386 



Tumors. 



the epithelium may become keratosed and formed into concen- 

 trically laminated arrang^ements (horny pearls). 



Sometimes these papillomata occur congenitally (two cases 

 of the kind in question fully described by Pirl and Trolldenier* 





v> % 











^*.5 



Fig. 114. 



Papilloma coralliforme in gullet of cow. (T"he oesophagus has been everted and 

 the mucous surface exposed ; the partly smooth appearance is due to the fact 

 that a piece of wood has been forced into the lumen of the tube turned in- 

 side out.) (Photograph.) 



in foals), probably due to traumatic intrauterine lesions of 

 the skin caused by amniotic threads. By some authors an inf^c- 



* Monatshep f, p, TierJieilk, 1903. 



