188 Major R. Ross and Dr. D. Thomson. Sleeping [Oct. 15, 
administration of this drug. His eyes were examined weekly by Dr. Hamilton, 
oculist to the hospital. 
On May 10 both legs became markedly cedematous and-remained so till 
his death. On May 13 he became much worse and developed paralysis of his 
sphincters. He seemed about to die, but on May 20 a sudden remarkable 
improvement took place. Soon, however, he again commenced to grow 
steadily worse. 
On June 25 he developed pleurisy and pneumonia. He died on June 29. 
Post mortem: performed 22 hours after death :— | 
Brain: membranes thickened and white. Vessels congested. Cerebro- 
spinal fluid increased. 
Left lung: broncho-pneumonia. 
Left pleural cavity: contained one pint of yellow pussy fluid. 
Spleen: soft and much enlarged; weight, 33 ozs. 
Liver: enlarged ; weight, 6 lbs. 
Blood: no trypanosomes could be found. Leucocytes, 17,000 per cubic 
millimetre. Polymorph excess. 
Smears of bone marrow, spleen, kidney, mesenteric glands, and cerebro- 
spinal fluid, all showed large numbers of small and large mononuclear 
cells, but no trypanosomes could be detected. 
(2) Continuance of the Periodical Cycle. 
The cycle recorded by us till April 30 in our previous paper continued till 
his death. From February 22 till June 25 there occurred 19 rises in the 
numbers of trypanosomes in his peripheral blood. This gives an average 
of six and a-half days between the heights of each rise. 
The shortest period between two successive heights is four days, as 
recorded between April 18 and 22, and again between June 3 and 7. 
This exceptionally short interval was due, we think, to artificial means, as 
we shall explain later under vaccine treatment. The longest period recorded 
between two successive heights is eight days, while the usual period between 
the heights seems to be seven days. It will be observed that the rise and 
fall is sudden, and that the height is not maintained. 
While the number of the parasites was increasing rapidly, we observed 
many forms with double nuclei and blepharoplasts (dividing forms). During 
the interval between the rises, few of these forms were present. This would 
seem to indicate that the sudden rise is due to an active multiplication of 
the parasites. 
On April 28 the numbers increased from 200 to 1536 in 24 hours, and 
on June 19 they increased from 100 to 1500 in 24 hours, suggesting that in 
