According to Emerson, "Three species are found in Massachusetts : "1st. The Hemlock has small, pointed, pendulous, terminal cones, and thin, flat leaves.

"2d. The Black Spruce has dependent, egg-shaped cones, with scales waved and jagged at the edge.

"3d. The White Spruce has longer cones, also dependent and spindle-shaped, with scales smooth and entire at the edge.

"Both have four-angled, awl-shaped leaves."

The Norway Spruce, now becoming well known as a hardy ornamental evergreen, is finer than either the Black or White Spruce, and is distinguished from them by its much longer cylindrical cones, thick foliage, and drooping branches.

Abies Canadensis. - The Hemlock. - This elegant tree, for some reason, has not been introduced into our pleasure-grounds to any great extent; for what reason, we know not. We have seen it, in great magnificence, in the grounds of Mr. J. S. C. Green, of Waltham, grown upon a lawn, singly, and intermingled with other trees. We remarked to the gardener, that these were the finest specimens we had ever seen, except in its native haunts, and said that it was supposed to be an exceedingly difficult tree to transplant. He replied, this was not the case,

- that it was no more uncertain with this than with other evergreens; and pointed to a tree, thirty or forty feet high clothed with branches to the ground, which, he said, he transplanted from another part of the ground to where it now stood but a few years since, it being then six inches in diameter. It was taken up so carefully that the growth was hardly checked. The great trouble with this, as with all evergreens when taken from the woods, is, that it is difficult to save all the roots. They are then often exposed to the sun and air, which, to an evergreen, is more hazardous to its prosperity, than it would be to a deciduous tree. The change of soil and location, to the tree, with only a portion of its roots, which, with the exposure, and, perhaps, too deep planting, proves to be death to the tree. For this reason, trees grown in a nursery are more sure to live than those taken from the forests; having been transplanted into rows and root-pruned, their roots are in small compass, and, as they are generally taken up with a ball of earth, they are almost sure to live. We hope to see the Hemlock more extensively cultivated in our nurseries.

"The Hemlock Spruce, or Hemlock, as, throughout New England, it is universally called, is the most beautiful tree of the family. It is distinguished from all the other Pines by the softness and delicacy of its tufted foliage; from the Spruce, by its slender, tapering branches, and the smoothness of its limbs; and from the Balsam Fir, by its small terminal cones, by the irregularity of its branches, and the gracefulness of its whole appearance.

"The young trees, by their numerous irregular branches, clothed with foliage of a delicate green, form a rich mass of verdure; and when, in the beginning of summer, each twig is terminated with a tuft of yellowish-green recent leaves, surmounting the darker-green of the former year, the effect, as an object of beauty, is equalled by very few flowering shrubs, and far surpasses that produced by any other tree.

" The Hemlock is said, by Pursh, to extend to the most northern regions in Canada, and was found by Mr. Menzies in Northwest America. It is found in every part of this State, on almost every variety of soil. It flourishes in the ruins of granitic rocks, on the sides of hills exposed to the violence of storms. As it bears pruning to almost any degree, without suffering injury, it is well fitted to form screens for the protection of more tender trees and plants, or for concealing disagreeable objects. By being planted in double or triple rows, it may, in a few years, be made to assume the appearance of an impenetrable evergreen-wall, - really impenetrable to the wind and to domestic animals. A hedge of this kind, seven or eight feet high, on a bleak, barren plain, exposed to the north-west winds, gave Dr. Greene, of Mansfield, a warm, sunny, sheltered spot for the cultivation of delicate annual plants. When I saw it, the annuals, several of which were rare exotics, were beautiful, but the Hemlock screen much more so." - (Emerson.)

The Hemlock is of slow growth till it gets well established; it then makes rapid progress, and finally becomes a large tree. The Hemlock should never be planted without some other tree to nurse or protect it. If designed for a single tree for the lawn, or in any other exposed situation, others of its kind should be planted to shade and shelter it, which may be taken away as soon as the tree becomes well rooted.