﻿OVULATE CONES. 



"3 



THE PEDUNCLE. INCLUDING A DESCRIPTION OF ITS BUNDLE SUPPLY. 



The peduncle as seated on the cortex is of flattened barrel-shape, and may 

 approach in dimensions and bulk the fruit it bears. As seen in various large sec- 

 tions cut carefully through an entire fruit in the radial longitudinal direction to the 

 trunk, and passing into and including a portion of the medulla {cf. photographs 

 3 and 4, plate xxiv, and figures 56 and 59), the peduncle is inserted axillary to a 

 leaf base, or doubtless at times in a position somewhat oblique to several adjacent 

 leaf bases. [Further details concerning the origin and cortical course of the peduncle 

 and surrounding leaf-trace bundles, based on a study of the bundle supply of 

 other cones borne on the same trunk (No. 393) as the present examples, have 

 already been given at length under the head of Trunk structure.] 



The structure of the peduncular and bract bundle system is on lesser scale, as 

 already noted, a repetition of the xylem zone of the trunk and the cortical leaf-base 

 bundle system. Likewise, in the peduncle itself, the distinct woody cylinder or 



Fig. 59. — Cycadeoidea Wielandi. T. 393. S. 392. Radial longitudinal section through middle por- 

 tion of trunk, cutting through the armor, cortex, woody cylinder, and into the medulla; also through 

 entire length of a lateral fruit-bearing branch or ovulate strobilus and its peduncle, thus showing the 

 direct course of peduncular bundles through cortex and their origin on the xylem. X 1 3- 



o, Megaspore ; b, bracts surrounding ovulate cone; s, insertion of dehiscent staminate disk at base of ovulate cone ; p, 

 branches of peduncular bundle supply passing out from xylem zone through the cortex and into th; base of the ovulate 

 cone; m, medulla ; X, xylem; ph, phloem ; c, cortex ; h, an obliquely cut horse-shoe bundle; r, ramentum of leaf bases; 

 1, leaf base to which the peduncle is axillary. Note that the lower branch of the peduncular bundle supply is either 

 directly connected with or envelops the supply of the leaf base ( I ). 



xylem is markedly like that of the trunk. There is the same well-marked xylem, 

 separated from the lighter phloem by an indistinct cambial line of darker color. 

 But while both the xylem and phloem regions of the peduncular cylinder are as a 

 rule well differentiated by coloration and striation, the individual cells, though often 

 well conserved, are not usually distinct, with the exception of the spiral and scalari- 

 form tracheids of the xylem, which seldom entirely fail of preservation. The 

 structure and relative development of the peduncular xylem and phloem of the 

 outer cortex are illustrated by photographs 3 and 4, plate XVI, and in addition 



