226 THE POPULAR SCIENCE MONTHLY. 



authorized right to the soil. Clover and the best of grasses may 

 be serious weeds, fit subjects to be uprooted by the cultivator or 

 hoe, when growing in a corn-field and injuring the maize crop. 

 If a field is devoted to wheat, it follows that all other plants 

 therein may be weeds, whether it be cockle, red-root, or an oak 

 tree. 



There is a possibility of any kind of a plant being a weed, but 

 this thought does not prevent some species always being out of 

 place. For example, there is no function in the economy of the 

 farm garden that the Canada thistle can do as well as many other 

 plants. As a forage plant, or a source of nutritious seeds or 

 beautiful flowers, the pig-weeds are a substantial failure, equaled 

 only by their success in occupying the soil and robbing it of 

 nourishment designed for useful plants. It would puzzle any one 

 to find a proper place for the horse-nettle, now advancing upon 

 the Eastern farmers from the Southwest, and destined to spread 

 its horrid, prickly, worse than worthless branches over our cult- 

 ured soil. The bur-grass, cockle-burs, burdock, and a long list 

 of congeners are practically universal every-day curses from which 

 all earnest crop-growers wish to be free. 



The natural covering of a fertile soil is a growth of vegetation. 

 Upon the broad, open prairie there is a dense coat of grass, 

 while in the Eastern States a heavy growth of trees clothed the 

 virgin soil. So strong is Nature's desire to assert this right that 

 if we allow one of our fields to lie fallow, at the end of the season 

 it will be covered with vegetation. She understands that a bare 

 soil is a wasteful soil, for while it is not producing anything it 

 may lose by leaching much fertility already in its bosom. Every 

 generation of plants inherits the deposits of all previous gen- 

 erations, and in turn should add to the accumulated stock in the 

 soil. By this economical and saving practice of Nature the fer- 

 tile newly broken grass lands have been made, while the upper 

 soil in the forest has received the enriching accumulations of 

 ages. Man overturns this harmonious system, and by breaking 

 up the sod destroys the very method by which sod is made. He 

 clears away the forest and many of the conditions which favor 

 the growth of trees. It is upon this newly exposed soil that 

 weeds assert their supremacy, and if the hand of man is withheld 

 they will soon weave a garment, in itself unattractive, that clothes 

 the bare earth. Weeds have a thousand ways of doing this to 

 one possessed by cultivated plants. Bring up, if you please, some 

 soil from the bottom of a newly dug well, and if exposed for a 

 season some weeds will have planted colonies upon the bare heaps 

 and vied with each other for the entire possession of the new ter- 

 ritory, at the same time gaining in forces for the occupation of 

 any similar place elsewhere. 



