The studies reported in this thesis fall into three parts: Part 1. Introductory review of the analytical methods currently available for analytical and structural studies of polysaccharides, together v/ith a brief review of the present state of knowledge of gum exudates of the Acacia family. Part 2. Comparative Analytical Studies. Comparative analytical studies were carried out on;- (a) sixteen samples of A.Senegal gum differing in origin. Only slight differences in the overall composition and physical properties of both the crude and purified gum were observed. (b) seven different, previously unstudied, species of Acacia gum. Marked variations in both composition and properties were observed from species to species, which were studied in both the crude and purified forms. (c) ten specimens of the gum from A.nilotica were analysed to assess the extent to which inter-nodule variation occurred. Fractionation of this gum was attempted on DEAE-cellulose. One major fraction and several minor fractions were obtained; on preliminary analysis, the major fraction did not differ significantly from the 'parent' gum. Part 3. Structural Studies. Detailed structural studies were carried out on a typical sample of A.nilotica gum.