PLANTS THAT ROB AND MURDER 61 



to form a kind of partnership with the host, where- 

 by each is equally benefited. All such plants are 

 degenerates and may justly be termed vampires. 



Robber plants have two ways of living: one 

 kind, such as the dodder, thrives upon living plants ; 

 the other, such as puff-balls, mushrooms, and toad- 

 stools, feeds upon a food material already prepared 

 by other plants or by animals. The other form 

 of parasite, like the mistletoe, which is partially 

 honest, pays for some of its food; it may there- 

 fore be politely classed as the "borrowing friend" 

 rather than the "highway robber." 



A striking example of a murderous parasite, 

 or robber plant, is the dodder or Devil's-thread, 

 as it is termed in many parts of Europe. Bot- 

 anists refer to it as the Cuscuta. It has many 

 relatives, among which even the respectable and 

 honest-working cypress and morning-glory vines 

 are numbered. Such a plant as the dodder has no 

 green colouring-matter, chlorophyll, in its body, 

 and it is therefore unable to secure food for itself, 

 because it is by means of chlorophyll that plants 

 are enabled to make food from the inorganic com- 

 pounds furnished to them by nature. 



The dodder has no leaves, nor does it need any, 

 as it gets all its food from the plant on which it 

 grows; it has a few small scales that are possibly 



