PIROPLASMA AND TRYPANOSOMA OF CATTLE. 151 



meters of blood from the "original calf" and afterwards showed no signs 

 of an infection. On the other hand, two monke3's of the same species, 

 to which Mr. Clegg of this laboratory gave, on the 19th of January, 1909, 

 1 cubic centimeter and 50 cul)ic centimeters, respectively, of blood from 

 the calf infected with surra, showed an enormous number of parasites in 

 the peripheral blood, and both died, one on the 2d of February, the other 

 on the 5th of February, 1909; the first having lived fourteen the other 

 seventeen days after the inoculation. The subcutaneous injection of one 

 of our cultures containing numerous trypanosomata into each of three 

 monkeys of the same species gave likewise a negative result. In other 

 experiments inoculations in this, same species of monkey were made for 

 the purpose of excluding the surra parasite, because it is well known in 

 the Philippines that these monkeys are extremely susceptible to this 

 disease. These investigations appeared to be necessary in spite of the 

 morphological differences which are evident between the trypanosoma 

 found in the "original calf" and the trypanosoma of surra (see Plate I, 

 fig. 7, and Plate V, fig. 27) ; for the surra trypanosoma has not yet been 

 cultivated artifically successfully and no one can know what form it 

 will assume in the culture. I, also, have been unsuccessful in cultivating 

 the trypanosoma of surra from the blood of cattle, horses, and monkeys. 

 In the culture media mentioned above which is favorable for the develop- 

 ment of the trypanosoma obtained from the "original calf," the trypano- 

 soma of surra appears to die out quickly ; this is another point of differen- 

 tiation between the two. Therefore, the trypanosoma cultivated from the 

 blood of the "original calf" is evidently not Trypanosoma evansi, but is 

 a form not hitherto described. 



PREPARATIONS FOR A CONTINUATION OF THE WORK. 



These investigations did not decide definitely whether the trypano- 

 somata were developed from the piroplasmata or whether the trypanoso- 

 mata being extremely scarce in the blood of the "original calf" or being 

 present in an undeveloped form simply multiplied in the culture, as 

 certain varieties of trypanosomata are known to do. In order to solve 

 these questions it was necessary to carry on other experiments. The 

 artificial transmission of the infection to other calves at once suggested 

 itself. This was undertaken, but great difficulties were immediately 

 encountered. The pathogenicity of both tlie piroplasma and trypano- 

 soma could only be determined by the inoculation of, nonimmune animals. 

 It was extremely difficult to obtain such animals, since in Luzon numerous 

 cattle diseases appear to be rife. It was, therefore, necessary either to 

 import cattle from disti'iets free from piroplasmosis or, as a last resort, 

 to use animals relatively sliglitly immune, that is, new-born calves. 

 The importation of cattle was impracticable, because it was desirable to 

 begin the inoculations at once, owing to the fact that it could not be 

 known liow long the parasites would remain in the blood of the "original 



