Looking upon the Deer generally, we find them inhabiting many parts of the world--Europe, Asia, and America. In Africa none occur south of the Sahara, they being there replaced by members of the Bovine section of the order. None are found in Australia, and in America they are far less common than in Great Britain. To understand the peculiar features and the distribution of the various species, it is necessary to classify them in groups of kindred genera, most falling into sections which are distinguishable without difficulty. In arranging the different members of the Deer-tribe for description, there are peculiarities in their outward conformation which agree with those internal differences upon which all correct notions of relationship alone can be established. In classifying animals, naturalists must always be guided by the totality of the structure of each member of each group; but, as in describing them to those who have not made the minute details of their organisation their special study it is impossible to lay stress on all the various parts which have to be included by the student in arriving at the desired result, those outward features only can be mentioned which are found to tally with their total structure, namely, their osteology, their visceral anatomy, and their muscular arrangement. As an example of the relative importance of different external structures, we may mention that the late Dr. J. E. Gray, in his Catalogue of the Ruminant Mammalia in the British Museum, gives the following arrangement of the genera, in which the length of the tail suggests one distribution of them, whilst the shape of the antlers is in favour of another, which is very different:-- 1.--_Tail very short 2.--_Tail elongate, with or clubbed._ longer hair at the end._ Antlers { Mantchurian Deer. Red Deer and its near allies. elaphine { Japanese Deer. { Fallow Deer. Eld’s Deer. } Barasingha Deer. } Antlers { Hog Deer. Schomburgk’s Deer. } rusine { Spotted Axis. Sambur and its near allies. } Roebuck. } Antlers Chinese Elaphure. } capreoline. This table is useful as a means of comparing the tails of the different genera; but other points of structure do not in the least support the classification suggested by that appendage, as a result of which it has to be ignored in the consideration of distant affinities, although, where questions of specific proximity are concerned, it is found to be of considerable value.