79 
A NEW PARASITE OF MAN 
By Major RONALD ROSS, F.R.S., F.R.C.S., C.B. 
PROFESSOR OF TROPICA L MEDICINE, UNIVERSITY OF LIVERPOOL 
LAST May, Major Leishman, R.A.M.C., described"' certain bodies which he 
had found at Netley Hospital in 1900 in the spleen of a soldier, who had been 
invalided from Dumdum, near Calcutta, for low fever, enlargement of the 
spleen, anaemia, and chronic dysentery, and who had died at Netley. Leishman 
thought that these bodies were trypanosomes which had become altered after their own 
death and that of the host. In July, Captain Donovan, I.M.S., stated' 21 that he 
had found the same bodies in Madras in the spleens of five similar cases after death, 
and also of one similar case intra vitam ; and pointed out that this last case, which 
showed neither malaria parasites nor trypanosomes, excluded the idea of Letshman's 
bodies being due to post-mortem changes. Donovan kindly sent me three of his pre- 
parations, together with drawings and charts of the last-mentioned case, and also of 
vet another case in which the bodies had been recovered by him intra vitam. One of 
these preparations was made post-mortem and two intra vitam. From these it was easy 
to confirm the descriptions and drawings of Leishman and Donovan ; and on the 
23rd October I despatched a paper on the subject to the British Medical Journal^ in 
which I recorded this confirmation, but at the same time dissented from Leishman's 
interpretation of the bodies, and said 1 thought that they were 'some quite novel 
organism.' On the 3rd November, before the publication of my paper, Dr. Laveran 
read a paper at the Academie de Medicine' 51 in which he stated that he also had 
received preparations from Donovan, and that he thought the parasites were neither 
trypanosomes nor malaria parasites, but probably belonged to the genus Piroplasma ; and 
he suggested the name Piroplasma donovani for them. Subsequently Leishman wrote' 51 
reiterating his opinion that the bodies are altered trypanosomes. 
As the nature of these bodies is a question of great interest and importance, I 
am now taking the liberty of reproducing Donovan's drawings (he being absent in 
India), together with some of my own, and a formal description based exclusively on 
the three preparations in my possession. It should be understood, however, that this 
description is merely supplementary to those of Leishman and Donovan, who have 
certainly seen all the forms I refer to. 
Of the three preparations, one consists of a smear from a cut spleen, made 
post-mortem ; and the two others of spread and fixed blood taken from the spleen of 
two cases intra vitam. All are well stained by the Romanowsk y-Ziemann method, 
and contain numbers of the parasites referred to. 
