227 
NOTES ON NAGANA AND ON SOME HAEMATOZOA 
OBSERVED DURING MY TRAVELS. 
By HERBERT E. DURHAM. 
I. Nagana. 
Several observations on the disease caused by the Trypanosoma 
brucei, which were made after the publication of the paper by Kanthack, 
myself and Blandford 1 , have not yet been published, and since the points 
have not attracted the attention of other writers, it seems worth while 
to place them on record. 
Longevity of guinea-pigs suffering from Nagana. 
It was stated in the above cited paper that the longest period of 
survival, which till then had been observed in guinea-pigs, was 183 days. 
A still smaller maximum was observed by Laveran and Mesnil 2 , namely 
only 61 days. 
When the virus was first received from South Africa, the experiments 
with guinea-pigs at first led us to believe that this animal was refractory. 
The guinea-pigs which had been inoculated and brought to England 
survived and did not show any signs of infection. Similar failure 
occurred with the earlier inoculations, which were performed by us with 
blood from the successfully infected dog which was delivered to us 3 . 
Further experiment however showed that the guinea-pig is not refrac¬ 
tory, and many observers have had no difficulty in maintaining the 
strain by means of this animal. 
The following observations are of interest, as showing that guinea- 
pigs may possess a considerable degree of resistance to the trypano¬ 
some :— 
Two guinea-pigs (“A” and “B”) were inoculated with blood of 
1 Proc. Roy. Soc., vol. xliv. 1898, p. 100, and Hyg. Rundschau, vol. vm. p. 1185. 
2 Trypanosomes et Trypanosomiases, Paris 1904. 
3 The syringe was used for all our earlier inoculations, later we used a surgical needle 
merely wetted with infective blood. 
Parasitology i 
15 
