Growth and Movement. 



127 



FIG. 63. 



IHontEa muscipula. Some of the leaves 

 stand open, and others are closed after 

 stimulation by contact with insects. 

 After Kerner. 



98. Action of Venus's Flytrap. — In Venus's flytrap, Dio- 

 ncea muscipula (Fig. 63), and in sundew, Drosera rotundi- 

 folia (Fig. 65), we find still 

 more wonderful sensibility 

 and transmissionsof stimuli. 

 The two halves of a leaf of 

 Venus's flytrap are capable 

 of closing together as if 

 they were hinged along the 

 median line (see Fig. 64). 

 The margin of each half is 

 provided with from 12 to 

 20 teeth, and at the center 

 of each half there are three 

 hairs and numerous rose- 

 colored glands. The three central hairs are specially con- 

 cerned with the reception of stimuli, for although the leaves 

 are impassive to contact at 

 other places, when any of 

 the hairs have been touched, 

 the two halves close up 

 rapidly until the marginal 

 teeth are interlocked. The 

 hairs are sensitive in this 

 way to solid bodies, but 

 not to the wind and rain. 

 When an insect has been 

 caught by the closing leaves, 

 the glands on each half pour 

 out a digestive ferment, 

 and the insect is held until 

 it is digested and absorbed, this process requiring from one 

 to two weeks, according to the size of the insect. Then 



Fig. 64. 



il/, leaf of DioTKBa muscipula ; N, cross 

 section of the trap part of the leaf in its 

 closed position. After KERNER. 



