Royal Physical Society of Edinburgh. 3835 



the top of the plant, passed, in ascending, from tripinnate to bipinnate, and assumed 

 finally the form of more alternately pinnate leaflets. Unlike Pteris, however, whose 

 stem remains bare of pinnae until its larger divisions lake place, the stem of Spheno- 

 pteris elegans sent forth on its opposite sides two decompound pinnae, the one about 

 an inch, the other about an inch and a quarter or so, below the first fork, — a peculia- 

 rity of structure that must have imparted a graceful fulness of outline to the lower 

 portion of the frond, which, had the rachis been bare, it could not have possessed. Al- 

 ternation, save in the bifurcations of the main, secondary, and tertiary stems, and in 

 the case of a few irregular pinnae that seem to have been placed opposite, or nearly so, 

 constituted the law that regulated the form of the plant. The pinnae alternated on the 

 greater stems, — the semi-pinnae alternated on the pinnae, — and finally, the minute, 

 closely nerved, spathulate leaflets alternated on the semi-pinnae. The entire frond 

 must have been of great lightness and beauty, of a style intermediate, from the slim- 

 ness of its leaflets and the slenderness of its secondary and tertiary stems, between that 

 of the frond of Pteris aquilina, and that of the fully developed sucker of the graceful 

 Asparagus. A hill-side clothed with these delicately fronded ferns must have rolled 

 its mimic waves of soft green to every light breeze that stirred the depths of the old 

 carboniferous forests ; and the light and flexile covering which it gave to undulating 

 plain or gentle acclivity, must have contrasted not unpleasingly with the columnar 

 trunks of fluted Sigillariae or scaly Lepidodendra, or with the huge rectilinear boles of 

 gigantic Araucarians. After several remarks on the numerous so-called species of 

 Sphenopteris found at Burdiehouse, most of which Mr. M. regarded as but mere vari- 

 eties of a single species, he went on to state that he had an opportunity of seeing, about 

 six years before, though but for an instant, the larger portion of a frond of Neuropteris 

 gigantea. He laid it open at a pit-mouth near Musselburgh, in a mass of gray shale, 

 sorely split and weathered ; but he could do little more than determine that, like Sphe- 

 nopteris elegans, and the common bracken, it too had a thick bare rachis, and that its 

 pinnae, like its leaflets, were alternate in their arrangement, when it fell to pieces in his 

 hands. Mr. Miller regretted that, during the glimpse which he enjoyed of this beau- 

 tiful frond, he failed to remark the order in which the larger divisions of the rachis 

 took place ; he merely saw, from the general effect, that the frond as a whole — balan- 

 ced on its strong club-formed leaf-stem — was greatly massier than that of either Pteris 

 aquilina or Sphenopteris elegans ; and that in the clustered richness of its leaflets, al- 

 though not in their disposition, it resembled our recent Osmunda regalis, or royal fern. 

 So transient was his glimpse of the plant, that it has since reminded him of those mo- 

 mentary glances caught, according to tradition, of long-buried monarchs in their sepul- 

 chres, that in one moment are seen august in all their robes, and in the next descend- 

 ing before the admitted air into a shower of light dust. Mr. Miller next exhibited 

 and described a very fine, and in some respects unique specimen of Ulodendron minus, 

 which he had disinterred from out a bed of ferruginous shale in the Water of Leith, a 

 little above the village of Colinton. Though little more than 10 inches in length by 3 

 in breadth, it exhibited no fewer than seven of those round beautifully sculptured scars, 

 ranged rectilinearly along the trunk or stem, by which this ancient genus is so remarkably 

 characterized. The specimen is covered with small, sharply relieved, obovate scales, 

 most of them furnished with an apparent mid-rib, and with their edges slightly turned 

 up ; and from these peculiarities, and their great beauty, are suited to remind the ar- 

 chitect of that style of sculpture adopted by Palladio from his master, Vitruvius, when, 

 in ornamenting the Corinthian or composite torus, he fretted it into closely imbricated 



