During the lesson the professor imparted much instructive information to his pupils. Among other things he told them that in the art of flower arrangement the student must be guided by nature and a careful study and observation of the character and habits of the flowers employed. Everything unnatural and inappropriate must be strictly avoided. Flowers of different seasons should never be arranged together, and no flower, however beautiful, should have a place in such arrangement out of its proper season. [Illustration: A Lesson in Flower Arrangement.] Symmetry in flower arrangement should be avoided, and under no circumstances should both sides of a composition correspond or match. (This principle, it may be said, is observed in all forms of Japanese art.) It would be in very bad taste, for instance, to allow two vines to hang symmetrically from either side of a suspended vase, or even for a flower of one color to be placed between two of another color. One of the fundamental rules of this art is that all flower arrangements should fit into a triangle, either vertical or horizontal, and that in itself serves more or less as a restriction against symmetrical compositions. Great attention should be given also to the manner in which the stems rise out of the water, as they should present a strong and vigorous appearance, and hold, in fact, the same relation to the flowers that the trunk of a tree bears to the branches and foliage overhead. Plants that grow erect should be given an upright direction in floral arrangements, while such, for instance, as grow overhanging the banks of streams or cliffs should be arranged in a hanging position. The professor demonstrated all this with numerous examples which he made and then distributed to the pupils. Each girl, upon receiving a finished example, made a low bow to the master; and retiring to the other end of the room, proceeded to take the flowers apart and rearrange them as before. [Illustration: Suspended Bamboo Vase in the Form of a Boat, Containing an Arrangement of Iris.] After having accomplished this to the best of her ability, she returned with it to the teacher's desk, when he pointed out to her any defects it might contain. The Japanese divide plants and flowers, without any regard to scientific facts, into the male and female sex. Trees, mountains, and streams are likewise classified as their fancy wills. This division of flowers and plants into sexes forms an important consideration in the art of flower arrangement. In a composition in which delicate plants and slender vines are used in connection with stems of trees, the latter represent the male element and should always form the centre or backbone of the arrangement and serve as a support for the former, the female element. [Illustration: Morning-Glory and Shion Arrangement, in Imitation Well Buckets.]