ORGANS OF REPRODUCTION. 



24: 



row {fig. 501, e), indicating the point at which the anther 

 will open to discharge the pollen, which is termed the suture. 

 By these farrows the face of the anther may be generally dis- 

 tinguished from the back, which is commonly smooth and 

 has moreover the filament attached to it. The face is generally 

 turned towards the pistil or centre of the flower, as in the Water- 

 Lily and the Vine {fig. 506), in which case the anther is called 

 introrse ; in some instances, as in the Iris, and Meadow Saffron 

 {fig. 507), it is directed towards the petals or circumference, 

 when it is said to be extrorse. 



Fig. 506. 



Fig. 507. 



Fig. 508. The Essential Organs of Reproduction of the Vine ( Vitis vinifera). 

 a. Anther, c. Furrow in its face which is turned towards the pistil, h. 



Suture or line of dehiscence. The anther is introrse. Fig. 507. The 



Perianth and stamens of the Meadow SaiFron {Colchicum autumnaJe) 

 showing its anthers turned towards the floral envelopes, and heuce termed 

 extrorse. 



In Structure each lobe of the mature anther consists of two 



layers (fig. 501, b, c) ; an outer b, 

 of modified epidermis termed epi- 

 thelium, and is called the exo- 

 thecium, upon -which stomata are 

 frequently found ; and an inner 

 c, which corresponds to the cover- 

 ing of the masses of pollen-form- 

 ing cells {fig. 500, cl), and is 

 termed the endothecium. This in- 

 ner lining consists of fibro- cellular 

 tissue, formed of either spiral, an- 

 nular, or more commonly reticu- 

 lated cells, arranged in one or 

 more rows {fig. 508 cf). The mem- 

 brane forming the walls of these 

 cells usually becomes obliterated 

 K 4 



which resembles that kind 

 Fig. 508. 



Fig. 508. Horizontal section of a 

 portion of the wall of an anther 

 ot the Cohcea scandcns at tlie 

 time of dehiscence. It is com- 

 posed of an external epidermal 

 layer ce, forming the exo- 

 thecium, and an internal layer 

 of fibrous cells cf, forming 

 the endothecium. 



