OF DENISON UNIVERSITY. 
29 
superposition follow three or four other buds or branches, not in a 
straight line, but placed alternately towards the right and left of such 
a line. The insertion, therefore, is similar to the arrangement of the 
uniparous scorpioid cyme. But, aside of mere appearances, there is 
no reason for considering them as anything but cases of superposition 
in which the different members of ithe same axil have alternately been 
thrown towards opposite sides. It is worthy of notice that this form 
of superposition is common among certain species of Lcguminosae 
{Medicago), where the ordinary forms of superposition are also abun- 
dant both among herbaceous and ligneous plants. 
Another form of superposition is very common in species of Solan- 
aceae, where the main axis ends in a flower or inflorescence, which is cast 
to one side by the first formed axillary bud. This bud grows into a 
branch and continues the main axis, taking an erect position and seem- 
ing to be its direct continuation. 'fhe leaf which subtends this branch 
usually contains a bud which is morphologically the second-formed bud 
of the axil. Eichler figures in his “ Bluethendiagramme” two of 
these accessory buds in the leaf axils of Atropa Belladona. 
And, finally, since flowers, thorns, tendrils, and other organs are 
frequently the morphological equivalents of buds, they will often be 
mentioned in speaking of superposed buds. 
In the following pages an enumeration will be made of such plants 
as will illustrate the general remarks made above, and any details 
not hitherto mentioned will be made under the particular species when 
cited. In these notes most attention will be paid to herbaceous 
plants, since less attention has been given to these, and they present 
some variations not noted in ligneous plants. 
I. INVERTED SUPERPOSITION. 
A. Of Leaf -buds and Branches. 
I. Buds. — The superposition of buds, none of which have devel- 
oped into branches, occurs chiefly among ligneous plants. Fraxinus 
sambucifolia., F. viridis., and vigorous specimens of F. Americana ( i ) 
have two buds in the same axil, placed close together, the lower about 
half the size of the upper. Cercis Canadensis shows two or three, 
the lowest of these often minute and somewhat covered by the petiole 
scar. Ptelea trifoliata (14) has also two superposed buds. In 
this case they are sunk into the .wood and almost inclosed by the cres- 
cent- or almost V-shaped petiole-scar, so as not to be evident. Carya 
