76 BONE IN THE HEART OF MOOSE—SOMERS. 
other herbivorous animals, not reported as existing either in man 
or other mammals. Through the kindness of Mr. Morrow, our 
President, I had the opportunity afforded me of making a dissec- 
tion of the heart of a moose, and of examining the bone found in 
the septum. The heart under examination weighed four pounds 
twelve ounces, avoirdupois ; length from base to apex, 10 inches ; 
circumference at the base, seventeen and one-half inches. Direct- 
ly at the aortic opening, where the semi-lunar valves are situated, 
and opposed to the auriculo-ventricular opening on the right 
side, I found a bony ring, or, more correctly, a section of a circle, 
measuring one and five-eights of an inch in length. It was 
roughened on its surface, widest at its centre where it formed an 
acute process on one side. From the centre it diminished towards 
the end on both sides, terminating in points tipped with fibro- 
cartilage. JI have since examined many hearts of oxen, and have 
invariably found this bone in the same situation as in the moose. 
In size and shape it differs but little from that of the moose. 
The quotations above—particularly from OwEN—would 
point to the presence of this bone as being due to eertain patho- 
logical changes consequent upon old age in the animals in which 
it appeared. But a stricter examination will prove that this 
bone is not a product of decay, due to the deposition of sclerous 
or a atheromatous matter in the fibro-cartilaginous tissue of the 
heart. It is a true bone, developed in a situation where its pre- 
sence serves an important physiological purpose. 
A microscopical examination proved it to possess the histo- 
logical characteristics of bone tissue, there being the lacune 
canaliculi and haversian canals. An atheromatous deposit 
would, on the contrary, exhibit the deposition of calcareous 
matter in the fibrous or other tissue without any attempt at 
organized structure. 
The position of the bone renders it an anatomical curiosity. 
As to its function, I think it serves the purpose of strengthening 
the aortic opening, maintaining its potency and giving support 
to the semi-lunar valves, It is a fact in physiology of the heart 
that the aortic semi-lunar valves will not permit, even under a” 
pressure, sufficient to rupture them, the passage of water from 
