172 The Great World's Farm 



pollen, before that of the surrounding stamens is ripe 

 enough to burst from the anthers. But the pistil cannot 

 go on waiting, and if pollen does not reach it at the right 

 time, it is of no use its coming at all; the time is gone by, 

 and the ovules are left to shrivel. 



Often, too, the pollen is ripe first and all scattered 

 before the pistil is ready for it; and here again the ovules 

 must perish, unless pollen is brought from elsewhere. 

 Even when pollen and pistil are ripe together, they may 

 be out of one another's reach; for the pistil may be taller 

 than the stamens, or the anthers may open outwards 

 instead of inwards, and in neither case will the pollen be 

 scattered on the pistil-tip, or be of any use to the ovules. 



But there are more difficulties even than these. A 

 perfect flower, as has been said, consists of a double set 

 of outer and a double set of inner organs; but very many 

 flowers are quite imperfect. One or both of the outer 

 set of leaves may be altogether wanting, and one or other 

 of the inner set may be also wanting; that is to say, some 

 plants grow the pistil in one blossom and the stamens in 

 another, but never both in the same blossom; and others 

 go a step further than this, and grow their pistils and 

 stamens not merely in different blossoms, but on different 

 plants. 



Those plants or blossoms which bear stamens only 

 are of course barren, for they possess no ovules, as they 

 possess no pistils; and those which bear pistils only are, 

 or may be, fertile, since they possess ovules, which may 

 become seeds provided pollen be brought to them from 

 another blossom or plant, but not otherwise. 



And then again, even when a plant bears perfect flow- 

 ers with both pistils and stamens, it not unfrequently hap- 



