78 



caused a mortality of 80 per cent. ; (2) a species of Mermis, affect- 

 mg- 25 per cent., and (3) parasites of tlie autumn brood, viz., 

 t3 species of Glugea, one rare and the others causing from 5 to 

 10 per cent, mortality, and a species of Gregarina causino^ up 

 to 50 per cent, mortality. He also says that from no other 

 locality m North America have these or similar parasites been 

 recorded. 



_ Considering the enormous amount of damage done to cattle in 

 districts in which Simulium is abundant, the importance of the 

 parasite in keeping them down is obvious, and inasmuch as the 

 localities in which the latest observations were made are relatively 

 free from the pest, although the larvae are to be found in enormous 

 numbers, the author concludes that it is the parasites which 

 keep them in check. His observations lead him to the belief that 

 there is a seasonal variation of parasitism, as the species of parasite 

 found in the spring were not taken again in the autumn and mce 

 ■versa, so that it is probable that only those species of Simvlium 

 whose life-history coincides with parasitised species could be 

 infected with the parasites of the latter. He is also strongly of 

 opinion that infection is only possible during the early stages of 

 larval life and that it will probably be necessary to collect the 

 parasitised species and place them in streams where the other 

 species is always abundant, some little time before the eggs of the 

 latter hatch. He thinks that the gregarine parasite should be 

 carefully studied, although he was able to find it only in one 

 species of Simulium. He regards the whole question of the 

 existence of these parasites and the possibility of their use in the 

 suppression of a serious pest, as one of great importance in 

 economic entomology, and Suggests that every effort should be 

 made to experiment upon the feasibility of transporting the 

 parasites to those districts in which the pest is serious. A biblio- 

 graphy concludes the article. 



Smith (F.). Dengue Fever among the Troops in Calcutta; its 



identity with Seven-day Fever and Three-day Fever. — Jl. 



R.A.M.C., London, xx, no. 4, 13th April 1913, pp. 453- 

 458. 



Year after year the troops in Calcutta are attacked by a short 

 fever Avhich produces much inefficiency but no mortality. In 

 1912 the author had an opportunity of dealing with the disease 

 and has experienced an attack in his own person. He has little 

 doubt that the outbreak of 1912 was similar in character to that 

 of 1911, and he is sure that the fever of 1912 was dengue, but 

 the same fever has previously been called seven-day fever and 

 three-day fever. It always comes on in hot weather. ITp to 

 2Tth October 1912, no less than 461 cases of European soldiers 

 Avere treated and 2 native regiments suffered severely. Officers, 

 men, and women suffered alike. The pain was considerable, but 

 the secondary rash was not so universal as it should be according 

 to Manson and Daniels. The author says that it may be objected 

 that the shorter fevers were reallv sand-flv fe^^er, but he ureres 



