THE TELOSPORASIDA AND THE COCCIDIA PROPER 



245 



however, Jansen (1931), for example-, 

 described one in Holland in which more 

 than 10% of a flock of 700 ducks died in 2 

 days. 



Treatment : Little is known of the 

 treatment of coccidiosis of ducks and 

 geese. McGregor (1952) reported that E. 

 truiicata infections of geese seemed to 

 respond to sodium sulfamethazine, and 

 the urinary excretion of sulfonamides in 

 general would suggest that they should be 

 particularly effective against this species. 



Prevention and Control : The same 

 measures should be used for the preven- 

 tion and control of coccidiosis in ducks 

 and geese as in chickens. 



FAMILY CRYPTOSPORIDIIDAE 



Members of this family are mono- 

 xenous. Development takes place on the 

 surface of the host cells or within their 

 striated border, and not in the cells 

 proper. The oocysts and schizonts have 

 a knob-like attachment organ at some 

 point on their surface. The oocysts con- 

 tain no sporocysts. The microgametes 

 have no flagella. There is a single genus, 

 Cryptosporidium . 



Genus CRYPTOSPOMDIUM 

 Tyzzer, 1907 



In this genus the oocyst contains 4 

 naked sporozoites. 



CRYPTOSPORIDIUM TYZZERI 

 NOM. NOV. 



Synonyms : Cryptosporidium parvum 

 Tyzzer, 1912 pro parte. 



Host : Chicken. 



Location : All stages occur in the 

 striated border (cuticular layer) of the 

 surface epithelial cells of the tubular 

 part of the ceca. 



Geographic Distribution : 

 America (Massachusetts). 



North 



Prevalence : Rare. 



Morpholo gy: Tyzzer (1929) did not 

 describe this form in detail, but illustrated 

 it and said that it appeared morphologically 

 identical with C. parriim of the mouse. 

 The following description is based primar- 

 ily on that given by Tyzzer (1912) for C. 

 parviim. The oocyst is ovoid or spherical, 

 4 to 5 by 3|i . The oocyst wall is smooth, 

 composed of a single layer, with a small, 

 knob-like attachment organ. A micropyle 

 is absent. An oocyst residuum is present. 

 The sporozoites are slender, bow- or 

 boomerang-shaped, 5. 5 to 6/1 long, with 

 a rod-shaped, slender nucleus near the 

 anterior end. 



Life Cycle : The following description 

 is based primarily on that given by Tyzzer 

 (1912) for C. parvum, which is morpho- 

 logically identical with C. tyzzeri. The 

 schizonts are 3 to 5|i in diameter when 

 mature and have an attachment organ. 

 They are attached to the cell surface or 

 embedded in its striated border. They 

 form 8 falciform merozoites 2. 5 to 5 by 

 0. 5 to 0. 7 /i , with a nucleus near the 

 thicker end, and a small residual mass. 

 The microgametocytes are smaller than 

 the schizonts and also have an attachment 

 organ. They give rise to 16 tiny micro- 

 gametes and a spherical mass of residual 

 material. The microgametes are chroma- 

 tin rods about 1 ii long and not more than 

 0.4jj, wide, without visible flagella. The 

 macrogametes are larger than the schi- 

 zonts and microgametocytes, and contain 

 tiny, retractile granules. They have a 

 thin, dense limiting membrane and an 

 attachment organ. 



Pathogenesis : Apparently non-path- 

 ogenic. 



Remarks : Tyzzer (1929) thought that 

 this was the same species he had pre- 

 viously found in mice, but he attempted 

 no cross-infection experiments. He said 

 that even if such experiments failed, the 

 morphological agreement was such that the 

 chicken and mouse forms could only be re- 

 garded as biological varieties of the same 

 species. However, such a narrow species 

 concept is no longer held, and it seems 



