163 BRITISH PHANEROGAMIC PARASITIC PLANTS. 
berries and have been seen to rub their beaks on a branch, and that 
on going to the spot, a seed has been found adhering to the branch. 
Another opinion is contained in the following note which is a quota- 
tion from the Royal Microscopical Journal for August, 1894. 
“ According to M. C. Guérin, the slime of the Mistletoe berry serves 
no purpose in glueing the berry to the branch, its function being 
the absorption of water. Propagation is effected almost entirely by 
birds, and especially by the missel-thrush, on which it has a purga- 
tive effect. Freezing does not destroy the germinating power of the 
berries. The seeds will only germinate in light.” 
It matters very little which of these theories is correct, as far as 
the Mistletoe is concerned. The seed in one way or another is stuck to 
the branch of a suitable tree ; it contains 2 and sometimes 3 embryos 
and is very rich in chlorophyll. It germinates in April or May, 
sending out two or three little green radicles, which turn from the 
light and push against the bark; the point becomes enlarged and 
flattened; it has the appearance of a sucker ; by degrees it penetrates 
the bark and down to the wood, It is probable that there is some 
solvent action; most likely this young plant secretes an enzyme 
that has the power of corroding the tough tissues of the bark, and 
also gets some nourishment at thesame time that it is making a road 
down, to get a firm hold on the wood of the host. This operation 
requires some time, and is not completed until the plumule is de- 
veloped. By the time the young plant has a pair or two of leaves, the 
attachment will be fairly firm. The growth is very slow the first 
3 years; the plant is then only about an inch high. After the 
primary root system is well established, the growth is more vigorous, 
lateral roots growing from it penetrating between the wood and the 
bark, parallel to the surface of the branch. They can be seen as 
light green strands when the bark is removed. These lateral roots 
send out adventitious buds on the upper side, which push their way 
outwards and become young Mistletoe plants; while on the under 
side, short roots called haustoria, are sent into the wood to obtain 
