95 



Further Observations on the Effects produced on Rats by the 



Trypanosomata of Gambia Fever and of Sleeping Sickness. 



By H. G. Plimmer, F.L.S. 



(Communicated by Dr. C. J. Martin, F.R.S. Received November 21, — Read 



December 13, 1906.) 



[Plate 1.] 

 In January, 1905, I published* a note of some experiments with the above- 

 named strains of trypanosomata, and I have continued the experiments up 

 to the present time, and have embodied the total results in this paper. 



1. Gambia Fever. 



The number of rats inoculated with this strain of trypanosomata was 

 altogether 129 in 90 successive inoculations. In all of these rats, with the 

 exception of the five mentioned below, trypanosomata were present in the 

 blood from two to three weeks after inoculation (average time 18 days) 

 until death ; generally in good numbers, and increasing to large numbers for 

 some days before death. The spleen was, in these cases, very much enlarged, 

 and there was considerable blood destruction, with large numbers of poly- 

 chromatophile corpuscles, these being the most obvious gross signs. 



In the first 14 of these rats, as noted in the paper referred to above, no 

 paralytic symptoms were present, but out of the total number inoculated, 

 five became paraplegic, and the course of the disease in these animals 

 differed from that in the remaining 124. 



In the series, the numbers of the paraplegic rats were 35, 42, 68, 101, 

 102, and there were no perceptible differences in their conditions and those 

 of the other rats used. 



The first rat which became paralysed (No. 35, of the 25th inoculation) was 

 inoculated on March 17, 1905, and on the 31st of the same month both hind 

 legs became paralysed. No trypanosomata were found in the blood until 

 April 18, and from that time till death, which took place on April 28, only 

 a few were to be found in ordinary blood films. The second rat (No. 42, of 

 the 28th inoculation) was inoculated on April 13, 1905, from the blood of 

 another rat which had been 20 hours in the stomach of a leech, in which 

 some of the trypanosomata will live for at least 36 hours. The rat became 

 paraplegic on June 15, at which time no trypanosomata could be found in 

 ordinary blood films. The rat was killed on June 16, and a few trypano- 



* « Roy. Soc. Proc.,' vol. 74. 



