334 PROCEEDINGS OF THE ACADEMY OF [NoV., 



separated into those that were parasitized and those that were not. 

 It was found much easier to handle the material in this manner 

 and the data given in Table 3 were based on a wholly separate set 

 of observations from those given in Table 1. It is, however, believed 

 that in obtaining the results set forth in Tables 1 and 2, the number 

 of cells counted is large enough. 



Turning our attention now to Tables 3 and 4, the percentages 

 obtained from the slides taken from the hearts of Cows 1025 and 

 1031, respectively, are probably not far enough apart to warrant 

 any conclusions, but a sharp distinction is to be seen between the 

 findings in the different organs of Cow 1031. Thus, whereas, in the 

 heart there were only some 38 per cent of the single parasites, this 

 percentage rises to nearly 94 in the case of the spleen. It has already 

 been suggested that the low percentage of parasitized cells in the 

 spleen may be explained by supposing that the parasitized cell is 

 more easily destroyed than that not parasitized. If this be so it 

 would be consistent to suppose that as the number of parasites 

 present increases, the invaded cell becomes more and more readily 

 destroyed. For, since the parasite must enter the cell as a single 

 organism, the multiplicative stages are indicative of a more pro- 

 longed occupancy, which in its turn is correlated with a greater 

 damage to the cell. Moreover, two or more parasites occupy a 

 greater volume than one, and this also would render the cell more 

 liable to destruction. It is in support of this explanation that the 

 liver stands next to the spleen both in regard to the proportion of 

 parasitized cells and in the proportion of those which contain but 

 a single parasite. These figures at least suggest that the- liver is not 

 a favorable environment for Babesia. 



In addition to the above, a number of the so called "free" para- 

 sites were counted, the results being given in Tables 5 and 6. This 

 could not be done with the spleen, which may be due either to the 

 fact that the smears from this organ are never so clean as those from 

 other situations, or to the fact that, as suggested, the parasites arc 

 here more quickly destroyed. The tables follow: 



Cow 1031 1. 



Heart 623 



Kidney 1044 



Liver 262 



Cow 1025 



304 



Totals 2233 1S20 54 63 2 1 4173 



