In all these phases of the development of our poetry, we notice, as one of its peculiarities, a strong inclination to the exercise of the witty side of our nature. Even if we leave out of consideration the so-called 'pillow word' (makura-kotoba), so profusely resorted to in our ancient poems, part of which were nothing but a naïve sort of jeu de mots, and the abundant use of other plays on words of later development, known as kakekotoba, jo, shûku, etc. (haikai-no-uta), it is noteworthy that poems of a