436 SKETCH OF PALEOBOTANY. 



manner to constitute a lower type than any other of the Phsenogams, 

 and they conclude that they form a more or less natural transition from 

 the Cryptogams to the Phanogams, between which they place them. 

 This result is most gratifying to the paleontologist, for nearly or quite 

 every work on fossil plants gives the Gymnosperms Ihis position at the 

 base of the Phsenogamic series, so sagaciously assigned to it by Brong- 

 niart. Paleobotanists have been compelled to do this in the face of 

 the prevailing botanical systems, because this is the position which they 

 are found to occupy in the ascending strata of the earth's crust. It is 

 astonishing that botanists could have remained so indifferent to such a 

 weighty fact, and it is certainly most instructive to find the geological 

 record, so long unheeded, confirmed at last by the facts revealed in 

 living plants. There is no evidence that those who have thus confirmed 

 it were in the least influenced by it, and Sachs is as silent as to paleon- 

 tology as is Bentham or Gray. 



The founders and perfectors of the prevailing system of botanical 

 classification have not been influenced in any marked degree by the idea 

 of development iu vegetable life. Pew of the earlier ones had ever 

 heard of development, and those who had heard of it rejected it as a 

 visionary theory. This system had become established long before the 

 doctrine of the fixity of species had received a shock, for although La- 

 marck, himself a botanist, had sown the seed of its ultimate overthrow, 

 still it required half a century for this seed to germinate, and it was 

 during this half century that the Jussisean system was supplanting the 

 Linnsean and gaining a firm foothold. 



It is our special task to examine this system by the light of the now 

 universally accepted laws of development and to see in how far it con- 

 forms to those laws. We shall see that, with a few important excep- 

 tions and some unimportant ones, this purely logical classification is in 

 substantial harmony with what we now believe to be the order de- 

 manded by the law of descent — an encouraging fact as showing that 

 natural truth may often be correctly discerned by i^urely rational x)ro- 

 cesses. Had Jussieu been told that the Monocotyledons and Dicotyle- 

 dons were the direct descendants of the Acotyledons he would probably 

 have treated the proposition with contempt. In his system the latter 

 were placed before the former merely because they represented a lower 

 grade of organization, and it was the relative grades of organization 

 that determined the position of the minor as well as of the major groups 

 throughout the Jussiaean system. 



5. MODIFIED SYSTEM PROPOSEP. 



Now, therefore, that we have been compelled, from an entirely differ- 

 ent class of evidence, to accept the fact of descent, we are glad to find 

 that this does not wholly revolutionize the system arrived at from con- 

 siderations of structure alone, while at the same time we must claim 

 that this substantial agreement furnishes a strong corroboration of the 

 theory of descent. 



