108 



THE FLOWER 



203. 



p 



The pollen-bearing organ is the stamen (Fig. 143) 

 Its parts are the stalk, called 

 the filament, and the anther, 

 containing the pollen in pollen 

 sacs. In the young condition 

 of the stamen four longitudi- 

 nal pollen sacs are found. 

 The whole mass of tissue 

 filling these sacs is finally con- 

 verted to pollen. At matu- 

 rity, if not before, the wall 

 between the two cavities on 

 143. a, a stamen ; p, pollen sac: c, the same side of the anther 



connective; f, tilameut; b, IT i 



a stamen with the anther commonly disappears, leaving 

 cut through at the time of a single pollen sac in either 



maturity. , , ,, , , ~, 



halt-anther. The middle part 



or axis of the anther between the two pouches thus formed 

 is the connective. 



204. The pollen sacs open for the liberation of the pollen 

 usually by a slit along the groove running down each side 

 of the anther ; in Pyrola and other members of the Heath 

 family, by terminal pores (Fig. 144) ; 



and in the Barberry by uplifting 

 valves (Fig. 145). And other modes 

 of dehiscence occur, suited to the 

 various means by which the pollen 

 is to reach its destination. 



205. The number of stamens is 

 often large, as in the wild Rose, the 



Buttercup, the Magnolia, and the 144, 145. stamens : 144, of 



, T *? ? . ,, Pyrola, the auther 



Water Lily. In a tew species there 

 is but one. Generally speaking, the 

 number is small, not more than ten ; 

 and, when small, usually definite for 

 each species. For example, most grasses have three sta- 

 mens, most Mints four, the Violets five, and the true 

 Lilies commonly six. Each pollen sac produces a vast 

 number of pollen grains. And when the flowers borne 



144 



opening by terminal 

 pores ; 145, ol Bar- 

 berry, the anther 

 opening by uplifting 

 valves. 



