110 
A Study of Trypanosonie Strain, 
of the process of differentiation would aid him. This is of especial importance 
if it should turn out, as I suspect, that the trypanosomes classed as T. brucei are 
either dimorphic, or belong to two different species. 
In another paper* we find the trypanosomes from G. morsitans, on the basis of 
their infective powers on monkey, goat and dog, resolved into T. brucei vel rhode- 
siense, T. pecorum, T. simiae and T. caprae. But it is clear that the differentiation 
was not done solely by infectivity, or there would have been no means of dis- 
tinguishing T. brucei and T. pecortim which attack all three — monkey, dog and 
goat. The question arises, whether T. pecorum, T. simiae and T. caprae being 
readily identified by microscopic examination or size, the remainder was classed as 
T. brucei, in which case the question of the heterogeneity of this group, which 
appears to attack all animals, is rather supported than otherwise by this paper. 
Frequencies of the Various Strains for Length. 
Length in Microns. 
Strain 
9 
10 
11 
12 
IS 
U 
15 
16 
17 
18 
19 
20 
21 
22 
23 
2I^ 
25 
26 
T. pecorum 
2 
6 
42 
193 
452 
618 
453 
178 
51 
5 
T. simiae ... 
7 
28 
76 
93 
126 
92 
47 
22 
6 
2 
1 
T. caprae ... 
1 
3 
8 
23 
49 
79 
95 
80 
(i) T. rhodesiense 
1 
3 
10 
19 
29 
35 
67 
54 
92 
51 
74 
56 
68 
59 
85 
(ii) T. brucei 
5 
8 
14 
17 
40 
63 
55 
66 
63 
75 
87 
93 
80 
82 
(iii) T. gambiense . . . 
z 
1 
9 
21 
56 
79 
114 
122 
110 
85 
85 
61 
47 
49 
(iv) Mzimba Strain 
8 
27 
79 
175 
180 
139 
109 
72 
66 
36 
32 
(v) G. morsitans . . . 
7 
31 
148 
230 
326 
252 
237 
184 
143 
115 
130 
110 
(vi) Wild Game ... 
1 
8 
53 
118 
252 
381 
348 
285 
200 
162 
149 
135 
(vii) Human Strain 
1 
10 
41 
154 
325 
494 
528 
577 
512 
525 
511 
464 
425 
(viii) Chituluka 
1 
8 
48 
81 
78 
71 
44 
46 
56 
53 
98 
120 
Length in Microns — {continued). 
Strain 
27 
28 
29 
80 
31 
32 
33 
34 
35 
36 
37 
38 
39 
Totals 
Source 
T. pecorum 
T. simiae ... 
T. caprae ... 
68 
— 
57 
24 
9 
2 
2 

2000 
500 
500 
R. S. Proc. 87, B, p. 13 
Ibid. 85, B, p. 477 
Ibid. 86, B, p. 278 
(i) T. rhodesiense 
(ii) T. brucei 
(iii) T. gambioise 
(iv) Mzimba Strain 
(v) G. tnorsitam . . . 
(vi) Wild Game . . . 
(vii) Human Strain 
(viii) Chituluka 
61 
72 
47 
24 
127 
125 
372 
111 
72 
50 
44 
22 
133 
110 
347 
128 
50 
38 
31 
16 
113 
62 
307 
138 
52 
27 
20 
7 
96 
55 
198 
99 
28 
26 
11 
4 
54 
33 
167 
117 
13 
18 
4 
4 
44 
12 
123 
91 
13 
11 
4 
11 
7 
77 
63 
5 
4 
7 
3 
36 
27 
1 
4 
2 
1 
12 
11 
1 
11 
9 
2 
1 
- 
2 
— 
1 
1 
1 
1000 
1000 
1000 
1000 
2500 
2500 
6220 
1500 
Ibid. 85, B, p. 227 
Ibid. 84, B, p. 331 
Ibid. 84, B, p. 330 
Ibid. 87, B, p. 31 
Ibid. 86, B, p. 419 
Ibid. 86, B, p. 405 
Ibid. 86, B, p. 330 
Ibid. 86, B, p. 291 
=■ R. 8. Proc. Vol. 86. B, p. 422. 
