248 SAGACITY AND MORALITY OF PLANTS. 



above species would become extinct if they were 

 obliged suddenly to reform and alter their habits of 

 life. 



When we remember that our pretty Convolvuluses 

 belong to the same order as the Dodders {Convolvu- 

 lacecB), we get a glimpse of how this confirmed and 

 highly -developed parasitic mode of life may have 

 originated. Most of the Convolvuluses have either 

 a twining or a creeping habit ; and some of them 

 twine so successfully that they go by the popular 

 name of Bindweeds. So far, therefore, they have 

 the same initial habit as the Dodder. The latter, 

 having commenced life thus as a hanger-on, proceeds 

 to its next stage as a parasite. Its leaves are 

 gradually aborted, until ultimately they are not even 

 produced in a rudimentary state ; and thus the 

 Dodder has grown leafless. Its dense clusters of 

 flowers are those of the ordinary Convolvulus on a 

 diminutive scale, and they produce numerous seeds, 

 all at the expense of the victimised host-plant. The 

 Dodders must have been at their trade an immense 

 period of time, for nearly all of their original organs 

 have disappeared, and their parasitic habits are 

 about as highly developed as any in the world. 



As if others had copied the evil but successful 

 mode of life thus set them, Sir Charles Bunbury 

 remarks that a " parasitic plant, common in the 

 neighbourhood of Cape Town, both on the hills and 

 on the flats, is the Cassytha filiformis, which has 



