ORGANIC AND INORGANIC MATTER COMPARED. 81 



Some plants propagate by gemmation as well 

 as by seeds. They throw out suckers, as we 

 commonly term them, from the root, and thus 

 are stems multiplied, each having its own root. 

 Of this the rose is a familiar example. Some, 

 after flowering, die down in winter, while, on 

 the return of spring, gemmation takes place in 

 the roots, and verdure is renewed. Of this the 

 garden-mint, the common nettle, and others, 

 are examples. Bulbous roots, as the hyacinth, 

 renew their leaves, stalk, and flowers in spring ; 

 but such roots multiply by a sort of spontaneous 

 division, young bulbs budding from the parent 

 root, and increasing in size until a final separa- 

 tion takes place. The potatoe and the Jerusalem 

 artichoke propagate by seeds, and also by 

 tubers, which form on the extremities of the 

 roots ; the plant dies, but these tubers remain 

 alive, and gemmate, more or less abundantly ; 

 each eye, as it is commonly called, being the 

 speck of gemmation. Hence from one tuber 

 numerous plants are produced ; each plant in 

 turn produces many tubers, and each tuber 

 again many plants ; and thus the species be- 

 comes multiplied. Some plants, with trailing 

 branches or stems, strike roots into the earth, 

 wherever the earth and stem, or branch, are in 

 mutual contact. Hence, from one small plant 

 a large bed will result, as in the case of the 

 garden sage. Carnations are thus artificially 

 multiplied. Garden pinks abundantly multiply 

 themselves by self-struck layers. The Indian 

 fig forms a forest by sending down euokcrs 



