NATURAL SCIENCES OF PHILADELPHIA. }'','< 



that there were four cotyledons and two germs, and that the place of anion 

 was midway between the paira 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 

 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 be- 

 lieved 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 be- 

 fore 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 coty- 

 ledon points, indicating, as had been suggested, that their properties were 

 rather of stem than of root. 



December loth. 

 The President, Dr. Ruschenberger, in the Chair. 

 Thirty-five members present. 



The following paper was presented for publication : 

 " Remarks on Dr. Asa Grav'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 hori- 

 zontally, with the unworn triturating surface directed towards the position 

 which had been occupied bv 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 uufrequent, but the one exhibited is the oldest 

 which Prof. Leidy had seen. 



Prof. Leidy also exhibited a wood carving from St. Paul de Loando, West- 

 ern Africa, presented to him by Dr. Charles L. Cassin, U. S. N. Ihe carving, 

 by a native African, represents two adult human figures apparently of the tu o, 

 united by an intervening plate, so as to remind one of the famons 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.] 



