III—The Organization of the Cell Wall of the Conifer Tracheid

The fundamental nature of the results which have been obtained during recent years by the application of physical methods to botanical research has demonstrated conclusively the advantages to be gained by the botanist from a close collaboration with the physicist. Especially has it become evident that only by the use of modern physical methods may we hope to obtain a clear idea of the structure and arrangement of the constituent units of the cellulose which forms the main bulk of the walls of such a tissue as the wood of the conifer. The present paper represents an attempt to elucidate certain problems connected with the growth of a softwood tree, using methods similar to those of crystal physics. It has been written in the hope of being of some interest and value to both botanists and physicists. To this end the development from the bud of the woody tissues of the shoot has been cut down to its essentials, and is illustrated by diagrams designed to convey to the physicist a mental picture of the relevant processes of growth. For the benefit of the botanist, on the other hand, reference to the physical principles involved is omitted wherever possible, and such mathematical conceptions as occur are discussed in a correspondingly simple manner.