INSECTS. 227 



ing. Many in their perfect state live on food quite different 

 from that upon which they subsisted when in the state of larvae ; 

 and yet, notwithstanding of this, they instinctively deposit their 

 ova upon the peculiar matters necessary for the food of the young. 

 Thus the Lepidoptera, which in the perfect state suck the honey 

 of flowers, never fail to place their ova on or near the plants 

 the leaves of which are proper for the nourishment of the cater- 

 pillar ; and thus it happens that the Culices, whose larvae are 

 destined to live and find their subsistence in water, drop their 

 ova on its surface. 



Among the insects which live in society there are some, as 

 the bees, which are under the necessity of making choice of a 

 dwelling for the purpose of storing up a supply of provisions for 

 unfavourable seasons, which would prevent the acquisition of a 

 daily supply. Others, such as the ants, unite and work in com- 

 mon to procure not only their own subsistence, but food for their 

 larvae, which are totally incapable of seeking it for themselves. 



Many insects seem confined to one species of food, and never 

 vary in their taste. Such are a great number of caterpillars, 

 which feed on certain leaves, and if these fail they die. The her- 

 bivorous insects besides eat often, and almost continually ; while 

 those which live on prey, like the carnivorous animals of the 

 higher classes, are capable of considerable abstinence. Certain 

 species of insects subsist on the leaves of trees, such as the larvae 

 of the Lepidoptera, and many of the Coleoptera and Hymenop- 

 tera ; others suck the juices of the leaves and stems, as the Cica- 

 dae and the Aphides ; some feed on the vegetable excrescences 

 named galls, and many on the buds of trees. Fruits of all kinds 

 are the subsistence of many insects and their larvae; while 

 others prove powerful destroyers of the different species of grain. 

 Even the solid matter of trees becomes the food of many larvae, 

 which perforate the timber in all directions, reduce it to powder, 

 and devour the particles. A food more delicate is necessary 

 for some insects, and this is found in that part of flowers termed 

 by botanists the nectary. From these nectaries the bees collect 

 the fluid, which, after having undergone some preparation in 

 their bodies, forms the substance termed honey ; and the ants 

 seek with avidity the saccharine fluid which is exuded from 

 openings in the abdomen of the Aphides, caressing them till 

 this evacuation so necessary to them is produced. 



