Until the third century, the south had been of no great economic importance, in spite of the good climate and the extraordinary fertility of the Yangtze valley. The country had been too thinly settled, and the indigenous population had not become adapted to organized trade. After the move southward of the Chin dynasty the many immigrants had made the country of the lower Yangtze more thickly populated, but not over-populated. The top-heavy court with more than the necessary number of officials (because there was still hope for a re-conquest of the north which would mean many new jobs for administrators) was a great consumer; prices went up and stimulated local rice production. The estates of the southern gentry yielded more than before, and naturally much more than the small properties of the gentry in the north where, moreover, the climate is far less favourable. Thus the southern landowners were able to acquire great wealth, which ultimately made itself felt in the capital. One very important development was characteristic in this period in the south, although it also occurred in the north. Already in pre-Han times, some rulers had gardens with fruit trees. The Han emperors had large hunting parks which were systematically stocked with rare animals; they also had gardens and hot-houses for the production of vegetables for the court. These "gardens" (_yüan_) were often called "manors" (_pieh-yeh_) and consisted of fruit plantations with luxurious buildings. We hear soon of water-cooled houses for the gentry, of artificial ponds for pleasure and fish breeding, artificial water-courses, artificial mountains, bamboo groves, and parks with parrots, ducks, and large animals. Here, the wealthy gentry of both north and south, relaxed from government work, surrounded by their friends and by women. These manors grew up in the hills, on the "village commons" where formerly the villagers had collected their firewood and had grazed their animals. Thus, the village commons begin to disappear. The original farm land was taxed, because it produced one of the two products subject to taxation, namely grain or mulberry leaves for silk production. But the village common had been and remained tax-free because it did not produce taxable things. While land-holdings on the farmland were legally restricted in their size, the "gardens" were unrestricted. Around A.D. 500 the ruler allowed high officials to have manors of three hundred mou size, while in the north a family consisting of husband and wife and children below fifteen years of age were allowed a farm of sixty mou only; but we hear of manors which were many times larger than the allowed size of three hundred. These manors began to play an important economic role, too: they were cultivated by tenants and produced fishes, vegetables, fruit and bamboo for the market, thus they gave more income than ordinary rice or wheat land.