SECT. V. tHE LEAF. 285 



shaped reversed, with a flattened and concave limb 

 attached by the one side to the orifice of the tube, 

 and constituting the upper portion of the leaf. 

 Linnaeus, who was acquainted with this singularity 

 of structure, accounted for it by supposing that it 

 was an institution of nature, meant for the purpose 

 of furnishing the plant with a supply of water, 

 which it could thus catch and retain in the leaf. 

 But as some species of the genus do not readily 

 admit water notwithstanding their capacity to retain 

 it, this hypothesis is regarded by Dr. Smith as 

 being extremely doubtful, who accordingly offers a 

 different solution founded upon the following facts. 



An insect of the Sphex or Ichneumon kind had 

 been observed by one of the gardeners of the 

 botanic garden at Liverpool, to drag several large 

 flies to a leaf of Sarracenia adunca, and to force 

 them into the tubular part of it On examination 

 the leaf was found to be about half filled with 

 water, in which the flies were now struggling ; the 

 other leaves were also examined, and were found 

 crammed with dead or drowning flies. The leaves 

 of Sarracenia purpurea are said to exhibit also the 

 same phenomena, and seem peculiarly well adapted 

 to entrap and confine flies, by having the margin 

 beset with inverted hairs rendering the escape of 

 such insects as may have accidentally fallen into 

 the watery tube, or are intentionally forced into it, 

 impracticable ; so that the putrid exhalation from 

 the dead insects contained in the leaf often offends 



