vi PREFACE. 
well as Professor Sachs,* attributes all the movements 
of tendrils to rapid growth along one side; but, from 
reasons assigned towards the close of my fourth 
chapter, I cannot persuade myself that this holds 
good with respect to those due to a touch. In order 
that the reader may know what points have interested 
me most, I may call his attention to certain tendril- 
bearing plants; for instance, Bignonia capreolata, 
Cobeea, Echinocystis, and Hanburya, which display 
as beautiful adaptations as can be found in any part 
of the kingdom of nature. It is, also, an interesting 
fact that intermediate states between organs fitted for 
widely different functions, may be observed on the 
same individual plant of Corydalis claviculata and 
the common vine; and these cases illustrate in a 
striking manner the principle of the gradual evolu- 
tion of species. 
* An English translation of of ‘Text-Book of Botany,’ and this 
the ‘Lehrbuch der Botanik’ by is a great boon to all lovers of 
Professor Sachs, has recently natural science in England. 
(1875), appeared under the title 
