82 ELEMENTARY BIOLOGY. [VIII. 



3. The corolla. 



a. Composed of five pieces or petals. 



a. On the dorsal side, a single large piece (vexil- 

 lum) expanded at its free end and folded over 

 the rest. 



/3. On the sides, two oval pieces (the alee), each 

 attached by a distinct narrowed stalk (unguis). 



7. The inferior part of the corolla (carina), com- 

 posed of two oval pieces united along their 

 lower edge but readily tearing apart. 



4. The stamens. 



a. Ten in number, each consisting of a stalk-like 

 part, the filament, terminated by a small knob, 

 the anther. 



b. The union of the filaments for three-fourths of 

 their length to form the stamen-tube : the sharp 

 bend of the filaments towards the upper side at 

 the point where they separate from one another. 



c. Tease out an anther in water and examine with 

 J obj.: there will be found numerous 



a. Pollen-grains: small oval bodies, with pro- 

 jections on them in the equatorial region. 



d. The anther of a bean is so small that sections 

 cannot be made of it without considerable skill: 

 the structure of an anther can however be easily 

 made out by imbedding one from a tiger-lily in 

 paraffin or holding it between two bits of carrot, 

 cutting transverse sections, mounting in water 

 and examining with 1 inch obj. 



