In writing the following chapters I have kept in mind the exemplary ‘Introductory Essay’ of J. D. HOOKER in his ‘Flora Indica’ (1855), the precursor of the ‘Flora of British India’. For the same reasons that moved HOOKER, I felt obliged to introduce the Flora Malesiana proper by some general considerations especially intended for co-operators less fortunate than I have been in acquiring an experience of long standing in the field. I may add that field experience often is invaluable when studying dried, always fragmentary, materials in the Herbarium.