115 
Institute), in which a similar form is recorded. I am inclined to doubt 
the fact of the hybrid nature of the form for reasons that need not be 
considered in this connection. Whatever the origin of the form, it is 
definitely established in the two stations indicated. I hope during the 
coming season, in the case of both the papaw and walnuts, to discover 
whether or not these variations show a tendency to a “‘place mode.” 
LIRIODENDRON TULIPIFERA L.—Tulip Tree. Yellow Poplar. 
White Poplar. 
Lumbermen distinguish between “yellow poplar’ and “white poplar,” 
a difference based upon the color of the wood. So far as I am able to 
judge, this difference is dependent upon the age of the tree and the soil 
conditions, being associated with no structural differences. In my opinion, 
it will be found that trees of this species, growing in tenacious clay soils, 
have the denser structure and darker color characterizing the yellow 
poplar, while in light, dry soils and loam, the white poplar is found. 
In both conditions the wood of the older trees is of a darker color, in some 
cases approaching brown. I hope that a series of observations now in 
progress will make it possible to determine the relation between the soil 
character and these alleged commercial varieties. If there is any method 
by which the two forms are to be distinguished by flower, fruit, leaf or 
bark characters, it has escaped my attention. 
DIOSPYROS VIRGINIANA L.—Persimmon. 
This tree shows at least two, perhaps three, sharply distinct forms 
existing in the same area without becoming confluent. <A discussion of 
these differences is unnecessary since in “The American Persimmon,” 
Bulletin No. 60, Vol. VII, of the Agricultural Experiment Station of Pur- 
due University, Messrs. Troop and Hadley discuss these variations fully. 
I quote a few sentences from this bulletin: 
“They differ in quality as much as our cultivated apples. Some are 
very astringent, others are insipid and worthless, still others are sweet 
and delicious. 
“The fruit differs in size from that of a small wild plum to an inch 
and one-half or two inches in diameter. They also vary greatly in form; 
