179 



patients, pointed out that they got cystes on the alimentary canal, made them sting 

 himself and got malaria which, in spite of quinine treatment, persisted almost for 

 two years. Quite similar experiments were made in other countries and always with 

 the same results. The supposition that ^4. maculipenms should he divided in separate 

 geographical and biological races some of which have receptivity with regard to 

 Plasmodia, others not, is therefore unquestionably wrong. 



It is also in accordance with the statement of ROUBAUD that the war with its 

 transport of troops etc. has actually as was expected carried malaria into areas where 

 it was not found; the troops have infected the Anophelines, after which these have 

 brought the malaria to natives, who for a long series of years have never set foot 

 on infected territories. I shall here not enter into details but only refer to the following 

 cases which may be augmented with a long series of others; most of them derive 

 from the west front or from England. JEANSELMK (1916 p. 693); ROUBAUD (191 1^ 

 p. 171); CAILLE (1918 p. 282); PEJU and CORDIER (1918 p. 1039 and 1919 .p. 23); PEJU 

 (1919 p. 1267); BRULE and JOLIVET (1916 p. 2304); JAMES (1919 p. 37). BACOT (1918 

 p. 241). MALONE (1919 p. 202). MACDONALD (1919 p. 669). ROUBAUD (1920 p. 181). 

 DIBLE (1915 p. 577). ROBLIN (1919 p. 605). The interesting and very consoling fact 

 with regard to all these cases is, that they never give rise to greater epidemics, 

 and that from an epidemical point of view they have hitherto really been quite 

 insignificant. CARTER (1919 p. 2605) states that though in 1917 over 10.000 infected 

 men were imported there were only 231 cases of malaria contracted in England. 

 In France only 258. 



If however great numbers of malaria carriers were spread over areas where 

 the Anophelines were abundant and, as we now r know, able to be infected, the 

 question arises why these malaria carriers have not caused great epidemics. Even 

 the above cited new investigations have in my opinion contributed to its solution, 

 but as far as I can see without the investigators having any intelligence of the fact 

 themselves. 



Already in the earlier entomological literature we find it stated that A. maculi- 

 penms does not suck blood; all these indications derive from the area north of 

 the Alps. England: THEOBALD (1901 p. 194). NUTTALL and SHIPLEY (1901 p. 10). 

 Austria: SCHINER according to SCHNEIDER (1914 p. 20). Germany: SCHNEIDER (1914 

 p. 21). Still in 191 8 2 (p. 430) ROUBAUD maintained that the Anophelines in North 

 France are only to a slight degree blood-suckers; it is very often stated that the 

 mosquitoes of both sexes are flower visitors. These indications are unquestionably 

 wrong, but still they contain a grain of truth. 



Already in 1900 GRASSI (p. 82) pointed out that the Anophelines suck blood 

 upon all mammifers also birds especially fowls; they show no particular predilec- 

 tion for man; if a horse and a man be placed in the same room, the horse will 

 be attacked before the man, but if man and a rabbit are placed in the same room, 

 it is man who will first be attacked. It is the volume of the evaporating smelling 

 surface which guides the mosquitoes. Various authors further maintain that it is 



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