The principal traditional arts of the Maori may be broadly classified as carving in wood, stone, or bone, geometrical designs in plaiting and weaving, painted designs on wood and on the walls of rock shelters, and, finally, tattooing. It is the habit of ethnologists to study Maori art as if it had come to an abrupt end on the arrival of the European settlers in New Zealand and to regard post-European work as being of little importance. It is necessary to point out, however, that the major forms of Maori art have never died out and that there is a continuous tradition from pre-European times to the present day. It is true that tattooing is no longer practised and that little stoneworking has been done by Maoris in the past 50 years. But it is probable that more major carved houses have been built in the last 30 years than in any like time in Maori history. Many of the present-day carvers are descended from families which have produced outstanding carvers for centuries. Modern life has caused many changes, but all arts must develop if they are to live.