CLASSIFICATION OF PARASITES. 159 
4, ABSORPTION OF NUTRIMENT BY PARASITIC PLANTS. 
Classification of parasites.—Bacteria.—Fungi—Twining parasites:—Green-leaved parasites.—Tooth- 
wort.— Broom-rapes, Balanophoreze and Ratilesiaceze.—Mistletoe and Loranthus.—Grafting and 
budding. 
CLASSIFICATION OF PARASITES. 
The ancients understood by parasites people who intruded uninvited into the 
houses of the rich in order to obtain a free meal. The designation was first applied 
to plants by an eighteenth-century botanist, named Micheli, in his work “De 
Orobanche” (1720) wherein are described amongst others, many kinds of “plant 
secundarize aut parasitice”. Micheli included under this term plants which with- 
draw organic compounds from living plants or animals, thus sparing themselves the 
labour of forming those compounds out of water, salts, and constituents of the air. 
For a long time all epiphytes, including mosses and lichens growing on the bark of 
trees, and indeed even many climbing plants, were held to be parasites. Thus, it is not 
long ago that Clusia rosea, which occurs in the Antilles, was described as a regular 
vampire, in whose embraces other plants met their death; and it has been asserted 
respecting a whole series of other plants of the tropical zone, including, for instance, 
several species of fig, that they attach their stems and branches to other trees, 
divest themselves of their bark, and cause the death of that of the neighbour 
attacked as a consequence of the pressure which they exert. The young wood of 
the invader would then come into direct connection with the young wood of the 
plant assailed, and the possibility would thus be afforded of draining the latter of 
all its juices. 
These assumptions, at least as regards the exhaustion of juices, have not been 
confirmed. When individuals of species of Clusia or Ficus, which have roots buried 
in the earth, and are themselves already grown up into stately leaf-bearing plants, 
attach their flattened stems and branches to other plants, investing them so 
completely as to interfere with the process of respiration, this constitutes, at all 
events, an invasion of one of the most important of the vital functions of the plant 
attacked, and may ultimately cause its death; but the killing is not under these 
circumstances due to drainage of juices, but is brought about by suffocation. 
Lichens, too, when they cover the bark of trees with a close-fitting mantle, may 
possibly restrict the process of respiration through particular parts of the cortex, 
and thereby injure the development of the tree in question; but they are not on 
that account to be looked upon as parasites any more than the fructifications of the 
species of Telephora, and other Basidiomycetes, which grow up rapidly from the 
ground, and, spreading out like plastic doughy masses, envelop all objects which 
come in their way, and ultimately stifle such as are living, namely, grass haulms, 
bilberry bushes, &c. Even creepers, which impose woody stems upon the trunks of 
young trees, winding round them like serpents, and restricting their circumferential 
growth at the parts in contact with the coils, so that ultimately the latter le 
