. There are four main trunks ( \ can. excrct.^, 



which extend throughout the entire length <> ; ,dy, two near 



each lateral margin. The two pairs of longii ! vessels are 



connected together in the head by a ring-like vessel, and in each 

 proglottis near its posterior margin by a straight, transverse, 

 connecting branch. Posteriorly the longitudinal trunk opens into 

 a pulsatile caudal vesicle, comrnunicajklg with the exterior. These 

 main trunks of the stem give origin to a number of 



bran in rum give oft' numerous fine canalicules, or 



capillaries, terminating in flame-cells similar to those of Distomum 

 hepatiemi,. 



The reproductive organs (Fig. 183) repeated in each fully 

 'formed proglottis, are in essential respects very similar to those of 



can,, excret 



ca,n,.ejccret 



va.s.def 



por.gerf. 



r'n.. 1S3. A proglottis of Tsenia solium with mature reproductive npp .'iratus. can. 



longitudinal excretory canals with transverse connecting vessels ; </!. vit. vitultHre-ghnrds ; 

 /. longitudinal nerves; or. or. ovaries; p<><\ gen. genital pi .re ; xctifii. shell-glands; 

 wter. u t urns ; rn ; /. vagina; I-H.X. */</. vas deferens. The numerous smaU round bodies are thu 

 loljes of the testes. (After Leuckart.) 



the Liver-Fluke. In the most anterior proglottides they are not 

 developed ; it is only at about the 200th proglottis that they first 

 appear: at first the male parts of the system are alone differen- 

 tiated : then in the succeeding proglottidesjtill we approach near 

 the posterior extremity of the body, the female organs are like- 

 wise developed. In the most posterior segments modifications and 

 reductions of some of the parts take place, owing to the great 

 increase in size of the uterus. Tin 1 male portion of the apparatus 

 consists of the testes with their cffnrnt <lm:tx, the vas /A/r/ry/x {vas. 

 '/';/.), and the cirrus or _/>/>/ /x, with its we. The testes consists of 

 numerous rounded lobes situated nearer the dorsal than the ventral 



