The question: whether the embryo was preformed in the egg and originated by a simple evolution; or whether it had to be developed by an entirely new formation, or epigenesis; was mainly solved by the theorj' of epigenetic evolution established by Driesch and numerous colabourers. The science of phylog- eny began when Lamarck, the founder of the modern theory of descent, controverted the immutability of species on scientific grounds.
The Chevalier de Lamarck (Jean-Baptiste-Pierre- Antoine de Monet de Lamarck) was born in 1744. .\t the age of forty-nine he became professor of the zoologj' of invertebrates in the Jardin des Plantes at Paris. His theory of evolution was fully explained for the first time in his "Philosophie zoologique" and later in his "Histoire naturelle des animairx sans vertebres". During the last seventeen years of his life Lamarck was blind and lived in extreme poverty. The last two volumes of his "Histoire naturelle" he dictated to an affectionate daughter, who re- mained at her father's side till his death in 1829. During its first period of energetic development the theory of evolution, as proposed by Lamarck and, in a modified form, by Saint-Hilaire, failed to super- sede the theory of the constancy of species, which was defended by such influential men as Cuvier; nor, indeed, were the facts known at that time in any way sufficient to easure its acceptance. However, after Charles Darwin had published his "Origin of Species", in 1859, the new science progressed with the greatest rapiditj', and at the present daj' there are but few prominent naturalists who do not con- tribute their share to phylogeny. At the same time it lias gone tlirough a considerable intrinsic develop- ment, mainly with respect to the rise and decline of the theory of natural selection as the chief factor in the development of species. Charles Darwin was born at Shrewsburj- in 1809. He studied at the uni- \ersities of Edinburgh and Cambridge, from 1831 to 1836 accompanied an English scientific expedition on board the "Beagle", and passed the rest of his life in the village of Downe. Kent, where he produced the numerous works which had such an incalculable influence on his age. Among Darwin's fellow-workers Alfred Russel Wallace (b. 1822) occupies the first place, since he was the co-discoverer of the principle of natural selection. Other distinguished men who took part in the development of this branch of biolog>' were Huxley, Lyell, Xiigeli, Weisraann, Asa Gray. Probal>ly the most important discoveries were those made by Hugo De Vries and by Gregor Johann Mendel, Abbot of the Augustinian Monastery at Altbrunn, where he died in 1884. Mendel's laws of heredity, based as they are on a splendid array of facts, will be of especial influence upon future theories of heredity and development.
Together with phylogeny the science of palseon- tologj', founded by Cuvier, developed mainly tlirough the influence and personal activity of such men as Joachim Barrande (1799-1883), Jean-Bap- tiste-Julien d'Omalius d'Halloy (1783-1875), James Dwight Dana (1813-95), Oswald Heer (1809-83), and many more. The.se giants in the natural .sciences were at the same time faithful Christians, the first two being Catholics. Still more impressive than the progress of pala?ontolog}- is that of systematic biology and bionomics, branches to which a thousand modern scientists have devoted llie entire energy of their lives. The result of all this scientific activity is apparent in the immense collections preserved in the museum.s of Washington. London, New York, and other large cities, and in the simple fact that the systematic species scientifically described amount to no fewer than 500,000 animals and 200,000 plants. The Linna?an system of classification was perfected in many ways, especially by the botanists A. L. von Jussieu (1789), A. P. Decandelle (1813), and by the
zoologists Cuvier, C. T. E. von Siebold (1848), and R. Leuckart (1847). The greatest of modern mor- phologists since the time of Albrecht von Haller are Richard Owen (1870-92), the comparative anatomist, Johann Muller, the father of German medicine, and Claude Bernard, the prince of physiologists. Muller was b. 14 July, ISOl, at Coblenz, and d. 28 April, 1858, as professor of anatomy and physiology in the University of Berlin. He was the teacher of such well-known men as Virchow, Emil Dubois- Reymond, Helmholtz, Schwann, Lieberkiihn, M. Schultze, Remak, Reichert, all of whom have done magnificent work in various departments of biology. Miiller was chiefly an experimental physiologist, and established a vast number of facts which he de- scribed with great accuracy. At the same time he defended with energy the existence of a special vital force, which directs the various physical and chemical forces for the attainment of specific structures and functions. In the present generation biologists are gradually returning to Muller 's views, which for a time they had more or less completely abandoned. The great physiologist lived all his life, as he died, a faithful Catholic. The same may almost be said of his contemporary in France, Claude Bernard, b. in 1813, at St.-Julien, not far from Lyons, and d. in 1880. Bernards main discoveries refer to the phenomena of nervous inhibition and internal glandu- lar secretion. For a time he yielded to the materialis- tic philosophy of his age, but he soon abandoned it, perhaps through the influence of his friend Pasteur.
Louis Pasteur (d. 28 September, 1895), the father of preventive medicine, was probably the most gifted and influential biologist of the nineteenth century. His discoveries, which are inscribed on his tomb, in the Institut Pasteur, at Paris, extend from 1848 to 1885, and relate to the nature of fer- mentations, to the minutest organisms and the question of abiogenesis, to the diseases of silkworms, to the propagation of diseases by microbes, and above all to the supremely important principle of experimental immunity to pathogenic bacteria. Pasteur was a model Catholic, the most ideal scien- tist known in the historj' of biology.
Many more prominent biologists, such as Ramon y Cajil, Wundt, Brooks, Strassburger, Wasmann, have done and are still doing admirable work in the interest of biological sciences.
Foster, Lectures on the History of Physiology during the 16th, 17th, and 18th Centuries (Cambridge, 1901): Knf.ller. Da3 Christentum und der Vertreter der neueren N aturmissen- schaft (Freiburg, 1903): Wasmann, Die modeme Biologie und die Entieicklungstheorie (Freiburg. 1906); Walsh. Makers of Modem Medicine (New York, 1907): Catholic Churchmen in Science (Philadelphia, 1906): Osborn, From the Greek,': to Darwin (New York, 1905).
Biondo, FL.\^^o, a distinguished Italian archaeolo- gist and historian, b. at Forh in 13S8; d. at Rome in 1403. He was the founder of the science of archaeology and of Christian and medieval topog- raphy. He studied under Ballistario of Cremona and was remarkable for learning even in his youth. He lived for some time at Milan, where he discovered and copied the only manuscript ot Cicero's dialogue "Brutus". In 1432 he became secretary to Pope Eugenius IV, who was afterwards driven out of Rome. Biondo accompanied the pope in his exile, was his secretarj' at Ferrara and Florence, and re- turned to Rome with him. Later he served in the same capacity under Popes Nicholas V, Calixtus III, and Pius II. An earnest student of antiquities and a man of wonderful erudition, he applied him- self with indefatigable industrj' to the task of collect- ing materials for his historical, archa;ological, and topographical works. He gathered his materials from original sources. Biondo was the author of three encyclopedias, which have formed the basis