SARCOSPORIDIA. 



193 



mammals and birds. They are common in the pig and mouse and 

 have been reported for man. 



They are known also as Miescher's tubes when in muscle fibers. 

 They are divided into three genera: Miescheria, when parasitic in 

 muscle fiber; Balbiania, when parasitic in the intervening connective 

 tissue of the muscles, and Sarcocystis. 



In addition to the protozoa previously referred to, there are certain 

 infections which are considered by certain authors to be protozoal in 

 nature. 



FIG. 60. Diagram showing development of different species of malarial parasites. 



Cytorrhyctes vaccinae. These parasites develop 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 scarlatinae was reported by Mallory to have been 

 found in the skin in four cases of scarlet fever. 



