174 



OTHER SPOROZOA 



plasm at the periphery of the animal continues to grow, constantly 

 becoming differentiated into new pansporoblasts. The young 

 pansporoblasts (Fig. 51, yg. pansp.), at first simple masses of 

 protoplasm, soon form within themselves one, two, four, and 

 ultimately as many as 12 spores, tightly clumped together so 



as to resemble Httle mul- 

 berries (Fig. 51, mat. 

 pansp.). From the mode 

 of development of the 

 cysts it is clear that the 

 older pansporoblasts are 

 the ones near the center 

 of the cyst, the younger 

 ones those toward the 

 periphery. When the 

 cysts have reached a 

 certain size the growth 

 of the periphery ceases, 

 all the pansporoblasts ma- 

 ture and the cyst ruptures, 

 liberating the spores into 

 the surrounding tissue, 

 each to develop into a 

 new cyst. How the parasites are transmitted to new hosts is 

 not known. 



A similar disease was found some years ago in South America 

 and a parasite, then named Coccidium seeberi, has been described 

 from the tumors. It is possible that this may be the same 

 organism as that of Indian nasal polypus, but according to Fan- 

 tham, who was one of the original describers of Rhinosporidium, 

 there are a number of differences between them. 



mat pansp 



Fig. 51. Portion of fully developed cyst of 

 Rhinosporidium; c. w., cyst wall; yg. pansp., 

 young pansporoblasts; mat. pansp., fully de- 

 veloped pansporoblasts containing spores, sp. 

 X about 100. (After Fantham and Porter.) 



Sarcosporidia, Parasites of the Muscles 



Brief mention should be made of a group of Sporozoa known 

 as the Sarcosporidia which develop relatively enormous cysts 

 in the muscles of vertebrate animals, especially in mammals. 

 These parasites are usually found in the striped muscles but they 

 also occur in other muscles. Infected muscles (Fig. 52B and D) 

 appear to have white streaks or patches in them, sometimes 



