Gemmule (pangenesis)
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Gemmule (pangenesis)
Pangenesis was Charles Darwin's hypothetical mechanism for heredity, in which he proposed that each part of the body continually emitted its own type of small organic particles called gemmules that aggregated in the gonads, contributing heritable information to the gametes. He presented this 'provisional hypothesis' in his 1868 work ''The Variation of Animals and Plants Under Domestication'', intending it to fill what he perceived as a major gap in evolutionary theory at the time. The etymology of the word comes from the Greek words ''pan'' (a prefix meaning "whole", "encompassing") and ''genesis'' ("birth") or ''genos'' ("origin"). Pangenesis mirrored ideas originally formulated by Hippocrates and other pre-Darwinian scientists, but using new concepts such as cell theory, explaining cell development as beginning with gemmules which were specified to be necessary for the occurrence of new growths in an organism, both in initial development and regeneration. It also accounted for ...
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Galen
Aelius Galenus or Claudius Galenus ( el, Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen () or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one of the most accomplished of all medical researchers of antiquity, Galen influenced the development of various scientific disciplines, including anatomy, physiology, pathology, pharmacology, and neurology, as well as philosophy and logic. The son of Aelius Nicon, a wealthy Greek architect with scholarly interests, Galen received a comprehensive education that prepared him for a successful career as a physician and philosopher. Born in the ancient city of Pergamon (present-day Bergama, Turkey), Galen traveled extensively, exposing himself to a wide variety of medical theories and discoveries before settling in Rome, where he served prominent members of Roman society and eventually was given the position of personal physician to seve ...
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Albrecht Von Haller
Albrecht von Haller (also known as Albertus de Haller; 16 October 170812 December 1777) was a Swiss anatomist, physiologist, naturalist, encyclopedist, bibliographer and poet. A pupil of Herman Boerhaave, he is often referred to as "the father of modern physiology." Early life Haller was born into an old Swiss family at Bern. Prevented by long-continued ill-health from taking part in boyish sports, he had more opportunity for the development of his precocious mind. At the age of four, it is said, he used to read and expound the Bible to his father's servants; before he was ten he had sketched a Biblical Aramaic grammar, prepared a Greek and a Hebrew vocabulary, compiled a collection of two thousand biographies of famous men and women on the model of the great works of Bayle and Moréri, and written in Latin verse a satire on his tutor, who had warned him against a too great excursiveness. When still hardly fifteen he was already the author of numerous metrical transla ...
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Pierre Louis Maupertuis
Pierre Louis Moreau de Maupertuis (; ; 1698 – 27 July 1759) was a French mathematician, philosopher and man of letters. He became the Director of the Académie des Sciences, and the first President of the Prussian Academy of Science, at the invitation of Frederick the Great. Maupertuis made an expedition to Lapland to determine the shape of the Earth. He is often credited with having invented the principle of least action; a version is known as Maupertuis's principle – an integral equation that determines the path followed by a physical system. His work in natural history is interesting in relation to modern science, since he touched on aspects of heredity and the struggle for life. Biography Maupertuis was born at Saint-Malo, France, to a moderately wealthy family of merchant- corsairs. His father, Renė, had been involved in a number of enterprises that were central to the monarchy so that he thrived socially and politically. The son was educated in mathematics by ...
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Charles Bonnet
Charles Bonnet (; 13 March 1720 – 20 May 1793) was a Genevan naturalist and philosophical writer. He is responsible for coining the term ''phyllotaxis'' to describe the arrangement of leaves on a plant. He was among the first to notice parthenogenetic reproduction in aphids and established that insects respired through their spiracles. He was among the first to use the term "evolution" in a biological context. Deaf from an early age, he also suffered from failing eyesight and had to make use of assistants in later life to help in his research. Life and work Bonnet was born in Geneva, the son of Pierre Bonnet and Anne-Marie Lullin de Châteauvieux. Although originally from France, the family had been driven into Geneva by religious persecution of Protestants in the 16th century. At age seven he lost hearing which pushed him into an interest in the natural world. His schoolmates troubled him due to the hearing handicap and the parents took him out and had a private tutor. Bonn ...
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Georges-Louis Leclerc, Comte De Buffon
Georges-Louis Leclerc, Comte de Buffon (; 7 September 1707 – 16 April 1788) was a French naturalist, mathematician, cosmologist, and encyclopédiste. His works influenced the next two generations of naturalists, including two prominent French scientists Jean-Baptiste Lamarck and Georges Cuvier. Buffon published thirty-six quarto volumes of his '' Histoire Naturelle'' during his lifetime, with additional volumes based on his notes and further research being published in the two decades following his death. Ernst Mayr wrote that "Truly, Buffon was the father of all thought in natural history in the second half of the 18th century".Mayr, Ernst 1981. ''The Growth of Biological Thought''. Cambridge: Harvard. p 330 Credited with being one of the first naturalists to recognize ecological succession, he was later forced by the theology committee at the University of Paris to recant his theories about geological history and animal evolution because they contradicted the Bi ...
