ON CORONITIS. 
431 
These terms express, if confined to their respective diseases, suffi- 
ciently clearly the distinctive characters of each ; for, though a 
chill may degenerate into a founder, and may frequently do so, 
yet the characteristic difference in the results or effects of each 
disease is never lost sight of. Though these two diseases are 
thus practically divided, the pathological difference is not known. 
This disease will also occasionally take on an epidemical form ; 
and I have no doubt that many of those lamenesses that have 
for the last few years been so prevalent, and which have by 
many been considered as mild forms of laminitis, belong to it, 
at least my own practice leads me to this conclusion. Low in 
cattle is a similar affection of the secreting organ ; and the disease 
which broke out around the coronets amongst the various animals 
during the prevalence of the late and still existing epidemic, 
belongs properly to coronitis. Seedy-toe is another well-known 
form of disease of the coronary body. 
I have found, during the progress of my investigations, very 
considerable difficulty in forming a correct diagnosis from the 
simulation of coronitis to laminitis, rheumatism, and carpitis*. At 
times it will assume much of the character of naviculitis, and is 
often mistaken and treated for incipient ringbone. It is these varied 
forms which have prevented it, I doubt not, from being correctly 
defined as a distinct disease long since ; but a little patient obser- 
vation will soon dissipate the seeming difficulty of diagnosis. 
The physiological consideration of the structure of the hoof 
would lead to the conclusion that a substance like the horn, pliable, 
and to a certain extent elastic, would not be so constructed without 
means being provided for keeping up such a state of pliability as 
would render it perfectly efficient for the due performance of its 
functions, and such is the fact. 
The horn is composed of fibres conjoined together with homy 
matter : these fibres have been shewn to be tubular, but are not 
pervious throughout. As they descend they become filled up with 
pulpy horn, which, filling up, takes place at irregular lengths in the 
fibres, and is so disposed that those parts of the crust that are 
most exposed to expansion have more porous fibres terminating in 
these portions : thus, the upper third is very plentifully supplied ; 
the lower third has few, if any, but is mainly, if not entirely, kept 
moist by the exudation from the parts above. That this, the lower 
edge of the crust, should be so sparingly supplied with perspiratory 
secretion, is only a farther illustration of the simple yet wonderful 
means to an end, which we find throughout the whole of the 
* Upon these two latter diseases I shall have a few remarks to make at 
some future period. 
