EXPLANATION OF PLATE 62. 99 



Figs. 2, 3. Vertical sections of agatised Petioles, com- 

 posing the false bark on the trunk of Cycadites 

 microphyllus, and of embryo Buds. In the bud, 

 Fig. 2. d. the division between the two woody circles 

 is not distinct. In Fig. 3. 'd. it is very obvious ; but 

 the intermediate circle of cellular tissue is repre- 

 sented only by a fine line. See V. I. p. 498, Note, 

 and p. 500, Note. (Original.) 

 In the sections of PI. 61, Figs. 2, 3, and PL 62, the 

 following letters are used to indicate the same parts, a, 

 cotton, or down ; h, integument of petioles or scales ; c, 

 bundles of vessels; dy woody circles; e, imperfect woody 

 circles; fj cellular tissue; g, embryo bud; A, gum ves- 

 sels.* 



Plate 62. V. I. p. 498, Note. 



Fig. 1. Longitudinal section of a Petiole of Zamia spi- 

 ralis magnified two times. It exhibits four bundles 

 of vessels passing longitudinally through the cellular 

 tissue, which is interspersed with gum vessels. V. 

 I. p. 499. (Original.) 



A. Transverse section of Fig. 1. magnified, and showing 



the irregular disposition of the bundles of vessels. 

 (Original.) 

 c\ Magnified view of one of the bundles of vessels at 

 A, c. (Original.) 



B. c". Magnified transverse section of a bundle of ves- 



sels in the petiole of Zamia horrida. (Original.) 

 Fig. 2. Longitudinal section of a portion of an agatised 

 petiole of Cycadites microphyllus, from Portland, 

 magnified four times. The down or cotton at «, is 



* These very beautiful and instructive Bections were presented to 

 me by Mr. Witham, being portions of a trunk which I had placed 

 at his disposition. 



