8 
PACIFIC SCIENCE, Vol. XIII, January 1959 
Fig. 7. Paradermal section of very young lamina showing about one half of an intersecondary panel with 
differentiating tertiaries, X 725. Leaf midrib at lower edge; leaf margin at top. Prominent procambial strand 
extending from right to left is a secondary vein. 
process has progressed farther in Figure 16. 
Thus areoles are produced which in the ma- 
ture leaf often occur in more or less parallel 
series (see also Fig. 21). 
During the differentiation of much of the 
minor venation, particularly below the qua- 
ternary category, there is a predominance of 
strands which are initially single celled (as 
seen in paradermal section). This is particu- 
larly true where a series of similar areoles have 
been delimited in a precise geometric manner 
as described above (Figs. 13-15). Most often, 
on the other hand, strands which apparently 
were initially more than one cell in length are 
curved (Fig. 16). Also included in this cate- 
gory are those forked strands (Fig. 15, upper 
half) which delimited areoles of various 
irregular perimeters. 
Much of the minor venation of Bohea shows 
less parallel orientation of veins than the pre- 
ceding account suggests. This is directly at- 
tributable to the fact that much of the original 
Figs. 8-13. Portions of paradermal sections illustrating stages in the initiation and early ontogeny of the minor 
venation, X 700 (except Fig. 8, X 1000). Figure 8 {tapper left): Intersecondary panel prior to appearance of any 
intersecondary procambium. Figure 9 {middle left): Similar panal with differentiated tertiary procambial strands. 
Note change in shape of ground meristem cells as compared with preceding figure. Figure 10 {lower left): Panel 
similar to Figure 9 in which subdivision of the ground meristem has proceeded further. Transverse procambial 
strands are tertiaries. Figures 11 {upper right) and 12 {middle right): Similar small areas illustrating the general 
nature of the ground meristem at the time quaternaries are being delimited. Figure 13 {lower right): Portion of 
intersecondary panel (midrib at left) with tertiary procambial strands. Another portion of the same panel is shown 
photographically by Figure 7. 
