216 MACROMOLECULAR COMPLEXES 



mannose and glucose present in a ratio of approximately 1:1 in the 

 fraction (termed glucomannan-protein I, or GMP-I) precipitated 

 by saturated ammonium sulfate, and approximately 2:1 in the frac- 

 tion (GMP-II) that remained in solution. The alkali-insoluble 

 residue proved to be a third polysaccharide-protein fraction, the 

 polysaccharide being composed very largely of glucose. This frac- 

 tion, termed glucan-protein, comprised approximatelv 40 per cent 

 of the weight of the wall material. 



Examination of Wall Components by Physical Methods. The 

 polysaccharide-protein fractions obtained in the manner just de- 

 scribed were examined by a variety of physical and chemical means 

 to ascertain their form, relative homogeneity, and composition. 

 Electron micrographs of GMP-I, evaporated from solution onto 

 Formvar membranes, are shown in Figs. 5, 6. The pronounced 

 globular appearance of aggregates of GMP-I can be seen to arise 

 from the clumping of much smaller spherical shapes that seem to 

 possess an electron-dense center. In Fig. 6, a "structure" that has 

 the size and shape of the inner portion of a bud scar is seen. This 

 "scar" portion is clearly distinct from the "bud scar" of the outer 



Fig. 7. Appearance of budding cells of bakers' yeast by aniline blue fluo- 

 rescence microscopy. Note localization of oriented dye molecules in toroidal 

 zone between bud and mother cell. (Courtesy, Currier, 1957.) 



