66 



THE ANATOMY OF WOODY PLANTS 



according to common consent, find their successors in the conifers 

 of the present age. 



Since it is highly probable that the Cordaitales gave origin to 

 the Coniferales, and since, as a consequence, they present us with 



FIG. 48. View of cordaitean wood in three dimensions. Explanation in the text. 



the starting-point of the radial parenchyma of the latter, it will be 

 well to consider the organization of this group in respect to the 

 structure of the rays. Fig. 48 shows the structure of a cordaitean 

 wood. The tracheids in this genus are usually extremely long; 



