468 
THE RELATION BETWEEN LATENT BODIES AND THE NUMBER 
OF TRYPANOSOMES IN THE PERIPHERAL BLOOD, WITH 
NOTES ON THE PARASITES FOUND IN THE 
INTERNAL ORGANS OF THE HOSTS 
Following on the work of R. Ross and D. Thomson (1910)011 
the enumeration of the parasites in the peripheral blood of a patient 
suffering from Rhodesian sleeping sickness, the periodic increase 
in the number of trypanosomes in the peripheral blood of rats and 
guinea-pigs inoculated with T. rhodesiense or with T. gambiensc 
has recently been found by Fantham and J. G. Thomson. 
Rats similarly inoculated and exhibiting such periodic increase 
and decrease were killed at various points in the cycle, as set forth 
in the following tables: — 
A. Rat i.— T. gambiense, Laboratory Strain, in Piebald d R at - 
weight 150 grams, inoculated with 50,000 trypanosomes. 
Day . . 
1 
2 
3 
4 
5 
6 
7 
Parasites per c.mm. 
_ 
_ 
_ 
4 
Temp.* . ... . 
55 
46 
7 ° 
62 
57 
ic8S 
Day 
9 
10 
11 
12 
13 
14 
15 
Parasites per c.mm. 
Temp.* 
- - L_. 
439 2 
60 
868 
68 
1656 
44 
2560 
46 
9288 
57 
6304 
54 
4.36. killed 
61 
he temperature is expressed according to the following convention, as in Major Ro=i = 
recent papers on Malaria ’ and * Trypanosomiasis ’ Temp. - (F — 95) X 10, where F is the 
emperature in egrees Fahrenheit, recorded with a clinical thermometer. 
Heart blood of Rat i examined fresh , immediately utter 
hilling.— A few living trypanosomes seen and some (fewer) rounded 
forms. 
Spleen. Very large; three to seven rounded forms seen in even 
held of the microscope (2 mm. objective and 2 ocular); no flagellates 
seen in fresh preparation. 
fii() and portal blood. — Living flagellates and rounded bodies 
Seen 1,1 about equal numbers (one of each per field). 
