on Permanent 3Ieadoic Land. 
253 
flowering and seeding stem, according to manure, is as follows : — 
The proportion of it in the total produce was considerably in- 
creased by the " mixed mineral manures " alone, by the " mixed 
mineral manures " and the smaller amount of ammoniacal salts, and 
by the farm-vard manure alone. On the other hand, its proportion 
was diminished whenever the ammoniacal salts were used in 
relative excess ; that is, when the ammoniacal salts were used 
alone, when they were used (with the mineral manures) in double 
quantity, and when they were employed in addition to the farm- 
yard manure. When the ammoniacal salts were used alone, the 
proportion of Graminaceous leaf and undeveloped stem was very 
high ; when those salts were used in excessive amount with the 
mineral manures, the proportion of tiDO other (p asses (the Woolly 
soft-grass and the Rough Cock's-foot) predominated over that of 
the Rye-grass ; and when the ammoniacal salts were used in ad- 
dition to farm-yard manure, three other plants (Woolly soft-grass, 
Tall Oat-like grass, and Smooth-stalked Meadow-grass) seemed 
to gain upon the Rye-grass in degree of luxuriance. 
Before passing to the next plant on the list, a few remarks 
may be appropriately made, which have a bearing not only on 
the interpretation of the results just given, but on that of those 
which have to follow. It must not be supposed, that figures 
which represent the proportion of jiowerhuj and seeding stem of 
a certain plant at one given period of the season, are at the same 
time accurate indications of the relative development of the total 
plant under the conditions in question. It must be borne in 
mind, that the numerous plants which constitute the complex 
herbage of our meadows, have each their natural period of flower- 
ing and seeding. This period will, however, be accelerated or 
postponed, as the case may be, by the external circumstances of 
soil, season, manure, and the association witli other plants. 
General observation shows, that nitrogenoiis manures have a cha- 
racteristic tendency to increase the development of leaves and 
shoots in our Graminaceous herbage. Mineral manures, on the 
other hand, induce much more the seeding tendency. With full 
supplies of mineral manures, therefore, wc should expect (other 
conditions being favourable) that there would be a larger pro- 
portion of the growing plant in culm, at a given period, than 
Avhen ammonia was supplied in relative excess. The general 
result was, indeed, that the proportion of the total Graminaceous 
plants which was iri culm, was the greater where the mineral 
supplies predominated, and the proportion in leaf and unde- 
veloped stem the greater when ammoniacal salts predominated. 
Hence, the effect of a manure on the development of the total 
plant, cannot be determined unconditionally by the proportion 
found in flowering and seeding stem. 
