244 THE PROTOZOA 



The best known infections of this group of diseases in man are smallpox, vaccinia, 

 rabies, trachoma, molluscum contagiosum, and foot and mouth disease. There are 

 many such infections in other animals. The cell inclusions are regarded as prod- 

 ucts of cellular reaction to a virus which is more or less impossible of demonstra- 

 tion. The discovery of exceedingly minute granules in some of these diseases, as 

 in variola and trachoma, has suggested that, as a reaction to the invasion by such 

 a granule, the cell throws an enveloping mantle about the invading particle. To 

 designate this we use the name Chlamydozoa. 



The generic name Cytorrhyctes has been applied to certain of these viruses, 

 thus C. vaccinias develops within the epithelial cells of stratified epithelium. In 

 vaccinia, Councilman and his colleagues consider that the development only takes 

 place in the cytoplasm of the cell. In variola, however, the developmental cycle 

 affects the nucleus. 



Cytorrhyctes luis, reported as the cause of syphilis, sporulates in the blood- 

 vessels and in the connective tissue, not in epithelial cells. 



Cytorrhyctes scarlatinas was reported by Mallory to have been found in the skin 

 in four cases of scarlet fever. 



