174 



OTHER SPOROZOA 



C.Vv' 



-yg.pansp. 



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

 becoming differentiated into new pansporoblasts. The young 

 pansporoljlasts (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 little mul- 

 berries (Fig. 51, mat. 

 pansp.). From the mode 

 of development of the 

 cj'sts 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 scebcri, 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 Rhino sporidium, 

 there are a number of differences between them. 



nicxt pansp. 



sp. 



Fic;. 51. Portion of fully developed cyst of 

 Rhinosporidhim: c. w., cyst wall; yp;. pansp., 

 young pansporoblasts; mat. pansp., fully de- 

 velopod pansporoblasts containing spf)r<'s, 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 relativelj' enormous c^-sts 

 in the muscles of vertebrate animals, especially in mammals. 

 These parasites are usually found in the striped muscles but they 

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

 appear to have white streaks or patches in them, sometimes 



