44 



HOW CERTAIN PLANTS CAPTURE INSECTS. 



fly-catching. Moreover, in one of our species with longer leaves {D. longifolia) 

 the blade of the leaf itself incurves (as an intelligent lady has observed), so as to 

 fold round its victim ! 



96. Another and a most practised observer, whose observations are not yet j)ub- 

 lished, declares that the leaves of the common Round-leaved Sundew act differ- 

 ently when different objects are placed upon them. For instance, if a particle of 

 raw meat be substituted for the living fly, the bristles will close upon it in the 

 same manner ; but to a particle of chalk or wood they remain nearly indifierent. 

 If any doubt should still remain whether the fly-catching in Sundews is acciden- 

 tal or intentional, — in other words, whether the leaf is so constructed and ar- 

 ranged in order that it may capture flies, — the doubt may perhaps disappear 

 upon the contemplation of another and even more extraordinary plant of the 

 same family with the Sundew, namely, 



97. Venus'S Flytrap, or Dionsea muscipula. This plant abounds in the low savan- 

 nas around Wilmington, North Carolina, and is native nowhere else. It is not 

 very difficult to cultivate, at least for a time, and it is kept in many choice con- 

 servatories as a vegetable wonder. 



98. The trap is the end of the leaf (see Figs. 39, 

 40). It is somewhat like the leaf of Sundew, only 

 larger, about an inch in diameter, with bristles still 

 stouter, but only round the margin, like a fringe, and 

 no clammy liquid or gland at their tips. The leaf 

 folds on itself as if hinged at the midrib. Three 

 more delicate bristles are seen on the face upon close 

 inspection. When these are touched by the finger or 

 the point of a pencil, the open trap shuts with a 

 quick motion, and after a considerable interval it 

 reopens. When a fly or other insect alights on the 

 surface and brushes against these sensitive bristles, 

 the trap closes promptly, generally imprisoning the 

 intruder. It closes at first with the sides convex and 

 the bristles crossing each other like the fingers of in- 

 nus'a Flytrap, tCT^^ of the terlockcd hands or the teeth of a steel-trap, as in the 

 larger one ,,ide opeo. gj^e figures of Fig. 39. But soon the sides of the 



trap flatten down and press firmly upon the victim ; and it now requires a very 



Fig. 39. Leaves of Dionaea or Ve- 



