Reflections on Joseph Lister's Edinburgh experiments on vaso-motor control.

JosEPH LIsmR's research on the neural control of the calibre of smaller blood-vessels was informed by two important, though unrelated discoveries, which had been engaging his attention for some time before his first surgical appointment in Edinburgh.1 These were the discoveries of (1) plain muscle-fibre, which had been observed and minutely described by Albert K6lliker, and (2) syndromes in the facial parts of mammals which followed upon the section of the cervical extension of the sympathetic chain. Kolliker's microscopic observations during the late 1840s of the structure of plain muscular 'elements', had shown that these consisted not of 'long, uniformly wide bands, which were studded with several nuclei, but of comparatively short, separate fibres, each of which contained one nucleus'.2 He described these cells-for such, of course, they were, as conforming roughly to three kinds of shapes. Some were 'short, roundish, spindle or rectangular flakes (Plittchen)'; others were 'fairly long laminae having rectangular, spindle or club-like shapes with pointed or jagged ends'; and others were 'spindle-shaped, narrow, cylindrical fibres with straight or wavy, delicately extended ends'.3 Now during some microscopic observations-probably with a Power and Lealand instrument-made whilst he was still completing his medical training at University College Hospital, London, Lister saw that the sphincter tissue of the iris had the same structure as those plain muscle-cells described by Kolliker.4 Lister's publication of the paper describing this research was mainly in defence of Kolliker against the views of Bowman and Brodhurst, who had denied the conclusions of the German physiologist respecting the nature of such tissue., During the next three years, Lister published papers on related topics, two of which were on involuntary muscle-fibres and on the muscular tissue ofthe skin,6and another, superbly illustrated, on the cellular nature of involuntary muscle-fibre.7 Again, these papers were mainly in defence of Kolliker, the last being directed against the findings of Mazonn and Ellis. In preparing muscular tissue for microscopic examination, Mazonn had employed