[Illustration:  FIG. 9.]

Thus the work of Raphael from the loggias follows in unbroken succession upon the forms from the Thermae of Titus.  It is only afterward that a freer handling of the traditional pattern arose, characterized by the substitution of, for instance, maple or whitethorn for the acanthus-like forms.  Often even the central part falls away completely, or is replaced by overlapping leaves.  In the forms of this century we have the same process repeated.  Schinkel and Botticher began with the Greek form, and have put it to various uses; Stuler, Strack, Gropius, and others followed in their wake until the more close resemblance to the forms of the period of the Renaissance in regard to Roman art which characterizes the present day was attained (Fig. 9).

Now, what plant suggested this almost indispensable form of ornament, which ranks along with the acanthus and palmetta, and which has also become so important by a certain fusion with the structural laws of both?

[Illustration:  FIG. 10.]

We meet with organism of the form in the family of the Araceae, or aroid plants.  An enveloping leaf (bract), called the spathe, which is often brilliantly colored, surrounds the florets, or fruits, that are disposed upon a spadix.  Even the older writers—­Theophrastus, Dioscorides, Galen, and Pliny—­devote a considerable amount of attention to several species of this interesting family, especially to the value of their swollen stems as a food-stuff, to their uses in medicine, etc.  Some species of Arum were eaten, and even nowadays the value of the swollen stems of some species of the family causes them to be cultivated, as, for instance, in Egypt and India, etc. (the so-called Portland sago, Portland Island arrowroot, is prepared from the swollen stems of Arum maculatum).  In contrast with the smooth or softly undulating outlines of the spathe of Mediterranean Araceae, one species stands out in relief, in which the sharply-marked fold of the spathe almost corresponds to the forms of the ornaments which we are discussing.  It is Dracunculus vulgaris, and derives its name from its stem, which is spotted like a snake.  This plant, which is pretty widely distributed in olive woods and in the river valleys of the countries bordering on the Mediterranean, was employed to a considerable extent in medicine by the ancients (and is so still nowadays, according to Von Heldreich, in Greece).  It was, besides, the object of particular regard, because it was said not only to heal snake-bite, but the mere fact of having it about one was supposed to keep away snakes, who were said altogether to avoid the places where it grew.  But, apart from this, the striking appearance of this plant, which often grows to an enormous size, would be sufficient to suggest its employment in art.  According to measurements of Dr. Julius Schmidt, who is not long since dead, and was the director of the Observatory at Athens, a number of these plants grow in the Valley of Cephisus, and attain a height of as much as two meters, the spathe alone measuring nearly one meter. [The lecturer here exhibited a drawing (natural size) of this species, drawn to the measurements above referred to.]