70 



ESSENTIALS OF BOTANY 



the first season's growth.^ 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. 



(6) 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 (and the bmidles separated) by the medullary rays. 



I I iiiim 1 Hi IB I I It 



Pig. 42. Stem of Box-Eldei One Year Old (Much magnified.) 



.4, lengthwise (radial) section ; _B, cross-section, e, epidermis; cfc, cork; 

 6, 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. jdm<otoc7iia sections will do very well. ' 



