426 CAUSES LIMITING PROPAGATION. CHAP. X. 



most common, at least as being indigenous to Bri- 

 tain, are the Missletoe, Dodder, Broom-rape, and 

 a sort of tuber that grows on the root of Saffron, 

 and destroys it if allowed to spread. 



Missletoe. The Missletoe, Viscum album, is found for the 

 most part on the Apple-tree ; but sometimes also 

 on the Oak. The fruit of it when ripe is a soft, 

 white, and shining berry, filled with a glutinous 

 and sweetish juice, and about as large as a Pea. If 

 this berry, whether by accident or design, is made 

 to adhere to the trunk or branch of either of the 

 foregoing trees, which from its glutinous nature it 

 may readily be made to do, it germinates by send- 

 ing out a small globular body attached to a pedicle, 

 which after it acquires a certain length bends to- 

 wards the bark, whether above it or below it, into 

 which it insinuates itself by means of a number of 

 small fibres which it now protrudes, and by which 

 it abstracts from the plant the nourishment neces- 

 sary to its future developement. When the root 

 has thus fixed itself in the bark of the supporting 

 tree, the stem of the parasite begins to ascend, at 

 first smooth and tapering, and of a pale green colour, 

 but finally protruding a multiplicity of branches 

 by continually dividing into jointed forks. The 

 leaves are of the colour of the stem, tongue-shaped 

 entire, smooth. The plant is an evergreen ; not 

 readily distinguished in the summer, when the 

 leaves of the tree on which it grows are fully ex- 

 panded ; but becoming very conspicuous in the 



