18 
blade. The most rapid growth of the later of these leaves occurs at a 
period which is a week or more after their emergence. They are plicate 
in vernation, but the folds are shallow and are almost or entirely smoothed 
out when the leaf is fully expanded. The result of this is an increase in 
the area of the leaf, without a corresponding growth of its margin; and 
this, in turn, causes it to become convex on the upper surface and to curve 
outward, whereby its exposure to light is materially increased, and the 
stomata-bearing nether surface is protected against wetting by rain. The 
first ones of these split leaves are apparently sessile, with blades about 20 
centimeters long; the later ones are short stalked, and the length of the 
blades may exceed 70 centimeters. 
The transition from split to pinnate leaves is a gradual one. At first 
only a few of the lowest folds separate, the appearance of the greater part 
of the lamina remaining like that of one of the merely split leaves imme- 
diately below it; in succeeding ones the pinnate lower part increases at 
the expense of the compact upper part until the latter ultimately disap- 
pears. The number of leaves sharing in this transition varies consid- 
erably, 6 being a common one. In length they may be from less than 
1 meter to a size considerably larger. The earlier leaves are all short 
lived, and, as each succeeding one is larger than the preceding, their 
dimensions on a young tree are constantly increasing. In cultivation the 
nuts are germinated collectively and the seedlings set out in their per- 
manent places during the split-leaf stage. The increase in diameter of 
the mass of the bases of the petioles is constant, and as the leaves have 
sheathing bases, as the tree grows, the latter rise into the air as a false 
stem, resembling that of the banana or abacé; this false stem reaches a 
height of about 150 centimeters before the real stem or trunk is visible. 
For several years after the appearance of the trunk, the leaves continue 
slowly to increase in number and in length. When the first nuts appear, 
at an age of from five to nine years, the tree is bearing at least twenty 
leaves. Even after this time there is usually some increase in their size ; 
in vigorous old trees the number is 25 to 30 or even 35; each of these 
leaves is from 5 to 8 meters in length, with about 80 pairs of pinne, large 
and small. 
The following table shows the rate of growth of the scales and split 
leaves of a number of seedlings. The measurements are from a mark 
on the lowest visible sheath, the husk not being dissected away; therefore 
there may have been some of the oldest sheaths invisible and not repre- 
sented ; and the growth being basal, the mark on the lowest visible sheath 
ean record no growth. The entire elongating region is always within the 
protecting sheaths of the lower leaves, so that zones marked on any visible 
part of the leaf retain their exact intervals. Leaf No. I is the one which 
was marked, the others being successively younger. The numbers in 
parentheses represent total length; the others, the growth during the time 
