The Trees of Texas ly 
water. In this way long continued heavy rains are required be- 
fore the excess water begins to flow off into streams and rivers. 
The water which percolates down into the soil gradually runs 
away to feed streams and springs, and thus maintains their 
steady flow throughout the year. It is a very noticeable fact 
that springs are much more common in forested lands than in 
the open, and that they usually cease to flow when the forest 
is removed. The water-holding power of a watershed is much 
greater if it is covered with timber than with any other vegeta- 
tion, but grassy plains catch and hold much more water than 
cultivated areas. The removal of forests, and the cultivation of 
_the areas once occupied by them, has given rise to the various 
floods which now occur on many rivers throughout the country. 
Concerning erosion, it has been estimated that 1,000,000,000 tons 
of sediment are annually pouring into the seas from the rivers 
of the United States. This material is derived from the surface 
layers, the richest part of the soil, and its land value, the annual 
loss, would exceed all the land taxes of the country. The soil 
actually removed does not, however, constitute the entire danger. 
The surface of the hillside areas frequently become so gullied 
that they can no longer be tilled, and all productive power is lost. 
SHADE TREES 
Aside from their more readily estimated value for fruit, timber, 
and fuel, trees are valuable for shade and ornament. The orna- 
mental shade tree ministers not only to our physical comfort, 
but also to the aesthetic pleasures which come to us through a per- 
ception of beauty. The chief value of trees for city streets, lawns, 
and parks is due to the beauty which can be developed by their 
use. It is a value not always appreciated by all, and one which 
should be enhanced by education. 
There is a growing sentiment throughout the country in favor 
of the planting and care of shade trees. In the past, each owner 
has planted along his property such trees as he saw fit, and given 
them such attention as his knowledge and circumstances permit- 
ted. This has resulted in miscellaneous collections of trees, de- 
void of design, harmony and adaptation of means to an end—the 
very principles upon which beauty depends. 
In many of the cities of this country the work of planting and. 
2—Trees. 
