THE MISTLETOE AND PARASITIC PLANTS. 
199 
fibres. As the parasite increases in size., and an additional 
supply of nutriment is required, lateral shoots are sent out from 
the surface, which also penetrate the bark, and are precisely 
similar in mode of attachment to the original seedling’ shoot. It 
is a curious fact that the fibres of the later shoots never penetrate 
further than those of their primitive attachment. In the adult 
plants the sucker-bearing shoots frequently run to a consider- 
able distance ; many of the stocks being literally covered with 
parasites, all of which have sprung from one seed. Mr. 
Griffiths says : — • 
I have seen such shoots, which had taken their course along a decayed 
branch, become reflexed and return in quest, as I may express it, of a part 
capable of affording nourishment. 
• 
The remarkable exception which the viscuni presents to the 
general law — that the radicle or root of the embryo shoots 
downwards and the plumule upwards, under all circumstances, 
has been confirmed by curious experiments. So certain is it 
that the radicle of the mistletoe will turn itself towards the 
body to which it is attached, whatever may be the position of 
that body with respect to the earth, that a cannon-ball, to which 
mistletoe seeds were glued on all sides, and suspended in the 
ail’, became the point of attraction for all the little radicles 
to direct themselves towards from all sides of the ball. This 
property insures their growing upon the branches of trees to 
whatever side they may happen to adhere. It is asserted that 
a branch of mistletoe, if placed in water, has no power of 
absorbing this fluid itself; but that when the branch to which 
it is attached is immersed, then the water is readily absorbed 
and penetrates into the mistletoe. The following experiment 
was performed by De Candolle. He immersed the branch of 
an apple-tree, bearing mistletoe, in water previously coloured 
red with cochineal, which, penetrating the wood and inner 
bark of the apple-tree, entered into the mistletoe, when its 
colour was even more intense that in the former. It would 
appear as if these parasitic plants had an eliminating power, 
for it is certain that they do not attach themselves to all trees 
or shrubs indiscriminately. Mr. Griffiths thinks, however, that 
they would grow on almost any plant whose duration is 
sufficiently long to allow them to establish themselves. Plants 
■with milky juice seem to be an exception. The seeds of 
Loranthus have been seen to germinate on a frond of Poly- 
I podium. The influence these parasites have on the stock is 
according to their respective proportions. If they attack a 
small or weakly tree, they injure it, and perhaps kill it ; but 
when they attack large vigorous trees, no ill results seem to 
follow. 
