Chap. I. 



STRUCTURE OF THE LEAVES. 



excellently adapted for the special purpose of catch- 

 ing insects, so that the subject seemed well worthy of 

 investigation. 



The results have proved highly remarkable ; the 

 more important ones being — firstly, the extraordinary 





Fig. 1.* - 

 {Drosera rotundifoUa.) 

 Leaf viewed from above ; enlarged four times. 



sensitiveness of the glands to slight pressure and to 

 minute doses of certain nitrogenous fluids, as shown 

 by the movements of the so-called hairs or tentacles ; 



* The drawings of Drosera and 

 Dionsea, given in this vrork, were 

 made for me by my son George 

 Darwin ; those of Aldrovanda, and 

 of the several species of Utri- 



cnlaria, by my son Francis. They 

 have been excellently reproduced 

 on wood by Mr. Cooper, 188 

 Strand. 



