76 



THE PLANT OELL. 



APPENDIX TO CHAPTER V. 

 Origin of the first Wood-Elements of the Proeambial Strands. 



The origin of the first WOOd-elementS may be studied in longitudinal 

 sections of the apex of a young shoot {Pinua). Here they take the form 

 of fusiform cells, characterised by the presence of large oval thin wall- 



Fig. 60. — Portion of a Longitudikai, Section near the Apex of a 

 Young Shoot of Pinus, to show the origin of the first wood- 

 elements. — c, Meristematic cells which soon undergo modification to 

 produce (x) the young wood cells (note the oval thin wall-area, 

 so-called "pits"); ph, rudimentary phloem elements (protophloem) ; 

 m, ground-tissue ; i, cortex (periblem). 



