356 THE ANATOMY OF WOODY PLANTS 



affinities, in reality have nothing to do with that group, but are 

 araucarian or pre-araucarian in their relationships. There is at the 

 present time no trustworthy evidence that the Taxodineae were in 

 existence before Tertiary times, although it is quite possible in view 

 of the general situation that they made their appearance in the 

 later Cretaceous. The Cupressineae must be regarded as a con- 

 tinuation of the taxodineous line and as having a similar relation 

 to the abietineous ancestral forms. 



In conclusion, it may be remarked that, whatever may be 

 the differences of opinion in regard to the reading of the evolution- 

 ary document supplied by the Coniferales as they now present 

 themselves to our gaze or are preserved for us as fossils from 

 earlier geological epochs, there can be no doubt that they con- 

 stitute the most important of all documents for the develop- 

 ment of general evolutionary principles as the result of inductive 

 reasoning. The treatment of the group in the present and 

 preceding chapters is intended to clear the way for their 

 further study by the development of general situations in relation 

 to particular anatomical and paleobotanical facts. A continued 

 investigation of the group, for which our American Mesozoic 

 deposits have already yielded so much material of crucial impor- 

 tance, is likely to result in the firm establishment of extremely 

 valuable general principles for that type of biological research 

 which bases its conclusions on inductive reasoning rather than 

 on any purely philosophical attitude, either mechanistic or vital- 

 istic. 



