SMALLPOX AND VACCINIA 571 



not yet determined by its discoverers. Noguchi and Cohen have 

 made the important observation that the conjunctive of certain 

 monkeys are susceptible to infection with material containing the 

 von Prowazek inclusion bodies, but not to the hemoglobinophilic 

 bacilli isolated from cases of epidemic conjunctivitis; on the other 

 hand, pure cultures of hemoglobinophilic bacilli cause an acute 

 inflammation in the testes of rabbits; at certain stages of the infection 

 numerous clumps of the organisms occur, which stimulate the von 

 Prowazek cell inclusions. Injection of conjunctival scrapings con- 

 taining the cell inclusion bodies alone is without effect in the rabbit. 



These observations have led Noguchi and Cohen to conclude that 

 a group of cases exists in which epithelial cell inclusions alone may 

 be demonstrated in smears; pneumococci and hemoglobinophilic 

 organisms are absent. The conjunctiva may become infected both 

 with the inclusion bodies and hemoglobinophilic organisms. The 

 susceptibility of the conjunctiva of certain monkeys to infection with 

 the hemoglobinophilic bacilli would appear to be an important method 

 for diagnosis of the von Prowazek inclusion bodies. 



Smallpox (Variola) and Vaccinia. Smallpox (variola) and vaccinia, 

 now generally regarded as an infection produced by the virus of small- 

 pox modified by successive passages through the cow, are of unknown 

 etiology. Guarnieri 1 has observed and described cell inclusions in 

 the epithelia of both smallpox and vaccinia lesions and in experi- 

 mental lesions in the cornea of rabbits as well, which he regards as 

 protozoa, and to which he gave the name Cytoryctes variola?. Coun- 

 cilman, Magrath and Brinkerhoff 2 have studied these vaccine bodies 

 in detail and incline to the view that they are parasites specific for 

 the disease. Calkins 3 has construed the various forms of the cell 

 inclusions to be distinct stages in the life history of a protozoal parasite. 

 The protozoal nature of the "vaccine bodies" is not universally con- 

 ceded, and the conservative statement of Ewing 4 that they may be 

 regarded as degenerative phenomena characteristic for the disease is 

 widely accepted at the present time. 



The close relationship between smallpox and vaccinia (cowpox) 

 has been recognized since Jenner's 5 classical researches published in 



1 Centralbl. f. Bakt., 1894, xvi, 299. 2 Jour. Med. Research, 1904, xi, 12. 



3 Ibid., p. 136. 4 Jour. Med. Research, xiii, 233. 



6 An Inquiry Into the Causes and Effects of the Variolse Vaccinise, a disease discovered 

 in some of the Western Counties of England, particularly Gloucestershire, and Known 

 by the Name of the Cow Pox, London, Sampson Low, 1789. (See Epoch-making 

 Contributions to Medicine, Surgery, and Allied Sciences, Carmac, Saunders and Co.) 



