1912.] 



Certain Hemiptera in Uganda. 



235 



The parasites considered belong almost exclusively to the herpetomonad 

 or crithidial type. I do not propose to attach species names, as the cycles 

 have not been worked out, and the nomenclature is already in a very 

 confused state. There is at present some considerable difference of opinion 

 as to what is the correct name of the genus, and as none of the literature ia 

 accessible this question is not touched upon at all. In every case the 

 specimens I have examined show a single broad tiagellum, and I have used 

 the term herpetomonas to describe all forms without an undulating mem- 

 brane, crithidia for forms with a membrane, and with the kinetonucleus 

 anterior to the trophonucleus. The word crithidia is not used in any generic 

 sense but simply as a convenient term to denote flagellates showing the 

 above-mentioned relation of membrane, kinetomicleus and trophonucleus. 



Several of the insects examined have, as will be seen later, shown a 

 confusing range of forms, whose real connection cannot be ascertained with 

 any satisfactory degree of certainty by the mere examination of a relatively 

 small number of natural infections. There is, therefore, every reason why 

 species names should be withheld until these points are settled beyond doubt. 



All the material was fixed by the wet method, using Schaudinn's fluid, 

 and stained either by Heidenhain's hematoxylin or by Mayer's hsemalum. 



Leptoglossus membranaceus Fab. (I) is a common Uganda species ; it feeds 

 on a certain gourd-like creeper, showing a marked preference for this 

 particular plant, and is hardly ever found except in its vicinity. The 

 specimens are frequently infected in the gut with a long slender herpeto- 

 monas, figs. 1-7 give an idea of its general characters and appearance. 

 The gut forms range from broad sac-like creatures with a short tiagellum 

 (fig. 7) to long slender forms with a flagellum of great length (fig. 1). The 

 nucleus in the broad forms is of the type so common in trypanosomes and 

 many other flagellates, and is made up of a large karyosome surrounded by 

 a clear space, the outer limit of which is marked off by a delicate membrane ; 

 between the karyosome and the membrane there pass fine radiating strands. 

 In the more slender forms there is to be noticed a lengthening out of the 

 nucleus and a tendency for the karyosome to fragment (figs. 2 and 3). 

 Finally, in the very long types, the nucleus is drawn out into a very narrow 

 and much elongated oval, the karyosome beiug represented by a row of 

 chromatin blocks of slightly irregular shapes (fig. 1). I have not been able 

 to detect any sign of the fine strands between the karyosome and the mem- 

 brane in this phase of the nucleus. The body of the long herpetomonads 

 is markedly flexible, which is a somewhat unusual feature in parasites of 

 this type. 



Although there is no direct evidence as regards the sequence of forms in 



E 2 



