AMINO ACIDS 1 1 5 



the right is the higher molecular weight. From the standpoint of 

 systematics the legume data appear to be more interesting. Two 

 major globuHn components, vicilin and legumin (mol. wts. 186,000 

 and 331,000, respectively), are of widespread occurrence and two 

 others were detected in certain species of Leguminosae. 



Some of the curves obtained by Danielsson have been repro- 

 duced to illustrate the nature of the information in these tests. In the 

 figure of Vicia faba (Fig. 6-4, lower left) two peaks are distinct. The 

 peak at left represents vicilin, that at the right legumin. In contrast 

 most species oi Acacia show legumin either weakly or not at all. With 

 the possible exception of Trifolium repens, Acacia is the only genus 

 showing so little legumin. 



In general, the curves of related species tend to show similar 

 relative proportions of vicilin and legumin in their seeds. In the closely 

 related genera Lathyrus and Vicia legumin always predominated, 

 while in the less closely related Phaseolus, vicilin predominated. The 

 distributions of the minor components seem not to be amenable to 

 any systematic interpretation. 



While this work is of interest, it is doubtful whether, in its 

 present form, a large diversity of critical data may be acquired. 

 Although the patterns definitely seem to bear resemblance at the 

 generic level, they are not likely to succeed in clarifying taxonomic 

 points in question or solving problems of phylogeny. Gerritsen (1956), 

 however, has obtained amino acid analyses of five highly purified seed 

 globulins of lupines, three globulins from Lupinus angustifolius, and 

 two from L. luteus. The highest molecular weight protein of each 

 species appeared to be identical; the next in size showed similarities 

 but also definite differences. The smallest (mol. wt. ca. 25,000) had no 

 counterpart in L. luteus. This type of investigation would seem to 

 offer much promise particularly at the intrageneric level. 



Blagoveshchenskii (1960), who also studied the seed proteins 

 of various legumes, inferred from his results that in the "primitive" 

 species alkali-soluble proteins predominated while the contents of 

 albuminus and vicilin were low. In more "advanced" species vicilin 

 predominated over legumin, and the content of alkali-soluble proteins 

 was low. His illustrations were not very clear, however, and are there- 

 fore difficult to evaluate. 



Sibley (1960) has utihzed electrophoretic patterns of egg- 

 white proteins in an extensive study of over 650 avian species. He has 

 assumed that the electrophoretic patterns are representative, in part, 

 of the genie complement of the species. It is indeed notable that 

 serologically related substances are found in the embryonic and adult 

 blood sera. The curves obtained from the egg-white proteins of 



