Interest in plant chemotaxonomy has greatly expanded in the last five years as attested to by the number of articles appearing in biological journals (cf. Alston, 1966; Turner, 1966, for reviews), the appearance of several books (Alston and Turner, 1963; Hegnauer, 1962-65; Leone, 1964; Swain, 1963) and the fact that many of the papers delivered at national systematic meeting, especially in the United States havu dealt with some aspects of this subject. With notably few exceptions most of the presentations have had to do with micromolecular approaches (i.e. working with small molecular weight compounds such as alkaloids, flavonoids, terpenes, etc.). Emphasis on the micromolecular has followed the development of chromatographic techniques which have made possible rapid and relatively easy surveys for such compounds. Indeed, many of the systematic papers have used mere spot-patterns or peaks (in the case of gas chromatography) to help resolve the problems at hand, a legitimate procedure if one assumes that molecular identity can be reasonable established by the techniques employed. Macromolecular data, with the important exception of serology, have been sparingly used in plant systematic investigations. The serological method utilizes injected rabbits (or other antibody producers) as an intermediary in the production of suitable test material. Because of this, and other problems inherent in the technique, most plant systematists have not attempted to undertake such studies. However, protein data may be obtained by techniques other than serological ones, since relatively easy electrophoretic techniques exist for their separation and detection. In fact, it is as easy to become familiar with the techniques for the acquisition of protein-band data as it is to perform paper chromatography for spot data. That protein-band data have a high potential for plant systematic purposes especially in hybridization studies, can be surmised from the interesting data of Johnson and Hall (1965) (also confirmed in this laboratory), in which complex allopolyploids could be detected through the analysis of the protein-bands found in hybrids and their putative parents. Numerous other examples could be drawn from the literature in systematic zoology (cf. Leone, 1964). Recently Vaughan et al. (1965), in comparing protein-bands obtained by serological techniques (gel immunoelectrophoresis) against those obtained by the relatively simple gel acrylamide techniques outlined below, came to the conclusion that the latter was at least equal to the former in the resolution of protein-bands (the same protein sources were used in both sets of experiments). Similarly, Turner, Boulter and Thurman (unpublished) have found a unique protein-band pattern for at least one species of Baptisia, where, using the same protein sources, no such differences could be detected by the serological techniques of Lester, Alston and Turner (1965). The systematic utility of protein data of the type outlined here is of small consequence when measured against the systematic implications to be expected from the knowledge of the sequential arrangements of the amino acids which comprise the proteins (Bryson and Vogel, 1965, for a recent symposium, especially the articles of Margoliash and Smith on cytochrome c), Unlocking this information with present techniques is time