46 NATURE STUDIES. 



different explanations elsewhere. The forms of leaves, 

 indeed, are among the most difficult problems of 

 botany, and it must not be supposed that we can 

 account for them all at once by a single simple and 

 easy formula. One might as well ask why the rabbit 

 is not as big as the red deer, or why the fox is smaller 

 than the lion. Each fills its own niche in nature ; so 

 each has been developed into exact correspondence 

 with that particular niche and no other. And different 

 means often subserve exactly the same end. The 

 fleetness of the hare is produced by quite other 

 adaptations than the fleetness of the stag; the 

 foliage of the daisy succeeds by being compact and 

 rounded, the foliage of the buttercup by being cut up 

 into numerous small divergent segments. In short, 

 whatever accidental habit happens to give a plant or 

 animal any advantage in the struggle for existence is 

 perpetuated in its descendants, and gradually perfected 

 by natural selection, and thus the most diverse means 

 often lead up in the long run to the same end. 



The reason why the daisy is able to send up buds 

 and blossoms at a moment's notice seems equally 

 clear. The buds are always lying by in readiness 

 close to the little perennial tufted stock. I cut it 

 down the middle with my pocket-knife, and see, in 

 the centre of the tuft, there are two or three unopened 

 flower-buds even now lurking unseen and waiting for 

 their turn to appear. Practically speaking, the daisy 

 is an evergreen, for it always has green leaves upon it 

 all the year round; and these green leaves are per- 

 petually engaged, summer andwinter, in manufacturing 



