LIFE HISTORIES OF FAMILIAR PLANTS 



which usually has five leaflets, while in the kidney 

 vetch the upper leaves often produce numerous 

 leaflets, but in the lower ones there is generally 

 one terminal leaflet of a large size, with a few 

 smaller ones along the stalk. Such species seem 

 to indicate how the trefoil form has most pro- 

 bably been evolved. 



Assuming that the gorse differentiated from the 

 family type by a tendency to develop foliage of 

 a thorny character, its tissues, nevertheless, would 

 be just as palatable to its herbivorous enemies, 

 supposing that they were able to resist the prickli- 

 ness. While food was abundant, however, such 

 plants would be left alone, just as would the in- 

 dividuals of the broom species that developed a 

 bitterness in their tissues ; thus the species steals 

 a march on its enemies, and only at times, when 

 the more palatable species were scarce, would 

 attacks be made upon the protected species. Dur- 

 ing the intervals of attack, though, the bitter pro- 

 perty of the broom would be continually increasing, 

 and the gorse would be ever perfecting the points 

 of its thorns, until at last each species, by its own 

 particular method of protection, would be able to 

 stand defiant before their enemies on the open 

 heath, just as we find them to-day. 



Where gorse is regularly cut down, the annual 

 shoots make a fodder that is greatly appreciated by 

 horses and cattle after it has been bruised suffi- 

 ciently, by chopping, to deaden the prickles ; many 

 a wayfaring horse is grateful for such a meal of 

 green food during the winter months. Also when 



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