26 



BOTA N Y 



In like manner the stems of the Opuntias (Fig. 28) are considerably 



Fio. 20. Part of a growing Potato plant, Solatium tubero.tiiin. The whole plant lias 

 been developed from the dark-coloured tuber in the centre. (From nature, 

 copied from one of UAILLON'S illustrations, J nat. size.) 



flattened, while the leaves are reduced to small thorny protuberances. 



Fio. 27. Twig of Jtusciisaculeat'us. f, Leaf; 

 cl, cladode ; bl, flower. (Nat. size.) 



I i' . 28. Opimtta MMOetMUta, Il,-iw., show-in 1 ,' llower 

 and fruit. (After SCHUMANN. |. nat. size.) 



In this case the juicy flat shoots perform not only the functions of 



