FOES r\ THE II AY FIELD, 97 



bird's-ncst is a very rare plant in England — a degraded 

 relation of the heaths, which has taken entirely to living 

 on the roots of trees, sucking up their juices by its net- 

 work of succulent rootlets. Its leaves have consequently 

 shrunk by disuse into mere pale yellowish scales, not 

 unlike those which one sees on the j'oung shoots of 

 blanched asparagus. Now, yellow-rattle and its kind 

 deserve notice as showing the first step on this down- 

 ward course : the initial stage through which the ances- 

 tors of the mistletoe must once have passed, and which 

 the ancestors of the yellow bird's-nest must ages ago 

 have left behind them. The plants are not in any way 

 related to one another : on the contrary, they are 

 extremely unlike, as far as pedigree goes ; but they have 

 all three independently acquired the same j)arasitic 

 habits, and they all exhibit different stages in the same 

 process of dcgcncresccnce. 



Ancestrally, yellow-rattle is a near relation of the 

 pretty little blue veronicas and of the big puri)le fox- 

 gloves and snapdragons. It has a flower of the very 

 highest type— one of those curious one-sided mask-like 

 blossoms with an upper and an under lip which are 

 the product of special insect fertilisation and selection 

 exerted throughout innumerable generations, {''lowers 

 of such a sort are the birthright of the most advanced 

 families alone. P>ut this particular snapdragon family is 

 one of the most plastic and versatile in all nature. It. 

 may seem fanciful to say so, but there are certain groups 

 of plants which really apjx^ar to be cleverer and shiftier 

 than all ethers, to have a greater power of adapting 

 themselves by strange side modifications to the most 

 diverse situations. Perhaps one ought rather to say that 



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