Conklin edward g (4 risultati)

Paperback. Condizione: New. Print on Demand. This book delves into the pathological ova and twin pregnancies discovered by the author, providing groundbreaking insights into the origins of human monsters. Previous theories of maternal impressions or supernatural causes are dismissed in favor of faulty implantation as the primary cause of these monstrous aberrations. The author presents evidence from a wide range of vertebrates, including extensive data from pathological human embryos, to support the idea that all monsters are produced from normal ova due to external influences. This book uncovers the truth behind the origins of human monsters, challenging conventional wisdom and revealing the intricate mechanisms that shape embryonic development. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.…

pp. 137-158. Original printed wrappers, a very good copy.

Paperback. Condizione: New. Print on Demand. This book delves into the early development of the pigeon's egg, with a particular focus on polyspermy, a process where multiple sperm cells enter the egg during fertilization. The author, drawing on a series of close observations and detailed illustrations, presents a comprehensive analysis of this phenomenon in the pigeon egg. They chronicle the distribution of nuclei during the first fourteen hours after fertilization, detailing the migration of supernumerary sperm nuclei into the periblast, a region surrounding the central area of primary cleavage. This detailed account provides valuable insights into the biological processes at play during the early stages of embryonic development in birds. The book also examines the disappearance of supernumerary nuclei around ten to twelve hours after fertilization, exploring the subsequent organization of the periblast with nuclei derived from the cleavage nucleus. The author compares the pigeon egg to other meroblastic vertebrate eggs, such as those of reptiles and selachians, highlighting the similarities in the organization and function of their periblasts. This comparative approach offers a broader understanding of the evolutionary relationships between different vertebrate species and the similarities in their early developmental processes. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.…

Pamphlet. Condizione: Very Good. Prompt Shipment, shipped in Boxes, Tracking PROVIDEDOffprint. 4 with the authors stamp on front wrapper. One inscribed presentation copy signed by the author to E. M. East "with thanks of the author for your recent reprints. E. G. Conklin" "Conklin, Edwin Grant, 1863-1952, American zoologist, b. Waldo, Ohio, B.S. Ohio Wesleyan Univ., 1886, Ph.D. Johns Hopkins, 1891. From 1908 he taught and conducted research at Princeton, principally in cytology (particularly cell division), embryology, and heredity. His chief interest was evolution. He wrote Heredity and Environment (1915) and many other works, and he was influential in organizing the marine biology laboratory at Woods Hole, Mass. " Columbia Encyclopedia. Zoology. Science. Offprints. Titles include: The development of centrifuged eggs of ascidians (1931) Inscribed presentation copy signed by the author to E. M. East; Facts and Factors of Development (1914) front cover torn, "with the compliments of E.G. Conklin stamp front wrapper. George F. Atkinson's autograph front cover and first page; The Basis of Individuality in Organisms from the Standpoint of Cytology and Embryology (1916) Author's stamp. Karl Sax and E. M East stamp front cover; Why Polar Bodies Do Not Develop (1915) Author's stamp, Karl Sax E. M. East stamp front cover; Effects of Centrifugal Force on the Structure and Development of the Eggs of Crepidula (1917) Author's stamp, Kark Sax and E. M. East stamp front cover, some paper missing at head of spine, else very good; Effects of Centrifugal Force on the Polarity of the Eggs of Crepidula (1916) author's stamp, Karl Sax and E. M. East stamp front cover; Phenomena of Inheritance (1914) Karl Sax and E.M. East stamp front cover; The Mutation Theory From the Standpoint of Cytology (1905) E. M. East stamps front cover; Body Size and Cell Size (1912) Karl Sax and E. M. East stamp front cover, some nicks to edges; Problems of Evolution and Present Methods of Attacking Them (1912). R.R. Gates signature front cover, Karl Sax and Evolution stamp front cover. Most in very good condition. Science. Evolution. Cytology. Biology. Eugenics. *. Signed inscribed presentation. …