Illustrations 



FIGURE PAGE 



38 Cross section of wood and bark of the west- 



ern yellow pine, showing two of the deep 

 cracks in the bark, at the bottom of which 

 lenticels are placed 152 



39 Extending buds of the tulip tree, birch, and 



almond 156 



40 A tip-end bud of a horse-chestnut bough . 159 



41 Sweet buckeye, a tree of the southern states 162 



42 An old willow living and leafing with all its 



heart wood gone 170 



43 An apple tree growing in an abandoned 



orchard now used as a pasture .... 170 



44 Cherry blossoms ; a flower cluster ; a flower 



blossom cut vertically ; one-half of the ripe 

 cherry 177 



45 Pollen grain emitting the pollen tube ... 180 



46 Flowers of the European linden, lime or 



basswood 183 



47 Blossoms of the oak; pollen-shedding, or 



staminate; pistillate 186 



48 Willow flowers. The silvery tassel; the 



golden tassel ; pistil with its covering 

 scale ; stamens and fringed scale .... 187 



49 Portion of a white lily leaf cut through and 



magnified showing a section of the thick- 

 ness, the difference between the upper 

 and lower tissue, and the breathing pores 194 



50 Structure of the epidermis of a leaf, show- 



ing the stomata, or little mouths .... 198 



51 Part of the upper surface of a leaf, showing 



one of the stomata with its lips closed . . 199 



52 A seedling pine 204 



53 Spray and berries of the red cedar or 



" savin " 204 



54 Needle-leaf cluster of the white pine . . . 205 



55 Tamarack or larch twisted into a complete 



circle 206 



