1910.]  § Drseases of Domestic Animals in Uganda. 7 
A. Lwing, Unstained. 
This species of trypanosome is extremely active in its movements. It 
dashes across the field of the microscope with such rapidity that it is 
impossible to follow its movements, cyclone-like leaving a clear path, the 
corpuscles in its track having been flung on either side. If it remains at 
the same spot for a time, as it sometimes does, it has an appearance of 
great energy and power, throwing the surrounding red blood corpuscles 
about in wild confusion. 
B. Fixed and Stained. 
The blood-films were fixed, stained and measured as described in the 
‘ Proceedings. * 
Length.—The following table gives the average length of this trypanosome 
in the ox and goat. Twenty trypanosomes are drawn and measured from each 
preparation, the average length reckoned, and the length of the longest and 
shortest given. 
Table L.— Trypanosoma vivax, Uganda, 1909. 
| In microns. 
NOU OE | Method Method 
Pi Animal, of of | | 
See ouneny. fixing. staining. Average | Maximum | Minimum 
length. | length. length. 
| 
290 Ox Osmic acid | Giemsa | 23 °7 28 ‘0 21-0 
45 iJ | i 7" i’ 23:8 26 -0 20-0 
450 iu i i 23-0 25-0 21-0 
450 i ‘i & | 23-4 25-0 22-0 | 
493 si 3 a 23 °7 25 O 21°0 
597 54 A a 2571 | 28-0 22-0 
598 a f i 25°38 | 280 24:0 | 
779 if a is 246 27-0 21-0 
982 hy ae 2 ‘ 23 °5 25 -0 22-0 
1267 i i a 24 °2 27-0 20-0 
1462 hs : ‘ 23:8 28-0 16-0 
864 Goat - 3 24 °2 25 °O 23 °°O 
864, « i i 24-7 26-0 19-0 
1036 es i : 23-5 29-0 19-0 
24°] | 29-0 | 16-0 
As is shown by the above table, this trypanosome varies in length between 
16 and 29 microns. Individuals only 16 microns long are rare, and only 
occur immediately after division. The following table represents the dis- 
tribution of length among 180 trypanosomes, and it will be seen by it that 
only three are found to measure less than 19 microns. 
* B, 1909, vol. 81, pp. 16, 17. 
VOL. LXXXIIT.—B. C 
