_fleur-de-lis_ was carved but yesterday; the stigmaria flourished when the earth was young, and had seen scarcely a third part of its known history. I have said that the stem of the stigmaria is called sigillaria. The name may be translated _signet-stem_,[22] and has reference to one of the distinguishing peculiarities of the plant. About twenty British species are enumerated, some of them very dissimilar, yet they all agree in having long fluted stems with parallel rows of prominent seal-like tubercules. The sigillaria differed so widely in its whole contour and ornamentation from every living plant, that it is impossible to convey an idea of its form by reference to existing vegetation. Some of the species, as _S. organum_ (Fig. 14), had their trunks traversed longitudinally by broad ridges separated by narrow furrows. Along the summit of each ridge there ran a line of tubercules, set regularly at distances varying from a third or a quarter of an inch to close contact. One may sometimes see no unfair representation of the bark of this ancient tree, when looking at a newly ploughed field in spring-time, having each of its broad ridges dotted with a row of potato sacks. Other species, while exhibiting the same plan, differed not a little in the details. In some the tubercules are round, in others angular, and in a third set double or kidney-shaped. In some they are far apart, in others they are strung together like a chain of beads. Sometimes they exist as mere specks, while occasionally they broaden out so as to equal in width the ridge that supports them. One species (_S. reniformis_), instead of the broad ridge and narrow furrow, exhibits an arrangement exactly the reverse. It looks not unlike a cast of the species first described, save that its broad flat furrows support rows of much larger tubercules. The breast of a lady's chemisette, with a thick-set row of buttons down each plait, would be somewhat like this species of sigillaria, with this difference, however, that the buttons on the plant were of a form that does not appear as yet to have come into fashion among the fair sex. Yet they had no little elegance, and like many other objects in the geological storehouse, might be a useful model for our students of design. They were neither round nor quite oval, but rather of a kidney-shape, or like a double cherry. [Footnote 22: The word sigillaria is really plural, and was used by the Romans to denote the little images which friends were wont to present to each other at the end of the Saturnalia. They answered pretty nearly to christmas-boxes and new year's gifts among ourselves. It is not uninteresting thus to find among the hard dry names of science, one that two thousand years ago was synonymous with all the kindliness of friendship.] [Illustration: Fig. 14. Sigillaria, with black carbonized bark partially removed.]