The editor of this magazine, stated in these columns some years ago that a dead branch on a tree makes almost as great a strain on the main plant for moisture as does a living one, and many of the practical directions in this magazine have been based on this fact. Some good people, not satisfied with the authority, called Prof. Bessey's attention to the statement, who thus replies in the New York Tribune :

" I have been asked whether the statement lately going the rounds of the American papers that ' a dead branch on a tree makes almost as great a strain on the main plant for moisture as does a living one ' is accurate or not The statement is coupled with another referring to its practical application in tree culture, the conclusion being that every dead branch ' should be at once cut away.' Briefly it might be answered that the first statement is true in the main, and that, without any doubt at all, the conclusion is a wise one, and ought to be followed in practice. To explain this matter will take considerably more space, and in order to understand it we must go to vegetable physiology and inquire into the nature of the evaporation of water from plants. It was long supposed to be a physiological process, and was considered to be entirely different from ordinary physical evaporation. As long as this view was held the process was called transpiration, to distinguish it from the physical process.

The breathing pores, the stomata, which occur in the epidermis of all leaves in great numbers, were supposed to be organs of transpiration, which was considered to be one of the most important functions of the leaf."