The Testimony of the Rocks. 89 



imately alternate ; and is everywhere covered, stem and branch, 

 by thickly set scale-like leaflets, that, suddenly narrowing, termi- 

 nate in exceedingly sHm points. It has, however, proportionally 

 a stouter stem than Lycopodium ; its leaves, when seen in profile, 

 seem more rectilinear and thin ; and none of its branches yet 

 found bear the fructiferous stalk or spike. Its resemblance, how- 

 ever, to this commonest of the Lycopodia, — a plant that may be 

 gathered by handfuls on the moors by which the flagstone are 

 covered, — is close enough to suggest a new reading of the fami- 

 liar adage on the meeting of extremes. Between the times of this 

 ancient fossil, — one of the oldest of land plants yet known, — and 

 those of the existing club moss that now scatters its light spores 

 by millions over the dead and blackened remains of its remote pre- 

 decessor, many creations must have intervened, and many a pro- 

 digy of the vegetable world appeared, especially in the earlier 

 and middle periods, — Sigillaria, Favularia, Knorria, and Uloden- 

 dron, — that have had no representatives in the floras of latter 

 times ; and yet here, flanking the immense scale at both its ends, 

 do we find plants of so nearly the same form and type, that it 

 demands a careful survey to distinguish their points of difference. 

 Here, for instance, to illustrate the fact, is there a specimen of 

 Lycopodium clavatum, from one of these Caithness moors, that 

 agrees branch for branch, and both in the disposition of its scales 

 and in general outline, with the specimen in the stone. What 

 seems to be an early representative of the Calamites occurs in the 

 same beds. Some of the specimens are of large size, — at least 

 from nine inches to a foot in circumference, — and retain their 

 thickness, though existing as fragments several feet in length, 

 with but little diminution throughout. They resembled the inte- 

 rior casts of Calamites in being longitudinally furrowed ; but the 

 furrows are flatter, and are themselves minutely striated length- 

 wise by lines as fine as hairs ; and, instead of presenting any ap- 

 pearance of joint, there. run diagonally across the stems, inter- 

 rupted and very irregular lines of knobs. These I find referred 

 to by Dr. Joseph Hooker, in describing a set of massive but ill 

 preserved remains of the same organism detected in South Ness 

 quarry, near Lerwick, by the Hon, Mr. Tuff"nell, as taking, in two 

 of the specimens, " the appearance of transverse knobs and bars 

 (mayhap spirally arranged) that cross the striae obliquely. But 

 though the knobs," he adds, " may perhaps indicate a peculiar char- 

 acter of the plants, they have more probably been caused by pres- 



