FROM THE ATTACKS OF ANIMALS. 147 



In the Barberry (Berberis vulgaris), there are 

 two kinds of leaves, the foliage leaves and others 

 which are not leaf-like at all, but are completely 

 converted into sharp thorns. These are grouped 

 in five to seven needle-like points at the base of 

 the branch ; higher up they are in groups of three 

 (Fig. 40, 6, 7). Contemporary with these meta- 

 morphosed leaves, and close above them, arise 

 short shoots, which are covered with ordinary 

 green leaves. These shoots are terminated by 

 buds, which develop in the next spring and form 

 either flowers or a long shoot. The leaves of the 

 rosette under this bud fall in the autumn; the 

 thorns at the base remain behind, together with 

 the winter buds, and stand out from the branch in 

 three directions with their three-forked needles. 

 In the following spring, when the terminal buds 

 swell and expand, the tender young leaves are 

 well protected from attack, during the time that 

 they are overtopped by the thorns. 



In the common Locust-Tree (Eobinia Pseu- 

 dacacia), the whole leaves are not metamorphosed 

 into thorns, as in the Barberry, but only the stip- 

 ules. These are not leaf-like, but are triangular, 

 sharp, brown thorns. When the leaf falls in 

 autumn these metamorphosed stipules remain 



