176 CHAPTER XXII L 



the stems of Cactus, and some other plants. Here 

 the epidermal cells are thickened by secondary 

 deposits. 



It is obvious that in the warfare with Phoebus 

 Apollo a herb or shrub may use more than one 

 weapon. Thus we see that the Cactus has three 

 devices at the least. 



Among the most successful drought-resisting 

 plants, wild or cultivated here, are Nicotiana glama 

 (Fig. 97) and Diplotaxis tenui folia-. And they are more 

 or less mysterious, for in neither case is it evident by 

 what means they retain their moisture. I have never 

 seen the former plant inconvenienced by drought ; and 

 as for the ubiquitous ever-flowering yellow crucifer, it 

 flourishes when most other weeds dry up and wither. 



Lastly, a large class of plants substitute for the 

 tender tissue of the leaf some tougher organ, which, 

 being supplied with chlorophyll, serves the same 

 purpose, and is better able to resist the sun. As I 

 have described almost all the following plants in 

 other chapters, I will now do no more than bring them 

 together and enumerate them. I confine myself, of 

 course, to those Leafless Plants which are common 

 on the Riviera. 



Ruscus (the Butcher's Broom) has flattened 

 branches instead of leaves. The closely- allied 

 Asparagus is also leafless. Opuntia (Fig. 68) and the 

 Cactus tribe possess no leaves. Kleinia (a succulent 

 Composite) seems to do quite well without them when 

 they fall off. Casuarina has thin jointed branches, 

 Polygonum platydadon has green ribbons, as a 

 substitute. Many Acacias (Wattle trees) use their 

 dilated leaf-stalks (phyllodes) as leaves, and look as 



