Tung Yüan and Chü Jan are considered by the critics as having founded a special school in the great tradition of Wang Wei. Their paintings were quiet in coloring and were executed with broad strokes in an impressionist style. These works must be viewed from a distance to see their apparent violence merge into extreme elegance. They furnish a complete demonstration of the laws of atmospheric perspective, with its feeling of distance and infinite space, in which forms are immersed. Here we find evidence that these painters were the first to attempt the arrangement of lines according to rule, which led ultimately to calligraphic painting. Among the heads of schools cited in the Chinese writings Ma Yüan and Hsia Kuei of the Sung dynasty must be placed in a class by themselves. Both of these masters lived at the end of the twelfth and the beginning of the thirteenth centuries. Their style can be described with accuracy since original examples are extant--both by themselves and by their disciples--in which their characteristics are fully revealed. Ma Yüan is classed with the Southern School by reason of his restraint in the use of color, his greatness of conception and his technical treatment of forms. But he brings to his work a virility in which the influence of the Northern School is plainly discerned. He has a broad stroke and a masterful manner which place his works in the front rank of all Chinese painting. His mountainous backgrounds rear themselves with fierce energy. His old pines, with branches wreathed in vines, would suffice alone to define his style, so freely do they express the force of plant life and the proud defiance of the aged tree. He loved the mountain solitudes to which he gave a new imagery, so authoritative and so perfect that it served to create a school. The influence of Ma Yüan was felt by his brother and by his son, Ma Lin. Although the death of the latter occurred under the Mongolian dynasty, he was an exponent of Sung art. The fierce energy of the old master gives way to a somewhat more melancholy and gentle quality in his son. There is the same restraint in the handling of the brush, the same reserve in the use of color, but the landscape stretches out into deep and dreamy vistas that are indescribably poetic. The melancholy of autumn, the sadness of flights of birds that circle in the evening light, the feeling of seclusion and silence, such are the things in which this poetic spirit finds its joy, true heir of the master mind whose genius found expression in the wild aspects of nature.