74: THE SECOND BOOK OF BOTANY. 



In describing the stamens of flowers you will now 

 observe the kind of dehiscence the anther exhibits. 



Name the various modes of dehiscence of anther- 

 cells shown upon the charts. 



EXERCISE XXI. 

 Introrse and Extrorse Anthers. 



When the valves of the anther are of equal size, 

 the dehiscence will occur laterally (Fig. 106) ; but, if 

 one valve be wider than the other, it will throw the 

 line of dehiscence nearer to the connective on one 

 side than on the other. The narrowed valves are 

 usually on the projecting side of the anther-cell, and 

 this is called the face of the anther (Fig. 104). 



FIG. 104. FIG. 105. 



Face. Back. 



The other side, where the connective is usually 

 visible, if seen at all, and where the filament is at- 

 tached in most cases, is called the l)ack of the anther 

 (Fig. 105). 



NOTE. The projecting side of the anther-cell is called its 

 face, and the opposite side is called its ~back, whether the valves 

 are unequal or not. 



