Chap. 37.] THE DISEASES OF TEEES. 523 



productive 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 4 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, which 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 5 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 6 that prevails 

 in Apulia, and the Olympias 7 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. 



4 See B. xviii. c. 74. 



5 On the contrary, this sweet juice is secreted by the insect itself, an 

 aphis or vine-fretter. 



6 The north-west wind. See Horace, Sat. B, i. s. v. 1. 71. 



7 See B. ii. c. 46. 



