MIXED WOODS 153 



therefore more conspicuous than those of the oak. The pistillate 

 flowers occur in clusters of two or three together, the bracts 

 forming the bristly " cupule " which encloses the fruits. This 

 box splits into four pieces, which turn back, showing the three- 

 sided fruit, or " mast/' as it is called. At one time swine used 

 to be largely fed on these nuts, but at present they are left to 

 squirrels and other denizens of our woods. 



The hornbeam is sometimes mistaken for the beech, but is 

 easily distinguished from it by the bark, which has white ir- 

 regular lines, forming almost a lattice-work pattern against the 

 dark ground. The leaves are somewhat like those of the beech, 

 but broader at the base, hairy on the under-side and with 

 dentate margins. The cupule is leaf- 

 like, and may be an inch and a half 

 in length. 



In natural woodland there seems no 

 doubt that certain trees are associated 

 with certain soils ; the beech, for in- 

 stance, likes chalk ; the oak clay, or deep 

 sandy loam. It is a question, however, A B 



whether the fact of lime, or clay, or sand FIG. 44. A, staminate flower of 

 being present in the soil has as much Beech ; Cringed perianth. B, 



, .,, ,, c f , f Pistillate flower of Beech. 



to do with the preference of a tree for a 



certain soil as its capacity for retaining moisture. The oak is a 

 case in point. It thrives both on clayey marls and in deep 

 sandy loams ; now clay retains moisture, but sandy soils are 

 porous. The oak likes only deep sandy soils, for in these its 

 roots penetrate as much as 5 feet, and obtain a regular supply of 

 water from the subsoil ; in fact, the oak is indifferent to lime, 

 and therefore grows well in deep moist marls which contain 

 lime, and also in sandy soil, provided it can get enough moisture 

 from the subsoil. Most trees like soil with plenty of humus, or 

 decaying organic matter ; this is largely supplied by the leaves 

 of the trees themselves. In woods, skeleton-leaves are often to 

 be picked up ; these are produced by the decay of the softer 

 tissues of the leaf. Probably insects first attacked the leaf, 

 riddling it with holes, then the work of minute fungi began, 

 until everything was destroyed except the harder parts of the 



