CH. XI] ANDRCECIUM. 147 



Androscium and Qyncecium. 



Above or within the petals the floral axis bears the 

 parts of the flower which are essential to reproduction. 

 The lower group of floral leaves is known collectively as 

 the androBcium because it is connected with the male or 

 fertilising part of the process of reproduction. Above the 

 andrcecium conies the gyncecium, where the egg-cell is 

 found. 



The andrcecium is made up of stamens, of which two 

 only remain in fig. 63 A, the others having been re- 

 moved; in fig. 63 B it may be seen that the stamens in 

 the buttercup are numerous, the precise number being 

 unimportant. Each stamen consists of a stalk the fila- 

 ment, and a swollen elongated head the anther. Within 

 the anther are developed minute bodies pollen-grains, by 

 means of which the male element is conveyed to the egg- 

 cell contained in the ovule. The pollen-grains are carried 

 by the wind or by insects or other means to a part of the 

 gyncecium where they germinate and by a long hypha- 

 like tube transfer the male element to the egg-cell (for 

 further details see Chapter XII). The pollen occurs in 

 large quantities, and is familiar to most people as a floury, 

 dusty material, frequently orange or yellow in colour, 

 coating the ripe anthers. The pollen is developed in four 

 cavities hollowed out in the anther : these pollen sacs are 

 afterwards converted, by degeneration of two dividing 

 walls, into two cavities. The fully developed anther opens 

 or dehisces by two longitudinal fissures through which the 

 pollen is set free. Above the stamens are the floral leaves 

 known as carpels, constituting the gyncecium ; and these, 



102 



