MINOR CARNIVORA. 



123 



the ground. The flowers rise from the centre of the 

 rosette singly, on erect footstalks five or six inches 

 in length. The common butterwort {Piiiguiaila 

 ^vulgaris) has about eight oblong, thickish leaves in 

 a rosette. They are not more 

 than an inch and a half in 

 length, with a very short foot- 

 stalk. When fully expanded 

 they fall outwards and lie with 

 their under - surface closely 

 pressed to the surface of the 

 soil. The margins of the leaves 

 have long been known to curve 

 inwards in a peculiar manner, 

 but the reason for this curving 

 had not until recently been at 

 all satisfactorily explained. That 

 they did so was an acknow- 

 ledged fact, but why they did 

 so was hardly suspected. The 

 surface of the leaves is clammy, 

 and small objects are apt to 

 adhere to them. It having been 

 observed that insects were often 

 found sticking to the leaves led 

 to an investigation of the habits of the plant, 

 and its structure. Here, again, we arc indebted 

 to Mr. Darwin for a solution of the mystery, 



Fig. 17. — Butterwort 

 {Pingidcula Lusitanicd). 



