162 
THE SCIENTIST. 
are not. The yellow oak and the 
prairie oak seem very distinct here, 
as the latter seldom attains the height 
of twenty feet, and the former is 
usually a large tree with larger 
acorns. The swamp white oak 
scarcely differs from the chestnut 
oak, except that the latter has longer 
acorns, whilst the peduncles of both 
are very short, being less than an 
inch long; perhaps both are but 
forms of either Q. hicolor or 
priniis, but the fruiting j^eduncles 
are shorter than the petioles in each. 
Further study will be necessary to 
determine the relationship of these 
two oaks. 
In other trees and shrubs the de- 
marcation is not so evident yet, but 
when the ground has been gone over 
more carefully and we are better 
acquainted with the distribution of 
certain species, then we will find, no 
doubt, that all are more or less af- 
fected as are the oaks. 
Of all the willows, only two, the 
black willow {Salix nigra^ var. 
Wardi) and the prairie willow [S. 
humilis) are common south of this 
line, and do not occur often north; 
the almond willow [S. ami/gda- 
loides), the diamond willow [jS. cor- 
data, var. vestila), the shining willow 
[S. lucida) and the long-leaved wil- 
low are abundant north, but do not 
occur to any extent south; the buck- 
thorn [BJiamnus lanceolatus) ^ and 
the fragrant sumach (Hhus aroma- 
tica) are common south, but not so 
north; the copal sumach (7?. copcd- 
lina) is common in the south part 
and rare in the north, while the 
poison oak [R. toxicodendron) is 
just the contrary. 
The only shrub so far that is com- 
mon to both divisions of our county 
is the common sumach [R. glabra)^ 
as is also the hazel ( Corylus Ameri- 
cana)'^ specimens were collected 
south which apparently were the 
beaked hazel ( C. rostrata) but later 
researches have failed to show that 
we have more than one species of 
hazel. 
J^i'C(xi7ins jmbescens Siud F. viridix, 
the red and green ash are common 
north, but not know^n south; the 
white ash (^F. Americana) is common 
north and occasionally south; Celtis 
Mississippiensis, the yellow hack- 
berry, is not known south, but is 
very common north; the common 
hackberry (6^. occidentalis) is com- 
mon north, but more rare south; the 
pawpaw [Asimina triloba), mulberry 
[3forus rubra) and persimmon (^Dios- 
pyros Vlrginiana) are very common 
north, but rather uncommon south. 
Of the grapes, three species, the 
river grape ( Yitis riijaria), the ashy- 
leaved grape ( Y. cinerea) and the 
false grape ( Y. indivisa) are com- 
mon north, but are very rare in the 
south, while the other two species, 
the summer grape [Y. aestivalis), 
and the winter grape ( Y. cordifolia) 
are occasionally found south, and 
commonly north. 
There are only four hickories in 
the county, and one, the big shell- 
bark {^Carya sulcata), does not occur 
south of the line; two others, the 
