T*he Natural History of Selborne 463 



FLOWING OF SAP. 



IF the bough of a vine is cut late in the spring, just before 

 the shoots push out, it will bleed considerably ; but after the 

 leaf is out, any part may be taken off without the least incon- 

 venience. So oaks may be barked while the leaf is budding ; 

 but as soon as they are expanded, the bark will no longer 

 part from the wood, because the sap that lubricates the 

 bark and makes it part, is evaporated off through the leaves. 

 WHITE. 



RENOVATION OF LEAVES. 



WHEN oaks are quite stripped of their leaves by chaffers, they 

 are clothed again soon after Midsummer with a beautiful 

 foliage; but beeches, horse-chestnuts, and maples, once de- 

 faced by those insects, never recover their beauty again for 

 the whole season. WHITE. 



ASH TREES. 



MANY ash trees bear loads of keys every year, others never 

 seem to bear any at all. The prolific ones are naked of 

 leaves and unsightly; those that are sterile abound in foliage 

 and carry their verdure a long while, and are pleasing ob- 

 jects. WHITE. 



BEECH. 



BEECHES love to grow in crowded situations, and will insinuate 

 themselves through the thickest covert, so as to surmount it 

 all : they are therefore proper to mend thin places in tall 

 hedges. WHITE. 



