260 EXPERIMENT STATION RECORD. 



Experiments to ascertain if certain Tabanidse act as the carriers of Try- 

 panosoma pecorum, D. Bruce et al. {Proc. Roy. Soc. [London^, 8er. B, 83 

 (1911), No. B 565, pj). 349-358, pi. 1). — " Tabanus secedens, T. thoracirms, and 

 T. fusconuirginatus appeared to be unable to transmit T. pecortmi from infected 

 to healthy cattle by the mechanical method of transmission. Owing to the 

 short life of these tabanids in captivity it is impossible, from the above experi- 

 ments, to state whether they can convey the disease (T. pecorum) after a period 

 of development of the trypanosome in the fly. We believe the three types of 

 flagellates found in T. secedens and T. thoracinus to be various stages in the 

 development of a harmless Crithidium in these flies." 



Experiments to ascertain if Trypanosoma gambiense during its develop- 

 ment within Glossina palpalis is infective, D. Bruce et al. (Proc. Roy. Soc. 

 [London], Ser. B, 83 (1911), No. B 565, pp. 345-348). — ''Trypanosoma gam- 

 Mense may retain their virulence, as ascertained by direct inoculation into 

 susceptible animals, for a period of 2 days after they are ingested by G. palpalis. 

 After the trypanosomes have been within the gut of the fly for 2 days the 

 power of infecting animals with sleeping sickness, when inoculated subcu- 

 taneously, is lost for a period of 22 days. T. gambiense regains the power of 

 infecting by direct inoculation after it has been about 24 days within the 

 intestine of the fly. The number of days during which the virulence of the 

 trypanosomes contained in the fly is lost roughly coincides with the time that 

 the infected fly is incapable of transmitting sleeping sickness by biting sus- 

 ceptible animals. There is some evidence that the salivary glands of the fly 

 are invaded by virulent forms of the parasite 36 days after the fly has fed upon 

 infected blood." 



Experiments to investigate the infectivity of Glossina palpalis fed on 

 sleeping sickness patients under treatment, D. Bruce et al. (Proc. Roy. Soc. 

 [London], Ser. B, 83 (1911), No. B 565, pp. 338-344)-— ^t was found that Glos- 

 sina palpalis fed on natives suffering from sleeping sickness, whether untreated 

 by drugs or treated by arsenic and other drugs, may become infected and be 

 capable of transferring the disease to healthy animals. 



Remarks on the egg-laying of Stomoxys calcitrans and rearing the larvae 

 of Muscidffi, M. Langeron (Compt. Rend. Soc. Biol. [Paris], 69 (1910), No. 28, 

 pp. 230, 231; abs. in Joxir. Trop. Yet. Sci., 6 (1911), No. 1, pp. 60, 6i).— The 

 author finds that boiled bran forms a very good medium for the development of 

 the larvae of the Muscidse. It must be kept moist and the light excluded. 



Third report on flies as carriers of infection (Rpts. Local Govt. Bd. [Gt. 

 Brit.], Pub. Health and Med. Subjs., n. ser., 1910, No. 40, PP- 48, pis. 7, figs. 3).— 

 Three papers are here presented, namely. Observations on the Ways in which 

 Artificially-infected Flies (Musca domestica) Carry and Distribute Pathogenic 

 and other Bacteria, by G. S. Graham-Smith (pp. 1— iO) ; Summary of Literature 

 Relating to the Bionomics of the Parasitic Fungus of Flies, Empiisa mtiscw, 

 with Special Reference to the Economic Aspect, by J. Bernstein (pp. 41^5) ; 

 and Note as to Work in Hand, but not yet Published, and as to Proposed Fur- 

 ther Work in Reference to Flies as Carriers of Infection, by S. M. Copeman (pp. 

 45-48). 



The experiments conducted by Graham-Smith show that nonspore-bearing 

 bacteria frequently survive for several days in the crops of flies and that after 

 a meal flies may regurgitate some of the contents of their crops through the 

 proboscis. "A fly which has access to abundant food produces between 15 and 

 30 deposits (vomits and feces) in 24 hours . . . Experiments with BaciJhis 

 prodigiosus show that flies may infect sugar 48 hours after feeding on infected 

 material, and that clean flies may infect themselves by feeding on the recent 

 deposits of infected flies. In the few experiments which were tried, milk and 



