The facts here set down for each specimen of verse group themselves in four divisions. In the first place, each line of verse is either "run-on" or "end-stopped"; and, in riming couplets, it is also of interest to know whether the second line of the couplet is run-on into the following couplet. In the second place, the cesural pause occurs either near the middle of the line or elsewhere, or--it may be--is omitted altogether. In the third place, the line may have a feminine ending. In the fourth place, it may contain some other foot than the regular iambus. There is some room for difference of judgment as to whether a given line is "end-stopped" or "run-on"; but with occasional exceptions the presence or want of a mark of punctuation may be made the determining element. Obviously one may find such clear phrase-pauses, without punctuation, as will justify the caption "end-stopped." There is far more divergence of judgment in the recognition of the cesura. Some writers on prosody treat practically every line of ten syllables as having a cesural pause, and certainly some slight phrase-pause may almost always be found. In the following table, however, the cesura has been recognized only when there is a grammatical or rhetorical pause so considerable as--in most cases--to require a mark of punctuation. Such a verse, then, as-- "Fate snatch'd her early to the pitying sky" is counted as having "no cesura." The cesura is counted as "medial" when occurring after the fourth, fifth, or sixth syllable; elsewhere it is regarded as "variant." The significance of this distinction is very clear in the comparison of the heroic couplet of the "classical" with that of the "romantic" school of poets.[60] It is in the last group of facts, those relating to substituted feet, that the subjective element is most embarrassing. There can be no very general agreement among readers as to the degree of accent necessary to change a pair of syllables from an "iambus" to a "pyrrhic" or a "spondee." The other two forms of substitution (inverted accent, giving "trochees," and trisyllabic feet, giving "anapests") are somewhat more definitely determinable. In the following table the naming of all these feet is based on what is believed to be the natural reading of the verse, with a due regard for both rhetorical and metrical accent. In the verse-- "By these the springs of property were bent" the fourth foot is counted a pyrrhic; so also in this-- "Their busy teachers mingled with the Jews," although here a certain secondary accent on the eighth syllable is possible. In such a verse as-- "There is a path on the sea's azure floor" the third foot is counted a pyrrhic and the fourth a spondee.[61]