Animal coloration : an account of the principal facts and theories relating to the colours and markings of animals / by Frank E. Beddard.

  • Beddard Frank E. (Frank Evers), 1858-1925.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Animal coloration : an account of the principal facts and theories relating to the colours and markings of animals / by Frank E. Beddard. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    17/312 (page 3)
    birds is chiefly cine not to one pigment, bnt to two apparently distinct pigments, wbicli give different chemical reactions; to these two pigments their discoverer, Kriikenberg, has given the name of Zoorubin and Pseudozoorubin respectively. An inspection of the feathers would not enable one to tell with certainty which of the two substances was the cause of the colour ; bnt an extract of zoorubin can always be detected by its change to a beautiful cherry red on the addition of the.minutest trace of blue sulphate of copper. The green colour of the feathers of the turacou is due to a pigment, turacoverdin, which is quite different from that which causes the green colour of the parrot.* Again, the crimson colour of the same bird is produced by a very different pigment from those which cause the crimson colour of any other birds the colouring-matter of whose feathers has been studied. This being the case, it is not surprising to find that animals only remotely allied are often coloured by quite different pig- ments, which yet produce the same effect. But on the other hand there are some pigments which have a very wide distribution among animals. Zoonerythrin, or tetronerythrin, as it has been also called, is found in both vertebrates and invertebrates.. The blood of the common earthworm owes its red colour to hfemoglobin, as does also the blood of all vertebrate animals, including man. Pigments may be even common to plants and animals: apart from chlorophyll (see p. 6), it has been stated that carotin (a vegetable pigment) is found in certain crustacea. Sometimes differently coloured animals have in reality the same skin pigments. The attention of the reader will be directed in a later chapter to the remarkable difference in colour between the males and females of certain parrots. In * The actual pigment here is yellow.