Thorny and Climbing Plants. (A walk) 95 



see and look at its thorns (Fig. 47). They are straight, 

 very sharp, and some of them are much longer than 

 those of the rose. You will find that you cannot 

 separate them from the main stem without cutting 

 through the wood. Moreover, if you peel the twig, you 

 will see that the skin covering comes off and leaves 



Fig. 47. Hawthorn twig. The thorns are converted branches. 



behind woody thorns which, though smaller than they 

 were before, are still the same shape. This time, there- 

 fore, the thorns are not merely on the skin as in the 

 case of the rose. What are they ? Do you see that the 

 longer ones have leaf buds growing from them ? This 

 shows us that they must really be branches which have 



