100 PLANT LIFE ON THE FARM: 
and rich, deep blue-green foliage of the plants in the ad- 
jacent ammonia plot is very striking. 
The effects of manure upon the struggle.—When in 
a long series of years the effects on the vegetation of a 
particular plot are observed to be uniform in their nature, 
if not in degree, the effects are obviously attributable to 
‘ the manure employed, and the fluctuations are as clearly 
dependent on climatal variations. In endeavoring to 
give an idea of the effect of different manures in influen- 
cing the nature and fierceness of the struggle, it will be 
convenient to allude first to those cases in which no 
change has been made in the condition of manuring, 
mentioning first those plots in which comparatively 
simple manures are employed, and afterwards those in 
which a more complex manure is employed. 
Mineral manures alone.—One of the plots at Roth- 
amsted illustrates the effects of mineral manures consist- 
ing of admixtures of various earthy and alkaline salts 
used by themselves, without the admixture of nitroge- 
nous substances. Speaking generally, it is there observed 
that, while graminaceous herbage has, with much fluctu- 
ation, slightly increased, the proportionate amount of 
leguminous Plants, as compared with grasses, has on the 
whole been largely increased, although latterly it has 
shown a tendency to decline. The large increase is 
mainly due to Lathyrus pratensis, which prevails over 
all its fellows. The grasses which hold their own best 
are Festuca ovina, Agrostis vulgaris, and Holcus lana- 
tus. Achillea Millefolium has increased considerably, 
Conopodium denudatum and Rumex Acetosa, have usually 
been abundant. ‘This description of manure seems un- 
favorable to most of the weeds of pasture-land other than 
the above mentioned. The crop is generally moderate, 
with an even and early ripening, and a marked tendency 
