Pliny: Natural History, Vol. V

vegetation for the very reason that it does not deluge it. In this way the earth also is made to ferment, and is filled with her own substance, not exhausted by seeds sown in her trying to suck her milk, and when lapse of time has removed her covering she greets the mild hours with a smile. This is the method to make corn crops fatten most abundantly—except in countries where the atmosphere is always warm, for instance Egypt: for there the unvarying temperature and the mere force of habit produce the same effect as management produces elsewhere; and in any place it is of the greatest benefit for there to be nothing to cause harm. In the greater part of the world, when at the summons of heaven's indulgence the buds have hurried out too early, if cold weather follows they are shrivelled up. This is why late winters are injurious, even to forest trees as well, which actually suffer worse, because they are weighed down by their own shade, and because remedial measures cannot help them, to clothe the tender plants with wisps of straw not being possible in the case of forest trees.

Effects of rain.

Consequently rain is favourable first at the period of the winter storms, and next with the wet weather coming before the budding period; and a third season is when the trees are forming their fruit, though not at the first stage but when the growth has become strong and healthy. Trees that hold back their fruit later and need more prolonged nourishment also receive benefit from late rains, for instance the vine, the olive and the pomegranate. These rains, however, are required in a different manner for each kind of tree, as they come to maturity at different times; consequently you may see the same storm of rain causing damage to some trees and benefiting others even in the same class of trees, as for example among pears, winter varieties require rain on one day and early pears on another, although they all alike need a period of wintry weather before budding. The same cause that makes a north-west wind more beneficial than a south-west wind also renders inland regions superior to places on the coast—the reason being that they are usually cooler—and mountain districts superior to plains, and rain in the night preferable to rain by day, vegetation getting more enjoyment from the water when the sun does not immediately make it evaporate.