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ARACHNQIDEA 



CASE that these species of Erineum, in almost every case, are growths 

 or products caused by some species of the small mite which 

 we have now under consideration; a mite so small and some- 

 times so crystalline and transparent (as in the Phytoptus of the 

 ash for example) that it cannot be seen in the gall at all, and 

 it is only by washing out the galls and searching for them in the 

 water in which they have been washed that it can be known that 



Leaf of lime-tree bearing nail-ffalls (work of a mite). 



Section of nail-gall of lime leaf. 



there has been a living creature there at all. The first step 

 towards a knowledge of them was made nearly a hundred and 

 €fty years ago, by Reaumur, the celebrated French entomologist. 

 There sometimes occurs on the leaf of the Hme-tree a number 

 of upright projecting small growths, varying from green through 

 red to brown in colour, and which look very much as if a 



