68 ELEMENTARY AGRICULTURE 
d’arc or Osage orange lasts much longer. We think of 
trees as requiring a very long time to grow from seeds. 
It is true that twenty years seems long to wait for trees 
to develop. That is all the more a reason for young 
people to become interested in planting trees. As our 
small woodlots become thin, trees may be planted which 
will greatly improve the quality of the timber. 
Fig. 45.—The sections of the log show dark heart wood and light sapwood. 
The fertility of the soil, the amount of water available, 
and the climate or temperature necessarily determine the 
kinds of trees grown. Cypress, sycamores, willows, and 
cottonwoods grow best along streams. Oaks, elms, and 
gums do better in rich soil a little higher than that 
suited to willows. Pines are usually adapted to higher 
altitudes or to shady coastal plains. 
