DARWIN. 139 



little has been made out in comparison with what remains 

 unexplained and unknown." 



The facts relating to Venus' fly-trap (Dioncea musdpula} 

 and other members of the order to which the sun-dew 

 belongs were better known, but Darwin elicited new 

 truths by his ingenious and varied experiments. The 

 rapidity with which the two lobes of the leaf of dionsea 

 close together when anything touches the tiny spikes 

 which stand up vertically from the upper surface of the 

 lobes, is astonishing, and any insect which causes the 

 closure is almost certain to be caught. Digestion is 

 accomplished in the case of the dionsea by a separate 

 agency, consisting of a large number of minute reddish 

 glands covering the surface of the lobes. These secrete a 

 digestive fluid when stimulated by the contact of any 

 nitrogenous matter, and of course this takes place when 

 any insect is caught. In fact, essentially the same process 

 of digestion and absorption takes place as in the sun-dew. 

 The insect is held firmly for days, until its juices have 

 been absorbed, and then the leaf slowly reopens, 

 not being able to close again for many subsequent 

 days. 



It is interesting to note the extreme caution with which 

 the great naturalist speculates upon the mode by which 

 the varied members of the sun-dew order became modified 

 from an ordinary plant-form to such a remarkable degree. 

 The details are too special for quotation here. He 

 suggests, but he does not in the slightest degree dog- 

 matise. For many years to come Darwin's suggestions 

 and comments must be the pregnant soil out of which 

 fruitful research will spring, and his caution will remain 



