ON THE MIXED HERBAGE OF PERMANENT MEADOW. 
1227 
its functions, is better or worse adapted to tbe circumstances in which it is placed—the 
better, the more probable is its victory ; the worse, the greater the probability that it 
will give place to others. 
Absence or Predominance of Certain Species .—When in the discussion of the par¬ 
ticular plants we speak of their absence from, or of their being driven out from, par¬ 
ticular plots, our language must not be interpreted too strictly. Such statements, 
though based on careful observation on the plots during growth, and on botanical 
analysis of samples, are of necessity approximately correct only, for it can hardly be 
imagined, that in all cases of disappearance the plants are absolutely banished from 
the plot, either by the direct action of manures or by internecine conflict. They 
may be present, but in such diminished numbers, or in such limited growth, that 
they are not obvious on the plots at the times when the observations are made, 
and still less are they found in the samples. That this may be the case is shown by 
the fact that when circumstances become favourable they again appear. As has been 
said, many of the plants on the plots seldom, if ever, ripen their seed. The reappear¬ 
ance of such plants after an interval is not likely, therefore, to be due to the transport 
of seed. It is more probable that the root-stocks of such plants have all along existed 
on the plots, but, owing to unfavourable circumstances, have not been able to develop 
themselves. Some plants, it is well known— e.g ., some of the Orchids—have the 
power of maintaining an underground existence for several years, producing at most 
only a few minute leaves, and no flowers at all; so that their presence is not suspected 
till at length, in a favourable season, flowers are produced freely, and hundreds may 
be seen where the year before not one was observed. Such cases are familiar to 
botanists. 
It is now generally recognised that the “ characters ” possessed by plants are either 
congenital— i.e., ancestral, or physiological and adaptive. Tbe former which are more 
particularly represented in the organs of reproduction are not subject to be changed by 
external conditions in short periods of time. Indeed, the hereditary tendency seems 
to preserve certain characteristics relatively unchanged, while, on the other hand, 
physiological characters (though of course also inherited) are much more liable to change 
under the influence of changed external conditions. As has been said, manures affect 
the degree of vigour of the foliage, roots, stems, &c., in a very marked degree; but they 
do not bring about any absolute difference in the nature of the organ or part affected. 
Certain characteristics are enhanced or degraded, as the case may be, but no absolutely 
new characters are engendered. The “ struggle,” dependent as it is partly on inherited 
and relatively invariable characters, and partly on other more pliable characteristics, 
can never be thoroughly appreciated until the structure of the plant, and its adaptation 
to the work it has to do, and to the conditions under which it has to do it, are better 
known. 
Then as to the predominance of certain species, whilst some are more or less gene¬ 
rally distributed on most or all of the plots, others are found only on some, and in 
