NATURAL HISTORY 



IV. BOTANY 

 WONDERS OF PLANT LIFE 



THE genealogical tree of living creatures may be thought 

 of as like a letter V. On the one side are animals ; on the 

 other side are plants ; at the base there are simple forms of 

 life which have not taken any decisive step in either direction. It 

 is easy to distinguish a buttercup from a butterfly, but it is not 

 so clear at first sight how a mushroom differs from a sponge ; and 

 at the base of the genealogical tree there are "Protists," which are 

 sometimes claimed by the botanist and sometimes by the zoologist. 

 Some of these very simple organisms give us a glimpse of what 

 the first living creatures may have been like. 



Dependence of Animals on Plants 



The image of the letter V is useful, because it suggests that 

 plants and animals, though both alive, are on very different tacks 

 of evolution. But we could improve on the symbol if we showed a 

 tracery of fine twigs, binding the two sides together; for plants 

 and animals have grown up together through the ages and are 

 linked together in mutual influence and dependence. This is the 

 subject of a separate article on INTER-RELATIONS. 



There are three great ways in which the animal world as a 

 whole is dependent on plants. First, there is nutritive depend- 

 ence, for it is wholly through the agency of green plants that ani- 

 mate nature continues as a going concern. Many an animal 



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