826 



THE FLAGELLATA 



variable length : the mouth opens near the insertion of the flagella and leads 

 to a tubular cavity in the protoplasm. 



The rounded and elongated nucleus and the blepharoplast are situated in 

 the granular protoplasm near the mouth. A slender hyaline rod is seen near 

 the middle of the body. 



The shape of the parasite is subject to considerable variation and on occa- 

 sions it throws out pseudopodia. In the intestine (mucus from a case of 

 dysentery) Ballet has seen a number of Trichomonas agglutinated together 



FIG. 400. A, Cercomonas intestinalis 

 (after Davaine) ; B, Trichomonas vaginalis. 

 FIG. 399. Trichomonas vaginalis. In this figure A and B are really iden- 



(After Grassi.) tical. In A, the parasites show only a single 



flagellum the others have been accidentally 

 destroyed. The flagella pictured on one of 

 the parasites in B are merely artefacts due 

 to the tearing of the undulating membrane. 



in a regular-shaped rosette, the individuals forming which soon become 

 changed into large, vacuolated, slightly motile, amosboid masses each having 

 a nucleus placed excentrically. 

 Reproduction is by longitudinal division. 



Methods of examination. Examination of the parasite is difficult on 

 account of its extreme motility and the details of its structure can only be 

 studied after fixing by one of the methods described when dealing with the 

 amoabse. 



Search must be made for T. intestinalis in stools while they are still warm, 

 as the parasite quickly dies when they cool. In carrying out this investiga- 

 tion all the precautions mentioned when dealing 

 with the amoebae must be observed, and if need 

 be the stools should be diluted with luke-warm 

 normal saline solution or Grassi's solution. 



Other species of Trichomonas. 

 Cercomonas termo. Cercomonas termo is an excellent 

 species for the study of these Protozoa. It occurs 

 in large numbers in vegetable infusions. 



Cercomonas termo consists of an oval body having 

 at one end a long, very motile flagellum. 



Food stuffs are introduced into the protoplasm at 

 the cytostome or mouth situated at the base of the 

 flagellum ; at this point the ectoplasm is interrupted 

 and the protoplasm is vacuolated; food stuffs are collected in the vacuole which 

 extends to the centre of the body, and here the ingested particles are digested. 

 Foreign bodies other than food particles which may hive been ingested are rejected 



ame point at which they were absorbed (Biitschli) 

 Reproduction is by binary longitudinal fission. The nucleus divides first and is 



FIG. 401. Cercomonas termo. 



