70 ESSENTIALS OF BOTANY 
the first season’s growth.1 Sketch the whole section without much 
detail, and then make a detailed drawing of a sector running from 
center to circumference and just wide enough to include one of the 
large bundles. Label these drawings in general like Figs. 40, 41. 
Note: (a) The general outline of the section. 
(b) The number and arrangement of the bundles. (How 
many kinds of bundles are there ?) 
(c) The comparative areas occupied by the woody part of the 
bundle and by the part which belongs to the bark. 
(d) The way in which the pith and the outer bark are con- 
nected i the bundles separated) by the medullary rays. 
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Fic. 42. Stem of Box-Elder One Year Old. (Much magnified.) 
A, lengthwise (radial) section; B, cross-section. e, epidermis; ck, cork; 
b, hard bast; s, sieve-cells; c, cambium; w, wood-cells; m, medullary 
, rays; d, ducts; p, pith. 
Examine a longitudinal section of the same kind of stem to find 
out more accurately of what kinds of cells the pith, the bundles, and 
the outer bark are built, Which portion has cells that are nearly 
equal in shape, as seen in both sections? 
1 Clematis virginiana is simpler in structure than some of the other woody 
species. Aristolochia sections will do very well. 
