Mr. 11. Spruce on the Musci and Hepaticce of the Pyrenees. 85 



that season we were able to reach an altitude of 7000 feet, and 

 might easily have gone higher, but the ground at that height, 

 though almost clear of snow, was frozen to the depth of several 

 inches, and the waterfalls were changed into sheets of ice. The 

 chief localities examined near Bagneres, and not previously 

 named, are the forests of Transoubat and of L'Escaladieu (the 

 latter on the road to Toulouse) ; the valleys of Campan, Serris 

 and Trebons ; the Bois de Lagaillaste and the Camp de Cesar, 

 both near the village of Pouzac ; the Cotes schisteux of Loucrup 

 and the Bois de Montgaillard, on the road to Lourdes. These 

 examinations enabled me to add extensively to the list of mosses 

 previously observed by MM. Philippe and 'de Lugo. Finally 

 quitting Bagneres early in ]\Iarch, a last visit to Pau rendered 

 my collection of the mosses of the Western Pyrenees still more 

 complete ; and in proceeding thence to Paris, two days spent at 

 St. Sever with the excellent Dufour, afforded me rarities unob- 

 served the preceding year. 



In this resume of my wanderings I have avoided alluding to 

 the species collected, but it will be seen, by tracing my track on 

 the map, that I executed a network of journeys sufficient to ex- 

 plore pretty fully the tract of mountains traversed, extending 

 from the Vallee d^Aspe on the west to the Vallee d'Aran on the 

 east, and to enable me to state with considerable confidence the 

 amount and distribution of species within these limits. 



Since my return from the Pyrenees I have had a few additional 

 species and habitats from my friend Philippe, and also from 

 M. Schimper, who passed through part of the Pyrenees in 1847 

 on his way into Spain. 



It must in conclusion be acknowledged, that it is only botanists 

 resident in the Pyrenees who have it in their power to present to 

 the world a complete flora, whether Phanerogamic or Crypto- 

 gamic, of these mountains. Botanical geography is a subject 

 that can be but very imperfectly studied in the cabinet, and in 

 sittmg down to arrange the materials collected on a distant ex- 

 pedition, one always finds some deficiency, some essential obser- 

 vation omitted, which, to a person on the spot, might be sup- 

 plied by travelling possibly only a few paces. 



General considerations on the structure, ^c. of the Pyrenees. — 

 The Pyrenees may be aptly compared to an immense barrier, 

 raised by nature's hand for the separation of two nations, and 

 extending from sea to sea. The transversal ridges which spring 

 here and there from the central chain may be considered as the 

 buttresses, or as the outworks of this great fortification. The 

 area occupied by these mountains lies between 3° 20' E. and 

 2° 0' W. long, (from Greenwich), and from a little north of the 

 43rd parallel nearly to the 42nd. Their direction, from the 



