316 REPRODUCTION 



of reserve food. Not all tuberous roots are capable of propaga- 

 tion however. Shoots originating in roots may be seen in old 

 specimens of Rubus, Ailanthus, Fagus, Crataegus, Syringa, Rosa, 

 Madura, Liriodendron, also in the thickened roots of the Convol- 

 vulaceae, Ericaceae, and others. 



409. Cuttings from Roots. Cut sections several cm. in length 

 from roots of old plants of Rosa, Populus, or Rumex, or from the 

 small lateral roots of horse radish, and imbed in moist sand and 

 keep under proper cultural conditions. Ascertain manner and 

 place of formation of buds. 1 



410. Propagation by Tuberous Roots. Secure a number of sound 

 sweet potatoes which have been kept in a cool dry place after 

 taking from the soil in the autumn, and place a few in moist sand 

 under proper cultural conditions. Cut one or two others into 

 segments by longitudinal and transverse incisions, and place the 

 pieces with the entire tubers and ascertain what regions are cap- 

 able of giving rise to buds. Clean a tuber carefully in water and 

 examine the superficial layers to determine the presence of latent 

 buds or growing areas in the ungerminated tuber. Identify the 

 substances stored in the roots. Note manner of translocation to 

 young plant. Are juvenile forms of leaves developed by the 

 plants arising in this manner ? The above experiments should 

 be carried on at temperatures of 1 8 to 22 C. 



411. Propagation by Stems. Buds on stems which undergo a 

 special development for the purpose of giving rise to a new indi- 

 vidual may or may not be supplied with reserve food, and may 

 or may not be separated from the parent plant before its death or 

 maturity. Such buds may be borne on underground branches 

 arising from the bases of the main stem, and such branches may 

 be developed to bear several buds, which like the potato are cap- 

 able of giving rise to many new individuals. In other instances 

 propagative buds arise from trailing or decumbent branches, 

 which place the young plant some distance from the parent, and 

 thus accomplish the incidental purpose of dissemination. The 



1 Bailey, L. H. Nursery book, 61. 1896. 



