The abundance of food in this country, as compared with the south, would lead one to suppose that animals here must attain a much greater size; but actual measurement now confirms the impression made on my mind by the mere sight of the animals, that those in the districts north of 20 Deg. were smaller than the same races existing southward of that latitude.  The first time that Mr. Oswell and myself saw full-grown male elephants on the River Zouga, they seemed no larger than the females (which are always smaller than males) we had met on the Limpopo.  There they attain a height of upward of 12 feet.  At the Zouga the height of one I measured was 11 feet 4 inches, and in this district 9 feet 10 inches.  There is, however, an increase in the size of the tusks as we approach the equator.  Unfortunately, I never made measurements of other animals in the south; but the appearance of the animals themselves in the north at once produced the impression on my mind referred to as to their decrease in size.  When we first saw koodoos, they were so much smaller than those we had been accustomed to in the south that we doubted whether they were not a new kind of antelope; and the leche, seen nowhere south of 20 Deg., is succeeded by the poku as we go north.  This is, in fact, only a smaller species of that antelope, with a more reddish color.  A great difference in size prevails also among domestic animals; but the influence of locality on them is not so well marked.  The cattle of the Batoka, for instance, are exceedingly small and very beautiful, possessing generally great breadth between the eyes and a very playful disposition.  They are much smaller than the aboriginal cattle in the south; but it must be added that those of the Barotse valley, in the same latitudes as the Batoka, are large.  The breed may have come from the west, as the cattle within the influence of the sea air, as at Little Fish Bay, Benguela, Ambriz, and along that coast, are very large.  Those found at Lake Ngami, with large horns and standing six feet high, probably come from the same quarter.  The goats are also small, and domestic fowls throughout this country are of a very small size, and even dogs, except where the inhabitants have had an opportunity of improving the breed by importation from the Portuguese.  As the Barotse cattle are an exception to this general rule, so are the Barotse dogs, for they are large, savage-looking animals, though in reality very cowardly.  It is a little remarkable that a decrease in size should occur where food is the most abundant; but tropical climates seem unfavorable for the full development of either animals or man.  It is not from want of care in the breeding, for the natives always choose the larger and stronger males for stock, and the same arrangement prevails in nature, for it is only by overcoming their weaker rivals that the wild males obtain possession of the herd.  Invariably they show the scars received in battle.  The elephant we killed yesterday had an umbilical hernia as large as a child’s head, probably caused by the charge of a rival.  The cow showed scars received from men; two of the wounds in her side were still unhealed, and there was an orifice six inches long, and open, in her proboscis, and, as it was about a foot from the point, it must have interfered with her power of lifting water.