I then determined upon a more intensive study Of the chief farm plants with a view of writing a series Of botanical monographs upon them as opportunity permitted. Administrative duties and teaching have prevented me from carrying out the project as designed. Nevertheless, I have kept alive the intention, and the present monograph is an embodiment of researches made upon the wheat plant. I hope that it may serve in a modest way as a model of the research that is needed upon all farm plants, and act as a stimulus to further effort. The plants with which the farmer has to deal provide limitless fields Of exploration for the plant physiologist, anatomist, student of variation and heredity, and indeed all ranks of botanists. Their study will satisfy the most ardent aspirations of the academic mind in its pursuit Of so-called pure science, and the discoveries to be made cannot fail to be Of service in enabling the cultivator to Obtain higher economic returns from the soil on which all animal life ultimately depends. In Part I. Of the monograph are given the results of my investigations of the morphology, anatomy, growth, and development of the wheat plant. Except where otherwise indicated, the various measurements and illustrations refer to the ordinary dense-eared type of Bread wheat (t. Vulgare) commonly grown in Great Britain.