608 SMALLPOX AND VACCINATION 



latter was accomplished was by exciting a leucocytosis in a 

 rabbit's peritoneum and then introducing the vaccinal lymph ; the 

 leucocytes phagocyted the bacteria so that the lymph no longer 

 gave cultures on ordinary media. It was, however, still potent 

 to produce vaccinia.) 



Klein and also, independently, Copeman, have observed an organism 

 in lymph taken from vaccine pustules in the calf, in human vaccine 

 lymph, and in lymph from a smallpox pustule. Copeman and Kent also 

 found the bacilli in sections of vaccine pustules stained by Loffler's 

 metlvylene-blue, or by Gram's method. The organisms are *4 to '8 /* in 

 length, and one-third to a half of this in thickness. They are generally 

 thinner and stain better at the ends than at the middle. They occur in 

 groups of from three to ten in both the lymph and the tissues. In the 

 centre of their protoplasm there is often a clear globule, which is looked 

 on as a spore. They resist the ordinary isolation methods. 



Various observers have described structures in the epithelial 

 cells in the neighbourhood of the smallpox or vaccine pustules, 

 which they have interpreted as being protozoa. Thus RufFer 

 and Plimmer describe as occurring in clear vacuoles in the cells 

 of the rete Malpighii at the edge of the pustule (in paraffin 

 sections of vaccine and smallpox pustules carefully hardened in 

 alcohol, and stained by the Ehrlich-Biondi mixture) small round 

 bodies of about four times the size of a staphylococcus pyogenes, 

 coloured red by the acid fuchsin, sometimes with a central part 

 stained by the methyl-green. These are described as multiplying 

 by simple division, and in the living condition exhibiting 

 amoeboid movement. Similar bodies have been described by 

 Reed in the blood of smallpox patients and of vaccinated 

 children and calves. 



These are probably the bodies described by Guarnieri, and to 

 which considerable attention has been paid. They are from 

 1 to 8 /A in diameter, are round, oval, or sickle-shaped, and stain 

 by ordinary nuclear dyes. They lie in the cells in- spaces 

 often near the nucleus, and are readily demonstrable in vaccine 

 pustules and also in the experimental lesions which can be 

 produced in the rabbit's cornea, the larger bodies being defined 

 in the cells towards the centre of the lesion. These bodies 

 have been looked on by many as protozoa, and Guarnieri himself 

 stated that multiplication could be seen occurring in them in 

 fresh lymph ; but Ewing and also Prowazek have brought forward 

 strong evidence for the appearances being due to nuclear changes, 

 though the latter observer considers them to be the effect of a 

 specific reaction of epithelial cells against the variolous virus. 

 Here, it may be said, Wasielewski has shown that they persist 



