258 SAGACITY AND MORALITY OF PLANTS. 



is performed by a few only out of the innumerable 

 hosts of insects ; and even the larvae of the former 

 make the leaves of the plants, whose flowers are 

 benefited by their parents, pay fine and toll for the 

 service. 



It may be that the remarkable habit of catching 

 flies, and afterwards of making a meal of them, has 

 been developed by adversity. I pointed out six 

 years ago, in Flowers : their Origin^ etc.y that " The 

 marsh-loving habits of most of these plants, both 

 British and foreign, show that they usually grow in 

 places where their roots can absorb but little if any 

 nitrogenous material. This duty is therefore thrown 

 upon other parts of the plant, some of which are 

 normally in the condition that the spongioles of the 

 roots are ; so that when decomposing animal matter 

 comes into contact with them, they can absorb it." 

 To the difficulty which marsh-plants have of getting 

 nitrogen might be added that of obtaining potash 

 and other salts, with which, however, captured in- 

 sects would provide them. Our English Sundews 

 {Droserce) may often be seen growing in myriads on 

 the surface of Sphagnum bogs, their slender roots 

 merely anchoring them to their places, and perhaps 

 providing them with water ; whilst the marvellously 

 altered and adapted leaves not only obtain carbon 

 from the atmosphere, but artfully contrive to get all 

 the nitrogen, potash, etc., the whole plant requires 

 from the capture of insects ! 



