The rocks are covered with a species of _Byssus_ long and rough to the touch, forming a kind of hoary beard; in many places they are deeply furrowed, carrying with them a singular air of antiquity, which combines with the whole of the romantic scenery to awaken in the minds of the poet and enthusiast the recollection of the Druidical ages. The Botanist will observe the common Thrift (_Statice Armeria_) imparting a glowing tinge to the scanty vegetation of the spot, and, by growing within the crevices of the rocks, affording a very picturesque contrast to their massive fabric. Here too the _Daucus Maritimus_, or wild carrot; _Sedum Telephium_, _Saxifraga Stellaris_, and _Asplenium Marinum_, may be found in abundance. The Granite in this spot is extremely beautiful, on account of its porphyritic appearance; the crystals of felspar are numerous and distinct; in some places the rock is traversed by veins of red felspar, and of black tourmaline, or schorl, of which the crystalline forms of the prisms, on account of their close aggregation, are very indistinct. Here may also be observed a contemporaneous vein of _schorl rock_ in the granite, nearly two feet wide, highly inclined and very short, and not having any distinct walls. On the western side of the Logan rock is a cavern, formed by the decomposition of a vein of granite, the felspar of which assumes a brilliant flesh-red, and lilac colour; and, where it is polished by the sea, exceeding even in beauty the _Serpentine caverns_ at the Lizard. Mr. Majendie observed in this spot numerous veins of fine grained granite, which he is inclined to consider as _cotemporaneous_; he also observed what, at first sight, appeared to be fragments, but which, upon closer examination, he pronounces to be _cotemporaneous concretions_; for large crystals of _felspar_ may be seen shooting from the porphyritic granite into these apparent fragments. These phenomena are extremely interesting in a geological point of view, and well deserve the attention of the scientific tourist. In Treryn cove, just below the site of the castle, Dr. Maton found several of the rarer species of shells, as _Patella Pellucida_, _P. Fissura_, _Mytilus Modiolus_, _Trochus Conulus_, _Turbo Cimex_, and _T. Fascitatus_ (of Pennant.) Before we quit this coast we beg to state, for the information of the geological tourist, that the _Granite_ which we have just traced from beyond the Land's End to this spot, continues until within half a mile of the signal post near Lemorna cove, where it meets with a patch of slate, and is lost for about the space of three quarters of a mile. At the western extremity of this junction (_Carn Silver_) the mineralogist will find embedded Garnet-rock with veins of _Epidote_ and _Axinite_. Here may also be seen the rare occurrence of a granite vein penetrating both the slate and the granitic rock.