1392 
MESSRS. J. B. LAWES, J. H. GILBERT, AND M. T. MASTERS, 
Avjma jlavescens, and, in a less degree, Poa trivialis , Lolium perenne, Avena pubescens, 
Holcus lanatus , Alopecuruspratensis, Poa pratensis , and Dactylis glomerata. Thus, the 
grasses which are in defect with the less-continued supply of mineral manure are, for the 
most part, either of better quality, or of freer growth, than those which are in excess. 
Of leguminous produce as a whole, there was very much less, as well as a greater 
or less deficiency of each species represented, with the less-continued supply of mineral 
manure, but the deficiency was by far the greatest in the case of Lathyrus pratensis. 
The yield of Leguminosae on the plot previously receiving ammonia-salts—under the 
influence of which they were almost excluded—has, indeed, been much less during the 
subsequent 12 years of the application of the mixed mineral manure including potass, 
than it was during the first 12 years of the application of the same manure to plot 7, 
in this case succeeding upon the unmanured condition of soil, and the coincident more 
complex condition of the mixed herbage. It might be supposed that the reserve of 
nitrogen to be rendered available under the influence of the mineral manure would be 
greater during the 12 years succeeding the application of an excess of ammonia-salts 
than during the first 12 years of the application of the mineral manure on plot 7. The 
great relative deficiency in yield of Leguminosae under the influence of the same manure 
applied upon a residue of ammonia-salts would seem to be explicable, therefore, on the 
supposition that the Leguminosae had been to a great extent really banished during 
the 13 years’ application of the ammonia-salts; whilst at the commencement of the 
experiment on plot 7 they were generally distributed, but of restricted growth, as 
is common without manure, or when the grasses are not forced into prominence by 
nitrogenous manures. That the deficient yield of Leguminosae on plot 6 compared 
with plot 7 is due to a want of plant, and not (as it cannot be) to a corresponding 
deficiency of food materia], is further rendered probable by the fact that, although the 
actual amount in each complete or partial separation-year since the change of manure 
on plot 6 is much less there than on plot 7, yet the amounts fluctuate somewhat 
correspondingly on the two plots from year to year according to season. 
So much for the distinctions between the botany of plot 5 with the continuous 
supply of ammonia-salts, of plot 6 with ammonia-salts succeeded by mineral manure, 
and of plot 7 with the continuous supply of the same mineral manure from the com¬ 
mencement. The figures in the table, and the foregoing comments, however, bring 
to view very inadequately the very great differences between the herbage on the 
respective plots. 
In the first season of the change of manure the herbage on plot 6 acquired a totally 
different aspect. Instead of the dark, almost blue, green colour, and restricted growth 
and development, which, in common with plot 5, it had, and which the latter still 
maintained, the Gramineae showed a much less patchy and more uniform, though still 
not luxuriant, growth, grasses of small habit, as has been shown, still remaining pre¬ 
valent ; the colour was of a paler and more lively hue; there was more tendency to 
form stem and seed, and there was fuller and more even bottom growth. Leguminosae 
