A Very Intklligknt Plant 265 



doubt, from deer and wild oxen and beavers, but 

 later on from the sheep and cows and j^oats 

 and donkeys which followed in the wake of aj^- 

 j^ressive civilisation. Under these circumstances, 

 most of the soft-leaved and unprotected plants 

 }4ot eaten down and killed off ; l>ut any shrub 

 which showed a nascent tendency to develop 

 stout spines or prickles on their branches must 

 have been favoured by nature in the struf^j^le for 

 existence. 'i'he consequence was that in the 

 end our upland slopes and open spaces all over 

 Western Europe came to be occupied by nothinj^ 

 but stronj^ly armed plants — brambles, thistles, 

 blackthorns, may-bushes, nettles, butcher's-broom, 

 and the various kinds of furze, all of which can 

 hold their own with ease against the attacks of 

 (■luadrupeds. Indeed, there is one not uncom- 

 mon Enj^lish herb, the little purple-tlowered rest- 

 harrow, which very well illustrates this curious 

 coimection between the production of thorns 

 and the habit of ^rowin^ in much - browsed- 

 over spots ; for when it settles in enclosed and 

 protected fields it produces smooth and unarmed 

 creeping branches, but when it happens to 

 lind its lot cast in places where donkeys and 

 rabbits abound, it defends itself aj^ainst the dreaded 

 enemy by coverinj^ its shoots with stout woody 

 prickles. 



Still, to the end of its days, the developed j^orse 

 plant never entirely forj^it^ that it is the remote 

 descendant of trefoil-beariu}' ancestors; for iu)t 

 only does every young gorse begin life with trefoil 



