182 



pointed out that in view of the impossibility of differentiating 

 morphologically the two main groups of Leishmania, which cause in the 

 one case kala-azar in man and dogs, and in the other Oriental and 

 Occidental sore, it is useless to try to separate the species or races of 

 flagellates by microscopic examination. The undoubted occurrence 

 of the disease in the absence of insect bites is considered as exceptional 

 and not as contradicting the theory of insect transmission. The 

 existence of some reservoir of the virus other than man is considered 

 probable, although nothing is loiown on the subject. If such a reser- 

 voir exists in the form of an animal, the latter must show some evidence 

 of Leishmania in the blood, if only after culture ; though it is very 

 unlikely that the animal would itself be attacked by Oriental sore. The 

 improbability of such a reservoir being found in the dog, or such 

 animals as the horse or donkey is explained. The theory of the gecko 

 is a very tempting one, but the recent work of the author in collabora- 

 tion with MM. Blanc and Langeron [see preceding paper] has failed 

 to prove it true. 



Much consideration has been given to the possibility of the camel 

 as the natural reservoir of the virus. The centres of infection of the 

 disease correspond exactly with the routes taken by the nomad tribes 

 and their caravans when they migrate durmg the cold season from the 

 plateaux towards the desert and on their return for the hot season. 

 If the camel were the reservoir of the virus, the presence of an 

 insect vector, owing to some condition of the flora or some other 

 factor particular to the region, would be sufficient to ensure the 

 transmission of the disease to man. While the occurrence of man is of 

 almost unlimited extent, that of the camel is more restricted, but 

 it covers the area of incidence of Oriental sore and even that of 

 certain centres apparently not reached by the disease ; the more 

 limited distribution of the insect vector would determine the occurrence 

 of the classic type of Oriental sore. It might also be supposed that 

 in South America the role attributed in the East to the camel would 

 be filled by related species of animals such as the llama and vicugna. 

 This hypothesis is an attractive one, but experiment has failed to 

 confirm it. Two camels that showed blood free from flageUates were 

 inoculated with a large dose of a culture of Leishnania tropica, the 

 inoculation being repeated ten days later. Even after 76 days the 

 camels have shown no sign of the sore, and tests of their blood proved 

 negative. The hypothesis of the camel as a reservoir of the virus is 

 therefore no more proved than that of the gecko. Neither theory, 

 however, has been completely abandoned. 



Sergent (Ed. & Et.) & DoNATiEN (A.). Infection experimentale des 

 Dromadaires par le Trypanosoma berberum du Debab. — Bull. Soc. 

 Path. Exot., Paris, xiii, no. 7, 7th July 1920, pp. 521-525. 



The course of the form of trypanosomiasis in camels in Algeria 

 known as " debab," due to T. berberum, is described from observa- 

 tions lasting for two years on some twenty camels that were inoculated 

 with blood taken from an individual sufi^ering from a naturally acquired 

 infection. The natives believe that debab produced by the bite of a 

 fly is almost always fatal. In the experiments described, tr}'pano- 

 somiasis has very seldom been the cause of death in spite of the 

 extraordinary number of trypanosomes revealed by direct examination; 



