40 MEMBERS OF PLANTS. 



and sometimes jointed 1 , forked 2 , branched 3 , tufted % 

 starred 5 , hooked 6 , or feathered 7 . When very long and 

 stiff, as in the bearded wheat, and the Russian oat, the 

 bristle is termed an awn 6 . 



Prickles 9 have much the same characteristics as 

 hairs, but are thicker and stronger, and always tipped 

 with a sharp point. They arise wholly from the bark, 

 and never from the woody part of a plant, as thorns 

 always do. According to Grew, prickles, as in the 

 thistle and the acacia, always point downward, while 

 all thorns point upwards. 



In the stinging nettle, the prickles 10 , as described by 

 Hook, arise from bulbs, containing an acrid fluid, 

 which, upon their being pressed down, is forced up into 

 their hollow tubes, and discharged through minute pores 

 in the tips, in a similar way to the poison discharged 

 through the fang of a viper, or the sting of a wasp. 



Thorns n differ from hairs or prickles in being woody, 

 and not superficially inserted in the bark. 



It has been most absurdly fancied that thorns are 

 abortive or degenerated buds, branches, leaf-scales, and 

 leaf-lobes, for want of sufficient nourishment, because, 

 when highly cultivated, the thorns disappear. On the 

 same untenable principle it might be maintained that 

 the hairs on the wild carrots are abortions which dis- 

 appear in the garden ; or that the stamens and pistils 



(1) In Latin, Articulattts. (2) In Latin, Furcatus. 



(3) In Latin, Ramosus. (4) In Latin, Fasciculatus. 



(5) In Latin, Stellatus. (6) In Latin, Uncinatus. 



(7) In Latin, Plumosus. (8) In Latin, Arista, or Barbie* 



(9) In Latin, Aculei. (10) In Latin, Setee urentes* 



(11) In Latin, Spina. 



