322 DARWINIAXA. 



never distinctly raised before, no one noticing any- 

 thing here that needed explanation. Darwinian tele- 

 ology, however, raises questions like this, and Mr. 

 Darwin not only propounded the riddle but solved it. 

 The object of the partial closing is to permit small 

 insects to escape through the meshes, detaining only 

 those plump enough to be worth the trouble of digest- 

 ing. For naturally only one insect is caught at a time, 

 and digestion is a slow business with Dionseas, as with 

 anacondas, requiring ordinarily a fortnight. It is not 

 worth while to undertake it with a gnat when larger 

 game may be had. To test this happy conjecture, Mr. 

 Canby was asked, on visiting the Dionseas in their 

 native habitat, to collect early in the season a good 

 series of leaves in the act of digesting naturally-caught 

 insects. Upon opening them it was found that ten 

 out of fourteen were engaged upon relatively large 

 prey, and of the remaining four three had insects as 

 large as ants, and one a rather small fly. 



" There be land-rats and water-rats " in this carniv- 

 orous sundew family. Aldrovanda, of the warmer 

 parts of Europe and of India, is an aquatic plant, with 

 bladdery leaves, which were supposed to be useful in 

 rendering the herbage buoyant in water. But it has 

 recently been found that the bladder is composed of 

 two lobes, like the trap of its relative Dioncea, or the 

 valves of a mussel-shell; that these open when the 

 plant is in an active state, are provided with some sen- 

 sitive bristles within, and when these are touched close 

 with a quick movement. These water-traps are mani- 

 festly adapted for catching living creatures ; and the 

 few incomplete investigations that have already been 



