INSECTIVOROUS PLANTS. 
CHAPTER I. 
DROSERA ROTUNDIFOLIA, OR 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, md 
of the manner in which insects are captured—Duration of the inflection 
of the tentacles—Nature of the secretion—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. 
Durine the summer of 1860, I was surprised by finding 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 gathered by chance a dozen plants, 
* As Dr. Nitschke has given (‘ Bot. 
Zeitung,’ 1860, p. 229) the biblio- 
graphy of Drosera, I need not here 
go into details. Most of the notices 
published before 1860 are brief and 
unimportant. The oldest paper seems 
to have been one of the most valuable, 
namely, by Dr. Roth, in 1782. [In 
the‘ Quarterly Journal of Science and 
Art,’ 1829, G. T. Burnett expressed 
his belief that Drosera profits by the 
absorption of nutritive matter from 
the captured insects.—F. D.] There 
is also an interesting though short 
account of the habits of Drosera by 
Dr. Milde, in the ‘Bot. Zeitung,’ 
1852, p. 540. In 1855, in the ‘ An- 
nales des Sc, nat. bot.,’ tom. iii. pp. 
297 and 304, MM. Greenland and 
Trécul each published papers, with 
figures, on the structure of the leaves ; 
but M. Trécul.went so far as to doubt 
whether they possessed any power of 
movement. Dr. Nitschke’s papers in 
the ‘Bot. Zeitung’ for 1860 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 in- 
stance on the transmission 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 Edin- 
burgh, which was published in the 
‘Gardener’s Chronicle,’ 1863, p. 30. 
B 
