198 



advocated whenever the material can stand it. Vondran's apparatus 

 requires the same time for its action as the still, hot air plant, is very 

 expensive, and serves only for disinfestation and not for disinfection. 

 For disinfestation on a large scale, the same effect is more economically 

 obtained b}^ the use of hot-air chambers provided with ventilators. 



Carbonell (M. v.). Experiencias de Desinfeccion por Medio del Aire 



caliente agitado. [Experiments in Disinfection by means of 

 circulating hot Air.] — Rev. Inst. Bad., Buenos Aires, iii, no. 1, 

 January 1921, pp. 49-54. [Received 1st October 1921.] 



The disinfection of clothing, etc., by means of circulating hot air 

 is considered very effective, its killing power being better than that 

 of formol, which only affects the surface and is apt to injure the objects 



treated. 



Smyth (E. G.). La Mosca del Ganado. [The Horn Fly.] — Porto 

 Rico Ins. Expt. Sta., Rio Piedras, Circ. 39, Februar\- 1921, 

 17 pp., 4 plates. [Received 1st October 1921.] 



This is a revision of an earlier paper on Lyperosia irri^ans [R. A.E., 

 B, viii, 201]. It is still hoped that further efforts will be made to 

 introduce insect enemies, though attempts in this direction have 

 hitherto failed. 



Departmental Activities : Entomology. — //. Dept. Agric. Union 

 S. Africa, Pretoria, iii, no. 3, September 1921, pp. 208-210. 



A theory is propounded b}' Mr. R. H. Harris, who is engaged on 

 tsetse-fly investigations in Zululand, in explanation of the extension 

 of infested areas. The fly [Glossina pallidipes] only persists where 

 shade is present, and it is suggested that areas that were once open 

 country are gradually becoming covered with Acacia, and consequently 

 favourable to the fly, through irregularity of burning off the grass. 

 The germination of the seeds of this thorn is greatly accelerated by- 

 heat, and after a bush fire young trees soon appear. If, however, the 

 ground were burnt regularly every year, the chance of survival of the 

 seedlings would be remote, but each year that they escape a fire 

 they become more resistant to it. Neglect of burning for a few years 

 therefore causes a gradual transformation from open grass to thorn 

 scrub ; this change takes place almost imperceptibl\-, but its resulting 

 influence on the numbers of tsetse-fly is very marked. 



Bates (L. B.), Dunn (L. H.) & St. John (J. H.). Relapsing Fever 

 in Panama. The Human Tick, (Jr)iitliodoros talaje, demonstrated 

 to be the transmitting Agent of Relapsing Fever in Panama by 

 Human Experimentation. — Ajiicr. Jl. Trap. Med., Baltimore, i, 

 no. 4, Julv 1921, pp. 183-210, 4 charts. [Received 3rd October 

 1921.] 



Several cases of relapsing fever are recorded from a village outside 

 the Panama Canal Zone and about eight miles from Balboa. The 

 tick, Ornithodorus talaje, Guer., was thought to be the transmitting 

 agent, and this was confirmed by experiments on various animals, 

 including monkeys {Macacits rhesus) and man. 



The authors have not been able to trace any previous record of 

 relapsing fever being definitely transmitted by 0. talaje. 



