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72

B A E Y E R — B A G E H O T

the distinguished physiologist Dollinger, father of the famous Catholic theologian, was professor. In teaching von Baer comparative anatomy, Dollinger gave a direction to his studies which secured his future pre-eminence in the science of organic development. He collaborated with Pander in researches on the evolution of the chick, the results of which were first published in Burdach’s treatise on physiology. Continuing his investigations alone, von Baer extended them to the evolution of organisms generally, and after a sojourn at Berlin he was invited by his old teacher Burdach, who had become professor of Anatomy at Konigsberg, to join him as prosector and chief of the new Zoological Museum. Yon Baer’s great discovery of the human ovum is the subject of his Epistola de Ovo Mammalium et Hominis Gsnesi (Leipzig, 1827), and in the following year he published the first part of his History of the Evolution of Animals (Ueber Entwickelungsgeschichte der Thieve), which Haeckel says “ even now is generally and rightly considered the most important and most valuable contribution to embryological literature.” Until von Baer’s discovery (for Wolffs cognate theory of epigenesis, promulgated seventy years earlier, had secured no adherents) it was believed that every egg contained, encysted as it were, the complete animal in miniature. On the logical assumption that the “ animalculist ” theory, as it was nicknamed, involved the existence of the preformed body in all ova, Haller made the ingenious calculation that the germs of two hundred billions of men were packed in the ovary of Eve! The “ ovist ” gave this fantastic speculation its quietus. 'V on Baer demonstrated, first, that the Graafian follicles (so named after their discoverer) in the ovary are not the actual eggs, but that they contain the spherical vesicle, which is the true ovum, a body about the y-g-oth of an inch in diameter, wherein, so great is the marvel of heredity, lie the properties transmitting the physical and mental characteristics of the parent or grandparent, or even of more remote ancestors. He next showed that in all vertebrates the primary stage of cleavage of the fertilized egg is followed by modification into leaf-like germ layers— skin, muscular, vascular, and mucous — whence arise by subtle differentiation the several organs of the body. He further discovered the gelatinous, cylindrical cord, known as the chorda dorsalis, which passes along the body of the embryo of vertebrates, in the lower types of which it is limited to the entire inner skeleton, while in the higher the backbone and skull are developed round it. His “ law ” of corresponding stages in the development of vertebrate embryos had example in the fact recorded by him concerning certain specimens preserved in spirit which he had omitted to label. “ I am quite unable to say to what class they belong. They may be lizards, or small birds, or very young mammalia, so complete is the similarity in the mode of formation of the head and trunk in these animals. The extremities are still absent, but even if they had existed in the earliest stage of the development we should learn nothing, because all arise from the same fundamental form.” And in his History of Evolution he suggests, “Are not all animals in the beginning of their development essentially alike, and is there not a primary form common to alii” (i. 223). Notwithstanding this, the “telic” idea, with the archetypal theory which it involved, possessed von Baer to the end of his life, and explains his inability to accept the theory of unbroken descent with modification when it was propounded by Darwin and Wallace in 1858. The influence of von Baer’s discoveries has been far-reaching and abiding. Not only is he the pioneer in that branch of biological science to which Francis Balfour, gathering up the labours of many fellow-workers, gave coherence in his Comparative Embryology (1881); the impetus to Huxley’s researches

in the structure of the medusae came from him {Life, i. 163); and Herbert Spencer found in von Baer’s “law of development ” the “ law of all development ” {Essays, i. 30). In 1834 von Baer was appointed librarian of the Academy of Sciences of St Petersburg. In 1835 he published his Development of Fishes, and as the result of collection of all available information concerning the fauna and flora of the Polar regions of the empire, he was appointed leader of an Arctic expedition in 1837. The remainder of his active life was occupied in divers fields of research, geological as well as biological, an outcome of the latter being his fine monograph on the fishes of the Baltic and Caspian Seas. One of the last works from his prolific pen was an interesting autobiography published at the expense of the Esthonian nobles on the celebration of the jubilee of his doctorate in 1864. Three years afterwards he received the Copley medal. He died at Dorpat on 28th November 1876. (e. cl.) Baeyer, Johann Friedrich Wilhelm Adolph (1835 ), German chemist, was born at Berlin, 31st October 1835. He studied chemistry under Bunsen and Kekule, and in 1858 took his degree as Ph.D. at Berlin, becoming privat-docent a few years afterwards, and assistant professor in 1866. Five years later he was appointed professor of chemistry at Strasburg, and in 1873 he migrated in the same capacity to Munich. He has devoted himself mainly to investigations in organic chemistry, and in particular to synthetical studies by the aid of “ condensation ” reactions. The Royal Society of London awarded him the Davy medal in 1881 for his researches on indigo, the nature and composition of which he has done more to elucidate than any other single chemist, and which he has also succeeded in preparing artificially, though his methods have not been found commercially practicable. The “ centric ” view of the constitution of the benzene ring supported by him, and others of his contributions to chemical theory, are discussed in the article Chemistry. Baffin, a barren insular tract in Franklin district, Canada, with an approximate area of 230,000 square miles, situated between 61° and 90° W. long, and 62 and 74° N. lat. The eastern and northern coasts are rocky and mountainous, and are deeply indented by large bays including Frobisher and Home Bays, Cumberland Sound and Admiralty Inlet. It is separated from Greenland by Baffin Bay and Davis Strait, from Ungava by Hudson Strait, from Keewatin and Melville Peninsula by Fox Channel and Fury-and-Hecla Strait, from Boothia Peninsula and North Somerset by the Gulf of Boothia and Prince Regent Inlet, and from North Devon by Lancaster Sound. The north-western portion is called Cockburn Land; the south-western, Fox Land; and the eastern, Cumberland Land. Bagehot, Walter (1826-1877), English publicist and economist, editor of the Economist newspaper from 1858-60 to his death, was born at Langport, Somerset, 3rd February 1826, his father being a banker at that place. Bagehot was altogether a remarkable personality, his writings on different subjects exhibiting the same bent of mind and characteristics, — philosophic reflectiveness, practical common - sense, a bright and buoyant humour, brilliant wit, and always a calm and tolerant judgment of men and things. Though he belonged to the Liberal party in politics he was essentially of conservative disposition, and often spoke with sarcastic boastfulness to his Liberal friends of the stupidity and tenacity of the English mind in adhering to old ways, as displayed m city and country alike. His life was comparatively