182 CLIMBING PARASITES. GREEN-LEAVED PARASITES. TOOTHWORT, 
The seed of Lathrea germinates on damp earth. The young root of the seedling 
grows at first at the expense of reserve material stored in the seed, penetrates 
vertically into the earth and sends out lateral branches, which, like the main root, 
follow a serpentine course and search in the loose damp earth for a suitable nutrient 
substratum. If one of these meets with a living root belonging to an ash, poplar, 
hornbeam, hazel, or other angiospermous tree, it fastens on to it at once and 
develops suckers at the points of contact; these suckers are at first shaped like 
spherical buttons, but soon acquire, as their size increases, the form of discs 
adherent to the host’s root by the flattened side and with the convex hemispherical 
side turned towards the rootlet of the parasite. These discoid suckers cling to the 
root attacked by means of a viscid substance produced by the outermost layer of 
cells. As in the case of the parasites already described, a bundle of absorption-cells 
grows out of the core of each sucker into the root of the plant serving as host, and 
the tips of the absorbent cells reach to the wood of the root. The shoot extremity 
of the seedling, thus nourished by the juices of the host, now develops very quickly, 
elongating and producing thick, white, fleshy, scale-like leaves which overlap one 
another closely, the whole thus acquiring the appearance of an open fir-cone. The 
scaly stems also branch underground, and thus a curious structure is gradually 
produced, consisting of crossed and entangled cone-like shoots covered with white 
scales, and this structure fills entirely the nooks and corners between the woody 
roots on which it preys. Individual plants extending over a square meter and 
weighing 5 kilograms are by no means rare. Later on, inflorescences raise them- 
selves above the surface from the extremities of the scaly subterranean shoots. 
Their axes are at first curved like crooks, but straighten themselves out by the 
time the fruit ripens. Whereas the subterranean portions are white as ivory, the 
flowers and bracts pushed up above the earth are of a purplish tinge. The roots, 
which issued originally from the seedling, and their suckers have long since ceased 
to meet the requirements in respect of nourishment of so greatly augmented a 
structure, and therefore additional adventitious roots are produced every year, 
springing from the stem and growing towards living woody branches of the 
thickness of a finger, belonging to the root of the tree or shrub that serves as host. 
When there, they bifureate, forming numerous thickish filiform arms, which lay 
themselves upon the bark of the nutrient root and weave a regular web over it. 
Sometimes two or three of these root-filaments of the parasite coalesce, forming 
tendrils, and the resemblance to a lace-work or braid is then all the more 
pronounced. Suckers such as have been described are developed by these root- 
filaments laterally, and more especially on the ends of the branches. 
Lathrea is interesting in so many different connections that we shall again 
return to this plant later on. As has been stated before, it affords a type of a series 
of parasites which resembles the species of Cassytha and Cuscuta in the absence of 
chlorophyll, Rhinanthacee in the shape and development of the seedling and the 
form of the suckers, and the Balanophorex, presently to be described, in being 
parasitic upon the roots of woody plants. Lathraa Squamaria, the species repre- 
