y8 Flowers and their Unbidden Guests. 



of Pedicularis. In the one case as in the others the 

 visitors are warned to adopt the right mode of entrance, 

 that is, the one most advantageous to the flower. 



The function of the minute pricklets which are to 

 be found inside the corolla of certain Asperifolise, 

 notably of some species of Symphytum, is slightly 

 different. The pricklets are here placed neither on the 

 inner surface of the corolla nor on the filaments, but on 

 certain epiblastemes of the coroUa. These epiblastemes, 

 which alternate with the stamens, are made of tough 

 tissue, have an elongated triangular outline, and are 

 beset round their edges with small sharp teeth, which 

 may almost be compared with the processes on a sword- 

 fish's spear. (See Plate II. fig. 74). They project into 

 the corolla-tube, and are so closely apposed to each 

 other as to form a hoUow cone, the apex of which 

 points towards the mouth of the flower, and has in 

 its centre an opening through which the style is seen 

 to protrude (Plate II. fig. 73, longitudinal section! 

 of a flower of Symphytum officinale). It is only at 

 their very tips that the epiblastemes or throat-scales 

 are without teeth. But it is these tips that sur- 

 round the small central hole in the apex of the 

 cone, which gives issue to the style ; and through this 

 hole such insects as have a proboscis long enough to 

 reach the bottom of the flower can therefore suck the 

 nectar without hurting that sensitive organ. It is, 

 moreover, only by this method of suction that they will 



