460 PROF. W. FREAM ON THE 
Of these, Triodia, Keleria, and Festuca gigantea, as well as 
F. ovina, grow close down to the border of the water-meadows 
and then disappear. Avena pubescens thrives luxuriantly on 
non-irrigated grass-land closely adjacent. But, of the species 
now under consideration, those of Dactylis and Catabrosa are, 
perhaps, the most remarkable in their behaviour. Very abundant 
in the adjoining dry meadows, and, under the name of Orchard 
Grass, well known in America on account of its partiality for moist 
cool situations, I have never yet found Dactylis on the water- 
meadows. Catabrosa, again, is the commonest grass in the way- 
side ditches of the district, its herbage and panicles being con- 
spicuously noticeable during the summer months, yet it never 
appears in the water-courses upon the meadows. The cause of 
this is difficult to determine, but it is possible that Dactylis and 
Catabrosa may be adversely influenced by the alternate flooding 
and drying of the meadows. 
Only two of the water-meadow grasses, Bromus mollis and B. 
racemosus, are of annual duration. These, therefore, are able to 
maintain their position, and that indeed rather a prominent posi- 
tion, amongst the herbage of the water-meadows, only through 
shedding their seed before the hay-crop is removed. The meadows 
are mown at the end of June or beginning of July, by which 
time these species of Bromus are ripe, and the effect of making 
the hay is to detach the “seeds "— or rather the dried florets 
containing the grain—and to leave them upon the meadows. 
In panicles of Bromus, taken from the hay as it is being carted 
from the meadows to the stack, each spikelet is found to be 
represented merely by the two empty glumes at its base. 
The most abundant of the water-meadow grasses is Holcus 
lanatus, which occupies on these moist lands a much more pro- 
minent position than it takes amongst the herbage in Rothamsted 
Park. The free development and multiplication of its roots 
combine with its tufted habit to secure it in a position it has 
once attained, whilst, independently of these properties, its early 
period of ripening seed would enable this species to keep its place. 
Ripe seed invariably appears before the end of June, though it is 
a little later than Bromus in this respect. Anthoxanthum is, how- 
ever, the first of the water-meadow grasses to ripen its seeds; 
moreover it may, from the end of May to the beginning of July, 
be found in all stages of growth, from the first appearance of its 
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