First Lessons in Geology. E-book. Formato PDF Alpheus Spring Packard   -  Forgotten Books, 2017  - 

Now if there has been a recent shower, and the stream is rather high and the water thick and turbid, should we take up a tumbler-full of the water and allow it to settle, we shall see that the coarser particles fall to the bottom first and form a layer or stratum of gravel; above it is next deposited a layer of sand, and finally when the water has become clear, all the sedi ment having fallen to the bottom, we shall find uppermost a stratum of very fine sand, so fine that we cannot easily distin guish the particles, and this is mud. The entire deposit is said to be, in geological language, a sedimentary deposit.

Lamarck, the Founder of Evolution: His Life and Work. E-book. Formato PDF Alpheus S. Packard   -  Forgotten Books, 2017  - 

Although it is now a century since Lamarck published the germs of his theory, it is perhaps only within the past fifty years that the scientific world and the general public have become familiar with the name of Lamarck and of Lamarckism. The rise and rehabilitation of the Lamarckian the cry of organic evolution, so that it has become a rival of Darwinism; the prevalence of these views in the United States, Germany, England, and especially in France, where its author is justly regarded as the real founder of organic evolution, has invested his name with a new interest, and led to a desire to learn some of the details of his life and work, and of his theory as he unfolded it in 1800 and subsequent years, and finally expounded it in 1809. The time seems ripe, therefore, for a more extended sketch of Lamarck and his theory, as well as of his work as a philosophical biologist, than has yet appeared. But the seeker after the details of his life is baf?ed by the general ignorance about the man — his ante cedents, his parentage, the date of his birth, his early training and education, his work as a professor in the Jardin des Plantes, the house he lived in, the place of his burial, and his relations to his scientific con temporaries.