676 A MANUAL OF BACTERIOLOGY 



resembling spores, which he regarded as the resting stage 

 of the specific microbe. 



De Korte finds that the vesicles, both in variola and in 

 vaccinia, are sterile before maturation, and regards the 

 bacterial forms that have been isolated as secondary 

 infections. 



The failure to isolate a bacterial form has induced many 

 observers to seek for a parasitic protozoon in variola and 

 vaccinia, and various " bodies " have been described. 

 Thus, Guarnieri found small bodies, about half the size of 

 the nucleus, in the epithelial cells of the skin in the pre- 

 pustular stage of variola and in the cornea after inocula- 

 tion. Somewhat similar bodies have been described by 

 L. Pfeiffer, J. Clarke, Ruffer and Plimmer ; and Council- 

 man, Magarth, Brinkerkoff, Tyzzer, and Calkins, 1 and 

 others. 



Much doubt exists as to the nature of these bodies. 

 Prowazek regards the cell inclusions (the Guarnieri and 

 Negri bodies, etc.) in this and other conditions (e.g. rabies) 

 not as parasites, but as tissue reactions consisting of 

 plastin and nuclease and enclosing the parasites, what- 

 ever these may be. 



Fornet, 2 by treating variola or vaccine lymph with ether, 

 finds a stage when all the bacteria are killed, but the specific 

 virus is uninjured. By inoculating this etherised lymph 

 into nutrient broth and keeping at 37 C., the broth culture 

 inoculated in man produces typical vesicles even after 

 two months' incubation, and moreover the culture can 

 be carried on from tube to tube. In the broth, minute 

 rounded bodies can be detected which may be the specific 

 micro-organism. 



The relationship of vaccinia to variola has been a very 



1 Journ. Med. Research, vol. xi, 1904, p. 173 ; Philippine Journ. of 

 Science, vol. i, 1906, p. 239. 



2 Trans. XVIIth Internal. Cong. Med Lond., 1913, Sect, iv, pt. ii, p. 119. 



