SEP 2 3 1914 



Division of Poresi 

 University of Califor 



PLATE LVII 



Fig. i. Cross-section view of shortleaf pine, showing open and partly closed ver- 

 tical resin canals (VRC}. These are typical of many canals in pine heartwood. 

 Shows thin- walled epithelial cells (E). 



Fig. 2. Heartwood of Sitka spruce, showing closed vertical canal (VRC). 



