LEUCOCYTOGREGARINES, AND THEIR 

 OCCURRENCE IN SOUTH AERICA. 



By Annie Porter, D.Sc.Lond., F.L.S., 

 Parasitologist^ South African Institute for Medical Research. 



(Abstract.) 



The Leucocytogregarines are a group of blood Protozoa 

 occurring in what may seem to be peculiar host cells, namely, 

 leucocytes. The parasitised leucocytes, usually of mammals, may 

 be either mononuclear or polymorphonuclear, and I have recently 

 found parasitised eosinophiles. It is somewhat remarkable that 

 the leucocytes, the destroyers of intrusive organisms in the blood, 

 should themselves be subject to invasion by parasites. 



Some years ago, in Science Progress, for October, 1909, I 

 wrote a short monograph on what were then known as the Leuco- 

 cytozoa, and in that monograph I separated the parasites of the 

 leucocytes of mammals from the Leucocytozoa of birds, as the 

 avian parasites enlarged and sometimes distorted their host cell, 

 and the exact nature of the avian host cell was and is a matter 

 of controversy. Further, for the strict haemogregarines of leuco- 

 cytes I gave the generic name, Leucocytogregarina, which has 

 received general acceptance. These parasites are closely related 

 to the haemogregarines of vertebrate red blood corpuscles. An 

 abridged account of some Leucocytogregarines recently found in 

 South Africa is now given. 



During last year (1917), since my arrival in the Transvaal, 

 I have seen leucocytogregarines in the dog, the rat, and the rabbit. 

 For the preparations of the parasite of the dog I am indebted to 

 Dr. J. G. Becker, who lost a valuable pet in Johainnesburg 

 through the pathogenic action of Leucocytogregarina canis. While 

 using rabbits for experimental work, I found a similar parasite 

 in the leucocytes of some of the animals, the infected hosts 

 having been obtained from Johannesburg and from Durban. In 

 both the dog and the rabbit mononuclear and polymorphonuclear 

 leucocytes were infected, but chiefly the mononuclears in the 

 rabbit. The parasite of the rabbits should be placed in the species 

 L. leporis, created by Patton in 1907 for an organism found in 

 leucocytes of the Indian hare, Lepus nigricollis. I also found 

 L. nuiris in the polymorphonuclear leucocytes of wild and tame 

 rats in Johannesburg, while the eosinophile leucocytes of the 

 rats were also infected. However, it is quite likely that the 

 various leucocytogregarines now given separate specific names 

 — and occurring in the dog, cat, rat, mouse, palm-squirrel, hare 

 and rabbit — are really only varieties of the first-described species, 

 L. canis, James, 1905. 



The parasites are at first small, vermicular organisms, which 

 become definitely gregariniform when adult. The parasites of 



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