78 MANUAL OF HUMAN PROTOZOA 



Sooner or later, each individual elongates and develops a 

 flagellum (Fig. 19, ^) and later an undulating membrane. 

 These young trypanosomes are set free in the blood. 



Trypanosoma crtizi should be looked for in thick and 

 thin stained blood films. In acute febrile stage, it is pres- 

 ent in the peripheral blood. Sometimes it is necessary to 

 centrifugalize the citrated blood and sediment to be exam- 

 ined in stained smears. Although the trypanosomes are 

 ordinarily not found in the lymphatic glands, it has been 

 reported to occur in some cases in the spinal fluid. If all 

 results are negative, 5-10 c.c. of the blood may be inoculated 

 into guinea pigs in which after about two weeks the trypa- 

 nosomes will appear in the blood. Examination of excised 

 muscle for leishmania forms of the trypanosome has also 

 been used by some. Brumpt advocates to allow laboratory- 

 bred (therefore free from T. crtizi) Triatoma to feed on 

 the suspected subject and examining in about two weeks 

 the digestive tract of the bugs for the flagellate. 



Leishmania 



The three species of Leishmania are morphologically 

 alike. In human host, they are represented by small ovoid 

 leishmania bodies. They invade various leucocytes of the 

 reticulo-endothelial system. Each trophozoite is a small 

 protoplasmic mass in which are found a nucleus, a blepha- 

 roplast, and sometimes a rhizoplast. All indications point 

 to the species of sandflies (Phlebotomus) as the vectors. In 

 the flies as well as in culture tubes, the leishmania bodies 

 become enlarged and elongate, and the blepharoplast gives 

 rise to a long flagellum, the whole assuming a leptomonad 

 form. In the mid-gut of the sandfly, the flagellate forms 



