Parasites. 579 



The Zoo-parasites may be sub-divided into Entozoa 

 and E6lozoa, the Entozoa embracing such creatures as 

 ' take up their residence in the soft and hard tissues 

 as well as in the cavity of the digestive organs of their 

 human and animal bearers,' such as the intestinal worms ; 

 the E6loza embracing ' all kinds of parasites having the 

 habit of residing in or upon the surface of the body of man 

 and animals'. Of both these sub-divisions British Guiana, or 

 rather the inhabitants of British Guiana, furnish numerous 

 examples — notably, amongst the Entozoa, being the 

 various worms inhabiting the intestines, such as the 

 Ascarides, of which the common round worm (Ascaris 

 lumbricoides) is an only too familiar example, the 

 Anchylostomum duodenale, chiefly or solely met with 

 in tropical climates, the whip-worm (Trichotephalus 

 dispar), thread-worm (Oxyuris vermicularis) and the 

 various forms of tape-worms (Bothriocephalus latus, 

 Tcenia solium, &c.). Of the Entozoa which 'take up 

 their residence in the soft and hard tissues of the body,' 

 may be mentioned the Guinea-worm (Filariamedinensis) 

 inhabiting the skin and subcutaneous tissues, the Filaria 

 sanguinis hominis a minute parasite existing in the 

 blood and associated with certain special tropical 

 ailments, and the Trichina spiralis inhabiting the 

 muscles of tfee body and giving rise to the serious disease 

 called Trichinosis. 



The E6lozoa likewise are only too well repre- 

 sented in British Guiana, and although generally 

 perhaps looked upon as more loathsome than their less 

 known confreres the Entozoa, are not capable of pro- 

 ducing the extreme ravages to the human frame as are 

 the latter ; but at the same time they leave to the un- 



