HEEPETOMONAS LYOail 183 



contractions retractile masses can be seen passing along the flagellum for a distance of 

 5 /[( or 6 /(. As these movements become more sluggish, granules are seen collecting in 

 the posterior portion of the parasite. The anterior portion then commences to enlarge 

 and dilate and becomes quite globular in shape ; this enlargement and dilatation extend 

 back to the posterior portion of the parasite and a complete alteration in its whole contour 

 is thus produced (Plate XI., fig. 16) ; what was previously a cigar-shaped body has now 

 become an irregular shaped cell with the flagellum still attached. That portion of the 

 cell from which the flagellum arises retains for a short time its original conical shape. 



Division of the kineto- and trophonuclei then occurs, the respective divided portions 

 going to opposite sides of the cell, and finally the latter splits by a line of cleavage Division of 

 passing from the anterior to the posterior end. The two cells lie adjacent to each other, '•'^ kineto- 

 the original one still retaining the flagellum. Before the original cell has divided a large trophonuclei 

 number of vacuoles and granules a^jpear, the latter showing very marked Brownian 

 movement. 



During the whole of this stage, which occupied about an hour, the flagellum remained 

 practically stationary, and longitudinal splitting of it was never observed. At regular 

 intervals the flagellum was measured. Its intra-cellular portion showed a distinct curve, 

 and this was associated with a diminution in length of the extra-cellular portion. This 

 diminution continued to go on till the flagellum had shortened by 4-5 /x — and one concluded 

 that this shortening was due to withdrawal of the flagellum within the cell. After this 

 preliminary withdrawal the flagellum underwent a change in appearance, became more 

 hyaline and often showed at its terminal end a granule. Finally, it ruptured from the 

 anterior end of the cell and was disintegrated. Further divisions of the cell occurred 

 till oval or pyriform bodies, about 2 /.t in length, were formed. These represented the 

 cysts which were found in large numbers in the faeces of Lygceus militarU. These cysts 

 resembled in appearance the cysts found in the crop and require no further description. 

 This cystic stage concluded the life-cycle of the herpetomonas found in Lygasus militaris. 



Method of Infection 



The method of infection is brought about by the accidental ingestion of the cysts 

 passed in the fieces ; the latter are deposited on the surface of plants, and infection is 

 thus brought about. 



The parasites were only found in the alimentary canal of Lyijseu)- militaris. The infection of 

 ova of a large number of infected bugs were examined and in no case were herpetomonads f-ys"'"^ "ot 

 found ; so one concluded that infection is not transmitted by heredity. This was borne "^ ' "^ 

 out by the simple experiment of removing the eggs, laid by an infected female bug, to a 

 clean jar. In about a week the larvte hatched out, and in the course of a month or so 

 became adult bugs. These were dissected at various stages of their growth, and in no 

 case did they show infection with herpetomonads. 



Culture .\nd Animal Expeeiments 



Owing to the close similarity that exists between Herpetomonas lyysei and the 

 Leishman body of kala-azar, it occurred to one that the relationship between the two was 

 a closer one than their mere morphology suggested, and that the presence of the flagellates, 

 found in the bug, might in some way account for a disease like kala-azar which exists in 

 certain parts of the Sudan. Accordingly, a number of inoculations and cultural experiments 

 was carried out. 



Emulsions of the crop contents of a heavily infected bug were injected into the 



