EXPOSURE TO LIGHT 



243 



Fig. 228. — Geranium growing near a window, toward which it is bending 

 and thereby bringing the leaves in a better position in reference to light. 



three kinds of tissues. First, there are the conductive tissues 

 which bring the water and mineral salts to the leaf and carry- 

 away the manufactured foods. Second, there is the protective 

 tissue consisting of epidermis which protects the deUcate tissues 

 within the leaf against drying, intense light, the entrance of 

 destructive organisms, and to some extent gives rigidity to the 



