FALLING LEAVES 91 



trees often show bright splotches of color long 

 before the first frost, and in very warm autumns 

 most of the changes in foliage occur before 

 there has been any frost. 



In the tropics trees retain most of their leaves 

 the year round, excepting where there is a se- 

 vere dry season. This would be impossible for 

 broad-leaved trees in our latitude. Soil-water 

 could not be absorbed with the ground at or 

 near freezing temperature, and without this 

 moisture the leaf would die. Again the leaves 

 would serve to catch the snow, the branches 

 would become heavily laden and break. Trees 

 that shed their leaves in the autumn are called 

 deciduous trees. The needle-Uke leaves of our 

 cone-bearing evergreen trees, such as pines, 

 spruces, and the like, are so constructed as to 

 withstand successfully winter blasts. Hence 

 they remain on the tree. But they are not 

 really evergreen. One by one they fade and 

 fall, making a brown carpet beneath the tree, 

 till, in the course of a few years, all the foliage 

 has been shed. We do not notice the discolor- 

 ation of aging leaves amid the general green- 

 ness of their surroundings, unless we look spe- 

 cdally for them, and the space left by their fall 

 is soon filled by fresh needles. Pines turn to a 

 brownish olive in winter, and spruces, seen 



