18 THE EVOLUTION OF PLANTS 



life, and not primitive or ancestral at all. Here, 

 I believe, there is no serious difference of opinion, 

 but there are a great many cases in which botan- 

 ists are divided on the question whether a simple 

 form represents an old and primitive type or a 

 mere reduction from something higher. 



One of the most important questions of the 

 kind is that of the relation of the Higher Crypto- 

 gams (Ferns and their allies) to the Bryophytes 

 (Mosses and their allies). The Fern group is 

 admittedly "higher" than the Moss group, and 

 most botanists have believed that the former was 

 derived, if not from Bryophytes, at least from 

 plants of that type. This view is now much 

 shaken, and it is beginning to appear more prob- 

 able that the Higher Cryptogams are a more 

 ancient and primitive group than the Bry- 

 ophytes, which would seem to owe their origin 

 to reduction from some higher type (see Chapter 

 VIII). 



Even if we take the very simplest organisms, 

 the Bacteria, minute cells in which not even a 

 nucleus can be demonstrated with certainty, it 

 is quite doubtful whether they represent early, 

 primitive forms, or degradations of higher organ- 

 isms the latter view, indeed, appears the more 

 probable. 



There is, however, as we saw at the beginning, 

 one class of cases where we can hardly go wrong; 



