760 SUBANTARCTlC ISLANDS OF NEW ZEALAND. [Soils and Soil- formers. 



with Acaena beneath. This soil differs from that of Fairchild's Garden in the much 

 larger amount of mineral matter, especially silica, which is present as an angular 

 quartz sand. Owing to the greater depth to which this was taken, it must be com- 

 pared with J 811, together with its subsoil J 812. It would be interesting to as- 

 certain if the content of angular silica is constantly correlated with the occurrence 

 of shrubby flora in this locality. 



Littoral Humus Soils (less than 10 per cent, inorganic, and more than 0*25 per 



cent. salt). 



J 803, 805, 806, 815, 834.— J 803 was collected at the littoral. Camp Cove depot, 

 Auckland Islands, on the 23rd November, 1907, to a depth of 18 in. The soil was 

 resting directly on the rock (basalt), which was only weathered to a slight depth, 

 a mere skin of about | in. or so (J 801), where the rootlets were resting upon it. 

 Below this was the unweathered rock (J 802). 



J 805 was a brown soil with many roots, taken on the 24th November at the 

 littoral of Masked Island, a small island off Camp Cove depot, to a depth of 18 in. 

 Aspect east. Flora : Poa foliosa and Stilhocarpa polaris. (See fig. 7, p. 202.) 



J 806 was the lower 18 in., a black soil with few roots, taken below J 805. 



This soil rested directly on basalt, which was only slightly weathered at the 

 point of contact — about ^ in. thick (J 807).* Below this was the unweathered 

 rock (J 808).* 



An interesting fact observed in sampling these soils was that the top soil con- 

 tained many roots and the subsoil few roots, but on the weathered rock below this 

 there rested a mat of small roots. It will be seen that the greatest amount of plant- 

 food soluble in hydrochloric acid is found in the top layer, while the greatest amount 

 of salt (sodium-chloride) is found in the bottom layer. 



J 815 was taken to a depth of 1 ft. on the west end of Adams Island, at the 

 entrance to Carnley Strait, from a pure formation of Poa litorosa, about a chain from 

 the sea. This grass, usually found in tussocks, was here — where it met the full 

 fury of the westerly salt-laden gales — densely miatted together, forming a dense 

 and thick sward. 



The amount of salt present is high enough to place these soils with the Snares 

 soils. 



On barer places, near the situation of J 815, are plants of a decided halophytic 

 nature, such as Samolus repens, Plantago Brownii, Tillaea moschata, Cotula plumosa, 

 while the nearest bush is mostly Veronica elliptica (a littoral species) and Draco- 

 phyllum longifolium ; and the rata {Metrosideros) is not so plentiful, and, where 

 present, is stunted. 



The tolerance which Poa litorosaf and its near ally Poa Astoni exhibit towards 

 salt, and the avidity with which the Enderby Island cattle have almost exterminated 

 the former and the Bluff stock the latter, suggest their economical use as a pasture 

 in salt, wind-swept areas. Experiments are being made to test the value of these 

 grasses, live specimens of which I collected and sent to the experimental farms of 

 the Department of Agriculture. 



* J 807 and 808 were not analysed, but J 799 and 800 are very similar in every respect to them, 

 f A fine specimen of this grass is shown in fig. 1, p. 187, with Dr. Cockayne standing. 



