It is desirable to have an instant and keen realization of this sex
quality, and to make this easier some sort of classification and
analysis must be attempted. Those things which are allied to and
partake of the nature of _time_ are masculine, and those which are
allied to and partake of the nature of _space_ are feminine: as
motion, and matter; mind, and body; etc. The English words "masculine"
and "feminine" are too intimately associated with the idea of physical
sex properly to designate the terms of this polarity. In Japanese
philosophy and art (derived from the Chinese) the two are called _In_
and _Yo_ (In, feminine; Yo, masculine); and these little words, being
free from the limitations of their English correlatives, will be found
convenient, Yo to designate that which is simple, direct, primary,
active, positive; and In, that which is complex, indirect, derivative,
passive, negative. Things hard, straight, fixed, vertical, are Yo;
things soft, curved, horizontal, fluctuating, are In--and so on.

[Illustration 6: WILD CHERRY; MAPLE LEAF]

[Illustration 7: CALLAS IN YO]

In passing it may be said that the superiority of the line, mass, and
color composition of Japanese prints and kakemonos to that exhibited
in the vastly more pretentious easel pictures of modern Occidental
artists--a superiority now generally acknowledged by connoisseurs--is
largely due to the conscious following, on the part of the Japanese,
of this principle of sex-complementaries.

Nowhere are In and Yo more simply and adequately imaged than in the
vegetable kingdom. The trunk of a tree is Yo, its foliage, In; and