HOW PLANTS MARRY. 79 



leaf of stonecrop, separated from the parent 

 plant, will root itself and grow into a fresh 

 colony ; and in some plants, like begonias, a 

 single fragment of a leaf, if placed on wet soil, is 

 capable of growing out into a new individual. 

 In other cases small leaves drop off from a plant 

 as bulbils, and root and grow ; while in others, 

 again, young plants sprout out from the edges 

 of old leaves to form new colonies. In short, 

 though the leaf is not usually a distinct plant, 

 it sometimes is, and it can often become one ; it 

 frequently gives rise in a sexless way to fresh 

 plant colonies. A graver difficulty is this: the 

 plant differs from the hive in being more closely 

 connected and subordinated in its parts the 

 stem and root (which bind and unite it), bringing 

 water and nitrogenous matter, while the leaves 

 elaborate the starch and protoplasm and other 

 chief food-stuffs. Even this difference, however, 

 is less grave than it seems, if we remember that 

 the queen bee and the larvae are similarly depend- 

 ent upon the workers for food and protection. 

 A plant, in short, is a colony of various forms of 

 leaves, very closely united together for mutual 

 service, and very much specialised in various 

 ways among themselves for particular functions. 



And now we are in a position to know what 

 work the flower has to do in the community. It 

 is a collection of special and peculiar leaves, told 

 off to act as fathers and mothers to the seeds, 

 whence are to be born future plant swarms or 

 future colonies. 



A flower, in its simplest form, consists of a 

 single stamen or a single carpel that is to say, 

 of one leaf or leaf-like organ, told off for the pro- 



