MISCELLANEOUS PLANTS F 299 
inconvenience and expense. We call them weeds.! Their domes- 
tication is not of our choosing but of their own making, and it 
has come about in any case because their individual require- 
ments fitted almost perfectly with those of some other species 
which we were trying to domesticate and produce in quantity. 
For example, chess (Bromus secatinus) is a plant having the 
same soil and seasonal requirements as wheat, though of a dis- 
tinctly different genus. The seeds are near enough alike, how- 
ever, to be separated with great difficulty ; hence some chess is 
nearly always sown with wheat. The chess plant is much hardier 
and much more prolific? than the wheat, so that if the two were 
thrown together, the chess would soon take the ground. 
As it is, if anything happens to the tender wheat, as in winter 
killing, there is generally enough chess at hand to make a 
showing, even with less than two hundred spears to the stool, 
giving rise to the absurd belief that the wheat has ‘turned 
to chess.” 
Every weed has some natural advantage, generally arising in 
the crop conditions with which it most easily and naturally 
associates, and here is the vulnerable point of attack for its 
extenuation, 
Weeds, of course, came out of the wild, and most of them 
still exist in the wild in the same regions which they infest as 
weeds. This is true of such as cocklebur, Canada thistle, 
quack grass,’ etc., but others, like cockle and chess, are not found 
except in association with growing crops; that is to say, they 
do not readily escape from cultivation. 
The behavior of a weed upon first introduction is little indi- 
cation of what its subsequent history will be. Wild lettuce, for 
example, spread over the western United States a few years 
1 The best definition for a weed is “a plant out of place.” 
2 The writer once counted two hundred and four species of chess, each 
bearing a full “* head” and all springing from a single root originating from a 
single seed. 
3 These weeds, however, are not, in most cases, truly wild, but have been 
“introduced” and afterwards have “ run wild” like feral animals. 
