THE BATTLE OF LIFE. 10? 



creased, while miscellaneous plants, especially Achillea 

 Millefolium and Rumex Acetosa, have increased. 



The increase of Festuca ovina is probably not so much 

 due to any favoring effect of the manure as to the en- 

 feeblement of its competitors. AnthoxantJium odoratum 

 has increased, but almost all the other grasses have 

 diminished. Ranunculacece, Composite, especially Achil- 

 lea, have increased since the disuse of potash. Umbel- 

 lifers, Plant ago lanceolata, and Rumex Acetosa have 

 decreased. 



On the plot where ammonia is added to mineral ma- 

 nures, but where potash is omitted, the grasses show a 

 large per-centage from the effect of the ammonia ; the 

 leguminous plants are almost banished, owing to the 

 combination of unfavorable circumstances, i. e. y the 

 presence of ammonia and the absence of potash. Kanun- 

 culaceae are diminishing, as are also Umbelliferae, Com- 

 posites, Plantago lanceolata, and Rumex Acetosa. 



As a general rule, it is recognized that the growth of 

 plants is checked if the quantity of potash be reduced 

 bevond a certain limit. Deherain has recently shown 

 that in the case of the buckwheat, starch is not gener- 

 ated from chlorophyll unless potash be present. If potash 

 be added, then starch begins to be formed. Neither 

 sodium nor lithium can usefully replace potash, though 

 extremely little is known as to the functions of the lat- 

 ter. Salts of potash and magnesia have also a general 

 tendency to augment the weight of leaves, while chloride 

 of sodium favors the development of stem. 



Substitution of Mixed Mineral Manures for Ammo- 

 nia. The consequences of the disuse of ammonia, and 

 the employment in its stead of mineral manures, are 

 shown in diminished produce, the grasses having been 

 diminished, the leguminous and the miscellaneous plants 

 increasing in number and proportion. Festuca ovina. 



