The _naos_, or _cella_, as it is more usually called, or temple itself, was comparatively small, even where the entire mass was of considerable size, gradual extension of plan being produced not so much by any great enlargement of the interior as by external columniation and its gradual development. It is probable that the earliest Greek temples consisted of the _naos_ only, and were accordingly plain ASTYLAR buildings, or without columns, except in front or at the entrance end, where an enclosed porch was formed by introducing columns, by continuing the side walls, and placing columns between them _in antis_, that is, between the two _antæ_ or pilasters forming the ends of those walls. The next step seems to have been to advance the porch before the main building, instead of keeping it recessed within the side walls, thereby converting it from a portico in antis, into a _prostyle_, or projecting line of columns: thus a _distyle in antis_, or a portico consisting of two columns between antæ, consequently of three _intercolumns_, or open spaces between the antæ and columns, would become a _tetrastyle_, or projecting portico of four columns and three intercolumns. By the other end of the building being similarly treated, the temple became _amphiprostyle_, or prostyle at both ends, in rear as well as in front, the sides still remaining _astylar_. The next and last style of advancement was to continue columniation all round, enclosing the _cella_ within colonnades along its sides as well as at its ends, which disposition of plan is expressed by the terms _peristyle_, or _peristylar_, and _peripteral_, which of necessity produces two columns and two intercolumns more in front; for what would otherwise be merely a tetrastyle prostyle, with four columns and three intercolumns (the number of the latter being always one less than that of the others), becomes by the colonnades being continued along the side, a _hexastyle_ (_six_ columns and _five_ intercolumns); or if originally a prostyle hexastyle, it would be rendered an _octastyle_ (_eight_ columns and _seven_ intercolumns), and so on.[5] It should be observed, too, that a building cannot at the same time be _peristylar_ and have a _prostyle_ portico, the latter being merged in the general columniation, instead of projecting from the rest of the edifice as a distinct feature. Of peristylar temples there were two sorts, viz. those with a single row of columns on each side, and those which have two, which last are distinguished by the term _dipteral_, i. e. having two wings or _aisles_ on each side. Although it did not at all affect the general external appearance, notwithstanding that it extended the plan by adding two more columns and intercolumns to the front, this last-mentioned mode was attended with greater richness of columniation, and the inner columns contributed not a little to variety of effect and play of perspective; besides which, greater sheltered space was gained