THEOET OF THE GROWTH OF CUTTINGS. 409 



"With this part of Sachs's theory I am not specially concerned ; 

 my chief object was to determine whether the phenomena of 

 growth in a cutting are the expression of a morphological force, 

 or are produced by the after-effect of gravitation. 



Observations and Experiments on the Bramble. 

 For reasons that will appear later on, I wished to study the 

 behaviour of cuttings in relation to the natural mode of growth 

 of their parent plants : with this object I chose the Bramble for 

 observation, because of its habit of forming roots at the end of 

 its branches. This curious habit does not seem to have attracted 

 much attention from botanists. It is briefly described by 

 Duhamel*, also by Nees and "Weihef, who refer to a mention of 

 it in Pliny. 



Lees J mentions the rooting of the branches in his paper, " On 

 the Mode of Growth of the British Fruticose Brambles." The 

 chief point of interest is, that the branches are by no means 

 always biennial ; the barren rooting-branches may produce barren 

 side-shoots, which flower in the third year and then die ; or the 

 barren shoot, after flowering in the second year, may send out 

 barren shoots in the third year, which do not flower until the 

 fourth year § ; and, under certain circumstances, life may be pro- 

 longed for at least five or six years. 



Bell Salter's "Observations on the Genus Bubus " || contain 

 some remarks on the habits of growth of Brambles. He describes 

 the ordinary habit of B. discolor (Weihe & Nees), " the commonest 

 of our English brambles," and agrees in the main with Lees as 

 to the way in which the growth continues for several years. 



Vaucher^" mentions this mode of reproduction as common to 

 Bubus fruticosus, ccesius, villosus, laciniatus, hispidus, and, gene- 

 rally speaking, to the biennial class of Bubus with palmate leaves. 



More recently, Germain de St. Pierre ** has called attention to 

 the rooting of the Bramble, and gives a general description of the 

 process. 



The essential facts are, briefly, that the end of the shoot makes 



* 'TraitS des Arbres,' torn. ii. p. 233 (1755). 



t Eubi Germanici, 1822-27, Introd. p. 4. 



\ Proc. Bot. Society Edinburgh, March 9th, 1843, vol. i. p. 171. 



§ He describes six modes of branching. 



U The ' Phytologist,' vol. ii. p. 91 (1845). 



«([ 'Histoire Physiologique des Plantes d'Europe,' 1841, t. ii. p. 272. 



** Bull. Soc. Bot. de France, t. xxii. 1875, Seance Extr. d'Angers, pi. liii . 



