100 
EXPLANATION OF PLATE 62 . 
most beautifully preserved, and the integuments of 
the petiole h, longitudinal vessels e, and gum ves- 
sels f, correspond with those in Fig. 1. See V. I. 
p. 499, Note. (Original.)* 
Fig. 3. Transverse section of a portion of the lowest 
Petioles, in PI. 61. Fig. 3, b, c, magnified four 
times. The disposition of the bundles of vessels is 
nearly parallel to the integument of the Petiole.T 
d. Magnified portion of the double woody circle, within 
the Embryo bud, PI. 61. Fig. 3, 'd. 
d'. More highly magnified portion of the embryo double 
woody circle d. 
c'. More highly magnified section of one of the bundles 
of vessels, adjacent to c. 
These bundles of vessels exhibit, in their transverse 
Section, a series of minute tubes, arranged in rows, and 
between these rows, opaque plates of compressed cellular 
tissue, resembling portions of medullary rays. 
The fibrous structure of the integument is preserved in 
several parts of b. See V. I. p. 501, Note. (Original.) 
* Mr. Robert Brown bas noticed in tlie cellular tissue of a silicified 
trunk of Cycadites, portions of Chalcedony bearing the form of ex- 
travasated gum within the trunks of recent Cycadese. He has also 
recognised spiral vessels, in the laminated woody circle of a mature 
trunk of fossil Cycadites, and also Jn the laminated circle witliin a 
silicilied bud of the same, near its origin. 
•j- A familiar example of a nearly similar disposition of bundles 
of vessels, passing into the Petiole or leaf-stalk, may be seen in the 
base of the fresh fallen leaves from a horse-chestnut tree, or in the 
scars on a cabbage-stalk, from which leaves have fallen otF. 
