NATURAL SCIENCES OF PHILADELPHIA. 
November 2. 
The President, Dr. Euschenberger, in the chair. 
Twenty-eight members present. 
Natural Hybrids. Quercus heterophylla.^ Mx. — Mr. Thomas 
Meehan said, that in reference to the minutes of the last meeting 
just read, he might offer a few additional remarks on Q. hetero- 
phylla, and its connection with Q. Phellos. It was a subject 
of much interest equally to the mere botanist, the student of the 
origin of species, and to those who were investigating the fre- 
quency or otherwise with which hybrids occurred in nature. 
He doubted, he said, whether hybrids often occurred naturally, 
and yet with the supposed abhorrence of plants to use their own 
pollen, and the consequent invitation which they extended to 
foreign pollen to fertilize them, it would be remarkable if some 
instances of hybridism did not occur, and perhaps remarkable 
that it did not occur oftener than it was supposed to do. It was 
such questions as these which gave the supposed hybrid origin of 
this oak its chief interest. In this connection he referred to the 
number of *the Revue Scientifique then on the table, with an ab- 
stract of some remarks of M. Ch. Naudin before the Academy of 
Sciences of Paris, in which he says, that, of a large number of cases 
of hybrids that he had experimented with, only two retained their 
hybrid forms beyond two generations, and these two, grasses of 
the genus JEgilops^ lost their respective forms, and reverted to 
that of the original female parent in four generations. 
Mr. Meehan said that the original tree described by Michaux 
grew on the original Bartram estate. That tree had long since 
been destroyed; but there were now large trees, both at Bartram’s 
an^d Marshall’s, which were said by the late Col. Carr, who had 
married Miss Bartram, and up to comparatively recent years 
owned the garden, to be seedlings from that original tree. If this 
were correct, it would sustain Naudin’s views, as these trees were 
so like the willow oak as to be scarcely distinguishable. They 
only differ from the willow oak, in an occasional lobing of the 
leaf, a matter of little consequence in determining a species in 
this genus. It is»more than likely, for reasons he would presently 
state, that William Bartram found young plants with lobed leaves 
growing, and transplanted them to his garden, believing them to 
have been seedlings of the Q. heterophylla., and not that they 
were from seed actually gathered from the tree. 
In his description Michaux speaks of it as probably having Q. 
imbricaria for one of its parents, but there is no proof nor pro- 
bability that this species ever grew in these parts. It could not 
