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Miss M. Robertson. Flagellate Infections in [Feb. 24, 



the material handled, there is little doubt, from all the work done on this 

 type of protozoon, that the long slender creatures may be regarded as the 

 adult individuals, and that they have been produced from the smaller broad 

 forms. In all the infected specimens of Leptoglossus so far examined, I 

 have not come across any of the curious crithidial forms which are so 

 characteristic a feature of two types of infection to be discussed later. 



Quite the most important point in the infection of Leptoglossus membranaccus 

 is the fact that, in adult specimens, the salivary glands are very frequently 

 strongly infected with the flagellates. Young specimens show the parasites 

 only in the gut, and, as in the histories of most parasitic flagellates, the 

 infection seems to work forwards, from the hinder part of the gut near the 

 Malpighian tubules. The flagellates are not present in large numbers in 

 the anterior part of the intestine in any of the specimens so far examined. 

 The individuals seen in the salivary glands show a considerable range of 

 shape and size, and curious small forms are present in fair numbers. It is 

 not proposed to enter into these relations in detail, as this herpetomonas will, 

 I hope, be the subject of more systematic study later on. 



In the infection of the salivary glands of Leptoglossus, we have the 

 independent development in a sucking insect of all the factors requisite for 

 the transmission of a flagellate, parasitic in the intestine, by way of the 

 mouth-parts of the insect host. This is a significant step in the history of 

 how the complex interacting circumstances which we now find in operation 

 in such diseases as trypanosomiasis, kala azar, and malaria may have arisen 

 in nature. I have not so far found the parasite in the plant, but this 

 part of the work has not been carried anything like far enough as yet to 

 permit of a statement being made in regard to the point. These conditions 

 in Leptoglossus are not at present of the slightest practical importance, but 

 I should like to point out that it has a certain interest to find this state 

 of affairs in Uganda involving a parasite of the same genus as that which 

 produces the diseases of kala azar and Oriental sore. 



Leptoglossus occasionally shows an infection with a coccidian, which I do 

 not propose to describe, but there is one point that bears on the matter 

 under discussion. This coccidian also invades the salivary glands, but 

 probably does it by way of the body cavity. Cysts containing sporozoites 

 were found in the salivary gland and in the gut, as also all the stages of 

 schyzogony or asexual multiple fission. Motile, sickle-shaped individuals 

 were found in the proboscis : morphologically, there is nothing in the live 

 state to distinguish sporozoites and young merozoites; the probability is, 

 however, strongly in favour of their being merozoites. I am inclined to 

 think that the presence of these forms in the proboscis has no significance in 



