800 THE LEISHMANIOSES 



development, as in the case of Herpetomonas, takes place in three stages 

 a pre -flagellate, a flagellate and a post-flagellate. The parasite is ingested with 

 the white cells of the blood and passes to the mid-gut of the bug where it 

 elongates into flagellated forms similar to those seen in cultures and often 

 forms masses of rosettes. About the seventh to the ninth day after a single 

 feed the mature flagellated parasites undergo a further developmental process 

 resulting in the rounding up of the parasite into its post-flagellate form. The 

 latter appears on about the eighth day and the changes are completed by the 

 twelfth day. The post-flagellate forms resemble the pre-flagellate forms in 

 shape only and differ from the latter in being slightly larger and in presenting 

 very different staining reactions the protoplasm instead of staining blue as 

 in the pre-flagellate forms stains pink. 



[In order to observe these changes the insects must have only one feed. If 

 fed during the flagellating stage the parasites are destroyed. In several of the 

 bugs which were fed once only Patton observed an enormous multiplication 

 of the parasites and masses of rosettes were seen. 



[Patton is of opinion that the post-flagellate forms gain entrance to a new 

 host by being regurgitated from the gut while the bug feeds, for the whole of 

 the multiplicative stage takes place in the mid-gut. 



[Donovan has failed to get the same results as Patton and from his 

 observations is inclined to suspect a tick (Conorrhinus rubrofasciatus).] 



On the other hand, Manson points out that the organisms are present in 

 small numbers in the peripheral blood while they abound in the ulcers on the 

 skin and intestinal mucous membrane : infection by contamination with 

 infected excretal matter might therefore be of great importance in the pro- 

 pagation of the disease and non-biting flies might possibly play a part. 



Experimental inoculation. [Until recently] all attempts to inoculate the 

 disease into vertebrate animals have failed. 



[Patton inoculated a white rat intra-peritoneally with 3 c.c. of an emulsion 

 of the spleen from a case of Indian kala azar. Fifteen days later a second 

 inoculation of 1 c.c. was given. The rat died two hours after the second inocu- 

 lation. Post mortem the liver and spleen were considerably hypertrophied and 

 contained large numbers of typical parasites. 



[Laveran inoculated into the peritoneal cavity of a mouse 0'5 c.c. of an 

 emulsion of bone marrow and spleen from an heavily infected dog (L. donovani). 

 A month later the animal was killed. Post mortem there was a slight peritoneal 

 exudate and the spleen was four to five times its normal size. Numerous 

 parasites were found in films made from the internal organs. ] 



2. Leishmania infantum. 



Cathoire was the first to notice a peculiar disease in Tunis which was 

 clinically like kala azar but only affected young children and especially 

 infants 1-2 years old, never being seen in children more than 6 years of age. 

 Cathoire's observations were confirmed by Nicolle and Cassuto. A similar 

 disease has been described as occurring in Italy Infantile splenic anaemia 

 (Pianese and others), [and in Greece Ponos]. 



This disease is due to a parasite microscopically identical with Leishmania 

 donovani but from which it differs in its cultural characteristics and in the 

 results obtained on inoculation into animals. Nicolle has provisionally classed 

 it as a new species ; Leishmania infantum. 



[Leishman gives the following as the differences between Mediterranean and 

 Indian kala azar. 



[" 1. The infantile attacks almost exclusively young children, while the Indian 

 is met with at all ages. 2. Certain differences of symptomatology have been 



