THE BATTLE OF LIFE. 101 
to stemmy as distinguished from leafy growth, the color 
of the foliage being of a light, yellowish-green. 
On the wheat plots, it has been shown that purely 
mineral manures scarcely increase the yield at all, though 
they are beneficial to the leguminous crops. These ex- 
periments confirm Boussingault’s assertion that alkaline 
or earthy salts, although indispensable to plants, never- 
theless, exercise no action unless combined with matters . 
capable of furnishing nitrogen. 
Superphosphate of lime only.—The scanty and stemmy 
produce on the plot, to which this substance is applied, 
has been but little greater than that on the unmanured 
-plots. The grasses and miscellaneous plants have been 
. slightly increased, the Leguminosw diminished. There 
has been a great admixture of species, but little luxuri- 
ance of any. Holcus lanatus, Avena flavescens, Poa 
trivialis, Lolium perenne, and Festuca ovina have been 
among the most prominent grasses, while the freer-grow- 
ing Dactylis does not apparently find so much sub- 
sistence as it requires. Lathyrus pratensis among the 
leguminous plants, and Rumex Acetosa and Achillea 
Millefolium among the weeds, have but slightly benefited, 
others yielding even less than without manure. Bous- 
singault’s observations, already quoted under the head of 
mineral manures, apply equally here. The great French 
ehemist found, as in the Rothamsted experiments, that 
superphosphate, uncombined with substances capable of 
yielding ammonia, produced little or no effect on vege- 
tation. Boshm’s experiments, however, go to show that 
young plants raised in distilled water, die before the nu- 
tritious matter stored up in the seed, or in the seed- 
leaves is exhausted, but if lime be added, especially in 
the form of ulmate, before this point is reached, the 
seedlings resume their healthy appearance, the develop- 
ment of the radicle, according to Dehérain, being par- 
ticularly favored by this substance. (See Pp 18), 
