APPENDIX 287 



pushing out projections divide into four parts, each of 

 which subdivides into two crescentic germs and a nucleus, 

 and becomes surrounded by an inner capsule. In this 

 condition the coccidium may remain unaltered for months 

 unless swallowed, in which case the germs are set free by the 

 digestion of the capsules, become rounded and amoeboid, and 

 usually divide into crescentic germs, which also become free ; 

 the result being that the intestine, gall-bladder, and bile- 

 ducts are filled with sporozoa. The sporules finally pene- 

 trate into the epithelial cells of the mucous membrane, and 

 there change back into the encysted form, which is set free 

 by the bursting of the cell. 



During their growth they produce great proliferation of 

 the neighbouring epithelium, causing the formation in the 

 bile-ducts of the liver of greyish-white adenomata, which 

 consist of epithelium and connective-tissue and are bounded 

 by a connective-tissue layer, the interstices between the 

 branching processes which grow from the mucous coat 

 being full of parasites in various stages of development. A 

 hypertrophy of the mucous membrane also takes place over 

 the affected areas of the small intestine. If the animal 

 recovers, the parasites are discharged or absorbed, being 

 in the latter case penetrated and digested by small-cell 

 infiltration, 1 and a scar of connective tissue is left on the 

 site of the tumour. 



Feeding with the ripe coccidia is the only method of 

 infection which has been attended with success. The 

 changes in the parasites may be observed by taking some 

 from recently killed animals, placing on a cover-glass, and 

 examining in drop cultivations. 2 



Amoeba dysenteriee. The occasional occurrence of proto- 



1 Buffer and Walker, Journ. of PathoL and Bacterial., October 1892. 



2 The above account is mainly taken from the Morton lecture of this 

 year, by Dr. Galloway. See Brit. Med. Journ. February 4, 1893, p. 217, for 

 bibliography, &c. 



