360 DISEASES OF THE FEET. 



interstices; and {2d.) by removal or absorption, as already 

 described under Navicular Disease. 



In addition to the results indicated by the above-described 

 pathological changes, ossification of the sensitive laminee and 



Fig. 71 represents a more advanced atrophied or absorbed 

 condition of the bone, with ossification of the laminae. 



suppuration are occasionally found, the latter occurring more 

 especially at the coronet, detaching a small portion of the upper 

 part of the wall ; whilst in other instances a serous fluid collects 

 between the sensitive and horny soles and frogs, and detaches 

 them from each other. 



Direct concussion causes laminitis, by its effects upon all the 

 structures of the feet. Usually this form is confined to the two 

 fore feet. But we must look further into the question, to under- 

 stand the operation of inflammation, or even irritation of an 

 internal organ, in the causation of this disease. 



Many writers state that affections of a serous membrane, 

 such as the pleura, terminate, by metastasis, in laminitis. I 

 have carefully studied the question for some years, and have 

 arrived at the conclusion that such is not the case ; that when 

 the feet become inflamed during the progress of another disease, 

 a mucous membrane is involved, and that the inflammation of 

 the laminae is due to an extension of the irritation from its 

 primary seat to the laminae of the feet, as explained by Professor 

 Dick in the words already quoted, namely, " The feet are 

 affected, as well as the whole surface of tlie body, the hair of 

 the mane and tail being often thrown off." To explain this, 

 it will be necessary to remember that the skin, mucous structures. 

 and laminje are continuous one with another, and secretory ; 

 the nature of their secretions being similar, namely, epithelium 



