208 PLANT LIFE 



become detached as a sort of bud or gemma, 

 and so reproduce the parent plant. Mosses 

 and liverworts are freely reproduced in this 

 manner. The gemmse are of all shapes and 

 sizes. They may be produced in a variety 

 of ways, e. g. as biscuit-like outgrowths from 

 the leaves, and sometimes, as in the moss 

 Tetraphis, the whole of the leaves at the 

 growing point of older stems may develop 

 into reproductive bodies of this kind. Pro- 

 pagative outgrowths may also occur on the 

 underground parts of the stems of mosses and 

 liverworts, and they are often filled with 

 reserves of food. Thus they enable the 

 species to tide over periods of drought, etc., 

 which might easily prove fatal to the indi- 

 vidual. On the return of better conditions 

 they sprout, and thus reproduce the plant 

 afresh. 



Passing to the higher plants, the vege- 

 tative propagative processes are seen to 

 exhibit almost infinite variety. The smallest 

 parts of some plants are capable of reproducing 

 the whole as any one may discover who 

 endeavours to eradicate troublesome weeds, 

 e. g. bindweed, from a garden. The regular 

 storage organs, bulbs, tubers, etc., are speci- 

 ally fitted to serve as propagative organs on 

 account of the stock of organic food they 

 contain. Bulbs, for example, consisting of 

 a short squat stem bearing fleshy leaves, 

 form the ordinary propagative bodies of lilies. 

 Even a single scale, detached from the bulb 



