Cereals in the Mediterranean are grown, as we have seen, on ploughed land, as elsewhere. A more characteristic form of cultivation is garden-culture, practised where water can be obtained for irrigation. Such gardens consist primarily of fruit trees, all the citrus fruits, peaches, apricots, pomegranates, pistachio, almonds, and many other forms of nuts, plums, even apples and pears, being grown in this way. So productive is the ground once water is supplied, that plants are grown in association in a fashion hardly suggested in the north. Thus among the fruit trees many different kinds of vegetables, such as garlic, cucumbers, leeks, salad plants, many sorts of melons, tomatoes, egg-plants, beans, and peas, etc., are grown. Elsewhere one may see corn sown beneath the olive trees, and the vine sharing the same ground with them. The picture of Mediterranean life may be completed by adding a few words about the domesticated animals. These are naturally in essence the same as those further north, but their relative numbers and the uses to which they are put are different. The dog and cat both occur, but the former has little importance in the pastoral industries, and is largely a watch animal, insufficiently fed, and therefore important as a sanitary agent in that it devours garbage. Among the ungulates or hoofed animals, the ass was domesticated in the region long before the horse, and it and the mule are still more important than the horse, partly, no doubt, because both are hardier, and the problem of food is a difficulty in the largely pastureless Mediterranean region. Few camels now occur in Europe, where they have been always closely associated with Mahometans, appearing and disappearing with them. The pasturage difficulty greatly reduces the importance of cattle, which are draught animals rather than a source of food. As draught animals cattle go back to the dawn of history, but their numbers are small and the use of either their flesh or their milk as food is insignificant. Philippson in his book on the Mediterranean gives some striking figures to illustrate the difference in numbers between the cattle of the Mediterranean countries and those of Central Europe. Spain has only 2.1 million cattle, and yet it is scarcely smaller than Germany, which has 19 millions; Switzerland has 1,340,000 head of cattle, and Greece, which is about half as large again, has only 360,000. It is to be noted, however, that the irrigated plains of North Italy now support a considerable amount of cattle, whose milk gives rise to a considerable cheese industry; but, then, the olive will not grow in North Italy, which is therefore not strictly within the Mediterranean area.