90 MISSOURI BOTANICAL GARDEN. 
Plate 44.— 1-3, Diagram of successively descending cross sections of 
young shoot at emergence of a branch, showing passage of the foliar 
bundles through the pulvinus and their union to form the petiole bundle, 
9; 4, collenchyma of petiole, 250; 5, radial section of subjacent paren- 
chyma, 250; 6, cross section of secretion passage of petiole, 350; 
7, cross section of midrib and adjoining lamina of leaf, 30, showing two 
forms of pubescence; 8, cross section of very young shoot, showing col- 
lenchyma, epidermis, and base of hair, 200; 9, cross section of young 
leaf, and stoma, 200, showing crystal layer of upper epidermis, palisade 
and spongy parenchyma, and striated lower epidermis. 
By accident, the position of the ovule in the upper figure of plate 33, 
f. 8 is shown inverted, the true position being that indicated in the cor- 
rected figure here given. 
26 
