296 Pox. 



fine granules which they observe in the lymph with highly magnifying 

 lenses, and Bose describes extremely small granules in the vaccinia as 

 well as in the ovina, which gradually become larger, and after the 

 appearance of a nucleus in their bodies divide by schizogony, the nucleus 

 breaking up into fine granules (merozoites). 



The findings of Prowazek are similar (1905). According to these, 

 the vaccinia contains as characteristic constituents in the smallest 

 epithelial fragments elongated motile bodies. These stain with hema- 

 toxylin, and consist mostly of two corpuscles (lymph corpuscles) 

 slightly varying in size, and contain in their structureless substance 

 one to two enclosures, l-l^/n. in size, exceptionally punctiform, mostly 

 however rod or club-shaped, so called initial bodies. They are also 

 found in the cornea of rabbits after inoculation with vaccine. In 

 such eases they are present within and without the Guarnie'ri bodies, 

 and their deveilopment may be explained by the fact that the nucleus 

 of the epithelial cell reacts with the production of vaccine bodies to the 

 invasion of the initial body, which should be considered as the carrier 

 of the pox virus. According to these findings, which were confirmed 

 by Volpino, the pox virus would belong to Prowazek 's so called 

 chlamydozoa. 



The spirochetes which were described by Bonhoff as the causative 

 factors of pox (sp. vaccinae) were considered by Siipfle,, Carini, 

 Miihlens & Hartmann as artifacts. 



The bacteriological examination gave positive results only insofar 

 as it showed that the pustules of pox always contain pyogenic bacteria; 

 thus Garre found in human pox the streptococcus pyogenes, Guttman 

 the staphylococcus pyogenes aureus, Grigorjew the same and the staph. 

 pyog. citreus. These, and probably also other bacteria (for instance 

 the bacillus necrophorus) however play undoubtedly only a subordinate 

 or secondary role, as compared to that of the true, as yet unknown cause 

 of pox. 



The contagion of pox is contained in the lymph of the 

 nodules and vesicles, and also in the scabs which develop in 

 place of the latter, while the infectiousness of the blood, and 

 of the exhaled air, and also of the skin exhalations of affected 

 animals during the fever period is doubtful. The secretions 

 and excretions contain the infectious material only in those 

 instances in which they become mixed with the virulent con- 

 tents of the vesicles. 



Pathogenicity. After inoculating infectious material into 

 the skin between the cells of the epithelial layer, characteristic 

 pox developed at the point of inoculation in susceptible indi- 

 viduals, sometimes however the inoculation results in a general 

 eruption of pox. This may sometimes also be produced by 

 intravenous or intra-tracheal injections of pox lymph. 



Pathogenesis. The epithelial layers of the skin and of the 

 mucous membrane are the most favorable places for the propaga- 

 tion of the pox virus. If this is inoculated or rubbed into these 

 parts it enters directly between the epithelial cells and. if the 

 infection occurs by inhalation the virus reaches the same 



