6 TECHNIC 



research (April 17, 1920) Mr. Bacot developed an illness be- 

 lieved to be trench fever (Bacot, 1921, p. 156). The use of his 

 stock was discontinued immediately after the onset of this ill- 

 ness in anticipation of the possibility of the lice becoming in- 

 fected with some micro-organism. Mr. Bacot continued to 

 feed his lice upon himself and after an appropriate period, 

 eleventh day of his illness, rickettsia bodies began to appear in 

 the lice excreta. Shortly afterwards large numbers of his lice 

 proved to be heavily infected with rickettsia restricted to the 

 alimentary tract and always extracellular. These rickettsia 

 in distribution in the lice and in morphology were identical 

 with Rickettsia pediculi of Munk and da Rocha-Lima (1917, 

 p. 1424, Fig. 2), and likewise identical with Rickettsia quintana 

 (Schmincke, 1917) (Munk and da Rocha-Lima, 1917, p. 1425), 

 and Rickettsia wolhynica of Toepfer '(1916). The last two 

 names were applied to rickettsia bodies by the authors named 

 in the belief that they were the cause of trench fever and dis- 

 tinct, though indistinguishable from Rickettsia pediculi. Ark- 

 wright, Bacot, and Duncan (1919 *, 1919 2 ) and Byam and 

 Lloyd (1919) described similar bodies in lice fed upon trench 

 fever patients. 



The symptoms and course of Mr. Bacot 's illness were those 

 of trench fever and the appearance in his lice of rickettsia 

 indistinguishable from Rickettsia pediculi indicates the prob- 

 able identity of Rickettsia pediculi with Rickettsia quintana 

 (wolhynica) . 



2. CONTROL EXAMINATIONS OF STOCK LICE 

 Although none of the various members of the Commission 

 who acted as hosts to the stock lice experienced any untoward 

 symptoms, thereby suggesting that the lice were free from 

 pathogenic micro-organisms, control examinations were made 

 of each of the three stocks before our experiments were com- 

 menced. Serial sections and smears of the organs of lice from 

 the three stocks were examined. These preparations were all 

 stained by Giemsa's stain; the technic described below was 

 used throughout our work. 



