SAXICOLA GENANTHE. 401 



beetles. I have examined the coops, and find insect Hfe, wireworms, and 

 small snail-shells, exactly corresponding to those which I have taken out of 

 the gizzards of the birds themselves. The insects and others fall into the 

 trench, and cannot get out till they are eaten. 



Having before me the contents of some eighteen dozen birds, I find 

 them to consist chiefly of comminuted and broken fragments of the elytra of 

 beetles, which, though composed of chitine, and nearly indestructible*, are 

 difficult to determine as regards species. There are seven sorts : — weevils 

 (perhaps Otiorhynchus ?) ; one nearly whole beetle of the genus Amara, but 

 out of some twenty-six species it is not easy to decide which ; one green 

 beetle (Agelastica halensis) ; tw^o caterpillars ; a field-bug ; some wireworms ; 

 and three kinds of shell, one QBelioa virgatd) swallowed whole, and fragments 

 of Clausilia laminata, Montagu, and C nigricans, Maton, with the usual grit. 

 Perhaps the shells were taken, instead of stones, to assist the triturating 

 process. 



On the whole, though of course some objects must pass through with- 

 out leaving a trace, yet at this season (August) it is clear that Wheatears, in 

 the main, live upon beetles, of which the cases are probably cast up. 



In one instance only did I find a small grain of w^heat (?) in a gizzard, 

 which remained just as swallowed, and w^ould have sprouted. 



It is the diet of beetles which perhaps gives these birds their flavour, 

 and has the effect of very quickly rendering the dead ones too high for use, 



* Certainly the nature of the coverings of beetles is indestructible. We see that they pass 

 through a bird without being changed^ except^ of course_, that they are broken. Professor Heer 

 tells us of 116 species of fossil coleoptera which he has obtained at that rich locality, Schambelen, 

 Switzerland, among the most ancient insects of that country; and he considers Schambelen is the 

 only locality on the continent where so many primaeval examples have been preserved. He says, it 

 is chiefly the elytra of beetles which have come down to us (' The Primaeval World of Switzerland,' 

 by Professor Heer, edited by James Heywood, M.A., F.R.S., vol. i. p. 81 et seq,). 



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