RESULTS, PHYLETIC AND MORPHOLOGICAL 717 



the vegetative system was established and amplified, while it tended 

 to become differentiated from the propagative system. In the later and 

 more specialised heterosporous forms, and particularly in the Seed-Plants 

 with their more refined methods, individual precision supersedes mere 

 numbers : and reduction of the propagative system has been its usual con- 

 comitant. The vegetative system which became fully distinct from the 

 propagative, often retained or even increased its dimensions and complexity. 

 Taking an evolutionary course of its own it diverged more and more 

 in character from the propagative system. The final result is seen 

 in the Angiosperms which are now dominant : here the flowers differ 

 widely from the vegetative shoots, though the plan of each resembles that 

 of the primitive shoot from which both sprang. But whatever the modern 

 complications may be, comparison along lines which have been pursued in 

 this volume indicates that the sporophyte, which is the essential feature 

 in the Flora of the Land, is referable back in its origin to post-sexual 

 complications : it appears to have originated as a phase interpolated between 

 the events of chromosome-doubling and chromosome-reduction in the primitive 

 life-cycle of plants of aquatic habit. 



