February, 1912.] 



119 



Timbers. 



experience of the Free Labour districts 

 will argue that a cooly is benefited 

 physically or morally by a system which 

 gives him incomparable facilities for 

 idling and indulging in riotous debauch. 

 The heavy drinking, which has become 

 such an evil in the Dooars of late years 

 and which is responsible for the witch- 

 craft cases often resulting in serious 

 bloodshed, if not murder, is directly 

 attributable to the ease with which 

 money is come by in that district. The 

 argument that liquor is the saving of 

 the situation, inasmuch as its consumpt- 



ion compels the cooly to spend money 

 which he might otherwise save, thus 

 enabing him to be more independent 

 than ever, is neither worthy of the 

 traditions as regards labour upon which 

 our industry has been built, the trust 

 which we hold from Government, nor of 

 the principles of the British race, if a 

 remedy is to be found for the deteriora- 

 tion of the working capacity of the 

 cooly it must be one that is clean and 

 wholesome, one that can face the light 

 of day and have for its furtherance the 

 support of public opinion. 



TIMBERS. 



LIGHT AND THE GROWTH OF 

 TREES. 



(From the Agricultural Neivs, Vol. X., 

 No. 244, September 2, 1911.) 

 Trees, like all other green plants, re- 

 quire light in order that they may pro- 

 duce material for the new growth with- 

 out which they cannot remain alive. 

 This makes it evident that, where a 

 large number of trees are existing to- 

 gether, the extent to which their require- 

 ments are satisfied in the matter of light 

 determines the number that are stand- 

 ing on a unit of area as well as the 

 manner of growth in those which con- 

 tinue to live. The importance of the 

 proper supply of light to trees has been 

 recognized first, in an organised, prac- 

 tical manner, in forestry, and it will be 

 well to give short attention to a recent 

 publication which presents particulars 

 of the latest considerations and results 

 belonging to the subject. 



In this Bulletin, reference is first 

 made to the ways in which plants are 

 affected by light. They are influenced 

 by this in the building up of food mate- 

 rials, and it is also responsible for the 

 structure, form and colour of the leaves, 

 and the form of the stem and of the 

 crown of the tree. In collections of 

 trees, as in forests, the growth in height, 

 the rate of thinning out and of natural 

 pruning, the character of the smaller 

 plants growing under the trees, and the 

 vigour of the younger trees, are all 

 matters that are determined by the sup- 

 ply of light. It is the recognition of 

 this fact that has stimulated enquiry 

 into the subject, in order that those 

 responsible for forest work may be in 

 possession of accurate information con- 

 cerning the light required by trees, 

 when growing together. 



It must be remembered that plants 

 are subjected to two kinds of light — 

 direct and diffused, and that the propor- 

 tion of the former is increased as the 

 equator is approached, while they both 

 decrease in amount with increase of 

 latitude. Height above sea-level also 

 affects the ratio of these two kinds of 

 light : the greater the attitude the less 

 is the amount of diffused light, and the 

 larger the quantity of that which is 

 direct. As far as a plant in any given 

 position is concerned, this is illumi- 

 nated by light which reaches it in 

 different ways, the kinds being over- 

 head light, which is the strongest, side 

 light, light reflected from surrounding 

 surfaces, and that reflected from the 

 ground. The first of these influences 

 the arrangement of the leaves on the 

 branches, their position, and the manner 

 in which the branches are developed. 

 The side light stimulates the growth of 

 the buds that are borne on lateral 

 branches; its effect is of ten seen in the 

 development of the branches on the 

 side of an opening in a wood or forest. 

 A.11 these must be considered in relation 

 to the illumination of any individual 

 plant, and attention must be given to 

 the fact, as well, that trees rarely receive 

 the total daylight, for this is lessened 

 in amount by the shading caused by the 

 foliage of the plant itself and by 

 neighbouring trees. 



In dealing with the behaviour of diff- 

 erent kinds of trees, under varying con- 

 ditions, regard is had to their tolerance 

 of shade or as it is often termed merely, 

 their tolerance. Trees which endure 

 shade well are said to be tolerant, while 

 those needing full light are termed in- 

 tolerant. Most trees, even in the tropics, 

 will thrive in full light, particularly if 

 they have grown under this condition 

 from the time of planting out. Diff- 



