INFECTIOUS ENTERO-HEPATITIS 319 
delicate tissues of the young are best adapted for the temporary 
habitat and rapid multiplication of this parasite.* 
The primary seat of the disease is the ceca. From these the liver 
is secondarily infested through metastasis. Other organs have not 
been found to be attacked. Hadley refers 
to lesions in the spleen, kidneys, pancreas, 
lungs, heart and oviduct. 
The lesions of the ceca are in substance 
a thickening of the wall, followed in most 
cases by a destruction of the epithelium and 
deeper portions of the mucous membrane. 
This destruction results in the outpouring 
of a coagulable fluid into the tube. The 
thickening of the wall may vary considerably 
in extent from case to case. 
It may be uniform over the greater por- 
tion of the tube or it may be limited to 
circumscribed patches. The commonest 
seat of these lesions is near the blind end 
of the tube where it evidently starts and 
whence it spreads to other portions. Not 
infrequently only one cecum is diseased, the 
other remaining normal. 
The affection of the cecum is due pri- 
marily to the multiplication of the micro- 
organism which may take place chiefly 
either in the mucous membrane, or in the 
submucous tissue; it may, though rarely, 
extend into the muscular coat. The thick- 
é : Fic. 71. CECA OF A TURKEY; 
ening of the wall is the result of several “‘(4) xp (b) ARE DISEASED 
processes—the multiplication of the para- areas, (c) 4 SECTION oF 
sites, the increase of the normal tissue ele- 9 77" 7#1CKENED WAML 
ments and later on the accumulation of masses of small cells and 
some giant cells. 
In the early stages of the invasion, the adenoid tissue between 
the tubules and in the submucosa becomes greatly increased, owing 
to the presence of large numbers of micro-parasites of round or 
slightly oval outline and from 6 to 104 in diameter which stimu- 
*In this regard it simply follows the rule observed by large numbers of parasites 
whose most destructive action is visited upon the young. 
