BOOK XMI. xLii. 251-XL111. 254 



the vine-dressers holding a pruning knife with a very 

 sharp edge in both hands press it into the trunk and 

 make long incisions do\vmvards,and as it were loosen 

 its skin. It proves that this treatment has been 

 beneficial if the scars Avidcn out and fill up with new 

 wood growing between their edges ; XLIII. and to 

 a large extent the medical treatment of trees re- 

 sembles that of human beings, as the bones of trees 

 also are treated by j^erforation." Bitter almonds are 

 made into sweet ones if the stem of the tree has the 

 earth dug away round it and a ring of holes pierced 

 in it at the bottom, and then the gum exuding is 

 wipcd off. Also elms can be reUeved of useless sap 

 by having holes picrced in them above the level of the 

 earth right into the cambium when they are getting 

 old, or when they are observed to be receiving exces- 

 sive nourishmcnt. The sap is also discharged from 

 the bark of figs when swollen by means of light cuts 

 made on a slant ; this treatment prevents the fruit 

 from falling off. Fruit-trees that make buds but pro- 

 duce no fruit are treated by making a cleft in the 

 root and inserting a stone in it, and this makes them 

 bear ; and the same result is produced in almonds by 

 driving in a wedge of hard oak, and in pears and 

 service-berries by means of a wedge of stone pine, 

 and covering up the hole with ashes and earth. It 

 also pays to cut round the roots of vines and figs 

 when over-luxuriant and to put ashes on the cut 

 parts. Late figs are produced if those of the first 

 crop are picked off the tree still unripe, when they 

 are a httle largcr than a bean, as a sccond crop 

 grows which ripens later. Also fig-trees are made 

 stronger and more productive if the tips of all the 

 branches are docked when they begin to make 



175 



