88 FOUNDATIONS OF BOTANY 



Note: 



(a) The general outline of the section. 



(ft) 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 bundles separated) by the medullary rays. 



FIG. 57. One Bundle from the Preceding Figure. ( x 100.) 



w, wood-cells ; d, ducts. The other letters are as in Fig. 56. Many sieve-cells 

 occur in the region just outside of the cambium of the hundle. 



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 ? 



