230 THE PROTOZOA 



while the smaller chromatin mass is generally rod-shaped and stains intensely. It 

 has been recently recommended that instead of liver or splenic puncture 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 leukopaenia 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 succeeded in obtaining flagellated forms 

 similar to Herpetomonas. An anterior flagellum proceeds directly from the blephar- 

 oplast. The bedbug is supposed to be the intermediary host. 



Patton has recently noted that when bedbugs feed on kala-azar patients who have 

 the L. D. bodies in their peripheral circulation that the parasites develop into the 

 flagellate stage in the bedbug and are present in great numbers from the fifth to the 

 eighth day. These flagellate forms change into postflagellate ones by the twelfth 

 day and are then found in the stomach. If, however, he allowed the bedbugs to 

 have a second feeding of human blood after the infecting feeding the flagellates dis- 

 appeared within twelve hours. This is apparently an important point in epidemi- 

 ology. Patton succeeded in infecting a white rat with intraperitoneal injection of 

 splenic emulsion from a kala-azar patient. 



L. infantum is transmitted from dog to dog by the dog flea, P. serraticeps and 

 the same agent probably transfers the parasite from dog to man. Experiments 

 would indicate that the Indian form of kala azar is not a disease which can be trans- 

 mitted to dogs. 



The genera Herpetomonas and Crithidia are frequently found in the alimentary 

 tract of insects and have caused confusion in the search for developmental forms of 

 various pathogenic flagellates in transmitting insects. In Herpetomonas, of which 

 the type species is H. muscae domesticae, the body is spindle-shaped with a rather 

 blunt flagellar end and an attenuated anterior end. In Crithidia both extremities 

 are pointed and the blepharoplast is situated toward the center quite near the tropho- 

 nucleus. In Herpetomonas the blepharoplast is near the rather blunt flagellar 

 extremity at some distance from the nucleus. 



There is no undulating membrane in either of these genera, this differentiating 

 them from Trypanosoma. 



Darling has reported from Panama a protozoon somewhat like Leishmania in 

 which the cells of lungs, liver, spleen, and lymphatic glands contained numerous 

 parasites about 3 to 4/4 in diameter, slightly oval in outline, and containing a large 

 and small chromatin staining mass. He has given it the name Histoplasma 

 capsulata. 



Trichomonas. 



Trichomonas vaginalis. This parasite has a fusiform body and is about 

 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 men- 

 struation, causes them to disappear. Forms similar to the T. vaginalis have been 

 found in the intestine and in sputum from putrid bronchitis. 



