The substances mentioned often injure the cambium layer to such an extent that the healing of wounds is greatly retarded.  Of the substances experimented with, white lead proved to be the best and is recommended wherever anything is used.  But it is not thought worth while to use even white lead for wounds two or three inches or less in diameter, though it may be advisable to use it on wounds where very large branches have been removed.

On the larger wounds, where much surface is exposed to decay, the white lead will help to keep out moisture and the organisms which cause decay.  The smaller wounds, however, heal so quickly that the evil effects of the covering may more than offset the benefits derived from its use.—­R.A.  McGinty, Colorado Agricultural College, Fort Collins, Colorado.

Annual Report, 1915, Montevideo Trial Station.

LYCURGUS R. MOYER, SUPT.

About twenty-six years ago a plantation of white spruce was made at this station.  The trees flourished for several years and bade fair to become a permanent success, but some six or eight years ago they began to fail and many of them have since died.  The survivors are all in poor condition.  It seems that this tree is not well adapted to prairie conditions, at least not to the prairies of Southwestern Minnesota.  Its native range is much further north.  Here it evidently suffers from heat and dryness.  The Black Hills spruce is commonly regarded as belonging to the same species.  It has not been tested nearly so long, but so far it seems to be entirely hardy.

Something like thirty years ago a few trees of black spruce, a few trees of European larch and a few trees of balsam fir were planted here.  They have long since disappeared.  White pine planted at about the same time disappeared with them.  A single tree of Scotch pine planted at about the same time, standing in the open, is gnarled and crooked and shows a great many dead branches.  A forest plantation of several thousand Scotch pine, made something like twenty-two years ago, is still in good condition.  Many of the trees are from twenty-five to thirty feet high.  Some of the smaller trees have been over-topped and smothered out, but generally the trees seem healthy.  A few hundred of the black, or Austrian, pine were set at the same time.  They are about two-thirds of the height of the Scotch pine, but they are as healthy and vigorous trees as one would care to see.  Some trees of rock, or bull, pine (Pinus scopulorum) were set at the same time.  They have grown at about the same rate as the black pine and are healthy, vigorous trees.

Norway spruce has done better here than white spruce, some old trees fruiting freely.  The Colorado blue spruce (Picea pungens) seems to be our best spruce, and so far as tested the Black Hills spruce is a good second.  Douglas fir has been planted in a small way in the parks, but it is young yet.