STAG-HEADEDNESS. 



681 



aspects, and the more superficial the soil, and the more 

 porous the subjacent rock, such as chalk or coarse gravel, and 

 the less the rainfall and relative humidity of the air in the 

 locaHty. 



(c) Any interruption of the leaf-canopy in forests of all 



" Scots j.iue, AVindsor Forest. 



kinds may cause deterioration of the soil and consequent 

 stag-headedness. 



((/) Drainage also, by lowering the level of water in the 

 soil of a forest, may deprive formerly thriving trees of suffi- 

 cient moisture, which their roots, adapted to reach water 

 near the surface, can no longer absorb in sufficient quantity. 

 Trees thus affected may become stag-headed. This happened 

 on a large scale with oaks growing in the Wild Park at 

 Carlsruhe, owing to the rectification of the course of the 



