160 MARTINI. 



Irypanosojuata aloiic and without tlie ])ii'()])lasiiiata had caused infection. 

 Experiment with calf No. 5 seemed to demonstrate tliat either the number 

 of trypanosomata in a single culture tube might not be sufficient to produce 

 an infection or that the culture, which was twenty-eight days old, had 

 become so attenuated that not only the pirosomata, but also the trypano- 

 somata had been deprived of their power of causing infection. The o1)ject 

 of the following experiment was to kill the piroplasmata and at the 

 same time to preserved the trypanosomata alive in the culture. 



Calf No. 8 {repatitioii of experiments on calves ISlos. 1, .i, and 5). — April 3, 

 1909; female Australian calf about 4 months old; free from ticks; blood smears 

 free fi'om parasites; blood culture negative; smear from the suj-face of the 

 eentrifugated blood free from parasites. The inoculation of two monkeys with 20 

 and 50 centimeters respectively of the blood of the calf gave negative results. 



April 12: After the blood of the calf had been found to be free from parasites 

 by daily examination of simple blood smears and smears from tlie surface of 

 the eentrifugated blood, the calf was given subcutaneously three five-day-old 

 trypanosoma cultures obtained from the blood of the "original calf." The cul- 

 ture had been gTOwn at a temperature of 29° to 31° C. A monkey was given a 

 similar culture subcutaneously. Piroplasmata could not be found in these 

 cultures. Cultures grown at this high temperature were chosen because under 

 such circumstances it was anticipated that the piroplasmata would die out, while 

 it had already been determined that the trypanosomata remained alive at this 

 temperature. Both the calf and the monkey remained healthy and lively. Daily 

 examinations of simple blood smears and repeated examinations of the eentri- 

 fugated fresh blood gave negative results. 



On April 21 and on May 5 trypanosomata were cultivated from its 

 blood, lut they could not he shown to be present in any other way. In 

 spite of most careful examinations piroplasmata were never found up to 

 the thirty-seventh day after the infection. 



On May 17, the thirty-seventh day after the infection, the calf was 

 killed. The autopsy sho^^'ed that the organs were normal. The plasma 

 bodies of Koch were not present in smears from either the spleen or 

 lymph glands. 



Calf No. 9 {repetition of the experiments on calves Nos. 1, 3, 5, and 8). — ■ 

 This experiment was planned in case experiment No. 8 should have been 

 imsuceessfiil. 



April 10: Australian male calf, 4 months old, free from ticks; blood smears 

 and smears from the surface of the eentrifugated blood showed no parasites ; blood 

 culture negative. A monkey was inoculated with 30 cubic centimeters of the 

 calf's blood but it remained well and no parasites appeared in its blood. 



On April 17 the calf received four ten-day-old cultures of trypano- 

 somata made from the blood of the "original calf." These cultures had 

 been grown at a temperature of from 29° to 31° C. and no longer 

 contained piroplasmata. The calf remained healthy and lively. Daily 

 examinations of blood smears and repeated examination of eentrifugated 

 fresh blood gave negative results ; neither piroplasmata nor trypanosomata 

 were found. However, trypanosomota were cultivated from its blood 



