EXPERIMENTS ON THE MIXED HERBAGE OF PERMANENT MEADOW. 317 
It is to be observed that there was an average of rather more hay, and of rather 
more nitrogen and mineral matter taken np, on plot 8 than on plot 7, during the first 
six years, the only difference in the treatment being that plot 8 received sawdust in 
addition to the other manures. It has been seen that when the sawdust was used 
alone it yielded no increase. Whether the result here is due to any reaction with the 
associated mineral manures, or to some accidental difference in the otherwise duplicate 
plot, it is not easy to say; but it may be remarked, in passing, that the increased 
amount of nitrogen taken up corresponded very closely with that contained in the 
sawdust. 
During the next 14 years the relations are strikingly reversed in every particular. 
There is an average of nearly one-fourth less hay produced, and of more than one- 
fourth less nitrogen and mineral matter taken up, on plot 8 without, than on plot 7 with 
potass. In fact, the falling off in amount of produce on the exclusion of potass from 
the manure was very great. The number of species has remained about the same on 
the two plots. The percentage by weight, in the total produce, of gramineous species 
was, during the earlier of the 14 years, and has been on the average, greater in the 
produce of plot 8 without potass, but, as already referred to, it has increased on plot 7 
in the later years. The percentage of the Leguminosse has diminished exceedingly on 
plot 8 since the exclusion of the potass, and over the 14 years has averaged less than 
half as much as on plot 7. The proportion of species of other orders has, on the other 
hand, been higher in the produce without potass. In weight per acre, however, the 
yield of gramineous herbage has averaged only about four-fifths as much, that of the 
leguminous herbage not two-fifths as much, and that of the miscellaneous herbage also 
has been somewhat less, without than with the potass. 
There is no very striking difference between the two plots in the relative proportion 
of the different species making up the gramineous herbage ; but whilst with the potass 
there was a very marked tendency to form stem and seed, without it there was much 
less of this character, the herbage being more leafy, less dense, and having much less 
tendency to mature, some of it, indeed, appearing to dry up from exhaustion rather 
than to ripen. 
Of leguminous herbage, there was a decline of both Trifolium repens and Trifolium 
pratense in the later years, both with and without the potass ; but the reduction 
was greater without than with it. Of the deep-rooting and hardy Lotus cornicidatus 
there was the more without the potass. But of the comparatively surface-rooting 
Lathyrus pratensis there was very much less without the potass. In fact, it was to the 
greatly increased growth of this with the potass, and to the greatiy reduced growth of 
it without it, that the great difference in the amount of total leguminous herbage on 
the two plots was chiefly due. 
Among the miscellaneous species those of Ranunculus thrived rather more without 
the potass, as also did Pimpinetta saxifraga, Centauria nigra, and Plantago lan- 
ceolata; and in a greater degree, Achillea millefolium. Conopodium denudatum was 
