PROTOZOA 431 



The coccidia in the liver show themselves in two principal 

 forms free or encysted. The free coccidia (schizonts, mero- 

 zoites, or young macrogametes) are most frequently spherical 

 or slightly elongated, and measure 11 /A to 14 /u, broad, and 

 17 ^ to 22 /x long. Some are almost homogeneous and very 

 ref rangent, with a darker central point ; the others are alto- 

 gether granular, without a central point; they resemble cells 

 undergoing fatty degeneration; their volume varies from 6 /* 

 and 8 /A to 30 /*. They are often included in epithelial cells, 

 and solitary or grouped in small masses in the same cell. The 

 encysted coccidia (oocyst) may also exist in the interior of a 

 cell; and like the preceding, they are sometimes lodged in 

 large giant-cells. 



It is not rare to find white particles floating in the bile, 

 similar to the contents of the tumors, and almost exclusively 

 formed of coccidia. Rivolta once found numerous encysted 

 coccidia in the epithelium of a dilated gall-bladder. 



A number of observers have recorded the presence of 

 coccidia that were not distinguishable from Coccidium ovi- 

 forme in the intestinal epithelium of lambs and other animals 

 such as horses, cattle, goats and swine.* In a few cases they 

 have been recorded in the livers of men who had to do with the 

 handling of rabbits. Other species have been found, one in 

 particular affecting the epithelial intestine of salmon and 

 house mice. In addition to the coccidia other closely related 

 genera of animal parasites have not infrequently been found 

 in animal tissues. 



Sjobring, 1 who studied a coccidium in the birds of Sweden, 

 describes forms belonging to two genera of coccidia. One was 

 found in pheasants and the other in many different species of 

 birds. He states that he did not find coccidia in the liver. 

 More recently Morse 2 has found coccidia in the intestine of 

 small chicks suffering from a disease popularly known as white 

 diarrhea. He designates the organism as Coccidium tenellum. 



* Quoted by Doflein, Die Protozoen. 



'Sjobring. Centralb. f. Bakt, Bd. XXII (1897) p. 675. 



- Morse. Circ. 128, B. A. I., U. S. Dept. of Agric., 1908. 



