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Percival has. It is somewhat furrowed and pierced with foraminse to be sure, but cer¬ 
tainly not to the extent his words would lead one to expect. The roughened and 
furrowed aspect he speaks of will be found only on diseased bones, neither are its lower 
edges “notched and widened into gaps” to such an extent except as the result of disease. 
The most casual examination also will demonstrate that it is not of a spongy, fragile 
texture. 
If any of you believe it is a delicate and easily broken down structure, take a saw 
and cut one in two from the top downwards and you will be convinced to the contrary. 
I find the external surfaces to be smooth compared with the description above given, 
slightly furrowed and numerously pierced with foraminas ; but each furrow and its 
» 
edges is smooth and well defined and each foraminse has a smooth rounded edge at its 
entrance into the bone. 
It has like the shaft bones a hard or compact tissue externally, its interior being 
somewhat hollow for the reception of the nutrient arteries. There is nothing about it to 
indicate that it is a spongy fragile structure, except the roughened surfaces having in 
some instances the appearance of being worm eaten, resulting from ulceration and 
absorption of its exterior surface-tissue, but it will be found from the solid character of 
the bony material of which it is composed, together with its shape and other character¬ 
istics, to be a bone of immense strength and solidity as the work it has to do, requires 
it to be. 
Bracy Clark gives quite a lengthy description of the coffin-bone and also two finely 
executed steel engravings, one showing what he designates as a “shed bone,” meaning, I 
suppose, one that had become shed or detached from its attachments during life. 
Evidently he did not know which was the healthy bone of the two or he made a mistake 
of some other kind. 
What he calls the “ shed bone” so tar as I am informed, is the most normal appearing 
one, having comparatively a hard substantial surface, well protected by its natural com¬ 
pact tissue just the same as other bones of the limb above it. The notion that the 
coffin-bone is thoroughly covered with ridges and channels and presents a honey comb, 
worm eaten appearance externally and that it is porous and a frail structure from its 
surfaces to its centre, comes from reading such descriptions as these and from viewing 
morbid specimens mistaking them for normal ones. 
I shall ask everyone interested in the subject to examine any collection of coffin- 
bones he may have access to, and see if he can find any two alike, even though they may 
belong to opposite feet of the same animal, as regards size, shape, number of asperities 
and depressions, channels, notches and other peculiarities belonging to, or not found in 
a healthy condition of the bone. I think after he has examined any number, great or 
small, that he will agree with me, that most of those examined will be found more or 
less affected by disease and if he is not satisfied that such is a fact, by calling on me, I 
think I can show him specimens that will convince him. 
I shall not attempt any detailed description of morbid appearances, for I know that 
the changes in shape, size and external appearances, resulting from interstitial absorp¬ 
tion and the ulcerative stage of inflammation exteriorly, would defy description. 
It will be more profitable to speak of the causes productive of these changes and 
these I shall now consider. 
It will be necessary to refer again to Percival for an account of the anatomy and 
physiology of the tissues involved. 
