202 Blossom and Seea 



But unless it receives also the liquid contained in the 

 pollen-grain, it remains lifeless, and sooner or later 

 shrivels and perishes. 



The quantity of pollen prepared and needed for the 

 ovules varies very greatly in different plants. The 

 violet, for instance, produces about a hundred grains in 

 each blossom, and the poppy more than three million 

 and a half. Some ovules need only two or three grains 

 of pollen to quicken them, and others several ; some of 

 the foreign orchids bear as many as seventy-four 

 million seeds, and though they are very small, each 

 seed requires the contents of about twenty grains of 

 pollen to fertilise it ; so that the quantity produced is 

 necessarily very large. Moreover, a good deal more is 

 required than the plant itself needs, as a considerable 

 margin must be allowed for waste, some being blown 

 away by the wind, some washed away by rain, and not 

 a little consumed by bees and other insects. 



Since the pistil with its sticky tip stands in the 

 middle of the blossom all ready to catch and hold fast 

 • the pollen which is discharged by the surrounding dust- 

 spikes, it would seem that there could be little difficulty 

 about the matter, and that stamens and pistils might 

 safely be left to manage it without help. But there are 

 various obstacles in the way of this apparently simple 

 arrangement. 



In the first place, even though stamens and pistil be 

 most conveniently placed, as it might seem, for the very 

 purpose of giving and receiving pollen, it does not 

 follow that they are so. For where is the use of their 

 being within easy reach of one another if they are not 

 both ready to act at the same time ? And this is a 

 thing which happens very frequently indeed. Some- 



