Bayliss, Leonard Ernest

(b. London, England, 15 November 1900; d. London, 20 August 1964)

physiology.

The youngest son of Sir William Maddock Bayliss and Gertrude Starling Bayliss, sister of the physiologist Ernest H. Starling, Bayliss grew up near Hampstead Heath, on the northern fringe of London. His parents entertained generously and attracted many overseas physiologists to meet their British colleagues in an atmosphere of tennis, good fellowship, and unending, searching arguments about the fundamentals of physical, biological, and medical sciences. Here his father had his private laboratory and workshop although, like Starling, he was also a professor in the physiological laboratory of University College, London. In such a home Bayliss developed his “do-it-yourself” attitude toward apparatus and his capacity for exacting and informed analysis of scientific problems.

After graduating from University College School, a day school for boys fairly near his home, Bayliss entered Trinity College, Cambridge, and graduated in physiology in 1922. He stayed on in the physiology department as Michael Foster Student and in 1925 received the Ph.D. with the thesis “Tone in Plain Muscle.” From 1926 to 1929 he was Sharpey Scholar at University College, and in 1928–1929 he worked under A. N. Richards at the University of Pennsylvania on a Rockefeller Fellowship; he returned in 1929 to University College, where he was awarded the Schäfer Prize (given for original work by a young physiologist associated with University College). In 1933 Bayliss was appointed physiologist at the Marine Biological Station, Plymouth, and the following year he became lecturer in physiology at the University of Edinburgh, from which he “retired” in 1939, hoping to be free to prepare a revised version of his father’s famous book Principles of General Physiology, the last edition of which had appeared in 1924, soon after his father’s death. Bayliss returned to University College as honorary part-time research assistant in the same year.

Bombing and fire interrupted Bayliss’ work in physiology in 1940, and he joined a group of pioneering scientists in the Army Operational Research Group, where he was later put in charge of research on antiaircraft gunnery and accuracy of fire against aircraft at various heights and against guided missiles.

Bayliss returned to physiology and to battered University College as full-time reader from 1945 to 1950. He resigned in 1950 in order to concentrate on rewriting Principles of General Physiology but retained his room near the Medical Sciences Library at the college. His accessibility to students and colleagues continued, and he pursued his research and writing with the title of honorary research associate. He also made an important contribution to advanced teaching of physiology. By 1960 he had completed his project, entirely rewriting the Principles and expanding it to two volumes.

His bibliography reveals Bayliss’ wide interests in physical approaches to physiology and in relevant instrumentation, but he was a reluctant and unambitious publisher; much work never reached the journals at all or did so only in the papers of friends. A great deal of his time was always given to helping others, and he was sought after as perhaps the most learned, ingenious, and cooperative of English physiologists. His early papers on the pH of blood (1923, 1926) were written when the newly developed glass electrode, still of very high resistance, was connected to a delicate electrometer—quite a challenge even to skilled experimenters in the sulfurous atmospheres of towns. While at University College he also worked with Starling on the metabolism of dog heart-lung preparations; devised pump-oxygenator perfusion techniques for kidneys; and studied serotonins in defibrinated blood, water diuresis, and glomerular permeability in both cold-blooded and warm-blooded animals. His interest in invertebrates, as shown in a 1930 paper, was strengthened at the Plymouth Marine Biological Station.

The rheology of blood was a major but intermittent interest during Bayliss’ later years. It began about 1930 with Fahraeus’ papers showing that the viscosity of blood, relative to water in the same tube, diminished as the diameter diminished, down to 0.03 millimeters, at which point cells blocked the tube. Bayliss had been making and using micropipettes, and had encountered the problem of cell clumping in his blood perfusion experiments with pumps and tubes. He extended the range of tube diameters down as far as that of arterioles and found the apparent viscosity nearly halved. This finding was published as a “personal communication” by colleagues (1933) and again in the second edition of Human Physiology (1936). Bayliss’ first definitive paper on blood viscosity did not appear until 1952, and many experimental findings have remained unpublished.

In 1939 Bayliss married M. Grace Palmer Eggleton, a physiologist at University College, whom he had known since about 1930. They took an apartment at the top of a tall old building near the college and, except for the early war years, lived there happily and frugally until his death. Also in the year of their marriage they bought a weekend cottage, isolated in the East Sussex countryside, and Bayliss spent much energy and ingenuity in improving and enlarging both house and garden, in anticipation of their retirement in 1966. He was physically active and enjoyed good health. Among his avocations were mountain climbing and playing the piano. He was quietly courteous to students and friends but unyielding in essentials.

Bayliss was a fellow of the Royal Society of Edinburgh and a member of the Physiological Society, the Society for Experimental Biology, and the Marine Biological Association.

BIBLIOGRAPHY

Bayliss’ earliest book was Human Physiology (London, 1930; 3rd ed., 1948; 5th ed., 1962), written with F. R. Winton. His major work was the complete revision and rewriting of his father’s Principles of General Physiology, 2 vols. (London, 1959–1960). His Living Control Systems, appeared in the New Science Series (London, 1966).

