78 



ZOOLOGY 



SECT. 



ORDER 2. COCCIDIIDEA 



The members of this order are extremely minute and simple forms which 

 occur as parasites, not in the intestine, but in the actual cells of various animals. 

 Eimeria (Fig, 57, 1), for instance, is found in the intestinal epithelium of the 



1 Eimcria 



2.CoccIdiuin 



FIG. 57. Coccidiidea. A, adult Eimeria (E) in enteric epithelial cell (ep.) of mouse ; 

 B, encysted form ; C, encysted form, the protoplasm contracting to form a spore ; D, formation 

 of falciform young (/.) in interior of spore (sp.) ; E, spore with falciform young ; F, adult 

 encysted form of Coccidium from liver of rabbit ; G, division into spores ; >H, cyst containing 

 ripe spores (sp.), each with a single falciform young ; I, single spore with falciform young (/). 

 (From BUtschli's Protozoa, after Leuckart and Eimer.) 



mouse and the sparrow, Coccidium (2) in the rabbit's liver, and Klossia in the 

 epithelium of the kidney of molluscs. They are not locomotive, but remain 

 quiescent in the cell (A), finally encysting (C), and producing one or more spores 

 (D), in each of which one or more falciform young (E) are developed. The 

 remarkable parasite, Drepanidium ranarum, found in the blood corpuscles of the 

 frog, is probably the falciform stage of some unknown member of this order. 



ORDER 3. MYXOSPORIDEA. 



This group includes a small number of genera, which differ from other 

 Sporozoa in being amoeboid (Fig. 58, A). Many nuclei are present, but whether 



FIG. 58. A, Myxidium lieberkuhnii, amreboid phase ; B, MyxoboUis mtilleri, 



spore with discharged nematocysts (ntc.) ; C, spores (psorosperms) of a Myxosporidian ; 

 ntc. nematocysts. (From BUtschli's Protozoa.) 



this condition is due to the multiplication of a single nucleus or to the organism 

 being a plasmodium is not known. A good example of the order is Myxi<li>nn, 

 found in the urinary bladder of the pike. 



