The decoration follows a development which permits of the division of Geometrical vases into three periods, in which we follow Kroker[944]: (1) for a long time it is exclusively limited to Geometrical patterns, and (2) even when quadrupeds and birds are introduced they are still only decorative (as in Boeotia); (3) finally, while the animals take a subsidiary place, human figures and large compositions spring into prominence. But this final development is chiefly characteristic of Athens. Wide distinguishes four varieties of the Dipylon ware: (_a_) amphorae, with black varnished bodies and designs only on the neck; (_b_) “black Dipylon ware,” mainly varnished, but more decorated than (_a_); (_c_) large vases, with linear decoration or figures all over in horizontal friezes (the tomb-amphorae); (_d_) as the last, but with vertical panels, divided like metopes. His view is that these represent a continuous development, but that the style did not last long in Attica. Returning to Kroker’s classification, it must be borne in mind that the three classes are not successive in point of _time_, only in artistic development; the plain linear decoration survived throughout, and is often found in tombs contemporaneously with the figure subjects. The patterns are mainly, though not exclusively, rectilinear, and sometimes extremely elaborate. The favourite are a large bold maeander, chevrons, chequers, and arrangements of hatched lines; also squares, with diagonals and much ground-ornament. Among the simpler motives are lines of dots, triangles, lozenges, and various forms of crosses; but concentric and “tangent” circles occur not infrequently, the latter being clearly derived from the Mycenaean spiral, and one vegetable motive appears in the form of a conventionalised leaf, later developed into a rosette. M. Perrot[945] gives a very instructive diagram of the typical scheme of ornamentation on the neck and body of a vase, including most of the principal varieties. It should also be noted that these patterns occur frequently on the field of the designs as ground-ornaments, to cover the vacant spaces.