164 MARTINI. 



4. In the Philippine Islands there occurs a trypanosoma of cattle which 

 is different morphologically and biologically from Trypanosoma evansi 

 and from the other trypanosomata of mammals. Its virulence for the 

 Indo-Chinese and Australian calves appears to be slight. 



5. This trypanosoma could not be discovered in the fresh blood by 

 microscopical examination, but could be cultivated in a mixture of blood 

 and bouillon, and could be transferred to healthy calves by the sub- 

 cutaneous injection of the cultures. 



6. The trypanosoma remains alive and capable of causing infection for 

 at least ten days in the bouillon employed when kept at a temperature of 

 29° to 31° C. Since the piroplasma which was present at the same time 

 in the blood of the "original calf" died out at this temperature within 

 the above-mentioned time, it was possible to isolate the trypanosoma and 

 to transfer it, thus separated from the piroplasma, to calves (JSTos. 8 

 and 9). 



7. These culture experiments prove the great importance of this 

 method for the differentiation of blood parasites. The absence of the 

 plasma bodies of Koch, the presence alone at autopsy of an icterus of the 

 liver, and the possibility of transmitting the infection to another animal 

 by a single inoculation of the blood, all indicated that a variety of Texas 

 fever and not one of Coast fever was present in the "original calf." I was 

 further confirmed in this belief by finding in the cultures made from the 

 blood of the "original calf," developmental forms like those of Piroplasma 

 higeminum which Koch discovered in ticks. Therefore, further proof 

 was given that a variety of the Texas fever parasite, Pirosoma higeminum, 

 and not the Coast fever parasite, was present. 



8. The value of the culture experiments may also be seen by the fact 

 that through them alone was it possible to demonstrate the presence of a 

 trypanosoma in the blood. This to-day is of especial importance in the 

 search for carriers of protozoa and in the study of the numerous drugs 

 employed in the treatment of the various forms of trypanosomiasis, and 

 especially of sleeping sickness. While the inoculation of animals can 

 give a positive result onl}' wlien the trypanosomata are virulent for the 

 species of animal used, one can employ the method of artificial cultivation 

 without regard to the vii'ulence of the trypanosoma and thus can obtain 

 results which are perhaps impossible by animal inoculation, or which at 

 any rate, may involve much work and expense. 



The cultivation of protozoa has in general an advantage over the 

 cultivation of bacteria, since for the identification of a bacterium usually 

 a tedious biological differentiation is necessary, while in the case of a 

 protozoon the morphology in the culture alone often suffices to identify it. 



For all these reasons careful attempts in the cultivation of these 

 protozoa after the manner of ]Srovy-McNeal(20), Eogers(21), Miya- 

 jima(7) and Nicolle(22) should be made until finally a simple and sure 

 method of culture has been discovered for all pathogenic trypanosomata. 



