Lateral growth in trees frequently begins later than growth in height, but the period of lateral growth is longer. Rates of lateral growth likewise are low at the outset, increasing after a few weeks and then diminishing. In view of the long annual period of lateral growth in trees, deleterious environmental conditions may exercise a pronounced effect on growth. In the wood of trees of temperate regions, narrow and wide growth rings may be observed, marking years characterized by unfavorable and favorable conditions for growth.
The problem of human growth—the population explosion—must be understood in the same context as the growth of populations of other organisms. At present the human population is in a growth phase with a mean doubling time of about 25 years. Although the number of humans an double every 25 years, the food supply cannot Jo so indefinitely.
While the reliance upon government's foster-care had historic precedent, the resort to it :r years of growth and independence closed era. Government aid had been for ventures, for protective custody. It had aided railroads en they were pushing back the frontier and ipling the West, when they were replacing the -sufficiency of sections with an articulated con-:ntal economy.
In that era railroads had helped set the forms national character.
Lateral growth in trees frequently begins later than growth in height, but the period of lateral growth is longer. Rates of lateral growth likewise are low at the outset, increasing after a few weeks and then diminishing. In view of the long annual period of lateral growth in trees, deleterious environmental conditions may exercise a pronounced effect on growth. In the wood of trees of temperate regions, narrow and wide growth rings may be observed, marking years characterized by unfavorable and favorable conditions for growth.