406 Sir D. Bruce and others. Trypanosome [Feb. 24, 



Table XVIII. — Comparison of the Percentages of Posterior-nuclear Forms 

 found among the Short and Stumpy Varieties of the Trypanosomes of 

 the five Wild-game Strains. 



Date. 



Experiment 

 No. 



Animal. 



Percentage among short 

 and stumpy forms. 



1912 



783 



Beedbuck 



8 -4 



1912 



1180 



Waterbuck 



30 -7 



1912 



863 



Oribi 



30 -3 



1912 



779 



Hartebeeste 



28 -3 



1912 



957 



ij 



33 -4 



Average 



26 -2 



It 'is evident from these tables and charts that the various strains of this 

 trypanosome, as they occur in wild game, are remarkably alike. This is 

 what might be expected. Here the trypanosome is at home : it is leading 

 a natural life. It may be supposed to be saved from variation by constantly 

 passing and repassing between the antelope and the tsetse fly. 



Comparison of the Human Strain with the Wild-game Strain. 



Table XIX. — Average Length of the Trypanosome of the Human and Wild- 

 game Strains. 



Strain. 



Number of 

 trypanosomes 

 measured. 



Animal. 



In microns. 



Average 

 length. 



Maximum 

 length. 



Minimum 

 length. 





3600 

 2500 



Eat 

 ?! 



24 -2 

 22 -6 



38 -0 

 35 -0 



15 -0 

 15 -0 



The length of the trypanosomes of the Human strain found in white rats 

 only is included in this table, in order to permit of comparison with the 

 Wild-game strain, which is also taken from rats. 



The curves (Chart 7) differ from each other in such a marked manner as to 

 be of no use in deciding as to the identity of the Human and Wild-game 

 strains. In spite of this, however, by a comparison of the two strains morpho- 

 logically and by the susceptibility of the different experimental animals to 

 their pathogenic action, the Commission are driven for the present to the 

 decision that the two strains belong to the same species of trypanosome. 



