S32 PROCEEDINGS OF THE ACADEMY OF [Nov., 



round cover glass with a diamond, and placed in the eye-piece 

 of the microscope. The square marked out a small region in the 

 smear and all the cells in this region were then taken into account. 

 These regions were selected wholly at random, in fact, without being 

 first seen. The only restriction was that those cases where the blood 

 cells were very closely crowded were not used. 



Taking up first the ratio of parasitized and non-parasitized cells, 

 the counts made gave the following results: 



Table 1. 



Cow 1031 Parasitized cells Non-parasitized cells Total 



Heart 4563 4083 8646 



Kidney 767 464 1231 



Spleen 348 249.'5 2843 



Liver 1048 1646 2694 



Totals 6726 8688 15414 



Cow 1025 

 Heart 2.50 3732 3982 



Reducing the above to percentages we obtain: 



Table 2. 



Cow 1031 Parasitized Non-parasitized 



Heart 52.8 per cent. 47.2 per cent. 



Kidney 62.3 37.7 



Liver 38.9 61.1 



Spleen 12.2 . 87.7 



Totals 43.64 56.36 



Cow 1025 



Heart 6.30 93.70 



The first distinction to be noted is that between the two cows. In 

 1031, at least as regards the heart, the split is about even, there 

 being practically as many parasitized as non- parasitized cells. On 

 the other hand, in Cow 1025, the ratio is roughly 1 to 15. This cow 

 eurvived for one day longer than did 1031, and this may be the 

 sxplanation, but a much more precise study than was made would 

 be necessary to elucidate this problem. 



Turning our attention to Cow 1031, it is easily seen that there is a 

 marked distinction between the conditions in the different organs. 

 The heart, kidney, and liver may be grouped, although the differ- 

 ences between them are too great to be accredited to a mere acci 

 dental variation. It may also be noted that the liver shows a lower 

 ratio of parasitized cells than does either the heart or kidney. This 

 is in contrast to what occurs in infections with trypanosomes, these 



