72 



septemnotata and Culex pipiens ; and the Chalcids, Stenomalus mus- 

 carum and Pteromalus deplanatus. The most numerous and trouble- 

 some fly was M. autmnnalis, while L. septemnotata occurred mainly 

 in certain rooms, the outer walls of which were covered with ivy. 



An unoccupied house near Cambridge in March 1918 was found to 

 contain hundreds of living and dead P. rudis, especially in rooms 

 facing west. 



Peacock (Lieut. A. D.). The Structure of the Mouth-parts and 

 Mechanism of Feeding in Pediculus humanus. — Parasitology, 

 Cambridge, xi, no. 1, November 1918, pp. 98-117, 2 plates, 6 figs. 



The information contained in this paper was obtained during 

 investigations to ascertain whether Pediciilus humanus is a carrier 

 of Weil's disease [Spirochaeta icterohaemorrkagiae]. Though the 

 enquiry did not demonstrate the presence of the spirochaete in the 

 body-louse, the author hopes that this description of the mouth- 

 parts and feeding mechanism will be of use to investigators engaged 

 in the study of the transmission of disease by lice. 



NuTTALL (G. H. F.). The Biology of Pediculus humanus. Supplemen- 

 tary Vi otes.— Parasitology, Cambridge, xi, no. 2, February 1919, 

 pp. 201-220, 1 plate, 1 fig. 



Experiments to determine the reaction of Uce (Pediculus humanus) 

 to colour and hght demonstrated that, when illuminated by rays 

 of light falling vertically upon them, they seek the shade, and a 

 black surface in preference to a white one. Experiments with lice 

 upon a polychrome carpet yielded no evidence of a preference for any 

 particular colour. 



Investigations on the influence on lice of temperature conditions 

 in clothing and the absorption of radiant heat by cloth showed that 

 man's clothing, depending on its colour, varies in its capacity for 

 absorbing radiant heat, therefore in warm weather black cloth, 

 which absorbs the maximum of heat rays, will prove inimical to lice 

 and cause them to wander away to where it is cooler so as to escape 

 (a) the direct effect of heat, and (b) its indirect effect in producing 

 perspiration in man, for lice object to excessive moisture in the vicinity 

 of man. 



That pigmentation in Pediculus is not an hereditarily transmitted 

 character, but that its presence depends entirely upon the nature 

 of the background upon which the insect lives, and that it is a character 

 that may be acquired in a couple of days, was proved by the experi- 

 mental raising of P. humanus on black, grey, white and coloured 

 backgrounds. 



Bacot (A.) & Talbot (G.). The Comparative Effectiveness of certain 

 Culicifuges under Laboratory Conditions. — Parasitology, Cambridge, 

 xi, no. 2, February 1919, pp. 221-236, 1 fig. 



The methods and experiments devised for the purpose of determining 

 for the War Office the comparative efficiency of certain culicifuges 

 show that, while some of the preparations afford a high degree of 

 protection, others are of dubious value. Since any preparation which 



