The Parallel Foods of Glen Boy. 395 



Meckel, to admit that this internal surface, this papillary sur- 

 face of the stomach and intestines, the seat of the most deli- 

 cate and active functions of the economy, and on which the 

 most irritating and energetic substances act, is deprived of all 

 other means of protection, except the simple mucus, more 

 or less abundant, by which it is lubricated, 



" Now, as we have just seen, the internal and papillary sur- 

 face of the stomach and intestines is not, in reality, a naked 

 surface. It is covered by two continuous and superimposed 

 membranes, whereby it comes under the general law both of 

 the skin and the mucous membranes, already considered in my 

 preceding memoirs, that is, being subjected, as the skin and 

 these membranes to the incessant action of external bodies, it 

 is covered, like them, by two superimposed and protecting la- 



Account of the Parallel Boads of Glen Boy, in Invernesshire,* 



Mr Darwin, in a memoir lately read before the Geological 

 Society of London, on the Parallel Boads of Glen Boy, gives a 

 rather novel view of their mode of formation. To some of 

 our readers, it may be necessary to state what and where these 

 Roads are. The deep natural cavity along which the Caledo- 

 nian Canal passes, is called the Great Glen of Scotland. 

 Several glens open into it, and among these is the glen through 

 which the river Spean flows, ten miles northward of Fort 

 WilUam. Glen Roy is a lateral branch of Glen Spean, about 

 eleven miles long, one mile broad, and pretty steep in the 

 sides. The Spean falls into the river Lochy near Loch Lochy, 

 and the Roy falls into the Spean five miles eastward. On 

 both sides of Glen Roy, there are three narrow terraces of 

 gravel and clay, called " the Parallel Roads." They project 

 a few feet or yards from the sloping side of the mountain, 

 forming three slightly marked lines along the valley from end 

 to end, and exactly parallel to each other. At some parts 



' This notice of the Parallel Roads of Glen Roy, which we have slightly 

 altered, is taken from a paper on the subject, lately published in a widely 

 circulated periodical, the Scotsman, by a gentleman well known to the geo- 

 logical world. 



