■~y 



PIROPLASMA AND TRYPANOSOMA OF CATTLE. 149 



animal was a female, one j^ear of age at the time the experiments were 

 beg'un and was kept protected from ticks, flies and mosquitoes in a 

 screened stall. 



PRELIMINARY EXPERIMENTS. 



On the 18th of January, 1909, 50 cubic centimeters of its blood were 

 drawn from the jugular vein and then defibrinated, care being taken to 

 avoid bacterial contamination of the blood. Two cubic centimeters were 

 placed into each of several tubes containing 10 cubic centimeters of 

 bouillon. Five of the tiibes contained 1 per cent alkaline bouillon and 

 five 1 per cent acid bouillon, phenolphthalein being used as an indicator. 

 The tubes were placed in the incubator kept at a temperature of 26° 

 to 27° C. 



Thirty-three hours after making the cultures a trypanosoma (a division 

 form) with a distinct flagellum was found in one of the tubes. Trypano- 

 somata appeared later in many of the tubes, but only after a period 

 of from forty-four to forty-eight hours. In general the parasites were 

 about the size of the rat trypanosoma {Trypanosoma lewisi) and, like it, 

 showed very considerable variation in size. There were some which 

 measured longitudinally, together with the flagellum, one and one-lialf to 

 three times the diameter of a red blood cell of the calf, and others about 

 six to seven times this length. Occasionally, and then generally in the 

 later days of the culture — that is, from the fifth to the sixth day — I found 

 forms which measured from twenty to twenty-five times the diameter of 

 the red blood cells of the calf. The smallest form was just as distinct and 

 well developed as the largest one. The principal characteristic was a club- 

 like swelling at the anterior (2) extremity of the flagellum, as is seen from 

 the drawings and especially from the photographs. (Plate I, fig. 6, h, c, 

 and d, and Plate III, fags. 10 to 13, and Plate IV, figs. 14 to 17.) The 

 blepharoplast lies with its long axis perpendicular to the axis of the 

 trypanosoma, and the nucleus parallel to this axis; the blepharoplast is 

 usually anterior to the nucleus and is posterior to it only in exceptional 

 cases. This trypanosoma reminds one of that found in the bison and 

 described by Wrublewski(8) in Russia. Wrublewski's article was called 

 to my attention after I had found the trypanosoma in my cultures. 



In the cultures on acid media numerous chromatin granules appeared 

 in the body of the trypanosomata. Both acid and alkali media seemed 

 equally good for the cultivation of the parasites. However, for the 

 further experiments only the acid medium was used. The motility of the 

 parasites was similar to that of other trypanosomata which bear the 

 flagellum at the anterior end. Only in the case of obstruction did the 

 parasite move posteriorly. 



Among the well-develo]ied forms observed there were a few very small 



- In this article tlie end of the trypanosoma upon which tlie flagellum is situated 

 is considered to be the anterior one. ( Co-Editor.) 



