What are Aftimals and Plants? ^6^ 



I 



I^B yi. Every living being is a creature requiring food, which 



I^P has the power of changing into its own substance, and so, 



at least for a time, augmenting its size by a process of growth. 



This growth is not a mere external increment, like the growth 



a crystal suspended in a suitable medium, but is an aug- 

 entation of its intimate innermost substance by what is 



ed intvssusception. 



YII. Every living creature thus grows according to a 

 ore or less definite law, from a single, minute, spheroidal 



s of protoplasm into that shape and structure which is 

 aracteristic of the group to which it belongs, 



VIII. In this process each such creature forms certain 

 substances which are not protoplasm, — at the very least it 

 forms minute granules which may be fatty or starchy ; while, 

 as a general rule, living creatures do form the most complex 

 structures, namely, all those found in the animal and vegetable 

 kingdoms — the woods, resins, oils, and sugars of plants, and 

 all the varied components of the bodies of animals ; this pro- 

 cess is known as 'secrefioTi.' 



By this latter process the living world, as one whole, is 

 continually taking matter from the earth's aerial and aqueous 

 envelopes and adding it to the substance of the earth's solid 

 crust. The past effect of this action we see, as before men- 

 tioned, in the enormous fields of coal and peat ; in the exten- 

 sive chalk formations and coral reefs (one reef extending for 

 a thousand miles along the coast of Australia, and such 

 structures forming a great part of Florida); in the vast 

 accumulations of fossil remains — evidenced by the fact that 

 the fossil ear bones of whales (a valuable manure) have given 

 rise to a lav/suit, and by the five million cubic feet of shell- 

 sand annually collected on the shores of Devon and Cornwall. 



As to the present activity of the vegetable world in this 

 direction, we have but to recollect that Brazil is mainly 

 a forest region which may be roughly represented as an 



