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 
