200 BROOM-RAPES, BALANOPHORE&, RAFFLESIACEE. 
the root upon which they are detained belongs to a Cissus plant, they germinate. 
On the other hand, such Rafllesiacee as occur on the woody branches of trees, 
shrubs, and undergrowths, or on lianes, develop suceulent fruits, which are eaten 
by animals. Their seeds are protected by a horny coat, and preserve their power of 
germination unimpaired as they pass through the animals’ alimentary canals and are 
deposited with the excrements on the stems of fresh host-plants; or the seeds may 
stick to some part of an animal that happens to rub against them, and be brushed 
off later on as being an uncomfortable appendage, and in this way also they may 
fall upon the stem of a host-plant. Those Rafllesiaces which occur in Venezuela on 
the woody lianes (Caulotretus), known by the name of “monkey-ladders”, owe their 
dispersion for the most part probably to monkeys. 
Now, if a seed has been deposited in one way or another upon a woody root, 
creeping along the surface of the ground, or upon the stem of a woody plant, the 
filiform embryo emerging from the seed finds a suitable nutrient substratum present 
and it pierces the cortex of the root, and develops beneath it a tissue, which incloses 
the wood like a sheath. In Rafflesia and in the Pilostyles parasitic on the 
suffruticose shrubs of Tragacanth (P. Haussknechtii, see fig. 431), this tissue consists 
of rows of cells, which to the naked eye look like threads. Some are simple and 
greatly elongated, others branched, and they are united together to form a net-work, 
so closely resembling the mycelium of a fungus as to be readily mistaken for one. 
The most complete similarity to these vegetative bodies living beneath the cortex of 
a host-plant is exhibited by the mycelia of the toad-stools which spread themselves 
in the form of nets and webs between the wood and the cortex of old trunks of 
trees. The vegetative bodies of the other species of Pilostyles consist, in each case, 
of a tissue composed of many layers of cells forming a parenchyma imbedded 
between wood and cortex in the host-plant and including some vessels and rows of 
cells capable of being interpreted as vascular bundles. Only in rare instances does 
this tissue of the parasite form an unbroken hollow cylinder encompassing the 
wood of the host; usually the elements of the host’s tissues penetrate into it and 
permeate and split up the cylindrical soma (vegetative body) in the form of bands, 
ribs, and fibres. Many elements of the tissues, which the imbedded parasite has 
displaced from the living wood, and carries, as it were, on its back, perish; but 
sometimes these discarded layers remain in connection with other living tissues and 
so preserve their own vitality and power of expansion, and develop layers of wood- 
cells covering the parasite. There is then a general confusion and entanglement, 
and it is difficult to say what part belongs to the parasite and what to the host. 
When the somatic tissue of the parasite has accomplished its connections with 
the host-plant in the manner just described, the latter is unable to rid itself of 
its occupant. A portion of the juices of the host-plant passes into the parasite’s 
cells and the unwelcome guest augments in volume, and endeavours forthwith to 
reproduce and distribute its kind by the formation of fruit and seeds. For this 
purpose buds are developed at suitable spots in the reticular body of the parasite, 
each of which is manifested as a parenchyma of pulvinate appearance, and is 
