THISTLEDOWN BLOWS. 143 



purple flower heads, closely surrounded by a set ef tight 

 but not prickly bracts. Living, as it does, in bushy 

 places, however, where cattle seldom penetrate, it has 

 not felt the need of protective defences ; and so it has 

 not been ousted from its own special haunts by the later 

 and more highly developed true thistles, which are by 

 origin weeds of the open grass-clad lowlands, evolved 

 under stress of damage from herbivorous animals. But 

 where cows and horses abound, or still earlier where deer 

 and antelopes are common, the defenceless sawwort 

 would have little chance ; and under such circumstances 

 only the harder and stringier plants, or those which 

 showed some tendency to produce protective spines and 

 bristles, could hope for success in the struggle for exist- 

 ence. Thus there has arisen a natural tendency in the 

 level plains to favor all weeds so protected ; and as a 

 matter of fact the vast majority of open lowland weeds 

 at the present day do actually possess some protective 

 device of stings, harsh hairs, prickles, or spines, or else 

 are very stringy or very nauseous to the taste. Our ob- 

 ject as cultivators is generally to keep down these 

 natively well-endowed races, in favor of the softer 

 grasses and clovers, which we are obliged artificially to 

 fence in and protect with all possible precautions. But 

 even so, in spite of all our endeavors to expel nature 

 with our civilized pitchfork, " tamen usque recurrit." 



The thistle that is overruning the Home Close ranks, 

 indeed, among the best adapted and most successful of 

 its kind ; which is only the converse way of saying that 

 it is a most troublesome and ineradicable weed. Creep- 

 ing-thistle, we call it, from its peculiar habits ; for, be- 

 sides its open mode of propagation by its floating seeds, 

 it has a sneaking trick of spreading underground by its 

 ouried rootstock, which sends up fresh stems every year 



