They are the power Of receiving impressions or stimuli from the exterior, and of communicating with each other, with the view of co-ordinating a suitable response.
By the device of a hypsographic curve co-ordinating the vertical relief and the areas of the earth's surface occupied by each zone of elevation, according to the system introduced by Supan, 2 Wagner showed his results graphically.
Welcker was a pioneer in the field of archaeology, and was one of the first to insist, in opposition to the narrow methods of the older Hellenists, on the necessity of co-ordinating the study of Greek art and religion with philology.
The first is theoretic or spiritual, aiming at the development of a new principle of co-ordinating social relations, and the formation of the system of general ideas which are destined to guide society.
But the nationalization scheme, though apparently the only effective method of linking together and co-ordinating an excessively subdivided system of lines, has proved a source of considerable financial embarrassment.