THE BROAD-SCLEROPHYLL VEGETATION OF CALIFORNIA. 



103 



between cavities, with one or two layers of thick-walled hypoderm behind it, the cuticle 

 papillate. In the areolae between the veins the lower epiderm is deeply invaginated to form 

 cavities, extending through half the thickness of the leaf and frequently compound, whose 

 entrances are often smaller than their interior diameters. The epiderm lining these is 

 very thin, not cuticularized, and bears an abundance of hairs, which fill the cavities with 



Fig. 36. — Arctostaphylos hookeri: section of leaf. 

 Fiq. 37. — Arctostaphylos vestita: section of leaf. 



X125. 

 X125. 



Fig. 38. — Eriodictyon californicum: section of leaf. X75. 



a dense felt. (4) The stomata are found within the cavities, and are raised above their 

 immediate surroundings. (5) Tannin is very abundant: in sheath surrounding bundles 

 and filling very large cells which in the region of the bundles are massed from epiderm to 

 epiderm, the individual cells being many times larger than the palisades; also in the cells 

 of the lower epiderm, where it lines the cavities, and in an occasional cell of the upper 

 layer of the palisade tissue. 



