20 HEALTHY ANATOMY.
posteriorly, but forming, anteriorly, a broad and thin ex- pansion. In the lumbar and upper part of the dorsal regions, the spine is somewhat curved ; but otherwise there is nothing unusual. 1847. Dr. J. C. Warren.
209. Episternal bones, as described by Breschet. The whole sternum is preserved, and upon its upper edge, posteriorly, are situated two symmetrical bones, one upon each side of the median line, and about the size of large orange-seeds. The mode of connection with the sternum was not ascer- tained by Dr. H. ; the bone having been found by him, in 1841, in a heap with others in the dissecting-room. This specimen and the next were formerly in the Cabinet of the Society for Medical Improvement.
210. A second specimen, essentially resembling the above, and that Dr. H. has since met with. 1847.
Dr. 0. W. Holmes.
Dr. J. Wyman refers to formations, similar to the above, that he has met with about the knee in man, and particu- larly in rodents ; and he questions whether they are to be regarded as anything more than sesamoid bones.
211. Sternum and clavicles of a rat, showing the true epister- nal bones between the two ; and the same, from a younger individual, in which they are not yet developed ; prepared by Dr. W., who refers to an article upon these bones, as they appear in Mammalia, and in Man, by C. Gegenbauer (Natural History Review, Vol. v. October, 1865). 1866.
Dr. J. Wyman.
212. An upper and lower extremity from the oldest of the above (No. 211) ; showing two sesamoid bones in the tendons of the gastrocnemii muscles, and one in a tendon at the head of the radius. 1866. Dr. J. Wyman.
These two last specimens are recorded here, though out of place, as they refer particularly to the two that pre- ceded.
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