2l6
MISCELLANEA
some of the falling soil will lodge on the wire, partially burying and weighting down the poles, which will consequently strike root and grow. The wire will serve to hold the mass of willows together until they have become firmly rooted. The ends of the woven wire should be made fast to wire cables running back over the bank some distance, and fastened to posts set firmly in the ground. The caving and erosion of the bank will soon round off its top corners, and the growing willows at the water’s edge will catch the soil as it rolls down the declivity, causing a bank to form of just the right slope to resist erosion most effectually.”
   Reclamation of River Sand and Shingle.—On the Continent of Europe the practice of recent years has tended to demonstrate the high value of the White Alder (Alnus incana) as a pioneer on all sorts of inhospitable and mobile soils. These include unstable mountain slopes, talus, river banks, and especially wastes of sand and shingle that cumber the beds of rivers liable to floods. Thus, on the River Ticino below Bellinzona, the Swiss have employed the White Alder with excellent results on the shifting shingly stretches of ground that border the actual channels.1
   The method followed is to plant alder seedlings in their second year in double rows in shallow trenches running parallel to one another, and at right angles to the direction of stream flow. From these plantings parallel alder hedges, 6 to 9 feet apart, quickly arise, and acting as groynes they stabilize the ground and collect silt whereby the surface is appreciably raised. The roots spread into the spaces between the hedges, and in time the whole area is covered with a thicket of alders. A great merit of this plant is its habit of producing nitrogen-fixing tubercles on its roots, whereby the nutritive value of the soil is much increased. This type of planting requires about 5000 seedlings to the acre.
   As the White Alder is quite hardy in Britain, and grows with great rapidity, it evidently deserves a full trial in connection with protective and reclamation work in this country.
   In South Africa in the district of Oudtshoorn, in the Little
1 See F. Aubert, Schiueixerische Zcitschrift fiir Forstwesen, 1914, p. 207.