BOOK XVII. xxxvii. 227-2;,o 



or even vheii a careless person ploughing underneath 

 them has displaced the roots or scalcd thc bark off the 

 trunk ; also a contusion niay be caused by pruning 

 w ith too bhint a knife. AU of these causes make it 

 inore difficult for a vine to bear cold or hot weather, 

 since every harmful influcnce from outside inakes 

 its way into the sore. But the most delicate of 

 all trees is the apple, and pai-ticularly any kind 

 that bears sweet fruit. With some trees weakness 

 causes barrenness but does not kill them, as is the 

 case with a pine or a palm if you lop off their top, as 

 they cease to bear but do not die. Sometimes also 

 the fruit by itself is attacked by disease but not the 

 tree, if there has been a lack of rain or of warm 

 weather or wind at the times whcn they are needed, 

 or if on the contrary thev have been too plentiful, 

 for the fruit falls otf or deterioi-ates. The worst 

 among all kinds of daniage is when a vine or oUve 

 has been struck by heavy rain when shedding its 

 blossom, as the fruit is waslied off at the same time. 



Heavy rain also breeds catcrpillars, noxious Caierpuiarj 

 creatures that gnaw away the foHage of oHves, and andihe^"' 

 others the flower too, as at Miletus, and leave the weather. 

 half-eatcn tree shamefully disfigured. This pesti- 

 lence is bred by damp sticky heat ; and another one 

 due to the same cause occurs if too keen a sun foHows, 

 and burns in the damage done by the damp and so 

 alters its nature. There is in addition a malady 

 pecuHar to oHves and vines, cafled cobweb, when the 

 fruit gets wrapped up in a sort of webbing which 

 stifles it. Tliere are also certain currents of air which 

 are specially bHghting to oHves, though they dry up 

 other fruit as well. As to worni, in some trees even 

 the fruits of themselves suiFer from it — apples, pears, 



