. Advanced biology. Biology; Physiology; Reproduction. CHAPTER XXXIV MUTATIONS. Hugo de Vries. Keystone View (Jo. August Weismann. What are mutations? What is the ijnportance of viutationsf The theory of germ plasm. August Weismann (1834-1914), a German biologist, tried to produce a race of tailless mice. He cut off the tails of tiny baby mice as soon as they were born. When these grew to adult mice, they mated and had offspring. These baby mice had long tails. He repeated this experiment generation after generation. Cutting the tails of the parent mice did not affect the germ cells of either
. Advanced biology. Biology; Physiology; Reproduction. CHAPTER XXXIV MUTATIONS. Hugo de Vries. Keystone View (Jo. August Weismann. What are mutations? What is the ijnportance of viutationsf The theory of germ plasm. August Weismann (1834-1914), a German biologist, tried to produce a race of tailless mice. He cut off the tails of tiny baby mice as soon as they were born. When these grew to adult mice, they mated and had offspring. These baby mice had long tails. He repeated this experiment generation after generation. Cutting the tails of the parent mice did not affect the germ cells of either males or females. He then selected mice with the shortest of stubby tails, mated them, and continued to select the shortest-tailed mice for parents. xAfter several genera- tions of this selecting and mating, a short-tailed race of mice was produced. He had selected mice whose germ cells carried the gene for short tails. As a result of this second experiment, Weismann formulated a theory explaining why offspring resemble their parents. He believed that the germ plasm does not arise anew in each organism, but is actually received from its parents. Explained briefly, his theory is this : Each new organism begins as a single cell, which is pure germ plasm. In higher plants and animals this cell is formed from the union of an egg and sperm. The cell, called a fertile egg, begins to divide. Very early in this division, and before differ- 335. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Wheat, Frank Merrill; Fitzpatrick, Elizabeth T. New York ; Boston [etc. ] : American Book Company
Size: 1474px × 1694px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubje, booksubjectphysiology
