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, etc., which nibble roots and 

 buds and destroy the acorns, etc. ; and a few birds ; and 

 certain beetles, which bore into the wood. 



Among the pests belonging to the vegetable kingdom 

 the following may be selected from a large number : 

 The honeysuckle occasionally twists tightly round the 

 young stem, and in course of time so compresses 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 horizontally round 

 the stem. 



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

 A much commoner parasite of the same family is Loran- 

 tlius europmis, which does considerable damage to oaks 

 in some parts of Europe. The sticky seeds are carried 

 into the trees by thrushes. Here they germinate, 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 hypertrophy of the tis- 

 sues, to which abnormal quantities of food materials 

 now flow (Fig. 41) ; and frequently bringing about the 

 death of the upper parts of the branches owing to the 



