674 MICROBIOLOGY OF THE DISEASES OF MAN AND ANIMALS. 



be an absolute cure for syphilis; it will also probably prove to be of distinct 

 value in the treatment of diseases caused by spirochaetes and by trypano- 

 somes. 



HERPETOMONAS. 



The two parasites belonging to this genus which require mention were 

 formerly known as Leishmania. The discovery of a herpetomonad stage in 

 their development made it necessary to reclassify them. Herpetomonas dono- 

 vani is the cause of kala azar, while Herpetomonas furunculosa produces 

 Delhi Boil. 



KALA AZAR. 

 Herpetomonas donovani. 



This disease occurs about the Mediterranean Sea and in many places 

 in Asia. 



It is caused by Herpetomonas donovani (Fig. 122). The parasite is rarely found 

 in the blood; when it is seen there, it lies within a white cell; it almost never occurs 



C * 



** * 



FIG. 122. Herpetomonas donovani. Free organisms and a few within red blood cells. 

 (After Donovan, from Doflein.) 



free. It is, usually, easily found by an examination of the juice obtained from the 

 spleen by puncturing that organ with the needle of a syringe. The liver is enlarged 

 and it, also, contains parasites. As the organisms are seen in preparations of spleen 

 juice, they are small ovals measuring about 2fi in length and 1.5/11 in width. They 

 consist of cytoplasm, in which lie two chromatic bodies, one of them large and 

 rounded, the other small and rod-like. This form of the parasite may multiply in 



