TIME AND CHANGE 



law of steady increase in size has been operative, 

 as seen in the FelidcBy the stag, and the antelope. 

 Man himself has, no doubt, been under the same 

 law, and is probably a much larger animal than any 

 of his Tertiary ancestors. In the vegetable world 

 this process, in many cases, at least, has been re- 

 versed, and the huge treelike club-mosses and horse- 

 tails of Carboniferous times have dwindled in our 

 time to very insignificant herbaceous forms. 



Animals of overweening size are handicapped in 

 many ways, so that nature in most cases finally 

 abandons the gigantic and sticks to the medium 

 and the small. 



Ill 



Can we fail to see the significance of the order in 

 which life has appeared upon the globe — the as- 

 cending series from the simple to the more and more 

 complex? Can we doubt that each series is the out- 

 come of the one below it — that there is a logical 

 sequence from the protozoa up through the inver- 

 tebrates, the vertebrates, to man.'^ Is it not like all 

 that we know of the method of nature? Could we 

 substitute the life of one period for that of another 

 without doing obvious violence to the logic of na- 

 ture? Is there no fundamental reason for the gra- 

 dation we behold? 



All animal life lowest in organization is earliest in 

 time, and vice versa^ the different classes of a sub- 

 kingdom, and the different orders of a class, suc- 



18 



