Chlorophyll ¹

Abstract

ALL who are accustomed to observe vegetation must have been struck with the great variety of shades of green which the foliage of different plants presents. Without pretending to generalise further, it may he stated that, at any rate so far as our common agricultural plants are concerned, they show somewhat characteristic shades of colour, according to the Natural Order to which they belong—the Leguminosæ differing from the Graminew, the Cruciferæ, the Chenopodiaceæ, and so on. But the same description of plant will exhibit very characteristic differences, not only at different stages of growth, but at the same stage in different conditions of luxuriance, as affected by the external conditions of soil, season, manuring, &c., but especially under the influence of different conditions as to manuring.