Karl Pearson 
117 
paucity of the total numbers that we have at our disposal. 1 will consider, 
however, from this aspect the relations of the three strains wild G. morsitans, 
wild game, and Mvera cattle. 
I compare first the lengths of 200 trypanosomes from wild G. morsitans and 
wild-game strains. These yield for the host, goat* : 
Microns. 
From Goat 
9 
10 
11 
12 
13 
u 
15 
IG 
17 
18 
19 
Totals 
Wild G. moi'sitans Strain 
1 
3 
12 
21 
55 
60 
32 
12 
4 
200 
Wild-Game Strain 
1 
16 
37 
73 
38 
26 
8 
1 
200 
giving: ^- = 26-782 and P = -0015. 
To further test this, I take the same two strains in the dog as hostj- : 
Microns. 
From Dog 
9 
10 
11 
12 
13 
H 
15 
IG 
17 
18 
Totals 
Wild G. morsitans Strain 
3 
14 
34 
41 
40 
19 
9 
160 
Wild-Game Strain 
12 
31 
57 
50 
24 
6 
180 
Here ^^=1-Q4<a and P = -3l7l. 
The value we had previously found for a mixture of all strains was P = '0002. 
Thus the two strains may be considered as identical when we deal with the 
trypanosomes from the dog, as showing considerable divergence when we take the 
goat, and as showing marked divergence when we take a great variety of hosts. 
The weight of evidence in favour of a standardised treatment thus becomes very 
great. 
Let us look at precisely the same material for the wild-game strain and for 
the Mvera cattle strain, first for the goat and then for the dog as host J. The 
grave difticidty is the paucity of measurements thus differentiated. 
Microns. 
From Goat 
9 
10 
11 
12 
13 
u 
15 
IG 
17 
18 
Totals 
Wild-Game Strain 
Mvera Cattle Strain 
1 
1 
1 
3 
16 
14 
37 
22 
73 
26 
38 
19 
26 
13 
8 
1 
1 
200 
100 
This gives j^- = 14-670, leading to P = -1013. 
* R. S. Proc. Vol. 87, B, pp. G and 11. 
t R. S. Proc. Vol. 87, B, pp. 6 and 11. 
X R. S. Proc. Vol. 87, B, pp. 3 and .5. 
