66 PLANT-LIFE ON LAND [CH. 



effected subsequent to the earlier segregation of the 

 nutritive from the propagative regions of the shoot. 



Thus we may figure to ourselves how the flower 

 as distinct from the vegetative region originated in 

 the higher plants. The main point to bear in mind 

 is that the propagative function recurred in each fully 

 completed life-cycle throughout descent. It was 

 never an innovation. The propagative organs can- 

 not at any time in descent have been superimposed 

 upon a pre-existent vegetative system. Their appear- 

 ance may have been deferred in the individual life, and 

 it is only natural that the nutritive phase should pre- 

 cede the propagative, since food-material is necessary 

 for the latter process. But however long the nutritive 

 phase might be, or however prominent the organs 

 which carry it out, the propagative phase supervenes 

 sooner or later in every completed life. All evidence 

 points to the belief that it was represented throughout 

 the course of evolution. 



Once the two pristine functions were allocated 

 to distinct regions of the shoot, these were open each 

 to its own distinct specialisation, and thus they became 

 fitted for their respective duties. And so it comes 

 about that while in simple cases there may be some 

 similarity between the flower and the foliage-shoot, 

 as for instance in Magnolia, which is on that account 

 held to be a relatively primitive type of Flowering 

 plant, the two may diverge widely in their characters 



