228 THE EVOLUTION OF PLANTS 



not go far enough back to give any strong sup- 

 port to either theory, they agree quite well with 

 the origin of the leafy plant from a thallus, while 

 there is no Palaeozoic plant known which we could 

 well suppose to have been constructed out of a 

 moss-fruit or any kind of sporogonium. 



It is at any rate safe to say that there is no 

 evidence, fossil or otherwise, for the evolution of 

 the higher Cryptogams from Bryophyta or any 

 plants at all like them. It is more probable that 

 they came direct from plants which were rather of 

 the nature of Algae; this view, however, is a pure 

 hypothesis and must not be considered as by any 

 means on the same level with the conclusions 

 as to the evolution of the various groups dealt 

 with in the preceding chapters, for these con- 

 clusions, whether proved or not, are all based 

 on genuine historical evidence. 



The question of the evolution of the Mosses 

 and Liverworts does not fall within our scheme; 

 at present we really have no clue. Far from 

 helping us to understand the evolution of the 

 higher plants, the Bryophytes are themselves 

 about the greatest puzzle of all. It now seems 

 fairly clear that the simpler forms of Liverworts 

 are reduced from more complex forms, and it is 

 not improbable that the whole class of Bryophytes 

 may have owed its origin to reduction from some 

 higher group, of which we know nothing except 



