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- 



