26 Comparison of the Floras of 



of the clifF the ground is covered with masses of limestone, 

 which have fallen down from the rocks above. Indeed, the 

 pastures shelving down to the river, at a few inches below the 

 surface, are composed of the debris which have by degrees 

 fallen, and are now become clothed with grass. Near Rich- 

 mond a vein of copper passes underneath the bed of the river ; 

 it was once worked, but, having been found a losing concern, 

 it was given up. 



As we ascend the river a circular hill, named the Round 

 How, is seen on the left bank, of much interest to the geolo- 

 gist. On the side facing the river it slopes with a gentle 

 descent, but on the opposite side it is precipitous, covered 

 with loose masses of stone, and overgrown with underwood. 

 It is completely detached by a narrow defile from the hills, 

 which form a semicircle behind it, and evidently appears to 

 have been cut off by some great acting force from them. The 

 same appearance, though to a much greater extent, is pre- 

 sented by Hood Hill, a circular mountain, in like manner 

 detached from the Hambleton Hills, and standing quite alone. 

 It is backed by Roulston Scarr, which is composed of the 

 old red sandstone, and rises to the height of about 800 ft. 

 above the level of the sea. 



The woods in the neighbourhood of Richmond vary much 

 in their appearance, and no less so in their vegetable produc- 

 tions. Indeed, even on the opposite wooded banks of the 

 river, the plants frequently differ in a surprising degree. 

 Most of the vegetables peculiar to the limestone districts are 

 found here in abundance. The bogs are seldom or never of 

 a peat character, and are formed by the rain which falls in the 

 spring, and by the mosses, especially A^phagna, is long retained. 

 On the higher grounds fir woods almost exclusively prevail ; 

 and a striking difference may be observed between the vege- 

 table productions of the upland and lowland woods. In the 

 neighbourhood of Thirsk peat bogs are not unfrequent ; and 

 it may not be uninteresting to observe the difference of vege- 

 tation between them and those in a limestone district. I have 

 generally remarked that peat produces the rarest plants ; but 

 to compare the two : — 



In a large bog near Richmond we find Calluna vulgaris, 

 ^rica cinerea and Tetralix, all flourishing extremely well ; in 

 peat E, Tetralix alone. Faccinium Myrtillus and JS''mpetrum 

 nigrum we have in vast quantities; in Leckby Car, a peat 

 bog near Thirsk, Oxycoccus palustris takes the place of V. 

 Myrtillus : the Eriophora flourish equally in both. With 

 us, O'phrys cordata, 5'phagnum, Polytrichum, ^lola palustris, 

 several species of ferns, carexes, &c., principally abound, 



