CELLS WITH SPECIFIC FUNCTIONS 



Fig. 65. — A Rbsin-Canal from 

 Pinus Stem, in longitudinal 

 section.— en, Endothelial layer; 

 g, thick - walled protective 

 cells (fibres) ; r, globules of 

 resinous material lying in the 

 duct. 



end, e Tvy 



Fig. 66. — A Drawing (from a photomicrograph) of a Transverse 

 Section of the Centric Leaf of Pinus to show distribution oi 

 resin-canals.— e. Epidermis; hy, hypodermis ; st, stoma; m, meso- 

 phyll ; r, resin-canals lying in the mesophyll ; end, endodermis ; 

 6, fibro-vascular bundles. 



6 



