The first account of Indian Timbers was published in 1831 by Dr. Aitken. His studies were confined to the Timbers of Assam. In 1881 J.S. Gamble published The Manual of Indian Timbers which comprised a brief survey of the various timbers of the different parts of India. A more complete and much more extensive edition of his work was published in 1920. Mr. R.S. Pearson and Dr. H.P. Brown, published a detailed account of the "Commercial Timbers of India" in 1932, During the past few years Dr. K.A. Chowdhury of Dehra Dun has made very extensive studies of numerous timbers, chiefly of N. India. The materials examined here are some of the lesser known timbers, particularly of Malabar (Travancore - Cochin State), They are mostly confined to the rain forest region and the adjoining plains. These trees nave not been studied in detail before. As yet no exhaustive or complete account of the timbers of S. India has been made, though some of the most important and well known commercial timbers have been described ay the persons mentioned above. The present work has been carried out with a view to describe the structure, to identify certain timbers, and to make an exhaustive and analytical study of the behaviour of the various wood elements of the dicotyledonous trees o the rain- forest area where growth is almost continuous throughout the year. The first part of the work comprises a detailed account of the anatomical structure of the various trees under investigation with a brief account of their external morphology, habit and habitat. The second part consists of a detailed account of the structural variations brought about in the various wood elements in the growth of the tree. No such work on Indian Timbers has been done before.