180 CLIMBING PARASITES. GREEN-LEAVED PARASITES. TOOTHWORT. 
root-stock, which is generally only from 4 cm. to 2 cm. long, issue fleshy rootlets of 
the thickness of a quill, but, in many species, as long and thick as a little finger. 
These rootlets are abundantly supplied with starch, and, in course of time, elongate 
till they measure 20 em. They radiate in all directions in the black soil of the 
meadow, wherein are buried the root-systems of grasses, sedges, and various other 
plants, and fasten on to suitable hosts by means of one or two suckers yearly, and 
repeating this process until at length their tips travel into earth devoid of roots, 
where no more prey is to be found, and there growth ceases. This explains also 
why these long Pedicularis-roots never descend vertically in the earth, but remain 
only in the upper strata of soil on a meadow, where a number of other roots are 
interwoven together, and where it is most likely that the tapering growing-point 
will meet with the root of some new host or other. 
The Alpine Bartsia (Bartsia alpina), one of the perennial Rhinanthacez 
prevailing in the aretie regions as well as in mountainous parts of Europe on damp, 
marshy, grass-covered spots, is distinguished by the sombre dusky violet colouring 
of its leaves, and has already been noticed amongst carnivorous plants. On the 
secondary roots are suckers exactly like those of the Yellow-rattle (Rhinanthus), 
and by means of these organs it clings to the fibrous roots of sedges and grasses, and 
sucks their juices. The long, subterranean, runner-like stems, which are covered 
with small, whitish scales, also bear, however, elongated absorption-cells (root-hairs), 
which are distinctly differentiated, and take up nutriment from the vegetable mould 
around. This Bartsia is, therefore, half-parasitie and half-saprophytic, and it is not 
improbable that many other perennial Rhinanthacex behave in the same way. 
The species of Pedicularis which constitute the most extensive group of 
perennial green-leaved and parasitic Rhinanthacee are, it is true, destitute of 
tubular absorption-cells (root-hairs) whether on the subterranean stem-structures 
or on the root-tip, with the exception of those which develop in the middle of the 
suckers. But the construction of the epidermal cells on the roots, and the cireum- 
stance that these epidermal cells are always in intimate connection with dark 
particles of humus, would favour the idea that these plants are capable of taking up 
organic compounds from the mould of meadows in addition to the food acquired by 
means of suckers from their hosts. This supposition is further supported by the 
fact that I succeeded in rearing a species belonging to the Rhinanthacez, namely, 
Odontites lutea, from a soil composed of a mixture of sand and humus, in which no 
other plants were rooted, so that the possibility of a withdrawal of nutritive matter 
from hosts was excluded. It is true that the plants thus reared remained 
comparatively small and poor, and only developed few flowers and fruits. But at 
anyrate they may be considered to prove that plants exist, which, though normally 
parasitic, are yet on occasion able to subsist in vegetable mould without the 
assistance of hosts. 
The third series of parasitic flowering-plants is very restricted, contrasting in 
this respect with the second series, composed of the numerous green-leaved 
Santalacex and Rhinanthacex. The species belonging to it differ from those of the 
