1894.] A Study of Quercus Leana. 177 
oaks to occur only where the shingle oak is found. Having 
frequently and extensively traversed the woodlands in the 
vicinity of Chicago, and carefully examined the oaks of dif- 
ferent localities, since they are the prevailing trees, I have 
only seen this form where we first meet with the shingle.oak, 
which comes up the valley of the Desplaines as far north as 
Willow Springs, at least. It ison the border of the northern 
limits of the species in this vicinity, for it becomes a common 
tree only to the south. Immediately east and south in the 
sandy region by the head of Lake Michigan the black oak is the 
Prevailing species, probably ten times as numerous as the other 
biennial-fruited oaks taken together. But leaves ofthe peculiar 
form shown by the hybrid have been detected nowhere else. 
There are plenty of transitions in leaf-forms between the black 
and the scarlet oak, and to some extent between these and 
the red oak, but none between them and the shingle oak ex- 
cept where Q. imbricaria was first encountered, for both the 
‘Pecies and the hybrid were found the first time of visiting 
the locality. Though the proof ftom proximity may not 
be conclusive, when it is taken in connection with the blended 
aracteristics of the form, it is hard to resist the conviction 
vidi Parentage was specifically double, and that the parent- 
agg those whose characters are most evident in the off- 
Englewood, Chicago. 
