WEEDS OF AGRICULTURE. 323 



as in the great hedge-bindweed (convolvulus sepium). I 

 have observed the roots of the thistle to be often curled up, 

 but it has always been in a dry crack in the clay where they 

 could not get out. I believe the roots of thistles, the living 

 roots, can seldom be seen or found, much less picked out, 

 in a fallow. If they have horizontal roots, they lie deeper 

 than we can plough : and, indeed, something of this sort 

 might be suspected, because the spring and summer plants, 

 especially on loose soils, often draw with a tap root (an 

 annual root) a foot long, or more, still leaving part behind. 

 However, this root or descending caudex may strike down, 

 from midway or higher, in the cultivated soil, as the ascend- 

 ing caudex or stem rises. I have found on light rich soils, 

 in spring, a great many small thistles, as it were, bursting 

 from their matrix, and have gently pulled the horizontal zig- 

 zag roots from the soil, v/ith many green buds and shoots 

 just appearing. These roots were jointed, white, and of a 

 very succulent texture. This, therefore, is the manner of 

 their reproduction : the fibres left, shoot out larger roots, 

 which also rise higher in the soil, and spread ; these form 

 buds, and hence come our annual crop of thistles. 



Now, what is the inference from the facts, that couch- 

 grass and thistles can by no means be extirpated ? Is it not 

 perpetual exertions, fallowing, and agricultural labour? 

 Some may be inclined to say, " A melancholy reflection ! " 

 — But I say no — not at all. Providence could not have 

 better contrived than that exertions should be perpetual, and 

 that success should be in proportion. There is not a weed 

 that vve ought to wish out of our fields, unless v;e remove 

 and destroy it ; because, if there were none, or very few, all 

 fields would be clean, and no praise could light on superior 

 modes of tillage. Some may say again, " So much the 

 better!" — But I say no: — Does any man think that our 

 various soils would have been sufficiently pulverized and 

 worked, had there been no enemies of this sort to challeno-e 

 forth our labour? Sterility would have seized on our turnip 

 lands, which are only continued in a state to bear their rela- 

 tions of crops, by the necessary periodical renewals of their 

 fertility. So might all our clays have gone to perpetual 



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