The Natural History of British Grasses, 



539 



5. A.Jiorescens — locustae of three florets, flowers small, yellow, 

 very numerous. 



Avena fatua is a grass which almost universally accompanies 

 agrarian circumstances, that is to say, it seldom if ever occurs in 

 a truly wild aboriginal state, but is an attendant upon tillage, 

 and in some soils is a most common and detested weed in various 

 crops, but more especially amid grain, whether of wheat, barley, 

 or oats ; sometimes too with beans or seeding vetches, or indeed 

 in any crop which is of sufficient duration to allow it to ripen, 

 and from which it is not eradicated in weeding by the hoe. 



It is a tall grass, rivalling the height of the finest cultivated 

 oat, from some forms of which, and especially those with a lax 

 panicle, it is at a first glance not readily distinguishable ; how- 

 ever, a more careful examination and comparison with the so- 

 called Avena sativa enables us to make out the following dif- 

 ferences : — 



Avena fatua — Wild Oat. 



Florets usually three, each armed 

 •with a stiff awn, which is bent in the 

 middle, the lower part twisted when 

 ripe ; covered, more particularly at the 

 base, with straight harsh bristles ; seed 

 small and worthless. 



Avena sativa — Cultivated Oat. 



Florets usually two, either with or 

 without awns, but straight and less 

 rigid when present than in A. fatua; 

 quite smooth externally, and somewhat 

 tumid from its enlarged seed or graiu 

 for which the plant is cultivated. 



The experiments about to be detailed were performed with the 

 Avena fatua. In the autumn of 1851 we collected some seed of 

 the wild oat, putting it aside for spring planting, and in the spring 

 of 1852 we drilled a plot of 2^ yards square with the seed that 

 had been kept during the winter — a fact to be carefully noted, 

 as it forms a first and most important link in our chain of evi- 

 dence, thus constituting what we shall hereafter revert to as a 

 cultivative process. The seed came up well, the plants on 

 ripening were tall and robust, and the grains presented a scarcely 

 apprecial)le difference from the wild examples, but if anything 

 there might have been a slight tendency to increase in the quan- 

 tity of flour. The seeds again collected and preserved through 

 the winter were sown in a patch of similar size in a different part 

 of the garden in the spring of the following years 1853-54-55, 

 with little alteration from year to year, though in some examples 

 the follovvino: tendencies seemed from the first to be srainina: 

 strength :-r- 



1. A gradual decrease in the quantity of hairs on the florets. 



2. A more tumid grain, in which the covering " skin " was 

 less coarse and the awn less stout and straighter. 



3. A gradually increased development of kernel or flour. 

 The seeds of 1855, without selection, were treated through the 



