77 



July, suddenly greatly increased up to the first week in August, after- 

 wards decreasing until it reached its original level at the end of 

 -September. There were thus two waves, a small one in May and a 

 large one in August. The civil population had been removed from the 

 •district and the military placed in occupation were practically free 

 from malaria. The first outbreak is attributed to infected Anophelines 

 that had hibernated. The incidence of Anophelines is roughly parallel 

 to that of the second outbreak, but about three weeks earlier. The 

 newly emerged mosquitos are not believed to have derived their 

 infection from the civil population, soldiers infected in the first 

 outbreak, Russian prisoners or deserters, or the Russian front opposite. 

 The survival of the hibernated mosquitos is also rejected as a possible 

 source, because it would give a uniform curve, decreasing gradually. 

 Apart from prolonged incubation in the troops, the inheritance of 

 malarial infection in the mosquito provides the only explanation of this 

 phenomenon. The inheritance of typhus infection in the louse and of 

 relapsing fever in the tick are analogous cases. 



In the section dealing with the biology of Anophehnes the preference 

 of these mosquitos for latrines is recorded [see this Review, Ser. B, v, 

 p. 62], as well as their remarkable power of resistance to intense cold, 

 they being found to occur in localities where for several weeks the 

 temperature was between 14° and — 15° F. 



Klingmuller ( — ). Ueber die Bettwanze. [The Bed-Bug.] — Munch. 

 Med. Wochenschr., Munich, Ixiv, no. 52, 25th December 1917, 

 pp. 1653-1654. 



This paper records a number of observations on bed-bugs [Cimex 

 lectularius], which are very abundant on the Russian front, where they 

 may perhaps be concerned in the transmission of disease, though the 

 author does not believe this to be the case. 



When moving, the bugs easily lose their hold and this accounts for 

 their falHng from ceilings on to persons sleeping beneath. They feed 

 on man and other mammals, though they do not, as a rule, suck blood 

 immediately they are placed on the flesh, but wander about for some 

 time. Their saliva probably contains a substance that prevents the 

 blood from coagulating, and this and the mechanical injury caused 

 probably give rise to the irritation produced. All persons are bitten 

 indiscriminately, though some suffer much more inconvenience than 

 others. Individual bugs can five for over a year, and one example was 

 kept in captivity for 440 days. They are very resistant to starvation, 

 some surviving after 221 days without food, while young bugs that had 

 never fed lived for 150 days. They can also withstand such low 

 temperatures as 0° F. [in the original, — 17°, which is assumed to be 

 Centigrade], living in a torpid state, and even quite young individuals 

 survive the winter cold. Bugs are therefore able to survive for over 

 six months in an uninhabited house. The eggs are more sensitive to 

 cold, and if exposed to low temperatures they fail to hatch. Odour does 

 not appear to guide bed-bugs in their search for blood, nor do they 

 seem able to distinguish colours. When not seeking food, they usually 

 remain in one place and appear to prefer a wooden surface. They are 

 easily killed in water and other harmless fluids, while soapy water, 

 alcohol, benzol, etc., destroy them very rapidly. 



