Cliap. 37.] THE DISEASES OF TEEES. 523 
producrive of a twofold result : if it grows beneath the skin, 
it will destroy the fruit, but if it is in the stone, it will only 
gnaw it away, making the fruit all the larger. The prevalence 
of showers after the rising of Arcturus^ prevents them from 
breeding ; but if the rains are accompanied with wind from 
the south, they will make their appearance in the ripe fruit 
even, w^hich are then very apt to fall. This happens more 
particularly in moist, watery localities ; and even if they do 
not fall, the olives that are so affected are good for nothing. 
There is a kind of fly also that is very troublesome to some 
fruit, acorns and figs for instance : it would appear that they 
breed from the juices*^ secreted beneath the bark, which at 
this period are sweet. These trees, too, are generally in a 
diseased state when this happens. 
There are certain temporary and local influences which cause 
instantaneous death to trees, but which cannot properly be 
termed diseases ; such, for example, as consumption, blast, or 
the noxious effects of some winds that are peculiar to certain 
localities ; of this last nature are the Atabulus^ that prevails 
in Apulia, and the Olympias^ of Euboea. This wind, if it 
happens to blow about the winter solstice, nips the tree with 
cold, and shrivels it up to such a degree that no warmth of the 
sun can ever revive it. Trees that are planted in valleys, and 
are situate near the banks of rivers, are especially liable to 
these accidents, the vine more particularly, the olive, and the 
fig. When this has been the case, it may instantly be detected 
the moment the period for germination arrives, though, in the 
olive, somewhat later. With all of these trees, if the leaves 
fall off, it is a sign that they will recover ; but if such is not 
the case, just when you would suppose that they have escaped 
uninjured, they die. Sometimes, however, the leaves will 
become green again, after being dry and shrivelled. Other 
trees, again, in the northern regions, Pontus and Phrygia, for 
example, suffer greatly from cold or frost, in case they should 
continue for forty days after the winter solstice. In these 
countries, too, as well as in other parts, if a sharp frost or co- 
pious rains should happen to come on immediately after fruc- 
tification, the fruit is killed in a very few days even. 
* See B. xviii. c. 74. 
5 On the contrary, this sweet juice is secreted by the insect itself, an 
aphis or vine-fretter. 
^ The north-west wind. See Horace, Sat. B, i. s. v. 1. 71. 
^ See B. ii. c. 46. " 
