50 



THE PLANT CELL. 



below the apex of a young shoot of a Dicotyledon (or Conifer) 

 will show, when examined under a low power of the microscope, 

 the following details : — 



(a) A general fundamental or grOUnd-tiSSUe. 



(5) A few patches, circularly arranged, towards the centre of the 

 section, which are, in reality, sections across the rudimentary primary 

 vascular bundles, or, as they are sometimes called, the prOCambial 

 Strands (see Figs. 29, 31, and 32). 



md i i 



Fig. 33 (diagrammatic).— A Transverse Section throttgh an Oldsb 

 Stem of Pinus, showing the complete Ring of Wood and Bast.— 

 k. Cortex ; md, medullary rays (secondary, see infra) ; m, pith. 

 Other letters the same as in Fig. 32. 



Each primary vascular bundle is composed of three portions, 

 viz.: — 



(i. ) An inner part made up of a few embryonic WDod-elements having 

 spiral or annular thickenings on their walls, and known as ppotoxyleill. 



