(_a_) In the n-syllable binary line the phrases may recur
at irregular intervals. In lines with regular ternary
movement phrasing is largely replaced by rhythmic
pulsation (cf. p. lxx).

(3) There must be rime of final syllables, or final
vowels, recurring at regular intervals.

(_a_) In some metrical arrangements of foreign origin the
rimes recur at irregular intervals, or there is no rime
at all. See the _silva_ and _versos sueltos_ under
_Strophes_.

Whether normal Spanish verse has, or ever had, binary
movement, with the occasional substitution of a "troche"
for an "iambic," or vice-versa, is in dispute.[8] That is,
whether in Spanish verse, with the usual movement, (1)
the alternation of stressed and unstressed syllables is
essential, or whether (2) the mere balancing of page xlv
certain larger blocks of syllables is sufficient. For
instance, in this line of Luis de León:

ya muestra en esperanza el fruto cierto,

is there regular rhythmic pulsation, much less marked
than in English verse, doubtless,--but still an easily
discernible alternation of stressed and unstressed
syllables? If so, there must be secondary stress on _es-_.
Or is _ya muestra en esperanza_ one block, and _el fruto