14 BRITISH BEETLES. 



are of the greatest use for reference, and many of the 

 characters detected by naturalists cannot fail to be very 

 nearly approaching to the truth. 



The beginner must in a great decree dismiss size and 

 colour from his mind in investigating Beetles critically, 

 and rather rely upon structure and sculpture, as the 

 former are bad guides, though good companions. An 

 examination of the number and shape of the joints of 

 all the tarsi, and the structure of the antennae and 

 palpi, will usually afford a sufficient clue as to the sec- 

 tion in which any individual species should be placed : 

 further characters are to be sought in the relative 

 length of the thorax and elytra, the development of 

 the different limbs, the existence or non-existence of 

 wings, and, above all, in the parts of the mouth. These 

 latter vary so much in different genera even, as to re- 

 quire the strictest examination. They may be dissected 

 in a fresh specimen, or in an old one which has been 

 first left for a day or two in laurel (as hereafter ex- 

 plained) or soaked in cold water (or weak alcohol and 

 water) for a day ; few instruments are needed, a cou- 

 ple of fine pins, hooked at the point, and mounted in 

 thin holders (such as paint-brush sticks) will be enough 

 for ordinary species ; but a dissecting knife, with a very 

 fine point, will be found most useful. The head of the 

 beetle may be removed from the thorax, and a fine pointed 

 piece of wood thrust into the occipital hole, to act as a 

 firm basis ; the jaws can then readily be opened, and 

 the smaller parts taken out and gummed on card. 

 Both hands are needed for this, so that it is well to get 

 accustomed to working without a glass ; for small in- 

 sects, however, a lens mounted on a stage, so as not to 

 require to be held, is very useful; and, for the very 



