"For the tat of the field is man's life." This being a well authenticated fact, how faithfully man should care for, and tenderly foster the precious life of the tree. The bark is the life-guard of all exogenous plants. Unlike the endogens, the seat of life in all northern trees is located in the cambium layer next to the bark. In order to insure along lease of life in certain plants,nature has endowed them with a thick rough bark, a protection so unique and perfect in all its equipments that the tree stands, in some instances, firmly and majestically against all the vicissitudes of summer and winter, for over 2,000 years.

The bark differs widely in quality ; on some trees it is coarse and spongy, and half an inch in thickness, perhaps no more potent in repelling heat and cold than the bark of another tree with very fine texture and one-half its diameter, especially if this latter tree happens to have rough bark like the yellow birch. This scaly, rough exterior will modify the direct rays of the sun, and thus prevent "sun scald." In a climate where the extreme summer heat surpasses that of central equatorial Africa, as appears to be the case in the northwest, trees with a thick, or even rough bark, cannot be too highly prized. It is a simple fact, when one comes to fully understand it, that no plant, however hardy in its inherent woody cell structure, can long endure 1050 of heat, and 500 below zero, unharmed, unless properly clothed. We were so elated when we made the discovery that a tree with a good thick bark or one with a very rough bark, like the shellbark hickory or hackberry, would not "sun scald" in this climate of tropical heat, that we had to invent a new phrase expressly for such worthy plants - trees with persistent bark.

This study of tree bark has led us to one of the most important discoveries ever made for the pomology of the northwest, that among all the different species of the apple tested in this climate, nature has endowed but one with a rough exterior finish that just fits it for this climate of great extremes of heat and cold, and that is the pyrus coronaria or wild crab. - A. W. Sias. Minnesota.