118 



produced in human beings by T. gambiense ; souma, a disease of horses 

 and cattle caused by T. cazalhoui; baleri, a disease of horses and 

 dogs, caused by T. pecaudi; and a disease of horses, cattle and dogs, 

 due to T. dimorphon. Human beings of any race seem to be equally 

 susceptible to trypanosomiasis, but different races of animals show 

 varying degrees of resistance. Pigs show a strong reaction against 

 the disease, and the small native races of domestic animals, such as 

 goats, horses and cattle, are far more resistant than the larger ones. 



Although infection is confined to fly areas, trypanosomiasis is 

 extremely localised in comparison with fly distribution, and may be 

 severe in one district, but absent from another equally fly-infested. 

 This, in the author's opinion, is due in a large measure to the biological 

 variations produced by climatic conditions referred to above. More- 

 over, in only a small percentage of the flies that feed on infective 

 hosts does the infective organism develop and become capable of 

 infecting another host. Although the question is a complex one, 

 it seems that there is no very great danger of a widespread extension 

 of human trypanosomiasis outside the zones in which it actually occurs 

 in French West Africa. 



The destruction of Glossina by artificial means is not an easy problem, 

 although in one instance a district that was highly infested, forming 

 part of a large area thickly populated with G. morsitans beside the 

 Gambia, has become clear of flies in consequence of clearing the land 

 and driving off the big game. For hygrophilous species, living in 

 wooded country beside water, partial clearing or thinning of the forest 

 belts is the only efficient remedial measure. It is owing to the clearing 

 operations on the banks of the Senegal and Niger that these rivers 

 have ceased to be infested with Glossina throughout their length. 

 Such clearing can be of much practical value if intelligently carried 

 out at the most appropriate places, such as frequented water-courses, 

 streams beside roads or native tracks, the outskirts of villages in forest 

 zones close to water, etc. While these measures would entail a large 

 amount of labour in the compact forest zone that covers a great portion 

 of the coast in Guinea, the Ivor}^ Coast, Togo and Dahomey, in the 

 more northern fly-infested regions, such as the Sudan and Senegal, 

 much might be done ; for example, at Nianing, on the Senegal coast, 

 there is a small circumscribed area that is a well-known centre of 

 sleeping sickness and various forms of animal trypanosomiasis. The 

 disinfestation of this area is very desirable in every way, and does not 

 ■present any serious difficulty. The permanent fly-breeding zones in 

 particular should be attacked. It is suggested that much is to be 

 gained by popularising information regarding the habits of Glossina. 



Sergent (Edm.). Sur PHivemage des Moustiques des hautes Mon- 



tagnes. — Bull. Soc. Hist. Nat. Afr. Nord, Algiers, xiii, no. 2, 



February 1922, p. 36. 



In view of observations made at an altitude of about 6,186 ft., near 



ChamxOnix, it is thought that mosquitos at high altitudes migrate 



to lower levels to hibernate. In the case under consideration, Aedes 



pullatus var. jugorum, Vill., was noticed following the author's party 



for about two hours, descending about 3,000 ft. 



La Plaga de la Garrapata en la Republica. — Rev. Agric, Mexico, vi, 

 no. 11, March 1922, pp. 640-644, 5 figs. 

 The role played by ticks in the transmission of Texas fever is 

 discussed ; the life-history of the tick [Boophilus annulatus] and the 



