148 
Effects of different Manures on the 
may be fully relied upon as showing; the general relation to one 
another of the individual species, or different orders of plants, it 
is by no means supposed that small numerical differences, or even 
in all cases greater ones, are to be taken unconditionally as repre- 
senting corresponding differences in the character of the herbage. 
It will be readily understood that in any case, and especially in 
that of a very heavy and luxuriant crop, there must be great 
difficulty in collecting a sample of no more than some ten pounds 
weight which will absolutely represent the bulk of the mixed 
herbage. Then again, the difficulty of separation and identifica- 
tion in the case of a mass of ill-defined and mutilated leafy 
produce is extremely great. It was with a full appreciation of 
these difficulties that we felt it necessary, if for no other i-eason 
than as a means of control over the numerical results, that the 
several series of notes to which reference has been made should 
be taken. And although the botanical separations have been 
conducted at the cost of an immense amount of care and labour, 
we shall, in the few remarks we have to make on the results on 
the present occasion, be guided by a careful consideration of the 
recorded observations, as well as of the figures given in the tables. 
Taking the distribution of plants in the produce of the un- 
manured land as the standard by which to compare that of the 
other plots, attention will be directed in some detail to its com- 
ponents. 
The Unmanured produce. 
Sixteen Graminaceous species were identified in the un- 
manured produce, constituting together about 74 per cent, of 
its weight ; and although their distribution was more even than 
in most of the cases of the manured land, the species of the five 
predominating genera amounted in one case to 43 and in another 
to 47 per cent, of the total produce. In the produce of the 
heaviest crops, however, generally over 60, and sometimes as 
much as 68 or 69 per cent, were referable to the five predomi- 
nating species, or at any rate to the species included within the 
five predominating genera. 
In the unmanured produce, Festuca duriuscula, or F. pratensis, 
which arc hardy and good grasses, Avena pubescens and A. 
flavescens, sweet and good grasses, adapted to dry and chalky 
land, and much liked in hay, were the most prominent ; but they 
were by no means in such large proportion as the predominating 
grasses on most of the manured plots. Next to these were Loliiim 
perenne, a very good and free-growing grass ; Agrostis vulgaris, 
a creeping-rooted plant, said to be not liked by cattle ; and 
Holcus lanatus, also a bad food-grass, being too soft and woolly. 
After these came Arrhenatherum avenaceum, a rather favourite 
