150 



and kept there for two days ; the animals had been freed from 

 ticks, and the openings into the stable were protected by wire- 

 gauze. In Bouffard's opinion the local abundance of the Stomoxys 

 readily explains the ravages caused by souma among cattle. 

 Unfortunately the species of Stomoxys used in the experiment is 

 doubtful, though there is reason to think that it was either Stomoxys 

 calcitrans, L., or S. nigra, Macq.* 



In French Congo, Gustave Martin, Leboeuf, and Roubaud have 

 shown that Trypanosoma brucei, PL and Br. (the parasite of nagana) 

 can be conveyed mechanically by either Stomoxys nigra, Macq., or 

 *S^. calcitrans, L. (or perhaps by both).f Three flies (two S. nigra 

 and one >S'. calcitrans) were allowed to imbibe a drop of virulent blood, 

 and then, after intervals of from half a minute to a minute and 

 a half, were successively made to bite a healthy kitten, in the blood 

 of which numerous parasites were subsequently found on the 

 twelfth day. From the conditions of the experiment it is uncertain 

 whether the trypanosome was carried by all three fUes used, i.e., 

 by both S. calcitrans and S. nigra. It may, however, be noted 

 that a subsequent experiment by the same investigators on similar 

 lines, in which three S. nigra and a guinea-pig were used, and the 

 intervals were ten minutes in the case of one fly and a quarter of 

 an hour in that of the other two, gave negative results. The authors 

 refer to direct-transmission experiments by Minchin, Gray, and 

 TuUoch in Uganda, with a trypanosome (that of " Jinja " cattle- 

 disease) allied to T. brucei and with no interval between the bites, 

 when, by using Stomoxys [either S. 7iigra or S. calcitrans, or both], 

 one positive result in four was obtained, while the use of Glossina 

 palpalis gave four positive results in five. J Messrs. Martin, 

 Leboeuf, and Roubaud add : — " It is therefore evident that, 

 even as simple carriers, the species of Glossina are of more 



* The species was actually described by F. Picard {Bulletin de la Socu'U' enio- 

 mologique de France, 1907, pp. 27, 28) as Stomoxys bouffardi, but the description, 

 which, as I am informed by the author, was based upon specimens in very bad 

 condition, is quite unrecognisable. 



f 6'/. Gustave Martin, Leboeuf, and Roubaud, Bulletin de la SociHe de Pathologie 

 Exotique, T. I., No. 6, p. 3.56 (1908). 



f Of. Minfliiii. Gray, and TuUoch, Reports oj the Sleeping Sickness Commission of 

 the Royal Society, No. VIll., p. 124 (February, 1907). 



