Among the taboos observed by savages none perhaps are more numerous or important than the prohibitions to eat certain foods, and of such prohibitions many are demonstrably derived from the law of similarity and are accordingly examples of negative magic. Just as the savage eats many animals or plants in order to acquire certain desirable qualities with which he believes them to be endowed, so he avoids eating many other animals and plants lest he should acquire certain undesirable qualities with which he believes them to be infected. In eating the former he practises positive magic; in abstaining from the latter he practises negative magic. Many examples of such positive magic will meet us later on;​[396] here I will give a few instances of such negative magic or taboo. For example, in Madagascar soldiers are forbidden to eat a number of foods lest on the principle of homoeopathic magic they should be tainted by certain dangerous or undesirable properties which are supposed to inhere in these particular viands. Thus they may not taste hedgehog, “as it is feared that this animal, from its propensity of coiling up into a ball when alarmed, will impart a timid shrinking disposition to those who partake of it.” Again, no soldier should eat an ox’s knee, lest like an ox he should become weak in the knees and unable to march. Further, the warrior should be careful to avoid partaking of a cock that has died fighting or anything that has been speared to death; and no male animal may on any account be killed in his house while he is away at the wars. For it seems obvious that if he were to eat a cock that had died fighting, he would himself be slain on the field of battle; if he were to partake of an animal that had been speared, he would be speared himself; if a male animal were killed in his house during his absence, he would himself be killed in like manner and perhaps at the same instant. Further, the Malagasy soldier must eschew kidneys, because in the Malagasy language the word for kidney is the same as that {p118} for “shot”; so shot he would certainly be if he ate a kidney.​[397] Again, a Caffre has been known to refuse to eat two mice caught at the same time in one trap, alleging that were he to do so his wife would give birth to twins; yet the same man would eat freely of mice if they were caught singly.​[398] Clearly he imagined that if he ate the two mice he would be infected with the virus of doublets and would communicate the infection to his wife. Amongst the Zulus there are many foods which are similarly forbidden on homoeopathic principles. It may be well to give some specimens of these prohibitions as they have been described by the Zulus themselves. “There is among the black men,” they say, “the custom of abstaining from certain foods. If a cow has the calf taken from her dead, and the mother too dies before the calf is taken away, young people who have never had a child abstain from the flesh of that cow.