12 



BOTANY AND PHARMACOGNOSY. 



In the COROLLA the epidermal cells are generally rhore or less 

 entrifugally developed, forming prominent papillae (Fig. ii8, 

 i, B), which give tlie petals a velvety dr. satiny appearance, as in 

 he rose ; glandular and non-glandular hairs are also developed. 

 i?hich are peculiar to the corollas of irregular flowers, as in La- 



FiG. ii8. Inner morphology of the flower as illustrated in Viola tricolor. A, epider- 

 :ial cells from the outer surface of the spurred petal showing papillse; B, epidermal cells 

 rom the under surface of the petals, some of the cells showing centripetal thickenings, the 

 wo without thickenings covering sub-epidermal mucilage-cells; C, epidermal cells from 

 he under surface of the petals showing a zigzaig outline and short centripetal thickenings; 

 ), surface view of the mesophyll of the petals; E, corkscrew-like hair from the inner sur- 

 ace of the spurred corolla near the throat; F, a hair from the edge of an anther; G, epider- 

 nal cells of the anthers; H, surface view of the mesophyll cells from the spurred stamen 

 howing coUenchymatous thickening; I, surface view of cells of endothecium; K, pollen 

 Tain viewed from the side; L, pollen grain examined in water; M, pollen grain observed 

 1 chloral solution. 



'andula vera (Fig. 285, A) and Viola tricolor (Fig. 118, E) ; 

 ;tomata are comparatively few in number. The epidermal cells 

 ire but slightly cutinized, and in surface view are strongly undul- 

 ite and appear striate owing to the papillose development (Fig. 



