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. 374, Note, 

 and p. 376, Note. (Original.) 

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

 lowing letters are used to indicate the same parts, a, cot- 

 ton, or down ; b, integument of petioles or scales ; c, bun- 

 dles of vessels; d, woody circles; e, imperfect woody 

 circles ; /, cellular tissue ; g, embryo bud ; h, gum ves- 

 sels.* 



Plate 62. V. I. p. 374, Note. 



Fig. 1. Longitudinal section of a Petiole of Zamia spiralis 

 magnified two times. It exhibits four bundles of 

 vessels passing longitudinally through the cellular 

 tissue, which is interspersed with gum vessels. V. 

 I. p. 375. (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 vessels 



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 a, is 



* These very beautiful and instructive sections were presented to 

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

 his disposition. 



