480 GEOGRAPHICAL DISTRIBUTION OF INSECTS. 
food by suction or mastication: in the carnivorous 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 
Lepidoptera), masticate it when they are /arve : 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 sack, but Jap 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 /ambent 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 
1:14; and amongst the phytiphagous, the fungivorous 
ones form about a ¢wentieth ; 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 farther the relative proportions 