His papers are “A Comparison Between the Colorimetric and the Electrometric Methods of Determining the Hydrogen Ion Concentration of Blood,” in Journal of Physiology, 58 (1923). 101–107, written with Ruth Conway-Verney; “Reversible Haemolysis.” ibid., 59 (1924), 48–60; “The Determination of the Hydrogen-ion Concentration of the Blood,” ibid., 61 (1926), 448–454, written with Phyllis Tookey Kerridge and Ruth Conway-Verney; “A Conductivity Method for the Determination of Carbon Dioxide,” in Biochemical Journal, 21 (1927), 662–664; “The Action of Insulin and Sugar on the Respiratory Quotient and Metabolism of the Heart-lung Preparation,” in Journal of Physiology, 65 (1928), 33–47, written with E. A. Müller and E. H. Starling; “The Energetics of Plain Muscle,” ibid., i–ii; “A Method of Oxygenating Blood,” ibid., 66 (1928), 443–448, written with A. R. Fee and E. Ogden; “A Simple High-speed Rotary Pump,” in Journal of Scientific Instruments, 5 (1928), 278–279, written with E. A. Müller; “The Adductor Mechanism of Pecten,” in Proceedings of the Royal Society, 106B (1930), 363–376, written with E. Boyland and A. D. Ritchie; “A Combined Flow Recorder and Pump Control,” in Journal of Physiology, 69 (1930), v, written with A. R. Fee; “The Electrical Conductivity of Glomerular Urine From the Frog and From Necturus,” in Journal of’ Bilological Chemistry. 87 (1930), 523–540; “Studies in Water Diuresis. Part III. A Comparison of the Excretion of Urine by innervated and Denervated Kidneys Perfused With the Heart-lung Preparation,” in Journal of Physiology, 69 (1930), 135–143, written with A. R. Fee; “Studies in Water Diuresis. Part IV. The Changes in the Concentration of Electrolytes and Colloids in the Plasma of Decerebrate Dogs Produced by the Ingestion of Water,” ibid., 70 (1930), 60–66, written with A. R. Fee; “The Action of Cyanide on the Isolated Mammalian Kidney,” ibid., 74 (1932), 279–293, written with E. Lundsgaard; “Fourteenth International Physiological Congress,” in Nature, 130 (1932), 705–707, written with P. Eggleton; “The Excretion of Protein by the Mammalian Kidney,” in Journal of physiology, 77 (1933), 386–398, written with Phyllis Tookey Kerridge and Dorothy S. Russell; ’Vaso-tonins’ and the Pump-oxygenator-kidney Preparation.” ibid., 34P–35P, written with E. Ogden; “The Action Potentials in Maia Nerve Before and After Poisoning With Veratrine and Yohimbine Hydrochlorides,” ibid., 83 (1935), 439–454, written with S. L. Cowan and D. Scott, Jr.; “Digestion in the Plaice (Pleuronectes platessa),” in Journal of the Marine Bilological Association of the United Kingdom, 20 (1935), 73–91; “A Drop Recorder for A.C. Mains,” in Journal of physiology, 84 (1935), 57P; “A Stimulation Unit for A. C. Mains,” ibid., 58P–59P, written with P. Eggleton; “Recent Developments in Physical Instruments for Biological Purposes,” in Journal of Scientific Instruments, 12 (1935), 1–5, written with Phyllis Tookey Kerridge; “Some New Forms of Visual Purple Found in Sea Fishes With a Note on the Visual Cells of Origin,” in Proceedings of the Royal Society120B (1936), 95–113. written with R. J. Lythgoe and Katharine Tansley; “The Photographic Method for Recording Average Illuminations,” in Journal of the Marine Biological Association of the United Kingdom, 23 (1938), 99–118; “The Visco-elastic Properties of the Lungs,” in Quarterly Journal of Experimental Physiology, 29 (1939), 27–47, written with G. W. Robertson; “A Circulation Model,” in Journal of Physiology, 97 (1940), 429–432; “The Part Played by the Renal Nerves in the Production of Water Diuresis in the Hypophysectomized and Decerebrate Dog,” ibid., 98 (1940), 190–2065, written with A. Brown; “Schack, August Steenberg Krogh,” in Yearbook of the Royal Society of Edinburgh (1948–1949); “Rheology of Blood and Lymph,” in A. Frey-Wyssling, ed., Deformation and Flow in Biological Systems (Amsterdam. 1952). pp. 355–418; “A Mechanical Model of the Heart,” in Journal of Physiology, 127 (1955), 358–379; “The Use of a Roller Pump for Long-continued, Infusion,” ibid., 128 (1955), 29P–30P; “The Process of Secretion,” in F. R. Winton, ed., Modern Views on the Secretion of Urine: The Cushnv Memorial Lectures (London, 1956), pp. 96–127; “The ’Brown Dog’ Affair,” in Potential: Journal of the Physiological Society of University College London. no. 2 (1957), 11–22; “The Axial Drift of the Red Cells When Blood Flows in a Narrow Tube,” in Journal of physiology. 149 (1959), 593–613; “The Anomalous Viscosity of Blood.” in A. L. Copley and G. Stainsby, eds., Flow Properties of Blood and Other Biological Systems (Oxford, 1960), pp. 29–62; “William Maddock Bayliss, 1860–1924: Life and Scientific Work,” in Perspectives in Biology and Medicine, 4 (1961), 460–479; “The Rheology of Blood,” in Handbook of Physiology, sec. 2. W. F. Hamilton, ed., I (Washington. D.C., 1962), 137–150; “Some Factors Concerned in Temperature Regulation in Man,” in Journal of Physiology, 172 (1964), 8P–9P, written with S. E. Dicker and M. Grace Eggleton; and “The Flow of Suspensions of Red Blood Cells in Capillary Tubes. Changes in the ‘Cell-free’ Marginal Sheath With Changes in the Shearing Stress,” ibid., 179 (1965), 1–25.

F. R. Winton