ORGANS OF REPBODUCTION. 



239 



That surface of the anther to which the connective is attached 

 is called the hack{fig. 499, a, a), and the opposite surface is the 

 face. The latter always presents a more or less grooved ap- 

 pearance {figs. 499 and 504, c), indicating the point of junction of 

 the two lobes. Each lobe also commonly presents a more or less 

 evident furrow {figs. 499, e, e, and 504, b), indicating the point 

 at which the mature anther will open to discharge the pollen; 



Fig. 504. 



Fig. oOo. 



Fig. 506. 



Fig. 504. The Essential Organs of Reproduction of the Vine (Vitis vinir 

 fera). a. Anther, c. Furrow in its face wliich is turned towards the 



pistil, b. Suture or line of dehiscence. The anther is introrse. Fig. 



505. The Perianth cut open and Stamens of the Meadow Saffron 

 (Colchicum autumnale) showing the anthers turned towards the floral 

 envelopes, and hence termed extrorse. 



this furrow is termed the suture. By these furrows the face of 

 the anther may be generally distinguished from the back, which 

 is commonly smooth and has more- 

 over the filament attached to it. The 

 face is generally turned towards the 

 gyncecium or centre of the flower, as 

 in the Water-Lily (/^. 507), Vine (/(7. 

 504), and Tulip (fig. 508), in which 

 case the anther is called introrse; 

 in some instances, as in the Iris, and 

 Meadow Saffron {fig. 505), the face 

 is directed towards the petals or cir- 

 cumference of the flower, when the 

 anther is said to be extrorse. 



In structure each lobe of the ma- 

 ture anther consists of two layers ; an 

 outer {figs. 499, h, and 506, ce), which 

 resembles that kind of modified 

 epidermis termed epithelixim, and is called the exothecium, upon 

 which stomata are frequently found ; and an inner {figs. 499, c, 



Fig. 506. Horizontal section of 

 a portion of the wall of an 

 anther of the Cobcea scandena 

 at the time of dehiscence. 

 It is composed of an ex- 

 ternal epidermal layer ce, 

 forming the exothecium, and 

 an internal layer of fibrous 

 cells c/, forming the endothe- 

 cium. 



