92 



Drs. B. Blacklock and W. Yorke. 



Table II. — Giving the Maximum, Minimum, and Average Lengths of each of 



the Three Strains. 



Strain. 



Animal. 



IN utu ber 

 of individuals 

 measured. 



Maximum 

 length. 



Minimum 

 length. 



Average 

 length. 



A 



Eat 



500 



36 



16 -0 



26 -9 





ovu 



or .r 

 uD O 



A.% 







Total 



1000 



36 -0 



14 -5 



25 -3 



B 



Eat 



250 



35 -0 



15 -5 



27 -7 



Guinea-pig 



250 



34 -0 



15 -5 



26 -3 





Total 



500 



35 



15 -5 



27 -0 



C 



Eat 



250 



33 -0 



17 -5 



25 -6 





Guinea-pig , , . 



250 



32 



18 -0 



24 -8 





Total 



500 



33 -0 



17 -5 



25 -2 



A survey of the curves obtained by plotting out in percentages the various 

 lengths of trypanosomes encountered in each of the three strains is of interest. 

 It will be observed that in the case of rats the curves of each of the strains 

 correspond fairly closely. They are those of monomorphic trypanosomes, the 

 main peak in Strains A and C being at 27, whilst in Strain B it is found at 

 29/i. A striking difference, however, is to be observed in the graphs com- 

 piled from the measurement of the parasites in guinea-pigs, for whereas in 



MICRONS 



„ 14 16 18 20 22 24 26 23 30 32 34 36 



