THE CULTIVATION OF THE OAK 155 



Of other animals which injure oaks I may mention 

 the various cattle, which bite off or rub the bark and 

 buds ; hares, squirrels, mice, &c., which nibble roots and 

 buds and destroy the acorns, &c. ; and a few birds ; and 

 certain beetles, which bore into the wood. 



Among the pests belonging to the vegetable king- 

 dom the following may be selected from a large 

 number. The honeysuckle occasionally twists tightly 

 round the young stem, and in course of time so com- 

 presses the cortex that the formative materials from the 

 leaf-crown have to pass in a spiral course between the 

 coils of the strangling plant, and the tightly-squeezed 

 parts may be starved as the tree thickens, and even the 

 death of the cambium may follow, especially if one or 

 two of the honeysuckle coils come to lie nearly horizon- 

 tally round the stem. 



As a rare event the mistletoe is found on the oak. 

 A much commoner parasite of the same family is 

 Loranthus europceus, which does considerable damage to 

 oaks in some parts of Europe. The sticky seeds are 

 carried into the trees by thrushes. Here they germi- 

 nate, and send their roots, or haustorial strands, into 

 the cortex of a branch as far as the cambium, where 

 they spread and feed on the contents of the young 

 wood- and cambium-cells, causing malformations of the 

 injured branch at the spot attacked owing to the hyper- 

 trophy of the tissues, to which abnormal quantities of 

 food materials now flow (fig. 41) ; and frequently 

 bringing about the death of the upper parts of the 



