MINOT 798 MINOT fessor Bowditch, for whom he had always the warmest friendship and the highest regard, he visited the physiological institute at Leip- zig; and under the direction of Carl Ludwig, who had been Bowditch's teacher, he studied the production of carbonic acid in resting and active muscle. After returning to America he conducted an extensive series of experiments on tetanus, published in 1878, and in that year he received from Harvard University the degree of Doctor of Science for his work on the physiology of muscular contraction. This marked the end of his strictly physiological studies. Although well trained in chemistry and initiated in physiology by Bowditch and Ludwig, morphology appeared to him as even more attractive. While at Leipzig. Minot studied also in the zoological laboratory under Leuckhart, com- pleting an investigation of the turbellarian worms begun at Wurzburg under Semper. He had mastered the latest methods of micro- scopic technique and had caught the spirit of the German universities. It was to the great task of raising the stand- ards of higher education in America, particu- larly in his own field, that Dr. Minot had com- mitted himself when, in 1880, he was appointed lecturer in embryology at the Harvard Med- ical School. In 1883 he was promoted to an instructorship in histology and embryology and took charge of a department which was then equipped with 18 Hartnack microscopes and supported by an annual appropriation of fifty dollars. It grew rapidly under his care, and in 1887 he was made assistant professor. In 1892, without limiting the scope of his work at the medical school, but in recognition of his preeminence in one branch of microscopic anatomy, he was appointed professor of human embryology. This was his title until 1905, when he became James Stillman Pro- fessor of Comparative Anatomy. He was the first to occupy this newly created position. On June 1, 1889, Dr. Minot married Lucy Fosdick of Groton, Mass. They had no chil- dren. ■ While professor of embryology, Dr. Minot developed his wonderful collection of over nineteen hundred embryos of various animals, cut into many thousands of sections, each of which was numbered and catalogued. He de- scribed this collection as "a sort of cyclopedia of vertebrate embryology to which one can turn at any time and get the desired informa- tion as to the principal features of develop- ment of any structure whatsoever." Only ad- vanced students had access to this collection, but the instruction of beginners was facili- tated by preparing for their use one hundred and fifty complete series of sections of pig embryos, at a stage most interesting to stu- dents of human anatomy. Such study of mammalian embryos, rather than those of chicks, was an innovation, and called for the preparation of a special "Laboratory Text- Book of Embryology." This was issued in 1903, many years after Minot had begun to use pig embryos, and being the first text-book of its kind, it led to a more general labora- tory study of mammalian embryology both in colleges and medical schools. A far more important book, which placed Minot at once in the front rank of embryolo- gists, was his well-known "Human Embry- olog}'," published in 1892, the "result of ten years' labor." This was an ambitious attempt to present in one large volume a summary of all that was then known concerning human development, with exact bibHographical ref- erences to every paper cited (nearly a thou- sand). It included also numerous contribu- tions based upon the author's personal ob- servations, especially in the chapters on the placenta and embryonic membranes. Wlen this work was issued in its German edition in 1894, Professor His described it as sub- stantial throughout, with the facts everywhere in the foreground. "Minot's work," he wrote, "is at present the fullest embryology of man which we possess, and it will retain its value as a bibliographical treasure-house even after its contents in many parts have been super- seded." A series of studies in which Professor Minot took the greatest interest were con- cerned with the nature of growth. They began in 1879 with a paper on "growth as a function of cells," in which it is stated that during growth "two fundamentally different processes display themselves : the gradual senescence which continually hinders and de- lays the multiplication of cells and their vital acts, at last suppressing them altogether at the moment of death; before senescence conquers, the sexual products are thrown ofl and effect the process of rejuvenation." Senescence and rejuvenation were studied by tabulating the weights of guinea pigs from birth to old age, and of rabbit embryos up to the time of birth, using weight as a measure of growth. The conclusion was drawn that the fertilized ovum is endowed with an enor- mous power for growth, over ninety-eight per cent of which has been lost at the time
