68 THE WOOD. 



they grow either on decaying substances, like 

 those which I have mentioned, or attach them- 

 selves to living plants, and indeed, in a few in- 

 stances, to living animals. Of the latter, the most 

 remarkable is a species of Fungus,* which is found 

 in New Zealand, growing from the head of I a 

 large caterpillar. Little is known about the 

 mode of its growth in this strange situation, but 

 it must be rapid; for, by the time that it has 

 arrived at maturity, it occupies the whole sub- 

 stance of the animal, the figure of which is pre- 

 served entire. Those which grow on living plants 

 are much more numerous, comprising a large por- 

 tion of the many-coloured and beautiful Lichens 

 which spot the trunks and branches of trees, a 

 great number of Mosses, and several Ferns. None 

 of these, however, actually insert their roots into 

 the substance of the wood on which they grow. 

 The Lichens and Mosses can scarcely be said to 

 possess roots ; the little threads which proceed 

 from their lower extremities seem only to attach 

 them to the bark ; and the Ferns, while they cling 

 closely to the rugged stems which support them, 

 depend principally for their nourishment upon the 

 mosses among which they grow, and the decayed 

 vegetable substance scattered among them. Some 

 plants, however, really live upon the juices of the 

 trees from which they spring. Among these, the 

 most remarkable is the Misletoe, so famous in 

 olden times with our forefathers. It attracted 

 their notice from two causes ; its flourishing with- 

 out the intervention of ordinary roots, and from 

 decking the trees on which it grew with its bright 

 green leaves and milky berries at mid-winter. On 

 * Sphteria Robertsii. 



