Herpetomonas lyg.ei 

 Cousidered from a Protozoological and Medical Aspect 



BY 



Captain R. G. Archibald, M.J)., K.A.M.C., attached E.A. 



Pathologist and Assistant Bacteriologist 



Wellcome Tropical Research Laboratories, Khartoum 



The relationship existing between the genera Trypanosoma, Herpetomonas, Crithidia 

 and various diseases which affect man, is still somewhat in a state of chaos. Some of 

 the parasites of these genera are known to have as their hosts various insects and biting 

 flies, but the role played by these as transmitting agents of such diseases as Kala-azar, 

 Trypanosomiasis, and Oriental Sore still requires further elucidation. While I was 

 engaged in studying a certain type of Herpetomonad which was found to infest the 

 alimentary tract of the dura plant bug in the Sudan, a paper was published by Patton' 

 describing a similar type of flagellate which is parasitic in the Lygieus militaris found 

 in India. The same insect, known as the dura plant bug, is also ubiquitous in the Sudan, 

 and a rich material enabled one to study in detail the morphology and life-cycle of 

 the parasite infesting its intestinal tract. Lijga3uii viilitarig is a brilliantly coloured Characters 

 hemipteron* which exists as a pest in various parts of the Sudan, doing considerable damage ° /yf,).'/" 

 to the dura or millet crops of the country. Its ravages, however, are not confined to 

 dura alone, for it has been found feeding on various plants, notably the Calotropis procera. 

 By means of a piercing apparatus it punctures the plant and destroys its vitality by 

 withdrawing the sap. 



If the alimentary tract of this bug be dissected out, it will be seen to consist of 

 a very short cesophagus opening into a large sacculated crop in which peristaltic move- 

 ments can be observed taking place. The crop opens into a narrow and long mid-intestine 

 which ends in a bulbous dilatation. At the other end of this dilatation a short ileum 

 extends posteriorly and connects with a dilated colon in which are found the openings 

 of the Malpighian tubes. From the colon, the remainder of the alimentary tract is 

 represented by a short tube opening into the rectum. 



Material and Methods Employed 



In order to study the different stages of the flagellate in the various portions 

 of the alimentary tract of Lygieus militaris, the method employed, and one which 

 gave satisfactory results, was to dissect out the alimentary tract of the bug in normal 

 saline solution and then to transfer the various portions, with their contents intact, to 

 several watch-glasses containing fresh normal salt solution, where emulsions were made 

 and transferred to slides, spread, and then stained in a suitable manner. Fresh hanging- 

 drop preparations were also made in order to study the various stages of the flagellate. 



A wet method of fixation was usually employed before the films were stained, Fi.\ation of 

 Leishman's modification of Eomanowsky or iron hematoxylin being the stains used. 

 The latter was chiefly used to differentiate the nuclear and chromatic structures present 

 in the herpetomonad. 



'■ Patton, W. S. (1908), Rerpeionumas lygcei. Arch.f. Protistenk. 

 * Fide Secoud Report of these Laboratories, lig. 56, p. 95. 



films 



