122 MARTINI. 



In the case of iut'eelioa with all of these parasites, ticks were demon- 

 strated as the means of transmission of the disease from one animal to 

 another. A recital of the names of the various sj^ecies of ticks concerned 

 in the transmission of the disease would be of little importance in the 

 present discussion. 



At least one, and perhaps more varieties of Piroplasmata exist in 

 East Asia and I have been able to discover recently a Piroplasnia in 

 calves in Manila. " The parasites lie within the red blood cells like other 

 species of Piroplasma, generally they are rod-shaped or have the form 

 of an arrow. It is seldom that they assume a ring shape. The chro- 

 niatin-mass is quite distinct and sometimes two chromatin-masses can be 

 seen; rarely four are visible. (Plate I, figs. 2 to 4.) 



Such is the appearance of the Piroplasmata- as they occur in the animal 

 body. I am convinced that other important species of these j^arasites 

 will be discovered in the near future. 



The discovery of a Trypanosoma in human beings, which had been at 

 first observed only in animals inspired a careful search for species of 

 Piroplasma in man. And these attempts have also been successful. The 

 cause of both typhus fever and of Rocky Mountain fever was first attri- 

 buted to Piroplasmata; in both instances, unfortunately, a confirmation of 

 these claims is wanting. Finally in 1903 a somewhat similar organism 

 to the Piroplasmata was found in man. Leishman and Donovan, working 

 entirely independently of each other, found the Piroplasma of Kala-azar, 

 the one in smears made from a spleen at autopsy the other in material ob- 

 tained by splenic puncture. Later, Homer Wright discovered the Piro- 

 plasma of tropical ulcer, which resembles that of Kala-azar. The 

 Piroplasma of Kaln-azar has received through Laveran the name of 

 Lrishniajii donovani, which indicates that in his opinion this parasite 

 belongs to a new group. Homer Wright has given the name of Helcosoma 

 tropicum to the parasite which he discovered. 



While the first mentioned Piroplasma, naniel}^ Pirosoma higeminum 

 and Piroplasma parvum occur within the red blood cells, the human 

 parasites just referred to are found in the leucocytes and macrophages. 

 This is very evident in specimens made from the spleen of a case of 

 Kala-azar. 



Whereas ordinarily the leucocytes and macrophages act as phagocytes 

 and destroy the microorganisms, in these instances the reverse is some- 

 times true and the parasites destroy the leucocytes and macrophages. 

 Therefore, the name Piroplasma levcocytophagum might be an appro- 

 priate one for the group. 



The suggestion to place these parasites, which are so different mor- 

 phologically, in the same group with the Pirosoma higeminum and Piro- 

 plasma parvum (the erythrocytophages), may seem at first surprising: 

 however, some support for such an idea may be received from the fact that 



