
18 | FLOWERING PLANTS 
The seeds of Dodder germinate late in the spring, independently — 
of the host plant, on damp earth, on putrefying matter. The 
embryo, when it has emerged from the seed-coat and used up 
all the endosperm, is a delicate thread, capable of standing 
erect for a time and curving round so that it may come in 
contact with some suitable support. If it does not come. in 
contact with some support, it may lie on the ground, even for 
four or five weeks, waiting for something. When it does 
become attached to a stem or some part of a living plant, it 
develops suckers, by means of which it fastens itself to its host, 
and then the part of the Dodder which was in contact with 
the ground dies off. This gives the plant the appearance of 
having germinated_on the host plant. The host on which 
some species of Dodder thrive well is the Hop or Nettle; it 
develops on these plants a number of suckers and tendrils, 
forming a regular network. Rose-coloured flowers are formed 
on filaments of this network, and from them balls of capsular 
fruits, which dehisce by means of a lid and have their seeds 
shaken out by the wind. The Greater Dodder is parasitic on 
a great variety of herbaceous plants; the Lesser Dodder on 
Thyme, Heaths, and other small shrubby plants. | 
The semi-parasitic plants belonging to the Scrophulariacez 
are discussed in connection with that Order (p. 127 and Figs. 
114-116) ; here it will be sufficient to give the Mistletoe. This is 
parasitic upon trees ; the Black Poplar is said to be its favourite. 
The berries are disseminated by birds, especially thrushes, — 
which thrive upon them; the seeds become attached to the 
bark of trees. When the seed germinates, the radicle of the 
embryo develops into a regular attachment disc, from which 
a process penetrates through the bark as far as the wood. 
This process is called a “sinker”; it always penetrates straight 
in, whatever the direction in which the seed reaches the 
branch, so that the Mistletoe may come off on any side of a 
branch. By the end of the winter the tip of the sinker has 
just reached the wood. The following spring, when fresh 
wood cells are added to the branch, the sinker becomes 
enclosed on each side by them ; at the same time, by means of 

