216 The Naturalist in Siluria. 



THE ANNUAL FORAY OF THE PHOTOPHAGI. 



Last year trees of nearly every sort suffered much 

 from what is commonly called " blight/' whole tracts of 

 woodland, especially where oaks abounded, showing bare 

 branches in May and June, when they should have had on 

 their brightest livery of green. It is a popular belief 

 that this blight is due to atmospheric influences " some- 

 thing in the air," as I have heard country people say of 

 it; and, in truth, the air has something to do with it, 

 but not in the sense understood or fancied by them. The 

 entomologist, of course, knows the real cause, in which 

 there is no atmospheric mystery, but a simple operation 

 of nature, though irregular in its workings, or, rather, 

 the amount of work done by it in the different years. 

 This irregularity alone is to be accredited to the atmos- 

 phere, the blight itself proceeding from the larvce of 

 certain species of insects belonging to the order of leaf- 

 eaters, and chiefly of the family Cynipidce. It is a 

 numerous family, the oak itself being the foster-mother, 

 as it were, to many of its members, the more notable ones 

 being nursed in what are indifferently called " oak- 

 apples " and " oak-nuts," but more properly " oak-galls." 

 And I may here remark that the famed " Dead Sea 

 apples " are similar excrescences, created by an insect of 

 the genus Cynips on the leaves of a species of Syrian 

 oak. 



There are few insects whose life and ways are more 

 interesting than those of the Cynipidtt, even the ants not 

 excepted ; and I hope, later on, to have an opportunity of 

 giving further and fuller details about them, the present 

 note being only meant to chronicle some facts which have 

 just come under my observation. In the Forest of 



