370 Mr. E. Gibson on the Ornithology of [Ibis, 



unattainably, though the long leagues gather behind one, 

 day after day ; while the only sounds are those of the breeze 

 among the grasses and scarlet verbena, the occasional cry of 

 a bird, and the continuous dull beat of the horse's hoofs on 

 the springy turf, to the jingling accompaniment of the 

 Spanish saddle-housings and the cheery bell of the ma- 

 drina mare leading the tropilla ahead. "Paja y cielo," as 

 Cunninghame Graham aptly puts it, " Grass and sky." 



The actual alluvial soil here is shallow, and consists of 

 about nine inches of black earth, followed by a foot of grey 

 clay (" greda"); then comes sand, a deeper belt of blue clay, 

 and after that — more sand ! I had hitherto written that the 

 preceding expressed all that was known of the depth of these 

 strata. But a few years ago the Government undertook 

 the sinking of an artesian well in the township of General 

 Lavalle or Ajo. The cost ran to several thousand pounds; 

 the boring reached a depth of over 2500 feet ; no potable 

 water was struck, and the geological formation throughout 

 was purely Pampean — sand, clay, loess, etc. Tliere are no 

 stones or pebbles in the soil, not even the dimension of a 

 pin- head ; but sea-shells make their appearance at from 

 eight to ten feet below the surface of the ground. Water is 

 found at a depth of from four to eight feet, but is often 

 brackish or even salt. It is, of course, surface or rain- 

 water, and is retained in situ by the second belt of blue clay 

 I have mentioned; if this is traversed, the up-welling is a 

 water not only salt, but liitter. Probably the district only 

 averages six feet above the level of the sea. 



Of the herbage or grasses, suffice it to say that they have 

 undergone various important modifications during the past 

 century of grazing — the Pampa-grass, for example, formerly 

 covering a large part of the centre of the estancia, being 

 only found in the rincones now, its place being taken by 

 soft grasses. De Moussy, in his work on the Argentine 

 Republic, includes this district among the highest class of 

 pastoral lands in the Province of Buenos Ayres; and Buenos 

 Ayres yields precedence to no other country in the world in 

 that respect. Rye-grass is the staple indigenous pasture ; 



