AMONG THE PINES AND FIRS 219 



the steam-plough, because this, like hard, binding 

 soil of any description, prevents the formation of 

 the pine's deep tap-root, affects its growth in 

 height and its general vigour, and predisposes it to 

 fungous disease. One of the most common forms 

 of the latter, which attacks young pine plantations 

 before they have succeeded in establishing them- 

 selves in the ground, is the 'leaf shedding' caused 

 by Hysterium pinastri. This has been uncommonly 

 prevalent in England during the last two or three 

 years of abnormal spring weather and summer 

 warmth. The weakly state predisposing to attacks 

 of this fungus is principally produced by drought, 

 though it can also arise from frost, as well as from 

 active transpiration through the needles on bright 

 sunny days in winter while the soil remains frost- 

 bound and unable to furnish the rootlets with 

 fresh supplies of water. But the reddening of 

 the needles and the death of the plants over 

 large areas often takes place from drought or 

 frost alone, without the fungus. Before forming 

 crops of pine, heather or similar soil covering 

 should be cut and burned for the advantage of 

 the young plants. 



Of spruces, the only two of any importance to 



