n.] THE BEAN-PLANT. 81 



d. Peel off a strip of epidermis from a leaf and ex- 

 amine ■with a low power : note — 



a. The large close-fitting cells, with irregularly- 

 wavy margins and no chlorophyll, which chiefly 

 make up the epidermis. 



/S. The openings here and there in it (stomata) ; 

 the two curved, chlorophyll-containing cells 

 bounding each stomate. 



e. Gently pull a midrib in two across its long axis ; 

 note the fine threads uniting the two broken 

 ends ; cut them off with a sharp pair of scissors, 

 mount in water and examine with -J or J ob- 

 jective : they will be found to consist of partially 

 unrolled spiral vessels. 



e. The flower. 



1. Its general structure. 



a. Borne on a short stalk (peduncle). 



h. Composed of four rows or whorls of organs. 



a. The external green cup-like calyx. 



/3. Inside the calyx the corolla: the most con- 

 spicuous part of the flower, 



7. Inside the corolla the stamens. 



S. Within the stamens the pistil. 



2. The calyx. 



A cup terminated at its free edge by five prominent 

 points, two dorsal, and three ventral: the five small 

 midribs running along it (one to the end of each of 

 the points) represent the free ends of five sepals, 

 which are upited below, 



6 



