492 GEOGRAPHICAL DISTRIBUTION OF INSECTS. 



food bysuctio?ior mastication: in the carni vorous ones, the 

 suckers to the masticators in Britain are nearly as 1:6; 

 but with respect to the phytiphagous tribe you must take 

 into consideration that some insects imbibing their food 

 by suction in their perfect state (as the great body of the 

 Lcpidoptera\ masticate it when they are larwe : deducting 

 therefore from both sides* the insects thus circumstanced, 

 the masticators will form about three fourths of the re- 

 maining British thalerophagous insects. Another cir- 

 cumstance belonging to this head must not be passed 

 without notice: there are certain insects feeding upon 

 liquid food that do not suck, but lap it. This is the case 

 with the Hymenoptera, who, though they are mandibulate, 

 generally lap their food (the nectar of flowers) with their 

 tongue, and may be called lambent insects : nor is this 

 practice confined to that order, but all the mandibulate 

 insects that feed on that substance merit the same appel- 

 lation. The absorption of this nectar is so important a 

 point in the economy of nature, that a very large propor- 

 tion of the insect population of the globe in their perfect 

 state, are devoted to it. Considerably more than half 

 the species indigenous to Britain fulfill this function, 

 and probably in tropical countries the proportion may 

 be still larger. 



To push this analysis still further Amongst our car- 

 nivorous thalerophaga, aphidivorous insects are about as 

 1 : 1 4 ; and amongst the phytiphagous, the fungivorous 

 ones form about a twentieth ; and the granivorous about 

 a twenty-fifth part of the whole. Again : in the sapro- 

 phaga the lignivorous tribes form more than half> and 

 the coprophagous ones more than a third. 



If you wish to know further the relative proportions 



