INJURIES INDUCED BY PLANTS 



in the Wiener Wald, it has proved very destructive in stored 

 coppice, where by killing the tops of the oak standards it 

 prejudicially affects their growth in height. An irregular 

 swelling of the size of a 

 man's head (Fig. 5) often 

 occupies the place of the 

 leading shoot. The oblong 

 seeds (Fig. 6,/) of the plant, 

 which is deciduous, are af- 

 fixed to branches by thrushes, 

 as in the case of Viscum. 

 There they germinate, and in 

 a few years the base of the 

 parasite becomes completely 

 enveloped in a large excre- 

 scence which forms on the 

 tree (Fig. 6, c). 



The root-system is to be 

 distinguished from that of 

 the Loranthacecs already de- 

 scribed by the fact that the few rhizoids which arise on the 

 radicle always grow downwards that is to say, in a direction 

 opposed to that of the ascending water and by these rhizoids 



FIG. 5. A swelling on Qiiercus Cerris, a, 

 bearing an old plant of LorantJms, bb. 



FIG. 6. Loranthus enropxus on a branch of Quercus Cerris. a, a young plant ; b, 

 a five-year-old plant ; c, an outgrowth of the oak ; d, longitudinal section of a 

 root of Loranthus ; x, apex of the root ; e, cross section of a root ; /, a seed. 



taking up water and food-materials directly from the wood 

 without forming sinkers. 



The pointed apex of the root (Fig. 7, x) does not grow outside 

 the cambium zone, but in the young wood that is to say, in 



