194 



BUDS AND STIPULES 



As an Assistance in Climbing 



There are two ways in which stipules may assist in 

 this respect, viz. (1) by being developed into tendrils, 

 or (2) into more or less reversed spines. 



The case of the tendrils of Smilax 

 is one which has occasioned much 

 discussion, but I agree with Tyler 

 (24) that the embryological, together 

 with the anatomical, characters in- 

 dicate that in Smilax the tendrils 

 are true stipules, found in connection 

 with the sheathing petiole. 



In Paliurvs australis (fig. 313), a 



Southern European plant belonging 



to the same family as our Buckthorn, 



the stipules are spiny, but the two 



stipules of each leaf are different in 



form and serve for different purposes. 



Those on the upper side of the shoots 



are long, subulate, and straight ; 



Fig. 313. Paliurus those on the lower side are shorter 



riTHo OT PORIION and deflexed. The former appear 



5 '' P fte- P s'\SSy al buds to serve as a protection against 



orS>^3 browsing quadrupeds ; while the 



&", the third scar in hooked ones also assist the plants 



the onler of arrangement, 



showing that the phyi- to climb or scramble up among other 



lotaxy is i. Nat. size. 



shrubs and bushes. 

 In Machcerium also, a tropical American genus of 



