﻿TRUNK STRUCTURE. 



7> 



Having explained how these sections were cut for the purpose of tracing 

 through the cortex the bundle supply of a particular cone and the leaf bases sur- 

 rounding it, one may best understand what this course proves to be in the present 

 instance by inspection of the serial figures. And this may best be doue by taking 

 up the several features in succession. 



257 



258 



M-hIt>+LR 



260 



i villi 



Fig. 38.— Cycadeoidea Wielandi Ward. T. 393. S. 257, 258, 260. 261. X|. 



Continuation of series shown in the two preceding figures. Lettering of bundle traces same as in preceding 

 sections of series, so far as considered possible to identify. Vertical distance traversed by entire series, 

 about 3 cm. (Cf. the succeeding figures 39 A-C, showing the structure of the peduncular trace lib, of 

 section 261 ; also figures40 and 41 A, showing xylem of S. 260.) 



In section 216, figure 36, the peduncular bundle marked la and lb, is that 

 traced as related in an exact and definite manner from a particular cone. It here 

 presents a highly characteristic transverse section, the bundle (L) being that of the 

 subtending leaf base. The structure of the cortical peduncular bundles is shown in 

 detail in figures 39 A-C, and photographs 3, 4, 6, plate xvi. 



