REPRESENTATIVE TREES AFTER SIX YEARS OF GROWTH 
A good illustration of vigor in a tree hybrid (second from left) combining features of both its 
parents—the small Japanese catalpa C. Kaempferi and the native C. bignonioides on either 
side. 
tion are expressed in an alternative 
fashion, the hybrid is intermediate for 
the most part. In every part of the 
tree contributions from both parents 
can be made out. This is shown very 
clearly in the leaves. The oriental 
catalpa is finely pubescent on the upper 
surface, the leaves having a velvety 
feeling, but are entirely smooth on the 
lower surfaces. The native tree is the 
reverse of this, being glabrous on the 
upper surface and hairy on the lower 
side of the leaves, with rather coarse 
filiments, especially on the veins. The 
hybrid, however, resembles both parents 
in these respects, the leaves being vel- 
vety on the upper surface and hairy on 
the under sides, the latter, sparingly 
however, and only on the young leaves. 
In the same way, one can trace the 
C. speciosa is shown at the extreme right for comparison. 
(Fig. 7.) 
other characters and find some influence 
of both parents on the hybrid in nearly 
every part of the tree. On the other 
hand, in the nature of the bark, the 
margin of the leaves, the coloring in cer- 
tain parts of the leaves and flowers, the 
inheritance is definitely alternate, the 
features of one parent in some parts, and 
of the other parent in other parts, being 
predominant upon the product of their 
union. In dimensional characters the 
hybrid is intermediate except in those 
parts which are affected by vigorous 
development such as height of plant, 
diameter of trunk, size of leaves and 
inflorescences. In these the hybrid 
clearly excels its parents. It is inter- 
esting to note that the size of cells, as 
shown by tracheid length, at least, is 
the same in both parents and the cross 
21 
