In reference to the case of Mr. Bird's Gayal breeding with the common Zebu, I may observe that this proves nothing beyond the bare fact stated; no inference whatever of an identity of species can be drawn from a thousand such cases. It is pretty well known that animals of perfectly distinct species will, when artificially brought together, produce hybrids, as in the familiar examples of the Horse and the Ass, the Canary and the Goldfinch; but a hybrid is neither a species nor (zoologically speaking) a variety. In a paper on the Gour, by General Hardwicke, ('Zoological Journal,' Vol. III,) he introduces the following observations on the Gayal: "Of the Gayal (_Bos Gavaeas_ of Colebrooke) there appears to be more than one species. The provinces of Chatgong and Sylhet produce the wild, or, as the Natives term it, the Asseel Gayal, and the domesticated one. The former is considered an untameable animal, extremely fierce, and not to be taken alive. It rarely quits the mountain tract of the south-east frontier, and never mixes with the Gobbay, or village Gayal of the plains. I succeeded in obtaining the skin, with the head, of the Asseel Gayal, which is deposited in the Museum of the Hon. East-India Company, in Leadenhall Street." [A drawing was taken of this head, of which the engraving on the opposite page is a copy.] "I may notice another species of Gayal, of which a male and female were in the Governor General's park, at Barrackpore. This species differs in some particulars from the domesticated Gayal, and also from the Asseel, or true Gayal; first, in size, being a larger animal than the domestic one; secondly, in the largeness of the dewlap, which is deeper and more undulated than in either the wild or tame species; and, thirdly, in the size and form of the horns." Thus, according to the opinion of General Hardwicke, there are three distinct species of the Gayal; but in this matter nothing can be decided without further evidence, which we hope will soon appear in the shape of complete skeletons, and accurate drawings and descriptions. [Illustration] THE TAME OR DOMESTIC GAYAL. [Illustration] The representation of the Gayal here given was taken from a living specimen in the Zoological Gardens, 1846. The scanty information I was able to glean concerning it, consists in its having been procured at Chitagong, and shipped, as a commercial speculation, from Calcutta for London, in January 1844, when about two years and a half old. It remained in the Zoological Gardens till the summer of 1846, when it died from inflammation of the bowels, brought on chiefly by eating too much green food. I had the above particulars from Mr. Bartlett, naturalist, &c., who had been commissioned to dispose of it. He preserved the skeleton, which he kindly allowed me to examine, and from which I made the sketches of the skull and horns, which appear on the following page. The skeleton has fourteen pairs of ribs.