100 PROTECTION OF WOODLANDS. 



extraordinary rapidity), in a very considerable degree, whilst un- 

 favourable weather, like violent downpours of rain, and a long- 

 continued cold damp time in summer, hard frost without snow, 

 or rain followed by frost in winter, not only interfere with their 

 prolificness, but also often cause excessive swarms of them to dis- 

 appear in a short time. 



Mice always love a certain amount of protection, such as is 

 afforded by scrub, dense seedling growth, a tangle of grasses, and 

 thick layer of fallen leaves. Any sort of protective soil-cover- 

 ing tends greatly to increase their numbers and reproductive 

 power. Young crops and plantations with strong growth of grass 

 are their favourite place of abode, partly for the protection they 

 afford, partly also because there they find rich supplies of reserve 

 material stored up in the roots of perennial and biennial grasses 

 and weeds ; but older woods are avoided when once the mast 

 has been devoured, unless there is a thick mantle of fallen leaves 

 on the soil. When a layer of twigs or dead foliage is spread over 

 seed-beds to protect the seed, this is of itself enough to attract 

 mice. 



The damage done by mice in woodlands consists, as has above 

 been briefly mentioned, in the destruction of mast and seed, and 

 in gnawing of the bark and roots. 



Of the seeds of forest trees, it is particularly acorns and beech- 

 nuts, also chestnuts, lime, and hornbeam seed that chiefly atti 

 mice, whilst the seed of other kinds of broad-leaved trees, ai 

 still more that of conifers, is less exposed to danger. Pii 

 Spruce, and Larch seed are occasionally, it is true, devoured, 

 Silver Fir seed appears to be protected by the turpentine whi< 

 it contains. As might be expected, sowings made in autumn 

 most likely to suffer during the winter, especially when Oak 

 Beech mast has been sown in strips or lines. The damage done 

 in seed-beds and nurseries is often very considerable, whilst the 

 extent of the injury inflicted in natural reproductions of the 

 Beech is less noticeable, although it can also often become 

 somewhat serious. 



So long as the bark is still young and tender it is eagerly 

 devoured as nourishment by several species of mice; the joints 

 that suffer most are Beech, Hornbeam, Oak, and Ash, and in 

 a less degree the conifers, the Silver Fir indeed only exception- 

 ally, then lastly Acacia and Sweet Chestnut. But in this 



