Applying what we have said of crystallisations to plants and animals, we find that symmetry is undoubtedly the predominant element in every flower. The plant developes itself from the ground, which is its horizontal basis. It shoots up generally in a vertical direction, as a radiation from our globe. In trees the branches, leaves, flowers, and fruits are clustered around a central line in eurythmical proportion. In flowers symmetry predominates, whilst in trees eurythmy prevails. In considering the branches of a tree in relation to its trunk, we find the same symmetry and eurythmy, though the direction be changed. We can study these forms best in plants of the coal formation--the Sigillaria, Stigmaria, Lepidodendra, and Calamites; and in ferns, fir-trees, cedars, &c. In the palm tree we see most distinctly the working of the conflicting forces of nature. The dynamic force of vitality drives the stem upwards, and the static force of gravitation towards a common centre is expressed in the beautifully-drooping curves of the leaves. Symmetry is further to be observed in the lowest animals, in polyps, radiata, &c., but never in higher species, in which it is not planimetrical (viz., cannot be treated on a plane) but linear, none of them being perfectly regular in any of the three dimensions of space. Man is altogether different from the products of the mineral or vegetable kingdoms, which give us the prototypes of conventional art. Man is not in all directions symmetrical in the strict sense of the word. He has not two heads, two noses, or two mouths. The component elements in man are different. His very nature revolts against a planimetrical treatment. This was perfectly understood by the masters of arabesque, who have always turned man half into a fish, a plant, a serpent, a tendril, or some other form adapted for planimetrical treatment. Eurythmy and _Proportion_ are the elements of higher organic forms--to which must be added direction or _Action_, and finally _Expression_. In most of the lower animals the vertebræ are horizontal, and coincident with the moving direction of the whole creature. In man, on the other hand, the vertebræ are vertical, in opposition to the moving direction which is horizontal; so that the vertebræ and line of motion are at right angles. In men, detached as they are from their horizontal basis, the soil--carrying their static force with them, and able to change it either from below, upwards, or from front to back--_direction_ is of a complicated nature, and must be well studied, so as not to produce incongruities.