by facts, and we must attribute the sterility of the mules to all the above causes, as they proceed from a mixture of these naturally unprolific species. In those species, on the contrary, which, like the sheep and goat, are numerous, and, consequently prolific, the mules proceeding from their intermixture, are not barren but ascend to the original species in the first generation, whereas, two, three, or perhaps four generations, are required to reinstate the mule produced by the horse and the ass, to the same degree and perfection of nature. It has been asserted, that another kind of mule is produced from the copulation of the bull with the mare. Columella is, I think, the first who has spoken of it. Gesner quotes the words of Columella, and adds, that he found these mules in Grenoble, and which are called in French _jumars_. One of these jumars I had brought to me from Dauphiny, and another from the Pyrenees. By the inspection of the external parts, as well as by the dissection of the internal, I discovered that they were only bardeaus, or mules produced between the horse and the she-ass. I think myself, therefore, authorized from this experiment, and from analogy, to suppose this kind of mule does not exist, and that the word jumar is only a chimerical name without any real object. The nature of the bull is too distant from that of the mare, to admit of their engendering together, the one having four stomachs, horns, cloven feet, &c. and the other being whole-hoofed, with no horns, and only one stomach. The organs of generation are likewise so very different, there is not the least reason to suppose they can copulate with any degree of pleasure or success. If the bull were to produce with any species besides his own, it would be with the buffalo, which resembles him in conformation and natural habits; yet we have never heard of any mules being produced by the junction of these two animals. What is related of the copulation and production of the stag and cow, is nearly as suspicious as the story of the jumars, though the stag is much less distant, in its conformation, from the nature of the cow, than the bull is from that of the mare. _END OF THE NINTH VOLUME._ Transcriber Note