386 



ENTERO-HEPATITIS IN TURKEYS 



Several types of these spots appear corresponding to different 

 conditions of the diseased tissue. We have in the early, most 

 active disease process sharply defined circular areas of a lemon 

 yellow, or a neutral gray or of an ochre yellow color. The 

 spot is not homogeneous in structure, but made up of a deli- 

 cate network of gi^yish yellow, dead tissue. 



In another class of spots there is a mottled brownish color 

 which contrasts only slightly with the surrounding liver tissue 

 by its darker color. It may contain a central yellow nucleus 

 of dead tissue and a narrow outer border of the same character, 

 or the border may be a dark brownish circular line. The 

 entire spot has an indistinct appearance and is flattened or 



even slightly depres.sed 

 below the surface. In 

 some cases the\' are 

 uniformly whitish and 

 shade off somewhat 

 gradually into the sur- 

 rounding tissue. In 

 sections of the affected 

 organ it will be found 

 that the surface .spots 

 represent masses of 

 liver tissue in the same 

 condition, the spots be- 

 ing simply the places 

 where these diseased 

 foci intersect the sur- 

 face. Some are found 

 deeply imbedded in the 

 liver tissue, and therefore not visible on the surface. The 

 lesion of the liver is thus represented by few or many foci of 

 disease having in general a spherical form and appearing on 

 the surface of the organ as round spots. Occasionally the 

 lesions become more extensive and the death of large portions 

 of liver tissue follows. 



The changes in the liver are most easily explained by 



Fig. I02. A draiving of a beginning ne- 

 crotic mass, (a) Giant cells, {c] free nuclei, 

 and [d) disintegrated necrotic tissue. 



