148 



LEAFLESS FLOWERING-PLANTS. 



a modification of another. In almost all the plants of this tribe, 

 there are tufts of prickles arising from regular points on the 

 surface of the stem ; and to these, the common designation of the 

 tribe is owing. It will be hereafter shown, that these prickles 

 are the rudiments of leaves ; and that, under circumstances dif- 

 ferent from those in which the plant naturally grows, minute 

 leaves will arise from these very points. 



220. A conformation somewhat similar may be observed in 

 some plants of our own country ; thus in the common Butchers 



Broom (Riiscus aculeatus), the 

 branches are flattened into a leaf- 

 like form, and the flowers arise 

 from the middle of their surface. 

 In another foreign genus, Xylo- 

 phylla, they are placed around the 

 edges of similar organs. 



221 . There are, however, some 

 flowering-plants of temperate cli- 

 mates, which are destitute not only 

 of leaves, but of leaf -like surfaces. 

 These grow by imbibing the juices 

 of other more perfect plants ; just 

 FIG. 59.-, LEAF LIKE BRANCHES OF ^ parasitic animals obtain their 



BUTCHER'S BROOM, bearing flowers in L 



their centre ; b, Xylophylla. food, by Sucking the blood of 



others. And as the juices that afford them support, have already 

 been elaborated or digested by the plant from which they draw 

 them, they have no need of leaves or any similar apparatus for 

 the purpose. Of this kind are the Orobancke, or broom-rape, 

 and the Cuscuta, or dodder. Their branching roots are furnished 

 with suckers, by which they affix themselves on the bark of the 

 plants, round which they cling, and through which they imbibe 

 their juices. (See . 343, 344). 



222. Although there are few instances, then, in which leaves 

 are absent in Flowering-plants, they are comparatively seldom 

 found in Cryptogamia. In FERNS we always meet with them ; 

 and their general structure is much the same as that, which will 

 be described as characteristic of leaves in general. But, in 



