On the zoölogical position of the albino rat / Shinkishi Hatai.

  • Hatai, Shinkishi.
Date:
1907
Catalogue details

Licence: In copyright

Credit: On the zoölogical position of the albino rat / Shinkishi Hatai. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    6/12 (page 269)
    colonies. In other words, the common brown and our albino rats cannot be distinguished from one another by their external characters. It is nevertheless true that the albino rats which we have ex- amined, are smaller in size than the. brown rats in the same locali- ties. In fact, the absolute size of the albino rat is nearly inter- mediate between Mus rattus and Mus norvegicus. It is possible Fig. 1. Copied from “ Encyclopedia Britannica,” in order to show the shape of the heads of the brown and black rats. 1. Mus rattus. 2. Mus norvegicus. that the confinement in which these albinos have been reared, accounts for their smaller size, as the result of lack of exercise and altered conditions of life. It is possible also that we have here a phenomenon similar to that described by Semper (’81) and De Varigtiy (’94) on snails, where the size of the animals diminished with the size of the vessels in which they were reared. It was thought that the character of the skull might serve for a more exact distinction of the forms under discussion. We therefore examined and compared the skulls of Mus rattus, Mus norvegicus, and of the albinos.1 1 In order to make this comparison, it was necessary to examine as many skulls as possible, and I am indebted to Professor J. A. Allen, American Museum of Natural History, at New York, Professor Elliot, Field Columbian Museum at Chicago, Dr. Greenman, The Wistar Institute of Anatomy at Philadelphia, and Professor Merriam, National Museum at Washington, for putting at my disposal various series of skulls, possessed by their several institutions.