LECT. V.] THE ROOT. 189 



LECTURE V. 



THE SUBJECT OF THE FORMER LECTURE CONTI- 

 NUED. OF SOILS AND MANURES. OF THE MEDI- 

 CINAL AND DIETETICAL PROPERTIES OF ROOTS. 

 \ 



I HE usual situation of roots is in the ground ; 

 but many plants, although their seeds be sown 

 in the earth, yet, will not vegetate in it, their 

 proper soil being the bark of other living plants. 

 Such are named parasitical, owing to their nou- 

 rishment being obtained from those plants on 

 which they fix, and which they rob of a part of 

 their juices, often injuring them to a very consi- 

 derable degree. The Misletoe (Viscum album) ; 

 the Broom Rape^ Orobanche ; the majority of 

 Lichens ; the Mosses ; some of the Ferns ; many 

 of the Orchis tribe ; those minute fungi, which 

 produce the diseases of corn and of some grasses, 

 known by the names of rust, blight, and mildew ; 

 the Sclerotium crocorum, a sort of tuber which 

 attacks the bulb of the Saffron ; . and the Dry Rot, 

 to the destructive powers of which the noblest 

 specimens of architecture occasionally fall sacri- 

 fices ; are parasitic plants. Some of this descrip- 

 tion of plants, however, originally grow in the 

 earth, and do not lose their attachment to it 



