THE BiETICAN WILDEKNESS APRIL. 71 



ing up between the opposing forces an impregnable rampart 

 of sand. The latter, overlying the margin of the rich 

 alluvial mud, is thus capable, in its hollows and deeper 

 dells, of sustaining a luxuriant plant-life, which in turn 

 serves to fortify and consolidate its otherwise unstable con- 

 sistency.* 



The largest of the Spanish marismas, and those best 

 known to the authors, are those of the Guadalquivir. If 

 the reader will look at a map of Spain, there will be 

 noticed on the Lower Guadalquivir a large tract totally 

 devoid of the names of villages, &c. From Lebrija on the 

 east to Almonte on the west, and from the Atlantic almost 

 up to Seville itself, the map is vacant. This huge area is, 

 in fact, a wilderness, and in winter the greater part a 

 dismal waste of waters. For league after league as one 

 advances hito that forbidding desolation, the eye rests on 

 nothing but water — tawny waters meeting the sky all round 

 the horizon. The Guadalquivir intersects the marisma, 

 its triple channel divided from the adjacent shallows and 

 savannahs by low mud-banks. The water of the marisma 

 is fresh, or nearly so — quite drinkable — and has a uniform 

 depth over vast areas of one or two feet, according to the 

 season. Here and there slight elevations of its muddy 

 bed form low^ islands, varying from a few yards to thou- 

 sands of acres in extent, covered with coarse herbage, 

 thistles and bog-plants, the home of countless wild-fowl and 

 aquatic birds. In spring the water recedes ; as the hot 

 weather sets in it rapidly evaporates, leaving the marisma 

 a dead level of dry mud, scorched and cracked by the 

 fierce summer sun. A rank herbage springs up, and 

 around the remaining water-holes wave beds of tall reeds 

 and cane-brakes. 



In winter the marshy plains abound with wild-fowl, 

 ducks, geese, and water-birds of varied kinds ; but of the 

 winter season in the marisma, its fowl and fowlers, we treat 

 fully hereafter. 



The spring-months abound in interest to the naturalist. 



* The mancha of Salavar in the Goto Donana is an example of one 

 of these green oases an^idst barren, hfeless sand-wastes. 



