INSTEAD of attacking a definite problem and completing it before starting another, the author has chosen to begin work by making a literature survey of the whole field, followed by experimental work on the fundamental structure of cellulose. This program has given a better perspective of the whole field of the x-ray analysis of textile fibres as a background for future work, and at the same time has suggested many interesting problems. Several investigations are now in progress with the intention of later concentrating on the more promising ones.The experimental work to date has been of a preliminary nature. None of the work has progressed to the extent that final conclusions may be drawn. However, this report includes in some detail the nature of the investigations, the results obtained and the program for future work.