290 SANITARY ENTOMOLOGY 



Conjunctivitis. — DeFont Reaulx (1912) and other writers regard 

 head Kce as the cause of PHLYCTENULAR CONJUNCTIVITIS, and 

 Hudson (1914) states that its sequela PHLYCTENULAR KERATITIS 

 prevails among Board School children in England, causing much suffer- 

 ing and corneal scars with resultant disabilities. He refers severer cases 

 primarily to head lice, infective material being carried from the scalp to 

 the eyes by the hands. 



Other Septicaemias. — Sobel in 1913 as a result of eleven years' 

 experience with New York school children states that head lice are the 

 indirect cause of pyogenic infection, frequently leading to involvement 

 of the lymphatic glands followed by suppuration, and that lice also 

 indirectly cause IMPETIGO CONTAGIOSA, DER:\IATITIS, FURUN- 

 CULOSIS, ECZEMA AND FOLLICULITIS. Pinkus in 1915 describes 

 similar results and states that the inflammation of the scalp may lead to 

 the falling out of the hair. 



Thallophyta: Fungi: Schisomycetes: Bacteriaceae 



Bacillus pestis Kitasato, the cause of PLAGUE, is referred to by 

 various authors. Swellengrebel and Otten (1914) experimenting with 

 clothes lice from plague patients in Dutch East India, and DeRaadt 

 (1916) have succeeded in causing death by plague in experimental ani- 

 mals by subcutaneous inoculations of crushed lice. Herzog in Manila 

 found Bacillus pestis in three head lice from a child dead of plague 

 (Bulloch and Douglas, 1909). There is no evidence that plague can be 

 carried by the bite of lice. 



Bacillus typhosus Eberth. — In like manner Abe (1907) claims to 

 have recovered Bacillus typhosus from body and head lice fed on 

 TYPHOID FEVER patients in 75 per cent of the insects examined. 



Bacillus leprae Hanson. — McCoy and Clegg (1912) have likewise 

 found Bacillus leprae in two head lice out of many examined from patients 

 suffering with LEPROSY. 



Sumvmary of Plant-Caused Diseases 



All of the various cases cited above are probably to be considered 

 purely as examples of mechanical transmission by scratching of the feces 

 of the lice containing the organism into the skin. The organisms of 

 impetigo contagiosa, tropical impetigo, favus, pityriasis, Pneumococcus 

 and Streptococcus septicaemias, phlyctenular conjunctivitis and keratitis, 

 plague, typhoid fever, leprosy, and meningitis are all bacteria or fungi. 

 It is to be hoped that experiments in inoculation of feces will be carried 

 out with those organisms in which the exact role of the louse is still unde- 



