﻿CULTIVATION OF A BOVINE PIROPLASMA. 89 



forms are peculiar cells, provided with numerous fine, protoplasmic proc- 

 esses; furthermore, he described a large, rounded form and a club- 

 shaped parasite which closely resembled the ookinetes of Plasmodium and 

 Halteridium. These important observations were later confirmed by 

 Kleine 13 who used a different method of investigation. He secured a 

 culture of canine piroplasma by diluting the infected blood with salt 

 solution and was also able to demonstrate the peculiar, star-shaped cells 

 and globular forms in his cultures. The further developmental forms, 

 after the majority of the cells had undergone degenerative change, did 

 not appear in cultures of Piroplasma canis. 



In comparing the results obtained by both of these authors with onr 

 own, we find many points of resemblance in respect to the morphological 

 features of the parasites. The star-shaped forms described by Koch 

 and Kleine probably correspond to the amoeboid cells (PI. I, fig. 4) 

 found in the early developmental stage of our parasite, though the latter 

 does not possess such a fine plasmic process as the former. The globular 

 cells (PI. I, fig. 3; PI. IT, figs. 5 and 6) are a common form occurring 

 in the development of all cases, and the club-shaped ones figured by 

 Koch seem to correspond to the first stage of the motile flagellate observed 

 with our parasite. On the other hand, the successful culture of the 

 intracellular parasite was first accomplished by Sogers with the Leishman- 

 Donovan bodies. The facts demonstrated by the above-mentioned authors 

 therefore greatly support our own observations. It may be well here to 

 add that the mode of formation of a flagellated form in the case of our 

 parasite is apparently different from that of others; especially does it 

 differ from that of the Leishmanial donovani, which transforms to the 

 flagellate by direct elongation of an enlarged globular form, whereas the 

 piroplasma, according to our observations, develops in the unusual man- 

 ner described above. 



Observation 5. — The final means by which we are able to reach a 

 definite conclusion in respect to the trypanosomata consists of animal 

 experiments with the cultures. It is a well-known fact that with the 

 parasite of coast fever (Piroplasma parvum) the direct inoculation of the 

 blood into cattle, even in a large amount, always fails to give rise to in- 

 fection with the appearance of parasites in the animal so inoculated, and 

 as regards this point the parasites investigated by us were already proved 

 to be identical with Piroplasma parvum. We selected three calves which, 

 after repeated examinations by microscopic and cultural methods, were 

 demonstrated to be free from parasites. The animals were then in- 

 oculated with a culture containing motile trypanosomata in abundance 

 and as a necessary prerequisite to the successful completion of the 

 experiment, they were kept under such conditions that danger of infec- 

 tion from any source, especially from ticks, was avoided. The blood 



13 Ztsclir. f. Jlyg. u. Infectionskrcmkh., Leipz. (1906), 54, 10. 



