The address I delivered on August 26 at the Fourth International Congress of Zoology at Cambridge, 'On our Present Knowledge of the Descent of Man,' has, I find, from the high significance of the theme and the general importance of the questions connected with it, excited much interest, and has led to requests for its publication. Hence this volume, edited by my friend Dr. H. Gadow, my pupil in earlier days, who has not only revised the text, but has also enriched it by many valuable additions a

At the end of the nineteenth century, the age of 'natural science,' the department of knowledge that has made most progress is zoology. From zoology has arisen the study of transformism, which now dominates the whole of biology. Lamarck [1] laid its foundation in 1809, and forty years ago Charles Darwin obtained for it a recognition which is now universal. It is not my task to repeat the well-known principles of Darwinism. I am not concerned to explain the scientific value of the whole theory of

First, we have to consider the relative place which comparative anatomy concedes to man in the 'natural system' of animals, for the true value of our 'natural classification' is based upon its meaning as a pedigree. All the minor and major groups of the system—the classes, legions, orders, families, genera, and species—are only different branches of the same pedigree. For man himself, his place in the pedigree has been fixed since Lamarck, [5] in 1801, defined the group of vertebrates. The most

The next question is, how the facts of palæontology agree with these most important results of comparative anatomy and ontogeny. The fossils are the true historical 'medals of creation,' the palpable evidence of the historical succession of all those innumerable organic forms which have peopled the globe for many millions of years. Here the question arises, If the known fossil specimens of Mammalia, and particularly of Primates, give proof of these Pithecometra-theses, do they confirm directly t

Let us now recapitulate the ancestral chain of man, as it is set forth in the accompanying diagram (p. 55 ), which represents our present knowledge of our descent. For simplicity's sake the many side-issues or branches which lead to groups not in the main line of our descent have been left out, or have been indicated merely. Many of the stages are of course hypothetical, arrived at by the study of comparative anatomy and ontogeny; but an example for each of them has been taken from those living

Jean Baptiste de Monet , Chevalier de Lamarck , was born on August 1, 1744, in Picardy, where his father owned land. Originally educated for the Church, he soon enlisted, and distinguished himself in active service. Owing to an accident affecting his health, the young Lieutenant gave up the military career, and, without means, studied medicine and natural sciences at Paris. In 1778 appeared his 'Flore française.' In 1793 he was appointed to a Chair of Zoology at the newly-formed Musée d'Histoire

The vegetable cell was discovered by Schleiden , Professor of Botany at Jena, in 1838. Next year Schwann found the animal cell. In 1844 Koelliker discovered that the egg cell, by division and multiplication, becomes an aggregation—a heap of new cells. In 1849 Huxley found the two primary layers (observed long before by Pander and Baer in the chick) also in certain Invertebrata, the Medusæ; and he called these layers 'ectoderm' and 'endoderm' respectively. In 1851 Remak , in his 'Untersuchungen ü

An organism, as living matter, does not stand in opposition to, or outside of, the rest of the world. It is part of the world. It receives matter from its surroundings, and gives some back; therefore it is influenced by its surroundings. It is acted upon, and it reacts upon the latter, and if these change (and they are nowhere and never strictly the same) the organism also varies . It adapts itself, and if it does not, or, rather, cannot, do so, it dies, because it is unfit to live in the world,