12 THE NATURAL HISTORY OF BRITISH GRASSES. 
not possessing the best character. Now, with respect to 
the first of these, it should be noted that though it in- 
creased rapidly up till the third year, it is now declining. 
This. is explained on the supposition that the drainage of 
the irrigated part was at first imperfect, and the water was 
consequently left in a partially stagnant state: this is often 
the case with such meadows on their first formation, but 
ultimately the water conduits become better managed, and 
they act more perfectly. And again, these changes become 
more evident where there is a gravelly subsoil: stiff clays, 
without a stratum of lighter matter, seldom succeed so well 
under irrigation. 
So much, therefore, for the changes which take place in 
the grasses: now if we take into consideration the same set 
of facts, as presented by herbs of other families, the alter- 
ation is still more striking, as attested by the following 
Table :— 
Tasre ITI. 
Representing the changes of Herbs found with the Grasses. 
Proportionals. 
Botanical Names. Trivial Names. ae After After 
Irrigation.) 2 years’ | 4 years’ 
= Irrigation. Irrigation. 
Ranunculus acris_ . .| Upright meadow crowfoot| 1 3 1 
bulbosus | Bulbous crowfoot .. 3 1 ss 
Plantago lanceolata | Narrow-leaved plantain 3 1 1 
media ..| Broad-leaved plantain .. 3 : me 
Trifolium repens ..| Dutch clover.. an 2 As 
pratense...) Broad clover. : 1 2 2 
Anthriscus vulgaris | Common beaked parsley 1 2 1 
Now this Table points out the important fact that large 
and innutritious herbs in pasture are destroyed by irriga- 
tion, and the previous one makes it clear that their places 
are supplied by the grasses. However, the beaked parsley 
sometimes increases at first, and though it soon gets less, 
it is not entirely eradicated without pulling ; this should be 
done, as it takes up much room, and is of little use itself. 
