that there were four cotyledons and two germs, and that the place of union was midway between the pairs of cotyledons. From the base of the cotyledons extending the whole length of the radicle, the union existed. The length of this united part was from half an inch to one inch, according to the vigor according of the plant.
Another lesson he thought was afforded by these specimens. Dr. Asa Gray had recently remarked, in Silliman's Journal, that European botanists still believed what American botanists had learned to doubt, that the radicle was a true root, rather than a morphologized joint of stem. Here was, he believed, an illustration of the American view. These radicles, which had evidently united together under the seed coat, had elongated after protrusion, just as a young shoot with all its parts formed in the bud elongates after the bursting of the bud scales. They comprised the half inch, or inch united portions before referred to. If these radicular portions of the seed were of the nature of root rather than of stem, we might expect to see lateral fibres push from them, as we do see from the true roots, which start out below the union. But these parts are as free from rootlets as any portion of the true stems above the cotyledon points, indicating, as had been suggested, that their properties were rather of stem than of root.
December 13th.
The President, Dr. Ruschenberger, in the Chair.
Thirty-five members present.
The following paper was presented for publication:
“Remarks on Dr. Asa Gray's Notes on Buckley's Rare Plants of Texas.” By Prof. S. B. Buckley.
Prof Leidy exhibited a lower jaw of an aged man, recently obtained in his dissecting room. The teeth had all been lost except one, and the alveolar border had been absorbed so that the body of the bone was reduced as usual to half its original depth. The remaining tooth is a completely developed and full grown third molar of large size, which lies imbedded in the jaw horizontally, with the unworn triturating surface directed towards the position which had been occupied by the teeth in advance. The tooth is perfectly sound, and in this old jaw, in which all the other teeth had been lost and the alveoli obliterated, favors the view that the teeth are liable to caries only when exposed to exterior influences. Similar specimens of teeth remaining imbedded in the jaw are not unfrequent, but the one exhibited is the oldest which Prof. Leidy had seen.
Prof. Leidy also exhibited a wood carving from St. Paul de Loando, Western Africa, presented to him by Dr. Charles L. Cassin, U. S. N. The carving, by a native African, represents two adult human figures apparently of the two, united by an intervening plate, so as to remind one of the famous Siamese twins. The connection may have been merely intended for support, though Prof. Leidy thought the carving may have been intended to represent a pair of united twins, similar to those just named, and which existed in the locality in which the carving was made.
December 20th.
Mr. Vaux, Vice-President, in the Chair.
Twenty-two members present.
1870.]
