510 



A MANUAL OF BACTERIOLOGY 



becomes condensed so as to form a spherical mass lying free within 

 the cyst (Fig. 58, A). In the intestine and bile-ducts the parasites 

 are attached to the epithelial cells, and in the liver, if the animal 

 lives beyond the acute stage, set up some remarkable changes. The 

 affected liver is studded with greyish-white nodules varying in 



FIG. 58. Diagram of Development of Coccidia. 1 



size from a pin's head to a pea. On making sections and examining 

 them microscopically, it is found that these nodules consist of 

 dilated bile-ducts filled with a much hypertrophied and convoluted 

 mucous membrane, which forms branched projections covered with 

 cubical epithelium, among which the parasites occur in great numbers 

 (Plate XXIII. b). A curious fact is that subcutaneous or intra- 

 venous inoculation, or inoculation into the liver of a healthy rabbit 

 with the coccidia from another rabbit, fails to induce the disease. 



1 This diagram is reproduced by permission from Daniel's Tropical 

 Medicine and Hygiene, 2nd ed. 1913 (John Bale, Sons, and Danielsson). 



