1 82 THE PROTOZOA. 



for the demonstration of these bodies, a blister be raised and a smear 

 from that containing many polymorphonuclears might show these 

 bodies. The affection is characterized by a leucopaenia so that it is 

 very difficult to demonstrate the parasites in ordinary blood smears. 

 By cultivating the parasites obtained from splenic puncture in 

 acidified sodium citrate solution at room temperature, Rogers suc- 

 ceeded in obtaining flagellated forms similar to Herpetomonas. ' An 

 anterior flagellum proceeds directly from the blepharoplast. The 

 bed-bug is supposed to be the intermediary host. 



Trichomonas. 



Trichomonas vaginalis. This parasite has a fusiform body and 

 is about 18 x 10/1. It has three flagella arising from the anterior end 

 and an undulating membrane. It lives in vaginal mucus which has an 

 acid reaction. A change of reaction, as at menstrutation, causes them 

 to disappear. Forms similar to the T. vaginalis have been found in 

 the intestine and in sputum from putrid bronchitis. 



These flagellates are generally considered harmless,, although 

 doubt as to this is expressed by some authors. 



Lamblia. 



Lamblia intestinalis. These parasites are about 10 x 15^ and 

 have a pear shaped body with a depression at the blunt anterior end. 

 This depression enables the flagellate to attach itself to the summit of 

 an epithelial cell. Around the depression are three pairs of flagella 

 which are constantly in motion. Another pair of flagella project from 

 either side of the blunt little tail-like projection. When stained, the 

 parasites have a pyriform shape with two chromatin staining areas on 

 either side of the anterior end. When encysted, they assume a circular 

 shape. This parasite is generally considered as of little importance, 

 but inasmuch as, when in great numbers in the csecum and appendix, 

 they may give rise to symptoms resembling appendicitis and as they 

 are responsible for a chronic and intractable diarrhoea associated with 

 mental and physical depression, this is undoubtedly an affection only 

 minor in importance to amoebic infection. It is a very common 

 infection in the tropics. 



