444 



THE POLEMONIALES 



Fig. 331. 



Fig. 332. 



Fig. 331. A common species of the mint family: .-/, inflorescence of the 

 skull cap (Scutellaria). Note the square stem, opposite leaves. Why are 

 all the flowers facing one way? B, flower enlarged, showing the two- 

 lobed under lip and the three-lobed upper lip which conceals the sporo- 

 phylls. C , section of the flower. Ovary four-lobed, stamens cohering with 

 the corolla and anthers concealed with the stigma beneath upper lip. Pur- 

 pose of the crest, c, on the calyx ? 



Fig. 332. Flower of the sage (Salvia) : A, flower after the anthers have 

 shed their spores. The two-lobed stigma is bending down into the position 

 occupied by them. B, sectional view of the flower, showing fourdobed 

 ovary with nectar glands at the base, stigma not receptive and bent back. 

 A s the insect enters the flower he pushes against the sterile lobe of the 

 anther, /, and thus causes the fertile lobe, a, to swing down upon his back. 

 f, filament of anther. 



