CH. V] POLLINATION AND FERTILISATION 69 



the stigma (Fig. 15, p. 73), where it is to develope 

 further. By fertilisatiou is meant the actual coales- 

 cence of two cells, the one derived from the develop- 

 ment of the pollen-grain, that is the male cell, the 

 other contained within the ovule or future seed, that 

 is the female cell. It will be at once apparent that 

 some interval of time must elapse between the two 

 events of pollination and fertilisation, an interval 

 which is usually short, but may in extreme cases be 

 as long as a year, or even more. Pollination in the 

 Flowering plant precedes fertilisation, and is a means 

 to that end, but fertilisation is the end itself 



It is not the object here to detail the various 

 methods by which pollination is secured. The chief 

 facts are already available in many published works, 

 some of them written for scientific, others for popular 

 readers. In all of them the importance of inter- 

 crossing is brought forward, involving the transfer 

 of pollen from one individual to another, a process 

 which brings with it definite racial advantages. The 

 specialisation of the fertile region of the shoot for 

 this purpose is as varied as it is often beautiful. The 

 very genesis of the forms of flowers, their tints, and 

 scents is in strict accordance with their efficiency as 

 pollinating mechanisms. Our own aesthetic pleasure 

 in them is purely subjective. It must not be permitted 

 to blind us to this simple fact. At the same time we 

 see that the expenditure of material in the production 



