In the first of these, known as _shin_, the polished formulas of Shubun were supplanted by a controlled boldness, with rocks and mountains outlined in dark, angular brushstrokes seemingly hewn with a chisel. The landscapes were not so much sublimely unattainable as caught and worked to his will. The reverence for nature remained, but under his hand the depiction was almost cubist; the essence of a vista was extracted in an intricate, dense design of angular planes framed in powerful lines. Delicacy was replaced by dominance. Precursors of this style can be found in the works of Ma Yuan and Hsia Kuei, both of whom experimented in the hard, Northern-influenced techniques of brushstroke, but it was Sesshu who was the true master of the technique. Writing in 1912, the American critic Ernest Fenollosa declared him to be the greatest master of the straight line and angle in the history of the world's art. Sesshu's second major style was _so_, an abstraction in wash combining the tonal mastery of the Southern Sung school with the "flung ink," or _haboku_, of the Ch'an school--a style in which line is almost entirely ignored, with the elements of the landscape being suggested by carefully varied tones of wash. A viewer familiar with the traditional elements of the Sung landscape can identify all the required components, although most are acknowledged only by blurred streaks and seeming dabs of ink which appear to have been applied with a sponge rather than a brush. In contrast to the cubist treatment of the _shin _style, the _so _defines no planes but allows elements of the landscape to blend into one another through carefully controlled variations in tonality. As effortless as the style appears to be, it is in fact a supreme example of mastery of the brush, an instrument intended for carving lines rather than subtle shading and blending of wash. Because Sesshu chose to live in the secluded provinces, he did not perpetuate a school, but artists in Kyoto and elsewhere drew on his genius to invigorate Zen painting. One artist inspired by him was So'ami, a member of the Ami family which flourished during the academy's heyday. The earlier members of the family had produced acceptable works in the standard Sung style, but So'ami distinguished himself in a number of styles, including the _so_. The other artist directly influenced by Sesshu was the provincial Sesson (ca.1502- ca.1589), who took part of the earlier master's name as his own and became adept in both _shin _and _so _techniques. Although he, too, avoided strife-ridden Kyoto, he became famous throughout Japan, and his works suggest what the academy might have produced had Sesshu chosen to remain part of the Zen establishment. Yet even in Sesson's work one can detect a polished, effortless elegance that seems to transform Sesshu's hard-earned power into an easy grace, a certain sign that the creative phase of Zen art had ended.