[Illustration: Skull of Domestic Gayal, viewed in front, with Section of Horn.] Inches. Distance from tip to tip (_a_ to _a_) 39 Length of horn (_a_ to _b_) 16 Circumference of horn at base 17 Distance of bases (_b_ to _b_) 11 Length of skull (_c_ to _c_) 19 Fig. _d_, section of the horn, at the base. [Illustration: Occipital view of the same Skull.] [Illustration: Head of Domestic Gayal.] In concluding these details of the Gayal and Gyall, let it be remarked that, when we hear one animal called Gayal and another Gyall, we are not, _on that account merely_, to set them down as of the same species. It is hardly necessary to say, that similarity or even identity of name, is not the slightest criterion of identity of species. The name Elephant is popularly applied to that animal, whether brought from Africa or Asia; they are, nevertheless, anatomically distinct. The same observation may be made respecting the Lions of those countries, and various other animals. It may further be observed, that the value of external characters in determining a species is very different when applied to ascertain the distinctions of domestic races, to what it is when applied to ascertain the distinctions of animals living in a natural state. In domestication, varieties ramify to an indefinite extent, and under such circumstances external characters are comparatively valueless. But wild animals retain their external characters with undeviating exactness; exceptional cases may indeed occur, but so very rarely, that they are not worth taking into the account; consequently, external forms, and in some cases even colours, become of importance in ascertaining specific distinction. THE JUNGLY GAU. _Bos Sylhetanus._ (Cuv.) [Illustration] Further information is requisite to decide the specific character of this animal. According to the opinion of Col. Smith, (see 'Synopsis of the Species of Mammalia' in Griffith's Translation of Cuvier's Animal Kingdom,) it is a mere variety of the Gayal (_Bos Gavaeus_); and Mr. J. E. Gray, in his 'List of the Specimens of Mammalia in the Collection of the British Museum,' classes it as a domestic variety of the same animal, but Mr. Fred. Cuvier regards it as an entirely new species. The following account of the Jungly Gau (which is the only one that has been published), is a translation from the splendid folio work of Messrs. St. Hilaire and F. Cuvier.