108 CRITIQUES AND ADDRESSES. [v. 



their associates, are all altered. And the tree-fern forest 

 of Tasmania, or New Zealand, gives one only a faint 

 and remote image of the vegetation of the ancient 

 world. 



Once more, an invariably-recurring lesson of geological 

 history, at whatever point its study is taken up : the 

 lesson of the almost infinite slowness of the modification 

 of living forms. The lines of the pedigrees of living 

 things break off almost before they begin to converge. 



Finally, yet another curious consideration. Let us 

 suppose that one of the stupid, salamander-like Labyrin- 

 thodonts, which pottered, with much belly and little leg, 

 like Falstaff in his old age, among the coal-forests, could 

 have had thinking power enough in his small brain to 

 reflect upon the showers of spores which kept on falling 

 through years and centuries, while perhaps not one in 

 ten million fulfilled its apparent purpose, and reproduced 

 the organism which gave it birth : surely he might have 

 been excused for moralizing upon the thoughtless and 

 wanton extravagance which Nature displayed in her 

 operations. 



But we have the advantage over our shovel-headed 

 predecessor or possibly ancestor and can perceive that 

 a certain vein of thrift runs through this apparent prodi- 

 gality. Nature is never in a hurry, and seems to have 

 had always before her eyes the adage, " Keep a thing 

 long enough, and you will find a use for it." She has 

 kept her beds of coal many millions of years without 

 being able to find much use for them ; she has sent them 

 down beneath the sea, and the sea-beasts could make 

 nothing of them ; she has raised them up into dry land, 

 and laid the black veins bare, and still, for ages and ages, 

 there was no living thing on the face of the earth that 

 could see any sort of value in them ; and it was only the 

 other day, so to speak, that she turned a new creature 



