ON THE MIXED HEBBAGE OE PEBMANENT MEADOW. 
1221 
will be seen in the sections relating to the plots, germinate freely, especially availing 
themselves of bare patches, occasioned by frost or drought killing the herbage. 
Doubtless the seedlings of other plants would grow equally well on such places, and 
sometimes indeed they do so, but the greater number of seedling plants of the Rumex 
give it an advantage over others which are less prolific. 
The early seeding tendency would necessarily give an advantage to the plants that 
possessed it, as others would be cut prior to the ripening of the seed. As the plants 
on the plots are almost all perennials, this is of the less consequence; nevertheless, it is an 
important element in estimating the results of the competition between species which 
must not be overlooked. Among those species which ripen their seed before, or about 
the time of cutting, and whose seeds are therefore liable to be dispersed, are— Anthox- 
anihum odor alum, Bromus mollis, Alopecurus pratensis, Poa trivialis , Ranunculus 
bulbosus, Pimpinella Saxifraga (in second crop), Conopodium denudatum (sometimes), 
Trifolium pratense (occasionally), Rumex Acetosa, Luzula campestris, &c. Of course, 
allowance must be made for season and for the influence of manures. 
General Effects of Manures on Vegetation. —In the experiments under consideration, 
the effects of the various manures on the vegetation were ascertained by observation of 
the plants during growth, noting the characteristic tendencies of development, by the 
botanical separation or analysis of the mixed herbage, and by the weight and chemical 
composition of the produce. The various results have been or will be brought out in 
detail elsewhere. But it should be called to mind here that a general tendency of 
nitrogenous manures is to favour luxuriant and continuous growth as distinguished 
from arrest and consolidation of that already formed; whilst that of mineral manures 
is to favour consolidation rather than luxuriance. Or, to put it in another way, a 
characteristic effect of nitrogenous manures is to favour the extension of foliage and 
give it depth of colour, whereas that of the mineral manures is to tend to stem- 
formation and production of seed. In fact, a relative excess of nitrogenous supply 
favours the extended growth of the organs of vegetation, prolonging their development, 
it may be until the resources of the plant are exhausted or the season is past. On 
the other hand, a relative excess of mineral manures may bring on premature ripening. 
It is the proper adaptation of the two descriptions of supply to the current require¬ 
ments of the plant and of the season that gives both full, properly proportioned, and 
well-matured growth. It is obvious, therefore, that when a number of plants of 
different habits, and different periods of flowering and seeding are growing in association 
as in the mixed herbage of grass land, the character of the manure must exert a very 
potent influence on the struggle.* 
It may be stated, however, that neither in the experiments at Bothamsted whether 
on individual plants or on plants growing in association, nor in those made at Chiswick 
* Bor tlie effects of manures on. individual species grown separately, see “ Eeports of Experiments on 
the Influence of Various Manures on Different Species of Plants/’ Journal of the Eoyal Horticultural 
Society, new series, vol. iii., p. 19, and “ Second Eeport,” vol. iii., p. 124 1870 ; also ‘ Botliamsted Eeports 
of Experiments on Different Crops.’ 
MDCCCLXXXII. 7 R 
