662 STUDIES IN FOSSIL BOTANY 



yet nothing is more difficult than to trace, in any given 

 instance, the true history of a field-crop or a garden plant, 

 or even, in many cases, to fix its origin with certainty. 

 In the history of natural groups, where the geological 

 record takes the place of the cultivator's notes, the 

 problem increases so immeasurably in difficulty, that a 

 full solution becomes impossible. 



But although, in endeavouring to form an idea of 

 the course of evolution of any part of the Vegetable 

 Kingdom, we can only hope, at the best, to construct a 

 scheme, representing in a much simplified form the real 

 succession of events, we must take care not to be misled 

 by our own constructions. We must remember that, at 

 all periods, competition among living things was as keen 

 as now, and that in every age all the available places 

 must soon have been filled. Hence, even in the earliest 

 times of which the palaeontologist take cognisance, 

 there must always have been specialised forms, and 

 even what we call " synthetic " types were themselves 

 specialised to suit some particular set of conditions. 

 Thus, at every step in the investigation of the fossil 

 evidence, the same caution in distinguishing between 

 the newer and the older characters is demanded, as 

 when we are dealing with recent organisms. 



Yet, in spite of these difficulties, and others, 

 more obvious, which will at once occur to the mind, 

 there can be no question that the study of the actual 

 records of the past is of inestimable value in at- 

 tacking a problem which is in its essence an historical 

 one. 



In these ' ' Studies " the fossil record has been considered 

 almost wholly from a morphological and evolutionary 



