1314 
MESSRS. J. B. LAWES, J. H. GILBERT, AND M. T. MASTERS, 
Whilst on plot 5, with ammonia-salts, the number of species found in the samples 
declined in the first three separation-years from 38 to 36 and 31, on plot 15, with the 
nitrate of soda, it was 39 in each of the three years; and whilst it declined to 29 in the 
fourth separation-year with ammonia-salts, it rose to 43 on plot 15 after the mixed 
mineral manure had been substituted for the nitrate. 
The table shows that there was much less fluctuation, and a lower mean percentage 
of gramineous herbage, on plot 15 than on plot 5 ; the highest amount was little over 
80 per cent., the fact being that a much larger number of miscellaneous species 
contributed their share to the yield. 
A glance at the figures more in detail brings to view the fact that no one grass 
contributed such an overwhelming percentage as on plot 5, and that a much larger 
number yielded a fair proportion. Here again, however, Festuca ovina furnished in 
the third separation-year rather more than one-third of the whole; but in neither 
year did Agrostis vulgaris contribute an excessive proportion as it did on plot 5. The 
most prominent among the other grasses were— Poa trivialis and Holcus lanatus , both 
of which increased in the second year (1867), Poa trivialis very considerably, although 
it diminished in the third year (1872); Alopecurus pratensis and Lolium perenne, both 
of which however declined; Arena flavescens in smaller but comparatively uniform per¬ 
centage; and Anthoxanthum and Bromus mollis which increased. Lastly, those which 
were in fair proportion in the first year, but which were reduced very considerably 
subsequently, were Arena pubescens and Dactylis glomerata. The mere length of this 
enumeration is sufficient to show how many more grasses were enabled to maintain or 
improve their position in the struggle under the difference of condition, and more 
extended distribution, of the manurial agent within the soil, the correspondingly in¬ 
creased root-range, and the greater command of the mineral food of the soil and subsoil. 
It is due to the same causes that the grasses showed a much greater tendency to the 
formation of stem; and an examination of the right hand columns of the table, in 
which the results are compared with those relating to plot 5 with the ammonia-salts, 
will show that several species of freer growth, and higher agricultural repute, were 
brought into greater prominence. 
As with the ammonia-salts so with the nitrate of soda, the highly nitrogenous 
Leguminosse were much discouraged, but in a somewhat less degree. 
Of miscellaneous plants one only, Rumex Acetosa, was really prominent on plot 5 
with the ammonia-salts, Conopodium denudatum coming second, and Centaurea nigra 
developed more occasionally. On plot 15, with the nitrate of soda, both Rumex 
Acetosa and Plantago lanceolata were prominent in the first and second separation- 
years ; but each went down considerably in the third; Conopodium denudatum , which, 
as already said, was the second in prominence with the ammonia-salts, is in quite 
insignificant amount with the nitrate of soda; Centaurea nigra is also less prominent 
with the nitrate. The plant which has developed in the most striking degree under 
the influence of the nitrate is Cerastium tririale, which increased from little over 
