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X. Agricultural, Botanical, and Chemical Residts of Experiments on the Mixed Herbage 
of Permanent Meadow, conducted for more than Twenty Years in succession on 
the Same Land .—Part I. 
By J. B. La wes, LL.D., F.R.S., F.C.S., 
and J. H. Gilbert, Ph.D., F.R.S., F.C.S., F.L.S. 
Received June 16,—Read June 19, 1879. 
INTRODUCTION. 
In the experiments at Bothamsted with different manures, wheat has now been grown 
for 36 years in succession on the same land, barley for 28 years, and oats for nine years. 
Somewhat in like manner, but with some breaks, beans have been grown over a period 
of more than 30 years, clover for many years, and “root crops” (turnips, sugar-beet, 
or mangel-wurzel) also for more than 30 years. Each of these individual crops has 
exhibited certain distinctive characters under this unusual treatment. But, withal, 
those of the same natural family—wheat, barley, and oats, for example—have shown 
certain characters in common ; those of the Leguminous family characters widely 
different; whilst the so-called root-crops, belonging to the Cruciferous and Chenopo- 
diaceous families, have exhibited characteristics differing; from those of either the 
Graminese or the Leguminosse. 
Compared with the conditions of growth of any one of these individual crops grown 
separately, those of the mixed herbage of grass land are obviously extremely compli¬ 
cated. Thus, it comprises, besides numerous genera and species of the gramineous 
and leguminous families, representatives also of many other natural orders, and of some 
of great prominence and importance as regards their prevalence and distribution in 
vegetation generally. And if, under the influence of characteristically different manuring 
agents, as has been the case, there have been observed notable differences in the 
degree of luxuriance of growth, and in the character of development, even between 
closely allied plants when each is grown separately, and much greater differences 
between the representatives of different families when so separately grown, might we 
not expect very remarkable variations of result when different manures are applied to 
an already established mixed herbage of perhaps some 50 species growing together, 
representing nearly as many genera, and more than 20 natural orders ? 
Such—far beyond what could have been anticipated—has been the case in the 
experiments to be described. So complicated, indeed, have been the manifestations 
of the “ struggle ” that has been set up, that even after more than 20 years of 
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