PROTECTION OF GREEN LEAVES AGAINST ATTACKS OF ANIMALS. 



449 



sketched in the case of the Barberry. As long as the young tender foliage-leaves 

 remain in this situation between the two spiny stipules (fig. 118*) they are avoided 

 by animals; the protection is only at an end when they have grown beyond the 

 points of the old spiny stipules. 



Most of the last-described protective contrivances only defend the green foliage 



Fig. 118.— Weapons of Plants. 



' Branch of the Tragacanth bush (Astragalus Tragacantha) in spring. » A single leaf of this Tragacanth from which the three 

 upper leaflets have fallen. » Leaf-axis from which all the leaflets have fallen. * Portion of a shoot of Rohinia Pseudacacia 

 in spring. « The spiny Cytisus (Cytisus spinosus). ». ' Portions of branches of the Barberry (Berberis vulgaris) in spring. 

 ' Vella spinosa ; the end of last year's shoot is dried up ; this year's shoot bears flowers. 



whilst it is young. But this is exactly the time when protection is most needed. 



If, later on, isolated foliage-leaves, which have grown beyond the points of the 



prickles, are eaten, this does not so much matter, as part of the foliage still certainly 



remains, and this is really the important point. 



From the fact that the protection of the young green leaves is secured by 

 VouL ^ o 29 



