ON THE MIXED HERBAGE OF PERMANENT MEADOW. 
1361 
more of other mineral constituents besides those supplied, taken up, and coincidently 
more total growth—that is, there was more carbon assimilated, and more dry substance 
produced, the result of a fuller development of some of the more vigorous, freer-growing, 
and early maturing grasses, as Alopecurus pratensis, A vena elatior, Poa pratensis, and 
Holcus lanatus. All of these are, especially compared with Agrostis, early ripeners; 
and with this character it is to he supposed that they would gain in consolidation, and 
with this in weight, at the same time that they would tend, both by their obtrusion 
and more rapid accumulation of material, to limit both the space and the resources at 
the command of their later maturing associates. With the increased growth there 
was great coarseness of herbage, but a less merely tufty and patchy condition of the 
plot, there being many fewer bare spaces of damaged herbage. The dark green and 
immature condition was also somewhat less marked ; whilst some species, specially 
Avena elatior in some seasons, flowered and seeded more freely; in other words, 
matured better. This plant, it may be noted, on both plots and in most seasons 
formed stem and seed more freely than any other species in the second crops; indeed, 
in some cases it apparently contributed more stem to the second crop on plot 11-2 
than all the other species over the whole series of plots. These circumstances must 
not be overlooked in accounting for the considerably increased predominance of Avena 
elatior, especially on plot 11-2, where the conditions for maturation were, as has been 
shown, somewhat more favourable than on 11-1. On the other hand, Dactylis was, 
as a rule, by no means the most prominent in the second crops, especially in the later 
years, during which they have for the most part been cut and removed from the land ; 
increasing, therefore, the exhaustion of the soil, and obviously introducing an element 
which should be borne in mind in judging of the causes of the changes in the flora 
from the third to the fourth separation-years. 
It has been pointed out in reference to the results on plot 11-1 that, so far as the 
nitrogen and the mineral constituents supplied and taken up were concerned, there was, 
so to speak, potential, beyond the degree of actual, growth attained. Now, on 11-2, with 
somewhat greater mineral supplies, more of nitrogen and of mineral matter taken up, 
and some more growth, we have still, as shown both by the insufficiently matured 
character of the herbage, and by its chemical composition, deficient carbon-accumula¬ 
tion in relation to the soil-supplies—nitrogen and mineral matter—taken up. In fact, 
it would seem that the limits of possible growth under the influence of the soil in 
question, and of the average climatic conditions of the seasons, had been reached. 
10. Nitrate of soda (550 lbs. per acre), with mixed mineral manure, including potass ; 
Plot 14. 
The same mineral manure, including potass, is annually applied to this plot as to 
plot 9, and the same amount of nitrogen also, but in the form of nitrate of soda instead 
of ammonia-salts. It has been shown that, when each of these was used without 
