PARASITIC PLANTS 



347 



Pear, Black Poplar, and Oak ; and thrives most luxuriantly on 

 those which have a soft tissue beneath the bark. It is found 

 principally in the southern and western counties of England, and 

 flowers from March to May. 



There is no doubt but that the seeds of the Mistletoe are 

 distributed from tree to tree by the agency of birds, especially 

 the thrushes, which devour the berries in large" numbers. The 

 seed of the bei-ry is 

 protected by a cover- 

 ing wdiich remains 

 quite untouched by 

 the digestive fluids 

 of the bird, and con- 

 sequently it is expelled 

 intact with the excre- 

 ment, and frequently 

 drops to a branch of 

 the tree, where it 

 lodges in a crevice of 

 the bark, and is 

 securely fixed in its 

 place by the slimy 

 excrement in which 

 it is embedded. 



Here the seed 

 germinates, sending 

 out a little rootlet 

 that always turns 

 towards the bark on 

 which it rests, and 



, . . r ,. MISTLETOE. 



subsists lor a time 



on the food-reserve 



that it contains. When the young root reaches the bark it 



becomes flattened against the surface, and spreads out, forming 



a disc that holds the seedling firmly to the tree. 



A projection (the sinker) is then sent inwards from the disc, 

 and this penetrates the Iiark, reaching the wood beneath, but does 

 not enter the latter. This terminates the growth of the seedling 

 for the fu'st year, but as soon as the warm weather of the following 

 spring commences, the sinker begins to spread over the surface 

 of the outer ring of wood, while at the same time a new annual ring 



