The discovery of the first systemic or hormone herbicides, 2,4-D, 2,4,5-T, and MCPA, initiated an agricultural revolution and modern weed science. The finding of these herbicides was a striking case of multiple independent discovery by four groups of workers in two countries, the United Kingdom and the United States: William G. Templeman and associates at Imperial Chemical Industries; Philip S. Nutman and associates at the Rothamsted Agricultural Experiment Station; Franklin D. Jones at the American Chemical Paint Company; and Ezra Kraus, John Mitchell, and associates at the University of Chicago and the U.S. Department of Agriculture. Because of wartime and commercial secrecy, the usual procedures of scientific publication and patent disclosure were not followed; instead, the first scientific report on these herbicides occurred in a publication by workers who were not original discoverers. Considerable confusion consequently resulted concerning the discovery and the discoverers. This confusion has not been completely dispelled in subsequent years. The present report summarizes the complete story, clarifies the chronology of the discoverers and their publications, and makes the case that all four groups of workers deserve credit for this revolutionary advance. The scientific background of the discovery and events in its immediate aftermath, especially the ticklish patent situation, are also briefly chronicled.

Recent studies of anthocyanin formation have involved the use of a varied assortment of plant systems: seedlings, leaves, fruits, petals, callus cultures, and Lemnaceous flowering plants (2,9). Each of these kinds of material possesses certain advantages and certain disadvantages. In the dark-grown buckwheat seedling anthocyanin synthesis can be induced in the hypocotyl by exposure of that organ to light (6, 8); this formation of pigment is not accompanied by photosynthesis, since the hypocotyl does not contain chlorophyll. However, under many conditions which might be used in a study of anthocyanin formation, growth of the seedling, especially of the hypocotyl itself, would be a complicating factor. Furthermore, the hypocotyl is not homogeneous from top to bottom in its anthocyanin-forming capacity (1, 6).These disadvantages might be overcome by removing the hypocotyl from the seedling before its experimental use. Accordingly, an investigation of anthocyanin formation in excised hypocotyls and hypocotyl segments was undertaken in order to ascertain the suitability of such a system. Materials and MethodsCulture of Seedlings. Achenes of Japanese buckwheat (Fagopyrum sagittatum Gilib.) were soaked for 20 minutes in a 2 % sodium hypochlorite solution, rinsed thoroughly with distilled water, and placed on wet filter paper for germination. The filter paper was laid across 2 plastic dishes (10 X 10 X 1 cm) which floated on 2 cm of water in a glass tray (15 X 25 X 4 cm). The tray was covered with another like it and placed in a controlled-temperature cabinet, where germination and growth of the seedlings took place in constant darkness at 200.Preparation of Hypocotyl Material. Only hypocotyl material was analyzed for anthocyanin content. Sometimes entire hypocotyls were taken, but in most cases segments 20 or 25 mm long were cut from the region just below the unopened hook. This procedure was followed to eliminate variation which might be introduced by inclusion of any part of the hook, since

