The latest development of Gothic in Germany, of which the Church of St. Catherine at Oppenheim (Fig. 48) is a specimen, was marked (just as late French was by flamboyant tracery, and late English by fan-vaulting) by a peculiarity in the treatment of mouldings by which they were robbed of almost all their grace and beauty, while the execution of them became a kind of masonic puzzle. Two or more groups of mouldings were supposed to coexist in the same stone, and sometimes a part of one group, sometimes a part of the other group, became visible at the surface. The name given to this eccentric development is interpenetration. [Illustration: FIG. 45.--DOUBLE CHURCH AT SCHWARTZ-RHEINDORFF. (A.D. 1158.)] Secular architecture in Germany, though not carried to such a pitch of perfection as in Belgium, was by no means overlooked; but the examples are not numerous. In some of the older cities, such as Prague, Nuremberg, and Frankfort, much picturesque domestic architecture abounds, most of it of the fifteenth and sixteenth centuries, and even later, and all full of piquancy and beauty. In North Germany, where there is a large tract of country in which building stone is scarce, a style of brick architecture was developed, which was applied to all sorts of purposes with great success. The most remarkable of these brick buildings are the large dwelling-houses, with façades ornamented by brick tracery and panelling, to be found in Eastern Prussia, together with some town halls and similar buildings. GERMANY.--ANALYSIS OF BUILDINGS. _Plan._ The points of difference between German and French Gothic are not so numerous as to render a very minute analysis of the Gothic of Germany requisite in order to make them clear. The plans of German churches usually show internal piers; and columns occur but rarely. The churches have nave and aisles, transepts and apsidal choir; but they are peculiar from the frequent use of apses at the ends of the transepts, and also from the occurrence, in not a few instances, of an apse at the west end of the nave as well as at the east end of the choir. They are almost invariably vaulted. As the style advanced, large churches were constantly planned with double aisles, and the western apse disappeared. Some German church plans, notably those of Cologne Cathedral (Fig. 46) and the great church of St. Lawrence at Nuremberg, are fine specimens of regularity of disposition, though full of many parts. [Illustration: FIG. 46.--COLOGNE CATHEDRAL. GROUND PLAN. (BEGUN 1248.)] _Walls, Towers, and Gables._