100 
Drought of 1870 and 
nured crops derived the water required for their growth, over 
and above that supplied by the rain actually falling during the 
period of active vegetation. But the questions obviously arise — if 
the unmanured subsoil retained so much more water, why did the 
crop suffer from the drought so very much more than the manured 
crops ? and why did the crop manured with mineral manure and 
ammonia-salts suffer so much more than that manured with 
mineral manure and nitrate of soda, and not avail itself so fully 
as did the latter of the stores of moisture within the soil ? To 
gain some information on the points here suggested, careful 
examination was made of the distribution of species on the 
square yard of the plot selected, of the section of the soil and 
subsoil, and of the distribution of roots within them. 
It should be stated that 53 species in all are found on the 
continuously unmanured plot ; this great complexity of herbage 
being maintained in consequence of the little encouragement to 
luxuriance of any. On the other hand, by the application of 
mineral manure and ammonia-salts on Plot 9, and of mineral 
manure and nitrate of soda on Plot 14, for many years in suc- 
cession, and the consequent great encouragement and predomi- 
nance of certain individual species, the total number discernible 
has become reduced to 30 on each of these plots. And whilst 
the herbage on the unmanured plot comprises 17 graminaceous, 
4 leguminous, and 32 miscellaneous or weedy species, that of 
Plot 9 includes only 15 graminaceous, 2 leguminous, and 13 
miscellaneous species, and that of Plot 14 only 14 gramina- 
ceous, 3 leguminous, and 13 miscellaneous species. 
But such, again, is the difference in the character of the two 
nitrogenous manures — ammonia-salts and nitrate of soda — in 
regard to their reactions upon the soil, and the consequent degree 
of rapidity and range of distribution of them or their products of 
decomposition within it, that they respectively encourage the 
development of species of widely different underground, as well 
as above-ground habit of growth. Thus, the dominant plants 
were very different on the two manured plots. Under the influence 
of the annual application of mineral manure and ammonia-salts, 
Dadylis f/lomerata (rough cock's-foot), Ar/rostis vulgaris (common 
bent-grass), Fesluca ovina (sheep's-fescue), and Poa pratensis 
(common meadow-grass), among graminaceous plants, and 
Rumex acetosa (sorrel-dock), among the miscellaneous herbage, 
prevailed somewhat in the order of enumeration ; whilst under 
the influence of mineral manure and nitrate of soda Bromus 
mollis (soft brome-grass), had become so prominent as to constitute 
probably about one-half the crop ; Poa trivialis (rough meadow- 
grass)was also very prominent, Holcus lanatiis (woolly soft-grass). 
