INSECTIVOROUS PLANTS. 



CHAPTER I. 



DROSERA ROTUNDIFOLIA, OR THE COMMON SUN-DEW. 



Number of insects captured Description of the leaves and theii 

 appendages or tentacles Preliminary sketch of the action of the 

 various parts, and of the manner in which insects are captured 

 Duration of the inflection of the tentacles Nature of the secre- 

 tion Manner in which insects are carried to the centre of the 

 leaf Evidence that the glands have the power of absorption 

 Small bize of the roots. 



DURING the summer of 1860, I was surprised by find- 

 ing how large a number of insects were caught by the 

 leaves of the common sun-dew (Drosera rotundifolia) on 

 a heath in Sussex. I had heard that insects were thus 

 caught, but knew nothing further on the subject.* I 



* As Dr. Nitschke has given 

 ('Bot. Zeituug,' ISO), p. 229) the 

 bibliography of Drosera, I need 

 not here go into details. Most of 

 the notices published before 18(30 

 are brief and unimportant. The 

 oldest paper seems to have been 

 ; ne of the most valuable, namely, 

 by Dr. Roth, in 1782. There is 

 ako an interesting though short 

 account of the habits of Drosera by 

 Dr. Milde, in the ' Bot. Zeitung,' 

 1S52, p. 540. In 1S55, in the ' An- 

 nalcs des Sc. nat. bot.' torn. iii. pp. 

 2i*7 and 301, MM. Greenland and 

 Trecul each published papers, with 

 figures, on the structure of the 



leaves; but M. Trtcul went so 

 far as to doubt whether they pos- 

 sessed any power of movement. 

 Dr. Nitschke's papers in the ' Bot. 

 Zeituug' for I860 and 1861 are 

 by far the most important ones 

 which have been published, both 

 on the habits and structure of 

 this plant ; and I shall frequently 

 have occasion to quote from 

 them. His discussions on several 

 points, for instance on the trans- 

 mission of an excitement from one 

 part of the leaf to another, are 

 excellent. On Dec. 11, 1862, Mr. 

 J. Scott read a paper before the 

 Botanical Society of Edinburgh, 



