Bower • Parasitism in Flowering Plants 37 



leather}' leaves and spikes of minute the eyebright, bartsia, cow-wheat, 



greenish flowers and ultimately the louse-wort, and the yellow rattle are 



white berries. root parasites with a pale or livid aspect 



The green of its shoot, though pale of their vegetative shoots. Finally, the 

 and golden, proves its ability for self- tooth-wort [Lathraea] is a full para- 

 nourishment by photosynthesis. But site, with its scaly and branched shoot 

 for water and a supply of the necessary blanched underground, and attached 

 salts, it is dependent upon tapping the to the roots of the hazel, 

 transpiration stream carried by the Examples of still further reduction 

 wood of the host. This is secured at of the vegetative system, accompanied 

 once on germination, and it is main- by flowers some of which are the largest 

 tained throughout life. An absorption in the vegetable kingdom, are seen in 

 of organic food also is by no means the fully parasitic family of the Raffie- 

 excluded; possibly the plant does not siaceae, and these may be held to mark 

 depend wholly upon the activity of the an acme of the parasitic habit in 

 imperfectly developed pigment. Mistle- flowering plants. It includes genera 

 toe stands thus in an intermediate po- and species which share a most remark- 

 sition as a green parasite which has not able character, for the vegetative sys- 

 dispensed with its own powers of self- tern is completely enclosed within the 

 nutrition. tissues of the host. A small form, Pilo- 



Another quite distinct family of styles, which grows on various Mimo- 

 flowering plants is addicted to root- seae, has been fully examined, and the 

 parasitism, which has clearly taken its vegetative system of the parasite has 

 origin from the contact of roots matted been found to consist of fine filaments 

 in the soil. While the majority of the like fungal threads which perforate the 

 snapdragons lead an ordinary inde- cells of the host, and traverse its con- 

 pendent life, the group of genera that ducting column. The attack is exactly 

 center round the eyebright {Euphra- along the same lines as that of a para- 

 sia) present above ground pale and sitic fungus. But the proof that this 

 livid colouring of the green shoot, and greatly reduced body is really a flower- 

 this goes along with the fact that their ing plant appears when it forms buds 

 roots fix themselves by suckers essen- that burst through the skin of the host 

 tially similar to those of the dodder plant, as flower buds. Though these 

 upon the roots of other plants, such as have a curiously specialized structure, 

 grasses and clovers. They are, in fact, their features are unmistakably those 

 root parasites. The yellow rattle is per- of a flowering plant, 

 haps the most injurious, and its effect To the same family, to which the 

 on .the meadow can be easily noted genus gives its name, belongs that most 

 from a distance by the stunted appear- wonderful object, Raffiesia, first dis- 

 ance of the crop where the parasite is covered on the island of Sumatra by 

 present in quantit}^ The plants of this Dr. Arnold. Its flowers are "a full yard 

 family, the snapdragons, show a very across," of a livid red colour; they smell 

 interesting progression towards com- like carrion, and are pollinated by car- 

 plete parasitism and the loss of the rion-flies. This is again the flower of a 

 chlorophyll function altogether. Start- parasite. Its vegetative system develops 

 ing with the fully self-nourishing types, within the rissues of the root of a vine, 

 such as the mullein and foxglove, and is, like that of Pilosty'les, of a de- 

 there is nothing to remark beyond the graded type. The flower buds borne 

 fact that they represent a family with upon it burst through the rissues of the 

 rather advanced floral characters. But host. The flower itself is not only large. 



