34 *Hi3 STOEY OP THE PLANTS. 



Observe the numerous points of similarity : all 

 these are white ; all are sweet-scented ; all are 

 moth-fertilised. Why is this? Because the 

 scent helps to show the moth the way to the 

 flower when there is hardly enough light for him 

 to see the white petals. Thus every plant is 

 adapted to its particular station in life, and its 

 adaptation is the result of the Struggle for 

 Existence, and Survival of the Fittest. 



Briefly put, whatever variation helps the plant 

 in any way in any particular place, or at any 

 particular time, is likely to give it an extra 

 chance in the fight, and is therefore reproduced 

 in all its descendants. 



So that is how plants began to vary. 



To sum up. Plants grow, because they keep 

 on continually taking in carbon and hydrogen 

 from the world outside them, under the in- 

 fluence of sunlight. They multiply, because 

 when they have attained a certain size they 

 split up to form two or more individuals. They 

 struggle for life with one another, because more 

 are produced than can find means of livelihood. 

 And the struggle results in Survival of the Fittest. 



Or, looked at in another light. Plants 

 multiply, and as they multiply by division the 

 new ones on the whole resemble their parents ; 

 this is the law of Heredity, But they do not 

 exactly resemble them in every detail ; this is 

 the law of Variation. And as some variations 

 are to the good, and some to the bad, the better 

 survive and produce young like themselves 

 oftener than the worse do ; this is the law of 

 Natural Selection. 



