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OTIS F 5 : 
OS: 7 T may at first sight appear to be 
( BN WA, a singular coincidence that such 
SN of our plants as have taken to 
Wy destroying insects and digestin 
2 ra) 
them, though belonging to widely 
separated families, agree in being 
the habitués of bogs and marshes. I have already 
described the carnivorous Sundews as being found in 
such places, and now have to mention the Butterwort 
and the Bladderwort, which grow in similar situations. 
The explanation of the insectivorous habit being 
common to several dissimilar plants growing under 
similar conditions is this: the soilin which their roots 
are found is very deficient in nitrogenous substances, 
consequently the roots themselves are very small, 
and used chiefly for the absorption of water. It is 
therefore necessary that the plant should obtain its 
nitrogen in other ways, and it has developed the 
necessary mechanism for catching, killing, and 
digesting insects, the animal matter thus obtained 
being afterwards absorbed and assimilated by the plant. 
267 
