EXTERNAL ANATOMY OF INSECTS. 601 
strengthen a soft one, and it is by these that the first ap- 
proach is made to the reticular structure of tegmina or 
the wing-covers of Orthoptera : Lycus palliatus, &c., in 
its elytra exhibits a direct resemblance of the reticula- 
tions of nervures. 
8. Clothing. To what I have before said on this 
subject in general? I shall here add a few remarks, 
which, though they more properly belong to elytra, may 
in many cases be extended to the whole body of a 
beetle. In various instances it happens that the beauti- 
ful markings of these organs, as in Acrocinus longimanus, 
whose elytra when denuded are black, are produced by 
short decumbent hairs; in some these variegations are 
the effect of scales resembling those of Lepidoptera, often 
of a metallic lustre; from these scales is derived all the 
brilliancy of the diamond-beetle (Eintimus imperialis); in 
some the scales are so minute as to resemble the pollen 
of flowers, as the white marks observable on the green 
elytra of the rose-chafer (Cetonia aurata). 
9. Colour. The organs of flight in the majority of the 
Orders with respect to colour are usually the most gaily 
decorated part of insects; I therefore deferred the notice 
of that subject till I came to treat of them. In general 
the colour of insects is either inherent in the substance 
of their crust, or produced by the hairs or scales or 
powder that either partially or totally cover it. To con- 
fine myself to the Coleoptera, of whose elytra we are 
treating, it may be observed, I think, in general, that 
the majority of those that feed upon putrescent sub- 
stances, the saprophagous tribes of Mr. W.S. MacLeay, 
* See above, p. 398—. 
