CHAPTER XIII 



DOGBANE AND MILKWEED 



"They lay wait as he that setteth snares." 



Jeremiah v. 26. 



THE story of the trap-setting and insect-eating 

 plants is a more than twice-told tale. The pitcher- 

 plant, which beguiles the hapless fly to his drown- 

 ing in its vase-shaped leaves, baited on the outside 

 with nectar-bearing glands, and filled with water; 

 the Venus's fly-trap, which shuts up on him and 

 crushes him; the sundew (Drosera), which chokes 

 him in a sticky secretion, are all known, at least 

 by pictures and descriptions, to the tyro in botanic 

 study. And we have learned that they all have 

 good and sufficient reasons for thus dealing with 

 the hapless flies. For, as Darwin has pointed out, 

 these plants usually grow rooted in moss, or in 

 very sandy and barren soil. Insect-eating leaves 

 are probably a device to supply the plant with 

 nitrogen by means of the foliage, in circumstances 



where the roots prove powerless for the purpose. 



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