HOW CERTAIN PLANTS CAPTURE INSECTS. 



41 



CHAPTER III. 



HOW CERTAIN PLANTS CAPTURE INSECTS. 



86. This is not a common habit of plants. Insects are fed and allowed to depart 

 unharmed. When captures are made they must sometimes be purely accidental 

 and meaningless ; as in, those species of Silene called Catch-fly, because small flies 

 and other weak insects, sticking fast to a clammy exudation of the calyxes in 

 some species, of a part of the stem in others, are unable to extricate themselves 

 and so perish. But in certain cases insects are caught in ways so remarkable that 

 we cannot avoid regarding them as contrivances, as geuMvae flytraps. 



87. Flower-Flytraps are certainly to be found in some plants of the Orchis 

 Family. One instance is that of Cypripedium or Lady's-Slipper, which, being a 

 contrivance for cross-fertilization, is described in the foregoing chapter (paragraph 

 62). Here the insect is entrapped for the purpose of securing its services ; 

 and the detention is only temporary. If it did not 

 escape from one flower to enter into another, the 

 whole purpose of the contrivance would be defeated. 

 Not so, however, in 



88. leaf-Flytraps. These all take the insect's life, 

 — whether with intent or not it may be difiioult 

 to make out. The commonest and the most ambig- 

 uous leaf-flytraps are 



89. Such as Pitchers, of which those of our Sarra- 

 cenia or Sidesaddle-flower are most familiar. Fig. 37 

 represents one leaf, and a section of another, of the 

 species most common in our bogs, especially at the 

 North ; and the vignette title-page, at bottom on 

 the right hand, shows the longer and more tubular 

 pitchers of another species of the Southern States. 

 S. flava, a common yellow-flowered species from 

 Virginia southward, has them so very long and ^llnS^^^LlZi^^^Z^^:^ 



