20 OBGANOGBAPHY. 



leaves, called chlorophyll (Gr. chloros, green ; phyllon, leaf), 

 in whose presence (in sunlight) the plant can convert the 

 inorganic matter into plant food — that is, organic matter. 



15, The Fungi (as Moulds, Blights, etc.) are parasitic 

 either on living or decaying substances. The Beech-drops 

 and Indian-pipe are attached to roots and draw their 

 nourishment therefrom. The leafless Cuscuta, or Dodder, 

 is a slender, yellowish parasite of peculiar nature. The 

 seeds sprout in the ground, but the plantlet, as soon as it 

 appears above the surface, seeks for plants around which to 

 twine ; if unsuccessful it soon dies ; but if it finds a proper 

 plant, it sends its rootlets, in the form of suckers, into its 

 host, by means of which it absorbs sufficient nourishment 

 for its growth and development ; the stem of the parasite 

 then dies, and thus severs its connection with the soil. 



16. The Mistletoe of Europe, and the false Mistletoe of 

 this country, have chlorophyll in their leaves, and are, 

 therefore, capable of assimilation, that is, of converting 

 inorganic into organic matter ; or, in other words, of pre- 

 paring their own food. Yet they do this only in part. 

 They draw a portion of their food from the trees on which 

 they grow, and are to that extent, therefore, parasitic. 



The nature of the yellowish or whitish leafless plants, 

 which are fixed to the ground, should not be misunderstood. 

 They do not draw their nourishment from the soil, but from 

 underground roots. Neither should all subterranean parts 

 of plants be regarded as roots, since stems sometimes grow 

 underground. Their true nature, however, is easily deter- 

 mined by the buds and scales (modified leaves) which they 

 produce. Such, for example, are the Irish-potatoes, root- 

 stock of Flag, etc. 



