ROOTS » 61 
' 73. Propagation by Means of Roots. —Some familiar 
plants, such as rose bushes, are usually grown from roots 
or root-cuttings. 
Bury a sweet potato or a dahlia root in damp sand, and watch 
the development of sprouts from adventitious buds. One sweet 
potato will produce several such crops of sprouts, and every sprout 
may be made to grow into a new plant. It is in this way that the 
crop is started wherever the sweet potato is grown for the market. 
- 74, Tabular Review of Experiments. 
[Continue the table begun at end of Chapter III.] 
‘75. Review Summary of Roots. 
| Kinds of roots as regards origin 
te co. 
< 
Sn oe me, 
( Kinds as regards medium in which they grow . 1 
Structure of root of a tree. 
materials. 
MIA BOE i a on i ag ee location. 
| uses. 
( apparatus. 
amount. 
proofs. 
| causes. 
Absorption of water by roots 
nature. 
causes. 
uses. 
Movements of roots. 
