NATURAL SCIENCES OF PHILADELPHIA. 125 



Mr. Thomas Meehax referred to a potato presented to the Academy some 

 months ago by Mr. Heuszey, a member, which had the appearance of one po- 

 tato growing out of the centre of another. The opinion of all who sa* it 

 was that it was really a case of this kind. It had been handed to him by tin' 

 curators, and on dissection, though no exact place of origin could be traced 

 there seemed nothing to indicate any other theory of origin than that one po- 

 tato had really grown out of the centre of the other. 



But there were serious physiological reasons in the way of such a theory. 

 A potato tuber is really but a thickened axis, in which the" greater part of the 

 interior structure would be incapable of developing a bud which would pro- 

 duce a tuber such as this one had done. The origin of a new tuber from an 

 old one would be nearer the obi ones surface. He had been looking for some 

 further explanatory facts, and believed he had them here this evening, in the 

 potato tubers he now handed to the members. They were about the size of 

 hen eggs, and were pierced in every dircetion by stolons of the common couch 

 grass, Triticum repens. They had gone completely through, as if they were so 

 much wire, and in one instance two tubers had become strung together by 

 the same stolon, as if they were two beads on a string. One would suppose 

 that the apex of the stolon, when it came in contact with the hard surface of 

 the tuber, would turn aside and rather follow the softer line of the earth ; but 

 there was no appearance of any inclination to depart from their direct course. 

 They had gone apparently straight through. He had no doubt the potato be- 

 fore referred to was a similar case, a potato stolon had penetrated another potato, 

 and instead of going through as these grass spears had done, terminated in 

 the centre, and formed the new potato there. 



It was worthy of thought whether so much attention had been given to this 

 direct force in plants as the subject deserved. It was well known that a 

 mushroom would lift a paving stone many times it own weight, rather than 

 turn over and grow sideways, which it would appear so much easier for it to 

 do ; and tree roots growing against walls would throw immensely strong ones 

 over, though one would think the pressure against the softer soil would give 

 room for their development, without the necessity of their expending so much 

 force against the wall. 



November 15th. 



The President, Dr. Ruschenberger, in the Chair. 



Twenty-seven members present. 



A paper was presented for publication entitled " A Sketch of the 

 Classification of the American Anserinse," by B. H. Bannister. 



Prof. Leidy directed attention to some fossil bones which had been sub- 

 mitted to his examination by Prof. J. D. Whitney. According to the accom- 

 panying label, they were found under Table Mountain, near Shaw Flat, Tuo- 

 lumne Co., California. 



The bones are friable, and have attached portions of a light ash colored 

 gravel. Several masses of the latter substance, accompanying the bones, 

 contain casts of some fruit. 



The bones are as follow : 



1. A metacarpal bone of a ruminant of large size. In form and construc- 

 tion it bears more resemblance to that of the Lama and Camel, than of other 

 ruminants with which I have the means of comparing it. As in the Lama 

 and Camel the lower articular extremities are divergent, and the articular 

 surfaces are provided with a median ridge only at the back part. In ordinary 

 ruminants, as in the Ox, Deer, Sheep, etc., the median ridge is produced the 

 entire extent fore and aft of the articular surfaces. The peculiar arrangement 



1870.] 9 



