DISTOMUM H^EMATOBIUM. 277 



testicles ; between these and the penis-sac the small, round 

 germ- stock, and behind this a blind sac (vesicula seminalis 

 inferior) in which a lively spermatozoid-swarming could be 

 detected. In the midst of these organs lie the oviducts in many 

 convolutions, and externally, quite at the sides of the body, the 

 branched yelk-sacs. The excretory organ also opens here in the 

 middle of the abdomen, and evacuates the well-known charac- 

 teristic corpuscles. The skin is beset with small spines directed 

 backwards, which are particularly numerous and distinct in front. 



Bilharz collected some hundreds of this Distomum in one 

 case, and still left a great number in the body. Its influence 

 upon the animal economy is unknown. 



Therapeutics. Where the existence of these animals is 

 ascertained, from specimens passing off with the faeces, I consider 

 it would be advisable to expel them with the ordinary anthel- 

 mintics (see the treatment of Tanice and of Ascaris lumbri- 

 coides}. Castor oil with oil of turpentine, and calomel alone or 

 with jalap, are particularly to be recommended. 



The following two Distoma live in closed cavities or organs. 



4. Distomum hamatobium (Bilharz). 

 Plate VI, figs. 113. 



Descriptio vermis secundum Bilharz. 



Distomum hcematobium, sexu distinct o. 



Maris corpus molle, albidum, filiforme, parte anteriore totius 

 longitudinis octava vel nona (" trunco") depressa, lanceolata, subtus 

 plana vel concava, supra leviter convexa 3 superficie l&vi, reliqua 

 corporis parte (" cauda") terete, margine corporis ab acetabulo 

 ventrali retro utrinque versus faciem ventralem conflexo, eoque 

 modo canalem " gyncecophorum" efficiente, apice postico, attenuate 

 superficie externa tuberculi spiligeris conferta, superficie canalis 

 interiore linea mediana laevi et partibus lateralibus aculeis minu- 

 tissimis scabra. Acetabulum oris apicale subinferum, triangulare. 

 Acetabulum ventrale sub finem f( trunci }) insertum, orbiculare 

 eadem magnitudine cum acetabulo oris. Superficies utiiusque 

 acetabuli granulis crebris minutissimis scabra. Canalis cibarius sine 

 pharynge musculari ante acetabulum ventrale in 2 paries divisus, in 



