72 THE LESSON OF EVOLUTION 



isms collected ; and here, in still water, they lived and 

 increased for a long time. Slowly they invaded -the 

 rough waters of the coast-line, and, at last, gained a 

 footing on the land. 



It was plants which formed the army of invasion 

 that conquered the land. This army was followed by 

 a mob of camp-followers and ragamuffins, in the shape 

 of cockroaches and scorpions, who fed and fattened on 

 the plants ; but who, notwithstanding their boasted 

 superiority, were quite incapable of reclaiming a single 

 acre of desert. The real victory belongs to the plants, 

 who, with undaunted courage, left the congenial water 

 to dare the vicissitudes of temperature and moisture 

 on land, and thus made civilisation possible. 



Plants left the ocean to live on land once only, in 

 the Cambrian or early Ordovician. Several times, in 

 later days, land plants both Cryptogams and Angio- 

 sperms went back to the water ; but never again did 

 water plants succeed in gaining the land. And, even 

 at the present day, every seed-bearing plant passes, in 

 its development, through a spore-bearing stage. And 

 every bird and mammal passes through a gill-bearing 

 stage, which they have inherited from their marine 

 ancestors. 



PART II. LATER LIFE ON THE EARTH 



The commencement of the Deutozoic, or newer 

 Palaeozoic era, forms a very convenient division in 

 the progress of life ; for before that time biological 

 development took place almost entirely in the ocean, 

 and it is not until we come near the close of the older 



