ENTOMOLOGY

502 SANITARY ENTOMOLOGYThe body, head, and pubic lice are found on all races of men andseem to show some varietal differences according to the host. Noneof these species occurs on any other host than man, although a closelyrelated species Pediculus consobrinus Piaget occurs on a monkey (Atelespentadactylus ).Children and old people are much more likely to be affected with headlice than active men and women, and girls because of thei.r long hair aremuch more ·frequently infested than boys. On the other hand, menseem to be more often the subjects of attack by corporis and pubis.In the civilian population of this country there are indications of im-PLATE XXI.- The clothing louse, Pediculu8 corporis. Fig. I.-Female, ventral view.Fig 2. Male, dorsal view. (Pierce and Hutchison, photos by Dovener.)porlant changes in the general problem. In times of peace the louseproblem is most acute in jails, poorhouses, and like institutions; amongvagrants and the extremely poor classes; among gangs of laborers, as inconstruction camps, lumber camps, threshing gangs, etc.; and among im~migrants. Since our entrance into the war there have been economicchanges which have shifted some of these centers of infestation. Forexample, there have been many camps of laborers engaged in temporaryconstruction work. Reports indi~ate that lice give considerable troublein some of these. There has probably been an increase in the size andnumber of lumber camps. On the other hand, we have been informed bythe captain in charge of the House of Detention at New Orleans, thatthe vagrant population, which has always been their worst source of