![]() Others, including Thomas Hunt Morgan and Oscar Hertwig, attempted to separate the two cells, for the matter was of great importance, particularly to the arguments between proponents of epigenesis and preformation, but satisfactory results could not be achieved. The reason for this discrepancy has been widely attributed to Driesch separating the two blastomeres completely rather than just killing one as Roux had done. He reported that, contrary to Roux's findings, he ended up with completely formed but smaller embryos. In 1892 Hans Driesch performed similar experiments on sea urchin embryos, but instead of killing one of the two blastomeres he put many embryos in a tube and shook it to separate the cells. He then observed how the remaining blastomere developed, and found that it became a half embryo. Results in embryology had been contradictory: in 1888 Wilhelm Roux, who had introduced the experimental manipulation of the embryo to discover the rules of development, performed a series of experiments in which he inserted a hot needle into one of two blastomeres to kill it. He wrote in his autobiography: "I found here a theory of heredity and development elaborated with uncommon perspicacity to its ultimate consequences.This stimulated experimental work of my own". Experiments in ontogeny ĭuring the winter of 1896, while quarantined in a sanitarium recovering from tuberculosis, Spemann read August Weismann's book The Germ Plasm: A Theory of Heredity. Spemann advocated a holistic approach to biology. thesis under Boveri, Spemann studied cell lineage in the parasitic worm Strongylus paradoxus, for his teaching diploma, the development of the middle ear in the frog. His degree in zoology, botany, and physics, awarded in 1895, followed study under Theodor Boveri, Julius von Sachs and Wilhelm Röntgen. In 1893–1894 he moved to the University of Munich for clinical training but decided, rather than becoming a clinician, to move to the Zoological Institute at the University of Würzburg, where he remained as a lecturer until 1908. In 1892 Spemann married Klara Binder with whom he had a daughter (Margaret) and three sons (Fritz, Rudolph, Ulrich). There he met the biologist and psychologist Gustav Wolff who had begun experiments on the embryological developments of newts and shown that, if the lens of a developing newt's eye is removed, it regenerates. ![]() In 1891 he entered the University of Heidelberg where he studied medicine, taking his preliminary examination in 1893. After he left school in 1888 he spent a year in his father's business, then, in 1889–1890, he did military service in the Kassel Hussars followed by a short time as a bookseller in Hamburg. Hans Spemann was born in Stuttgart, the eldest son of publisher Wilhelm Spemann and his wife Lisinka, née Hoffman. ![]() Spemann added his name as an author to Hilde Mangold's dissertation (although she objected) and won a Nobel Prize for her work. Hans Spemann ( German pronunciation: ⓘ 27 June 1869 – 9 September 1941) was a German embryologist who was awarded a Nobel Prize in Physiology or Medicine in 1935 for his student Hilde Mangold's discovery of the effect now known as embryonic induction, an influence, exercised by various parts of the embryo, that directs the development of groups of cells into particular tissues and organs. Nobel Prize in Physiology or Medicine (1935) ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |