ROOTS 



39 



it may readily be transferred to moderately damp soil, 

 and that the whole plant presents curious modifications 

 when made to grow in earth instead of water. 



51. Parasitic Roots. 1 The dodder, the mistletoe, and a 

 good many other parasites, live upon nourishment which 

 they steal from other plants, called hosts. The parasitic 



FIG. 15. Aerial Adventitious Roots of the Ivy. 



roots, or haustoria, form the most intimate connections 

 with the interior portions of the stem or the root, as the 

 case may be, of the host-plant on which the parasite 

 fastens itself. 



In the dodder, as is shown in Fig. 16, it is most inter- 

 esting to notice how admirably the seedling parasite is 

 adapted to the conditions under which it is to live. Rooted 



1 See Kerner and Oliver's Natural History of Plants, Vol. I, pp. 171-213, 



