ABSTRACT
The eighteenth century displays on the whole great activity in the sphere of the natural sciences. In physics and chemistry the successors of Newton and Stahl worked at extending the spheres to which their masters had opened the way. In the realm of biology Linnæus and his disciples held sway and were fully occupied in incorporating known species into the system and in discovering fresh ones. As already mentioned, Buffon's activities belonged rather to the future. But besides this there worked during the eighteenth century a number of naturalists whose achievements connected them more or less directly with the great biologists of the preceding century. Towards these pioneer anatomists, microscopists, and physiologists their successors during the eighteenth century have to some extent the character of Epigoni: they made no such epoch-making discoveries as Harvey's or Malpighi's, but, on the other hand, they took advantage in many and various ways of the discoveries that had already been made; the problems which had already been of direct importance were discussed from various points of view, while at the same time ideas were expressed in more than one field of research which gave a presage of future ends to be gained. Malpighi's and Swammerdam's investigations into the anatomy of the lower animals were thus resumed and carried a step further, as also Borelli's and his successors' physiological work; Leeuwenhoek's and de Graaf's discoveries in the field of reproduction were elaborated, and the discussion between the animalculists and the ovists went on, particularly in the first half of the eighteenth century, with undiminished liveliness; the epigenesis and preformation theories were also keenly debated, although at first with the balance decidedly in favour of the supporters of preformation. Later in the century, however, contributions were made in these very spheres which put a different complexion on those questions. And even for several other spheres of biology the latter half of the eighteenth century represents a period of decisive preparation for the development that took place during the nineteenth century. —In the following paragraphs we shall review, to begin with, some of the more important contributions to the biology of the lower animals, and afterwards the advances made in the spheres of anatomy, physiology, and evolution.
