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species besides the above. Also it is of the more importance to 

 get at the true economy of this family of insects, from the damage 

 done by some species to our forest trees. A few years back the 

 oaks in this country sufifered greatly from their attacks, and I 

 believe the evil still prevails in places. The young shoots and 

 leaves were loaded with galls of the size of hazel nuts caused by 

 the punctures of the parent insects, the gall being both the nidus 

 and the food of the larva; and the healthy growth of the trees in 

 young plantations was much interfered with by these abnormal 

 excrescences. Whether the particular species of gall-fly in this 

 instance was actually new to this country or not I am ignorant, 

 but it does not appear to have been noticed before in such abund- 

 ance ; it came like a plague, appearing first in the western counties 

 and gradually spreading from thence in different directions. It 

 was in Devon in 1853, the following year in Somerset, and all the 

 woods about Bath were full of it as I myself witnessed; in 1855 

 and 1856 in Gloucestershire, in 1857 in Worcestershire, and within 

 three or four years afterwards it had reached N. Wales, Sussex, 

 and Kent. * 



There is yet another subject to which I would briefly call the 

 attention of the Local Entomologist, as one which we cannot as 

 yet be said thoroughly to understand, though diff"erent theories 

 have been put forth to explain it, and that is mimicry. This 

 name, as many are aware, has been applied to cases in which we 

 find certain species of animals adopting the form and colouring of 

 other species to which they bear no direct affinity ; so that in a 

 general way and without close examination we might easily be led 

 to mistake one for another. Such cases of similarity are sparingly 

 met with in many very difierent classes of animals, but it is 

 amongst insects, and especially the diurnal Lepidoptera, or Papi- 

 lionidoe, that they are found to prevail most. They have been long 

 known to Naturalists, and at one time attracted much attention, 

 as relations of analogy, a name given to them, in contradistinction 

 to relations of affinity, by Macleay and Swainson, who brought 



• This gall-fly is alluded to by Sir John Lubbock (PhU. Trans. 1857, 

 p. 95), under the name of Cynips Ugnicola, and he remarks that among 

 " several thousand specimens not a male occurred." 



