808 
THE PRINCIPLES OF BOTANY. 
consideration of the origin, cultivation, and properties of the 
crop, cereal, corn, or cultivated oat. 
Origin of Crop Oats . — Professor Lindley, in the article 
“ Avena,” in Morton’s s Cyclopaedia of Agriculture,’ suggests 
that the cultivated oat “ is a domesticated variety of some 
wild species, and may he not improbably referred to Avena 
strigosa, bristle-pointed oat;” but our experiments would 
show that the Avena fatua is the form from which at least 
the domestic sorts in general cultivation seem to have 
sprung. 
The Avena fatua (wild oat) is an annual grass which 
almost universally accompanies agrarian circumstances ; that 
is to say, it seldom, if ever, occurs in a truly wild aboriginal 
state, and is therefore not found in uncultivated tracts, but is 
the common attendant on tillage, and in some soils is a most 
common and disagreeable weed in various agricultural crops, 
but more especially amid grain, whether of wheat, barley, or 
oats. Sometimes it is found with beans, peas, and vetches, 
and indeed it may be said to be a common weed in some 
districts in any crop from which it has not been eradicated 
by the hoe — an operation almost impossible in grain, as its 
growth is so much like that of the crop itself. 
It is a tall grass, rivalling the height of the finest culti- 
vated oat crop, from some forms of which, and especially 
those with a lax panicle, it is at first not easily distinguished ; 
however, a more careful examination and comparison with 
the so-called Avena sativa (cultivated oat) enables us to make 
out the following differences : — 
Avena fatua , L. 
The valves of the inner pales 
which adhere to the seeds, thick, 
and covered with stiff hairs, espe- 
cially towards the base. The exter- 
nal valve has a long, stiff awn, which 
in the ripe seed is usually twisted at 
the lower part and bent at nearly 
right angles at about the middle. 
The grain very small and worth- 
less. 
Averia fatua , var. sativa. 
The valves of jthe inner pales not 
so coarse as in A. fatua , and quite 
devoid of hairs. The outer valve 
with or without an awn, which, when 
present, is not so stiff as in the wild 
plant ; sometimes twisted at the base, 
but seldom bent ; seeds large and 
full, forming the grain for which the 
crop is cultivated. 
The experiments about to be detailed were performed with 
the Avena fatua. 
In 1851, a quantity of this plant was noticed by the author 
on the farm of C. Lawrence, Esq., near Cirencester. It was 
mixed with a patch of mangel wurzel which had been planted 
for seed ; and from these specimens sufficient seeds were pre- 
served wherewith to sow one of our experimental plots. 
It should be noticed that the substratum was forest marble, 
