316 The Botanical Gazette. [July, 
appreciate the fact that the Liriodendron leaf could not pos- 
sibly assume the position it does in the bud if the stipules 
were not free. If we now consider Mr. Hollick’s figure of L. 
alatum, it is easily understood that this leaf could not show 
such vernation as our tulip-tree. The winged petiole would 
not allow any considerable curvature and the leaf-blade would 
meet no obstacle to the development of its apex. The notch 
of this leaf, Z. alatum, if it is natural and not due to acci- 
dental injury or defective preservation, must depend on en- 
tirely different causes. It may be for the. same reason that 
so many leaves have a more or less emarginate apex. 
this is we can not explain. One thing is evident, however, 
that Mr. Hollick’s explanation is altogether too superficial to 
convince one that the ancestors of the tulip-tree had adnate 
stipules. If we consider his leaves as belonging to Lirioden- 
dron, we must suppose the apex to have been acute, that the 
notch was not natural to the leaf, and finally that the vena- 
tion was entirely different from our recent type. We must 
express the same opinion as to Mr. Hollick’s comparison of 
Liriodendron alatum with Liriophyllum populoides, viz. : that 
they were closely related on account of their adnate stipules 
and notched apex. It may be so, but to say the least the 
chances are quite as strong the other way, and in all proba- 
bility none of these leaves have ever had anything to do with 
ancestral forms of Liriodendron. 
Washington, D. C. 
EXPLANATION oF PLaTE XXIII. 
Figs. 1 and 2. Leaves of Liriodendron Tulipifera drawn from na- 
ture, natural size. — Fig. 3. Liriodendron simplex Newb. (copied).— 
ig. 4. Lirtodendron alatum Newb. (copied).—Fig. 5. Colutea primor- 
dialis Heer (copied). 
