. Animal parasites and human disease. Insect Vectors; Parasites; Parasitic Diseases; Medical parasitology; Insects as carriers of disease. 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 little mul- berries (Fig. 51, mat. pansp.). From the mode of development of the cysts it is clear that the older pan
. Animal parasites and human disease. Insect Vectors; Parasites; Parasitic Diseases; Medical parasitology; Insects as carriers of disease. 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 little 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 —-^ ug. pansp. ~| mart, ones those periphery. cysts have certain size toward the When the reached a the growth 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.) 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. 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,
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectparasites, bookyear19
