INSECT SIPPERS AND GNA WERS. 267 
children are more helpless even than those of bees. 
A young bee eats its own food placed for it in its 
cell, but the ant can take nothing but what is actually 
put into its mouth. 
It is most tempting to try and trace out this 
gradual progress to increased intelligence in age and 
helplessness in youth among the membrane-winged 
insects. Thus we should begin with the caterpillars 
of the saw-flies, placed within their proper plant by 
the saw-like instrument of their mother, and creeping 
over it in their youth ; then pass on to the grubs of 
the gall-flies which lie helplessly within the gall-nuts 
eating the food which their mother has prepared for 
them by leaving an irritating liquid which causes a 
lump to grow up around them on the plant. Next 
would come the grubs of the cunning Ichneumon fly 
which, though feeding on honey herself, pierces the 
skin of the caterpillar or the beetle, and leaves her 
eggs in their flesh, where the young ones live as 
parasites during their sluggish infancy. 
From these we should go on to the still more 
wonderful burrowing insects, such as the Cerceris, the 
Sphex, and the Sand-wasp, which, after laying their 
eggs in a hole, pierce beetles, grasshoppers, or cater- 
pillars with their sting, not killing them, but paralysing 
them, and then storing them up with their eggs as 
fresh healthy living food for the young when they are 
hatched, two or three weeks later. Then we should 
come to the true wasps, with their beautifully -con- 
structed paper nests, built of wood fibre moulded into 
paste, and their helpless infants each in its cell tended 
with the utmost care ; and we should learn almost 
to have an affection for these industrious creatures, 
