122 PROCEEDINGS OF THE ACADEMY OF [1881. 



two miles above Austin, also near Mount Bond, about three miles 

 from the eit^-. 



In 1872, Mr. Elihu Hall, of Athens, Illinois, was at Austin col- 

 lecting plants. I showed him Durand's oalc, which is referred to 

 as a good species in his " Plants TexanjE," published in 1873. 



Mr. Charles Mohr, Botanist for the Tenth Census Department of 

 Forestry in tlie Gulf States, was here, last November, and obtained 

 sections of the wood, and specimens of the leaves and acorns of 

 Q. Durandii for the Department of Forestry under the direction 

 of Prof. Chas. S. Sargent, for the United States Government. 



Lastly, Prof. Sargent came here tliree weeks ago, and together 

 we visited the banks of Shoal Creek, where there were several small 

 trees of this oak, the largest being nearly two feet in diameter. 

 He was satisfied it was a good species. 



I have been thus particular in giving the history of this oak to 

 the present time, because all who have seen the living trees regard 

 it as a good species, which is not the case with some who have not. 

 In Dr. Engelmann's " Oaks of the United States," published at 

 p. 392, " Transactions of St. Louis Academy," speaking of the 

 forms of Quercus undulata, he says: •' The var. Gamhelii runs 

 into variety Gunnisonii on one side, and on the other into variety 

 breviloba {Q, ohtusiloha var. hrevifolia^ Torrey, Bot. Bound, and 

 probably Q. Durandii and San sabea, Buckley)." Dr. E. thus 

 regards it as probably identical with a marked variety of Quercus 

 undulata^ an opinion which a better acquaintance with living trees 

 would surely lead him to revise. Without extensive field expe- 

 rience it is almost impossible to decide on the limits of species in 

 oaks, as well as in grapes and other difficult genera. 



