50 



LEECHES 



each account for 5-10%. This is a much higher proportion of 

 ammonia than is produced by earthworms and is accounted for 

 by the presence in the nephridial capsule of bacteria which convert 

 more complex nitrogenous compounds into ammonia. Busing 





anip.i. 



amp. 3 



Fig. 25. Longitudinal section of nephridial capsule of 

 Hirudinaria showing numerous funnels opening into a coelomic 

 ampulla (X ca. 180). ampy 1, 2 and 3, three coelomic ampullae; 

 h.c.y communications between ampullae and botryoidal tissues; 

 b.t.y botryoidal tissue; cr, coelomic corpuscles; d.c.y dividing 

 corpuscles; /, funnel of nephridial capsule; h.n.b.y nephridial 

 branch of coelomic sinus system; /./., initial lobe of nephridium ; 

 res, reservoir of nephridial capsule ; tr, trabeculae. After Bhatia, 



1941. 



et «/. (1953) showed that there are two species present, Corynebac- 

 terium vesiculare which forms a layer like the pile of a carpet on the 

 bladder wall (this has been mistaken for ciliation) and C. hirudinis 

 which floats freely in the fluid. When urine was removed from 

 the bladders and stored in sterile containers the ammonia content 

 progressively increased. When leeches were treated with antibiotic 



Fig. 26. Symbiotic bacteria on the wall of the nephridial 

 bladder of Hiritdo. From Grasse, 1959; after Jaschke, 1933. 



