438 PROCEEDINGS OF THE ACADEMY OF 



then be considered in this relation. Moreover, hybrids, which 

 cannot necessarily be abundant in nature, or there would not be 

 the order we see, seldom come in more than one place, or if so, be 

 exactly alike, and yet investigation shows this form to be by no 

 means uncommon. Michaux rashly undertakes to say that there 

 is not another tree to be found within a hundred miles of Phila- 

 delphia, yet Professor Buckley found one in a single daj^'s botan- 

 izing in New Jersey near Camden, as recorded in our Proceedings ; 

 he had himself found it during one day's botanizing in Delaware 

 as recorded in Gray's manual. Professor Leidy, Mr Smith, Mr. 

 Cope, and Mr. Burk have found it in New Jersey, and there were 

 now on the table specimens gathered by the latter gentleman 

 near Woodbury, who had found two trees on this occasion, and 

 had seen quite a number on other occasions. There is no 

 doubt that when these casual visitors meet with trees, there is no 

 great scarcity, and this is not in accordance with what we have to 

 expect from hybrid trees. 



Now as we see in these specimens of Mr. Burk, as well as in 

 the original drawing in Michaux, the venation is wholly distinct 

 from Quercus Phellos, and Q. imbricaria, and it is here that we 

 find the best characters for distinguishing the species of oak. 

 There is a petiole nearly an inch long in these specimens, and also 

 in Michaux's drawing, and more or less of a petiole in all the 

 specimens he had seen; and, while the leaves of the Q. Phedos 

 are thin, those of Q. heterophylla are coriaceous. A hybrid unites 

 the characters of two parents, but there were no two parents here 

 in the North which could unite and form a character like this, 

 and so the supposed Bartram and Marshall progenies are out of 

 the question. 



In the monograph on Gupuliferse by Alphonse De Condolle in 

 the Prodromus, this oak is made a form of Q. aquatica. This 

 suggestion, misled by the probably historical error in regard to 

 the living Bartram tree, he had regarded as preposterous, and he 

 believed most North American botanists had agreed with him. 

 The forms of leaf most familiar to Quercologists, in Quercus aqua- 

 tica, were the triangularly wedge-shaped, nearly sessile ones, com- 

 mon in the South on mature trees. But further north, and in 

 young and vigorous frees south, the leaves were petiolate, ap- 

 proaching those now exhibited by Mr. Burk. Besides this there 

 was in Michaux's figure an outline of one of these forms of leaves, 

 which one could see by comparison with his figure of Q. hetero- 

 phylla to be the same. The habit of growth of the trees of Q.- 

 aquatica is very distinct from that of Q. Phellos, and Mr. Burk 

 reports these trees in New Jersey to be so distinct from the Q. 

 Phellos among which they grow, that he can distinguish them a 

 long distance away. The only remaining difficulties to students 

 would be that De Candolle classes Q. aquatica, variety heterophylla, 

 among the " sempervirentes" while we know it is deciduous, and 

 then that it is a too high northern range fortius species. The first 



