As the sworn adversary of Evolution, transformism, and Darwinism in particular, but a believer in the constancy of species, the great and renowned pathologist has been driven to the incredible contention that all variations of organic forms are pathological. Four years ago, as honorary president of the Anthropological Congress at Vienna, he attacked Darwinism in the severest manner, and declared that 'man may be as well descended from the elephant or from the sheep as from the ape.' Such attacks on the theory of transformism indicate a failure to understand the principles of the theory of Evolution and to appreciate the significance of palæontology, comparative anatomy, and ontogeny. The thousands of other objections which have been made during the last forty years (chiefly by outsiders) may be passed over in silence. They do not require serious refutation. In spite of, or perhaps because of, these attacks, the theory of Evolution stands established more firmly than ever. It is easy for the outsider to exult over the difficulties which our problem implies--difficulties which we who have given our lives to the study understand likewise, and try our best not only to bridge over, but also to point out. Anyhow, we do not conceal them; while those who reject the explanation offered by Evolution make the most of the gaps, and pass silently over the far more numerous points favourable to our theory. How fruitful during the last thirty years the astonishing progress in our palæontological knowledge has been for our Pithecometra-thesis is best shown by a short glance at the growth of our knowledge of fossil Primates. Cuvier,[13] the founder of palæontology, continued up to the time of his death, in 1832, to assert that fossil remains of monkeys and lemurs did not exist. The only skull of a fossil lemuroid which he described (namely, Adapis) he declared to be that of an ungulate. Not until 1836 were the first fragments of extinct monkeys found in India; it was two years later, near Athens, that the skeleton of _Mesopithecus penthelicus_ was discovered. Other remains of lemurs were found in 1862. But during the last twenty years the number of fossil Primates has been augmented by the remarkable discoveries of Gaudry, Filhol, Milne Edwards, Seeley, Schlosser, and others in Europe; of Marsh, Cope, Osborn, Leidy, Ameghino, in South America; and Forsyth Major in Madagascar.[14] These tertiary remains, chiefly of Eocene and Miocene date, fill many gaps between existing genera of Primates, and afford us quite a clear insight into the phyletic development of this order during the millions of years of the Cænozoic age. [13] See notes, p. 87. [14] F. AMEGHINO: 'Contribucion al conocimiento de los mamíferos de la república Argentina.' In _Actas de la Academia nacional de Sciencias en Cordoba_, 1889.--Another article in _Revista Argentina de Historia natural_. Buenos Aires, 1891.