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The case of diffusion of a gas from a single circular stoma through an unstirred boundary layer of finite thickness into a perfectly stirred atmosphere free of convective effects is examined theoretically, with the gas assumed to be at constant concentration across the stoma. The analysis employs a mathematical solution to an analogous problem in electrostatic physics previously obtained by Kuz'min (1972 Sov Phys Tech Phys 17: 473-476). The diffusion flux is shown to be no more than 1% greater than that into a perfectly unstirred atmosphere if the boundary layer is thicker than 40 times the stomatal radius. Under the conditions assumed, for realistic boundary-layer and stomatal dimensions, taking the diffusion flux through the boundary layer to be Unear with the stomatal radius would usually involve no significant error. This result may indicate that the principal effect of wind velocity on mass exchange between leaf and atmosphere may be exerted through influencing convection outside the boundary layer rather than through determining the thickness of that layer.Contemporary models of water transport in plants are usually formulated in terms of various pathway resistances, that is, the modeling approach is usually based on circuit theory. But circuit theory, although extremely useful, treats three-dimensional phenomena with one-dimensional approximations which may be inadequate in some cases, especially when the inclusion of circuit elements with different characteristics introduces mathematical discontinuities (3, 11). (Note, however, that the classical circuittheoretical approach of Brown and Escombe [2] has recently been justified by Kelman [7] and Parlange and Waggoner [15].)Much of modem physical science, on the other hand, is rooted in the powerful principles of field theory, which treats generally of fluxes in two or three dimensions (11,12,22). In addition to retaining the higher dimensionality, field theory is appropriate to a wide range of applications-electrostatics, electrodynamics, magnetostatics, fluid flow, heat conduction, and diffusion, to name a few. Since the treatments of all these phenomena involve the definition of scalar potential functions, the mathematical developments used in field-theoretical approaches are similar. This mathematical similarity and the wide applicability have the extremely important consequence that analogies can be deduced and solutions transferred from one area of application to another. In other words, ifa problem is solved in one area, analogous problems are thereby solved in the other areas to which field theory applies. Cooke (3) has pointed out the relevance of these concepts to the case of stomatal diffusion.The gas diffusion problem is analogous, for example, to the problem of the electrostatic field of a conductor. Thus (22), when e is the dielectric constant, P is the electrostatic potential, D is the diffusion coefficient, and C is the concentration or chemical potential of the diffusing gas, the associated field vector for the electrostatic fi...

The morphology of the hypothalamo-hypophyseal tract of 35 hibernating bats (Myotis lucifugus lucifugus ) was studied in chrome-alum-hematoxylinphloxine-stained serial coronal and sagittal sections. Vinyl acetate and wax-plate reconstructions also aided in describing the two neurosecretory hypothalamic nuclei of this system. The most prominently defined nucleus, the supraoptic, consisted of a smaller portion rostra1 to the optic tract that was tenuously connected to a larger caudal portion. The probability that some of the posteriorly located cells of the caudal portion represent other hypothalamic nuclei is discussed. The shape and location of the paraventricular nucleus was more difficult to determine. Although the neurosecretory cells of this nucleus were similar in their irregular or eliptical shape to those of the supraoptic nucleus, the majority of the paraventricular cells were smaller and had less of an affinity for the chrome-alum-hematoxylin stain.The majority of CHP-positive axons originating in the supraoptic nucleus converged toward the median eminence and terminated in the pars nervosa. Most of the axons from the paraventricular nucleus coursed laterally toward the supraoptic nucleus where they followed the pathway described from this nucleus. The localization of CHP-positive material in the neurohypophysis is presented. Comparisons were made between the morphology of this system in the hibernating bat and that of other species of mammals reported in the literature.Many studies have been made concerning the location of "neurosecretory material" in the hypothalamo-hypophyseal system of various species of animals. These have been ably reviewed by Scharrer and Scharrer ('45), Bargmann and Scharrer ('51 ), Zuckerman ('54) and Bargmann ('60). Since Bargmann ('49) observed that this substance can be demonstrated by Gomori's chrome -alum -hematoxylin stain, several investigators have indicated that this neurosecretory material may be identifiable as the hormones vasopressin and oxytocin of the pars nervosa (Sloper, '55), or is possibly an inactive protein (neurophysin) that appears to be bound to these hormones (Acher, '58).In light of this evidence it seemed pertinent to study neurosecretory material in an animal that exhibited marked normal changes in metabolism during its annual cycle and, also, may have varying demands for water conservation. A hibernating mammal, the little brown bat (Myotis lucifugus Zucifugus), was selected for this study in as much as it demonstrates ANAT. REC., 151: 77-92. extremes in its metabolic rate throughout the year (Hock, '49; Troyer, '59), hibernates in sites where water is readily available, and will arouse from its lethargic state to drink water during hibernation. Since there was a paucity of information regarding the topography of the hypothalamus of the selected bat, it was felt that the extent and localization of the hypothalamohypophyseal system could be best elucidated by study of serial sections and reconstruction of this portion of the hypothalamus. MATER...

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