32 THE STORY OF THE PLANTS. 



like the jasmine, the tuberose, the stephanotis, 

 and the gardenia. 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 Exist- 

 ence, and Survival of the Fittest. 



Briefly put, whatever variation helps the plant 

 in any way in any particular place, or at any par- 

 ticular 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 influence 

 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 multi- 

 ply, 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 resem- 

 ble them in every detail ; this is the law of Vari- 

 ation. 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. 



