151 



distini^uishing it from 0. iuricata, to which it is nearly alHed [R. A.E., B, 

 vii, 86j. The authors of the present paper, examining some individuals 

 of Oynithodorus collected in Morocco, observed a constant character- 

 istic not mentioned by Vein, though it occurs in his type specimens, 

 namely, the presence on each side of the camerostome of two processes 

 which incompletely covered the buccal parts. These structures are 

 generally composed of three or more pieces. Vein's description is 

 therefore completed by the addition of this feature. The authors 

 regard the species in question not only as resembling O. iuricata, 

 but as being intermediate between 0. titricala and 0. talajc. 



RouBAiD (E.) & Lf,ger (j\I.). Observations sur le Paludisme en Corse, 

 (Mars-Avril 1921). [Observations on Malaria in Corsica (March- 

 April 1921).]— Bull. Soc. Path. Exot., Pan's, xiv, no. 6, 1921, 

 pp. 340-351. 



The Institut Pasteur had been studying the problem of malaria in 

 Corsica since 1912, but research was interrupted by the War. Clinical 

 reports during the last few years have all recorded a distinct recru- 

 descence of the disease, many cases occurring even in the winter, 

 under circumstances that made it impossible to decide whether they 

 were primary or recurrent attacks. The authors therefore undertook 

 a survey of the island during March and April, visiting principally the 

 more highl}^ infected regions. The incidence of the disease in various 

 districts is discussed ; a marked recrudescence was noticeable in all 

 directions ; in Casabianda, for example, the index for children examined 

 was 37i per cent., as com.pared with 12| per cent, in 1912. The cause 

 of this general recrudescence was unknown. Meteorological conditions 

 in the preceding year had been adverse to the multiplication of Anophe- 

 lines, the season being so dry that breeding-places were reduced to the 

 minimum. Certain conditions may, however, have fostered the disease, 

 such as movements of the population, introduction of the parasite 

 from outside sources, the different standard of living, etc. 



At the season in which these observations were made, when Anophe- 

 line activity was onh^ just beginning, no gravid females were found 

 in houses ; all those examined showed ovules still in course of develop- 

 ment, so that all the haematozoa found in human beings were due to 

 previous infections. 



Out of sixteen cases examined, gametes were only found in three 

 {Plasmodium vivax twice, P. praecox once), which points to the impor- 

 tant conclusion that the sexual elements upon which the next epidemic 

 will depend appear at the same period, practically in the same pro- 

 portions for the two forms, without their relative frequency bearing 

 any relation to the schizonts in the blood. This is contrary to pre- 

 vious observations recorded by Grassi, who found the crescent form 

 appearing in Italy only in July, quite suddenly, in primar}- infections. 

 In Corsica, Anophelines may evidently become infected by the parasites 

 of both forms almost equally from the beginning of spring. In two 

 children examined, who showed no symptoms of disease, one revealed 

 gametes of P. vivax and the other of P. praecox in almost the same 

 proportion, without any admixture with schizonts. This finding is 

 in accordance with the theory previously expounded [R.A.E., B, 

 vi, 230-235], namely, that the ulterior differentiation of the primary 

 infection in favour of the benign tertian type, during the early warm 

 months, is due, at least in part, to the more rapid development in the 

 mosquito of P. vivax. This organism, entering the human S3-stem first 



