ISO COLIN CLOUT'S CALENDAR. 



But even after the thistle tribe had separated from 

 its sister-composites of the daisy and dandelion groups, 

 it was far from having reached the fully developed 

 thistly type. The lower members of the tribe have no 

 prickles, and some of them are very simple unarmed 

 weeds indeed. The common sawwort, which abounds 

 in copses and hangers in the south of England, re- 

 presents the first rough draft of a thistle in this nascent 

 condition. To look at, it is very thistle-like indeed, 

 especially in its purple flower heads, closely surrounded 

 by a set of 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 low- 

 lands, evolved under stress of damage from herbivorous 

 animals. But where cows and horses abound, or still 

 earlier where deer and antelopes are common, the de- 

 fenceless sawwort would have little chance ; and under 

 such circumstances only the harder and stringier plants, 

 or those which showed some tendency to produce pro- 

 tective spines and bristles, could hope for success in the 

 struggle for existence. Thus there has arisen a natural 

 tendency in the level plains to favour all weeds so pro- 

 tected ; 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 object as cultivators is 

 generally to keep down these natively well-endowed 

 races, in favour of the softer grasses and clovers, which 



