Carnivorous Plants. 



215 



short account of the structure and physiology of these two 

 types will sufficiently explain the mode of operation of the 

 mechanism employed in either case. 



Drosera rotundifolia. The sundew, found in quantities" 

 on our marshy hill-sides, is a small plant consisting of a few 

 small roots, a rosette of peculiarly shaped leaves, and an 

 upright flower-bearing stem. The leaves are the organs by 



FIG. no. -LEAF-TENTACLE OF Drosera. (Darwin.) 



A, glandular head with drop-et of the secretion, B, anatomy of the gland. 



\\hich the nutrition is carried out, and therefore merit fuller 

 description. Each leaf consists of a long petiole with a 

 flat spoon-shaped lamina, which is of a greenish purple or 

 red colour, and beset with tentacles, which are morpho- 

 logically soft thorns, from one to two hundred in number. 

 Each tentacle is tipped by a bulb-like gland, surrounded by 

 a minute drop of a viscid secretion, which gives to the plant 

 its popular name of sundew. Microscopic examination 

 shows the tentacle to be composed of a small fibre-vascular 



