THE STEM OF VASCULAR PLANTS. 141 



The young branches almost always have a tendency to 

 take a direction upwards; but as they increase in size, 

 they become a little more horizontal, either on account 

 of their weight, or because their extremity, always 

 seeking the light, is obliged to bend towards the base in 

 order to extend beyond the upper branches. But if the 

 angle formed by each branch varies according to the 

 age of it in most trees, it is pretty constant in each 

 species, and presents great differences in different plants 

 when compared together. Thus, when the angle is very 

 acute, we say that the branches are Erect (droits, serres), 

 as in the Poplar, and the whole tree is said to be 

 Pyramidal (pyramidaUs, fastigintus ; pyramidal) ; 

 when the angle is almost a right angle, if the branches 

 are placed opposite to one another, we say that tliey are 

 Straggling (rami divaricati ; divergentes ; if they are 

 scattered, we simply call them Spreading (patentes ; 

 etaUes, ouvertes). It happens in some individuals, that 

 the angle, instead of being acute, is obtuse, and then 

 the branch is directed towards the base. "VVe see this in 

 certain varieties of GincJco hiloha audi Fraxinus excelsior; 

 they are commonly called by the name of the Weeping 

 or Drooph^g Gincko or Ash ; but we must not confound 

 them with trees which, as the "Weeping Willow, have 

 their branches so long and weak that they fall down at 

 their extremities. The former have the branches 

 Turned backwards (retroversi ; rebroussisj, that is to 

 say, directed downwards from their origin ; the latter 

 have them Pendulous (penduli ; pendans), that is, erect 

 at their origin, and afterwards falling down on account 

 of their weight. 



In general, the lower branches are longer than the 

 upper, because they are ahvays older ; this difference in 

 length is scarcely perceptible in trees with upright 

 branches, but is much so in those with spreading ones, 



