VIII.] 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. 



/3. 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 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). 



b. 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. 



8. 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 united below. 

 M. 6 



