18. In connection with the horses it is worthy of notice that the quagga zebra, which never comes together with the dauw zebra, nevertheless lives on excellent terms, not only with ostriches, which are very good sentries, but also with gazelles, several species of antelopes, and gnus. We thus have a case of mutual dislike between the quagga and the dauw which cannot be explained by competition for food. The fact that the quagga lives together with ruminants feeding on the same grass as itself excludes that hypothesis, and we must look for some incompatibility of character, as in the case of the hare and the rabbit. Cf., among others, Clive Phillips-Wolley's Big Game Shooting (Badminton Library), which contains excellent illustrations of various species living together in East Africa. 19. Our Tungus hunter, who was going to marry, and therefore was prompted by the desire of getting as many furs as he possibly could, was beating the hill-sides all day long on horseback in search of deer. His efforts were not rewarded by even so much as one fallow deer killed every day; and he was an excellent hunter. 20. According to Samuel W. Baker, elephants combine in larger groups than the "compound family." "I have frequently observed," he wrote, "in the portion of Ceylon known as the Park Country, the tracks of elephants in great numbers which have evidently been considerable herds that have joined together in a general retreat from a ground which they considered insecure" (Wild Beasts and their Ways, vol. i. p. 102). 21. Pigs, attacked by wolves, do the same (Hudson, l.c.). 22. Romanes's Animal Intelligence, p. 472. 23. Brehm, i. 82; Darwin's Descent of Man, ch. iii. The Kozloff expedition of 1899-1901 have also had to sustain in Northern Thibet a similar fight. 24. The more strange was it to read in the previously-mentioned article by Huxley the following paraphrase of a well-known sentence of Rousseau: "The first men who substituted mutual peace for that of mutual war--whatever the motive which impelled them to take that step--created society" (Nineteenth Century, Feb. 1888, p. 165). Society has not been created by man; it is anterior to man. 25. Such monographs as the chapter on "Music and Dancing in Nature" which we have in Hudson's Naturalist on the La Plata, and Carl Gross' Play of Animals, have already thrown a considerable light upon an instinct which is absolutely universal in Nature. 26. Not only numerous species of birds possess the habit of assembling together--in many cases always at the same spot--to indulge in antics and dancing performances, but W.H. Hudson's experience is that nearly all mammals and birds ("probably there are really no exceptions") indulge frequently in more or less regular or set performances with or without sound, or composed of sound exclusively (p. 264). 27. For the choruses of monkeys, see Brehm. 28. Haygarth, Bush Life in Australia, p. 58.