Evolution and genetics / by Thomas Hunt Morgan.

  • Thomas Hunt Morgan
Date:
1925
Catalogue details

Licence: In copyright

Credit: Evolution and genetics / by Thomas Hunt Morgan. Source: Wellcome Collection.

    35/228 page 21
    at the other. These types, with the fluctuations that occur within each type, furnish a complete series of gradations; yet historically they have arisen inde¬ pendently of each other. Many changes in eye color have appeared. As Fig. 7.—Mutants of Drosophila melanogaster, arranged in order of size of wings; a, cut,; b, beaded; c, stumpy; d, an¬ other stumpy; e, vestigial; f, apterous. many as fifty or more races differing in eve color are now maintained in our cultures. Some of them are so similar that they can scarcely he separated from each other. It is easily possible beginning with the darkest eye color, sepia, which is deep brown, to pick out a perfectly graded series ending with pure white eyes. But such a serial arrangement would
    digitised image 1
    digitised image 2
    digitised image 3