CHLAMYDOZOA 



243 



SARCOSPORIDIA. 



Sarcosporidia are sporozoa found in the striped muscles of various 

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

 have been reported for man in three well-authenticated cases. In the 

 last, Darling found these protozoa in the biceps muscle of a negro patient 

 in Panama. In Baraban's case the laryngeal muscles at autopsy were 

 found to show cysts about 1/15 inch long which contained sickle-shape 

 sporozoites about g/* long. 



They are known also as Miescher's tubes when in mus- 

 cle fibers. They are divided into three genera: Miescheria and 

 Sarcocystis when parasitic in muscle fiber; Balbiania, when 

 parasitic in the in tervening connective tissue of the muscles. 

 The method of transmission is unknown. In some places more 

 than 50% of the sheep and pigs may show infection. 



Miescheria has a thin membrane surrounding the cyst while 

 that of Sarcocystis is thickened and radially striated by small 

 canaliculi. 



As the young trophozoite grows nuclei increase and a definite 

 membrane forms which the sporoblasts eventually fill. Ac- 

 cording to Minchin the Sarcosporidia contain only one genus, 

 Sarcocystis. It is never parasitic for invertebrate hosts and 

 while occasionally found in birds and reptiles it is pre-emin- 

 ently a parasite of the higher vertebrates. As a rule, they are 

 harmless parasites but the Sarcocystis muris is very pathogenic 

 for the mouse. Closely related to the order Sarcosporidia is the 

 parasite Rhinos poridium kinealyi. 



Rhinosporidium kinealyi. It causes pedunculated tumors of 

 nasal cavity. The pansporoblasts enlarge in the center of the 

 connective tissue of the nasal polyp and contain about 12 

 sporoblasts. When mature the cystic-like polyp bursts and the 

 sporoblasts are liberated to extend the infection. 



FIG. 63. Mie- 

 scher's sac from 

 the musculature 

 of a hog. X30 

 diameters. (After 

 Ostertag.) 



CHLAMYDOZOA. 



These organisms are generally considered as being protozoal in 

 nature and as a rule belong to the filterable viruses, which is the desig- 

 nation for the infectious principles of those diseases, in which filtration 

 of defibrinated blood or serum through a Berkefeld filter capable of 

 holding back so small an organism as the M. melitensis, does not pre- 

 vent the infection being transmitted when introduced by the proper 

 atrium of infection. The Chlamydozoa are also characterized by the 

 occurrence of "cell inclusions." 