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John Ray
John Ray FRS (29 November 1627 – 17 January 1705) was a Christian English naturalist widely regarded as one of the earliest of the English parson-naturalists. Until 1670, he wrote his name as John Wray. From then on, he used 'Ray', after "having ascertained that such had been the practice of his family before him". He published important works on botany, zoology, and natural theology. His classification of plants in his ''Historia Plantarum'', was an important step towards modern taxonomy. Ray rejected the system of dichotomous division by which species were classified according to a pre-conceived, either/or type system , and instead classified plants according to similarities and differences that emerged from observation. He was among the first to attempt a biological definition for the concept of ''species'', as "a group of morphologically similar organisms arising from a common ancestor". Another significant contribution to taxonomy was his division of plants into th ...
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Nicolas Venette
Nicolas Venette (28 May 1633–18 August 1698) was a physician, sexologist and French writer. He has also been identified as the writer of an anonymous work on nightingales ''Traite du rossignol'' published in 1697. Biography Born in La Rochelle, he studied medicine at Bordeaux where he received his doctorate in 1656. He then went to Paris where he studied under Guy Patin and Pierre Petit, before travelling to Spain, Portugal and Italy. He then returned to La Rochelle working as a doctor at the Charite hospital in 1664, Saint-Louis hospital in 1669 while also becoming Regius Professor of Anatomy and Surgery in 1668. He married Marie Texler in 1673 and they had eleven children. Works In 1671, Venette wrote ''Traité du scorbut'' (Treatise on scurvy), and the better known ''Tableau de l’amour conjugal, ou l'Histoire complète de la génération de l’homme''. This book, published in 1686 in Amsterdam under the title ''Tableau de l'amour humain considéré dans l'état du ...
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Levinus Lemnius
Levinus Lemnius (20 May 1505 in Zierikzee – 1 July 1568 in Zierikzee) was a Dutch physician and author. Life Lemnius studied medicine at the University of Leuven under Rembert Dodoens and Konrad Gesner; and under Vesalius at Padua. He also travelled to Switzerland and England. After his wife's death, he became a priest. Works *''Occulta naturae miracula'' (1559, Antwerp) by the University and State Library Düsseldorf) This was translated as ''De gli occvlti miracoli'', ''Les Occultes Merveilles et Secretz de Nature''online text ''The secret miracles of nature'', and ''Wunderbarliche Geheimnisse der Natur'online text. *''De habitu et constitutione corporis'' (1561, Antwerp). As ''The Touchstone of Complexions'' (1576) (translation into English by Thomas Newton) *''Herbarum atque arborum quae in Bibliis passim obviae sunt et ex quibus sacri vates similitudines desumunt''. In English as ''An Herbal for the Bible'' (1579, Newton translation). *''De miraculis occultis natura ...
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Jerome Cardan
Gerolamo Cardano (; also Girolamo or Geronimo; french: link=no, Jérôme Cardan; la, Hieronymus Cardanus; 24 September 1501– 21 September 1576) was an Italian polymath, whose interests and proficiencies ranged through those of mathematician, physician, biologist, physicist, chemist, astrologer, astronomer, philosopher, writer, and gambler. He was one of the most influential mathematicians of the Renaissance, and was one of the key figures in the foundation of probability and the earliest introducer of the binomial coefficients and the binomial theorem in the Western world. He wrote more than 200 works on science. Cardano partially invented and described several mechanical devices including the combination lock, the gimbal consisting of three concentric rings allowing a supported compass or gyroscope to rotate freely, and the Cardan shaft with universal joints, which allows the transmission of rotary motion at various angles and is used in vehicles to this day. He made sig ...
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Paracelsus
Paracelsus (; ; 1493 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance. He was a pioneer in several aspects of the " medical revolution" of the Renaissance, emphasizing the value of observation in combination with received wisdom. He is credited as the "father of toxicology". Paracelsus also had a substantial influence as a prophet or diviner, his "Prognostications" being studied by Rosicrucians in the 1600s. Paracelsianism is the early modern medical movement inspired by the study of his works. Biography Paracelsus was born in Egg an der Sihl, a village close to the Etzel Pass in Einsiedeln, Schwyz. He was born in a house right next to a bridge across the Sihl river (known as ''Teufelsbrücke''). The historical house, dated to the 14th century, was destroyed in 1814. The ''Restaurant Krone'' now stands in it ...
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Pietro De' Crescenzi
Pietro de' Crescenzi ( 1230/35 – c. 1320), la, 'Petrus de Crescentiis', was a Bolognese jurist,Robert G. Calkins, "Piero de' Crescenzi and the Medieval Garden", in ''Medieval Gardens'', ed. Elisabeth B. MacDougall, Dumbarton Oaks, 1986: 155–173Selected pages at Google Books/ref> now remembered for his writings on horticulture and agriculture, the ''Ruralia commoda''. There are many variant spellings of his name. Life Pietro de' Crescenzi was born in Bologna in about 1235; the only evidence for his date of birth is the annotation "septuagenarian" in the ''Ruralia commoda'', dated with some certainty between 1304 and 1309. He was educated at the University of Bologna in logic, medicine, the natural sciences and law, but did not take his doctorate. Crescenzi practiced as a lawyer and judge from about 1269 until 1299, travelling widely in Italy in the course of his work. In January 1274 he married Geraldina de' Castagnoli, with whom he had at least five children. She died in ...
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