INSECTIVOEOUS PLANTS 



CHAPTEB I. 



Dkosera rotundifolia, ok the common Sun-dew. 



Number of insects captured — Description of the leaves and their 

 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 size of the roots. 



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

 ing liow 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 leaves; but M. Trc'cul went so 



('Bot. Zeitung,' 18G0, p. 229) the far as to doubt whether they pos- 



bibliography of Drosera, I need sessed any power of movement, 



not here go into details. Most of Dr. Nitschke's papers in the ' Bot. 



the notices published before 1860 Zeitung' for 1860 and 1861 are 



are brief and unimportant. The by far the most important ones 



oldest paper seems to have been which have been published, both 



one of the most valuable, namely, on the habits and structure of 



by Dr. Roth, in 1782. There is this plant; and I shall frequently 



also an interesting though short have occasion to quote from 



account of the habits of Drosera by them. His discussions on several 



Dr. Milde, in the ' Bot. Zeitung,' points, for instance on the trans- 



1852, p. .540. la 1S55, in the ' An- mission of an excitement from one 



nales des Sc. nat. bot^' torn. iii. pp. part of the leaf to another, are 



297 and 304, MM. Greenland and excellent. On Dec. 11, 1862, Mr. 



Tre'cul each published papers, with J. Scott read a paper before the 



figures, on the structure of the Botanical Society of Edinburgh, 



