EXPERIMENTS OX THE MIXED HERBAGE OF PERMANENT MEADOW. 349 
scarcely any of it on plot 9 ; Holcus and Poet pratensis are the less prominent on 
plot 10; Dociylis glomerata has decreased on plot 10, but increased on plot 9; 
Festuca ovinci has considerably increased on both plots, but the most on plot 10. On 
the other hand, Arena pubescens, Arena jlavescens , Poa trivialis, Bromus mollis, and 
Lolium perenne have almost disappeared on both plots. 
On both plots leguminous species are represented by only a small fraction of 1 per 
cent, of the total produce, and by less on plot 10 than on plot 9. 
Miscellaneous species also have considerably decreased, and more in weight than in 
number, on both plots—and again the most on plot 10 ; excepting that the Rumex 
acetosa, which is the most, and very, prominent on both, is upon the whole the more 
prominent on plot 10. Next, but in much less quantity, come the Conopodium 
denudatum, and the Achillea millefolium, both of which are much declining, but are 
somewhat more prominent on plot 9 than on plot 10. 
Thus, there was considerable similarity in the number and description of species on 
the two plots, and some, but less, in the proportion by weight of individual species; 
whilst, the weight per acre of total gramineous herbage was much less, and that of 
both the leguminous and the miscellaneous was also the less, on plot 10. The character 
of development also was extremely different. On plot 9, with the continuous supply 
of potass, the grasses showed much tendency to produce stem and seed, and to mature. 
On plot 10, on the other hand, with the only temporary supply of potass, the propor¬ 
tion of leaf to stem was very much greater, the herbage was patchy, of a much darker 
green colour, and matured unevenly, and imperfectly. There was, in fact, a relative 
plethora of nitrogen, and with the deficiency of potass a deficient assimilation of 
carbon. 
With these great differences in the character of development apparent to the eye, 
there were corresponding differences in the chemical composition quite consistent with 
them and their cause. 
In the dry substance of the produce grown with the deficient supply of potass there 
was a considerably higher, and an abnormally high, percentage of nitrogen, and a 
lower percentage of total mineral matter. There was a considerably higher percentage 
of lime, magnesia, phosphoric acid, and sulphuric acid ; a quadruple percentage of 
soda; with this a considerably increased percentage of silica, and at the same time 
a very greatly increased percentage of chlorine. There was, on the other hand, in 
the diy substance of this leafy, highly nitrogenous, and immature produce, over the 
average of the 14 years, considerably less than half as high a percentage of potass 
as in that where it had been more liberally supplied, and where the herbage was better 
developed and more matured. 
The actual amounts taken up per acre over the 14 years were, of lime, magnesia, 
phosphoric acid, sulphuric acid, and silica, much the same on the two plots; of 
chlorine one-and-a-half time, and of soda three-and-a-half times as much was taken 
