118 RICKETTSIA 



blood plasma of typhus cases, but only with greaf rarity. 

 The former they describe as "bacilliform bodies 2/x long and 

 ^H wide, showing at the extremities two rounded masses 

 colored in violet-purples, the central part remaining white." 

 The latter as " bodies \p wide composed of two spherical cor- 

 puscles; one of the corpuscles is tinged in purple-red in the 

 Giemsa, the other in blue." 



Hegler and von Prowazek, in 1913, described appearances 

 in neutrophilic leucocytes from fifty-one typhus cases which 

 they believed to be micro-organisms. The bodies described 

 by them were in the form of paired granules, resisting decolori- 

 zation with alcohol after Giemsa staining and lying in vacuoles. 

 No satisfactory confirmation of Hegler's and von Prowazek's 

 conclusions have been offered by other workers, and from our 

 own experience we confess inability to distinguish characteris- 

 tic features of the granules to be noted in leucocytes in typhus 

 when compared with leucocytes from other sources. 



Hegler and von Prowazek (1913) mention also one instance 

 of the finding of small coccus-like double organisms in a smear 

 from a louse fed upon typhus cases. 



A later report by von Prowazek (1915-16) again contains 

 observations on the paired granules in leucocytes. 



Sergent, Foley, and Vialette (1914) described cocco-bacilli 

 from lice collected from typhus cases, and not in lice from per- 

 sons without typhus. These organisms were described as ex- 

 hibiting bi-polar staining, and as Iju to 3/-t in length and 0.5/z 

 to 0.8/i in width. Very small forms were described as were 

 granules. All of the forms were seen singly, in pairs, and in 

 short chains. The proportion of lice containing these organisms 

 and the number of organisms in the lice increased with the 

 duration of the cases from which they were collected. They 

 did not find these micro-organisms in thousands of lice taken 

 from individuals without typhus. They did not attach 

 etiological significance to these organisms and regarded them 

 as compatible with the micro-organisms described by Ricketts 

 and Wilder (1910 2 ) and the cocci-bacilli cultivated by Galesco 

 and Slatinearo (1906) and by M. Rabinowitsch (1909). 



