564 THE ECONOMIC STATUS OF INSECTS AS A CLASS. 



bodies of dead animals not destroyed by insects in this way, and, still 

 more, were the destruction of dead vegetation not hastened as it is by 

 the attacks of countless insects, it is perfectly easy to see that the 

 earth would not be inhabitable; its surface would be covered with the 

 indestructible remains of what was once life in some form. 



Large groups of insects, comprising many thousands of species, take 

 part in this inestimable work, and it will probably be unnecessary in 

 order to bring about a realization of this value to dwell further upon 

 the subject. 



AS MAKERS OF SOIL,. 



It is a fact not generally realized that insects must take an important 

 part in the changes in the character of the soil which are constantly 

 going on. Occurring in such countless millions, as they do, constantly 

 penetrating the soil in all directions, frequently dragging vegetation 

 below the surface and bringing the subsoil up to the surface, changing 

 the character of the soil humus by passing it through their bodies, and 

 fertilizing the earth by their own death and decay, it is probable that 

 insects are responsible for even more soil change than are the earth 

 worms, which Darwin has placed before us in such an important light. 



Insects are found beneath the ground in incredible numbers. Some 

 of them pass their whole life underground, feeding upon roots and root- 

 lets, upon dead and decaying vegetable matter, upon soil humus, and 

 upon other insects. Many of them have their nests underground, 

 although they get their food elsewhere, while others hide their eggs 

 or pupse underground. 



The depth to which they penetrate is something surprising-; the 

 minute insects of the family Poduridre have been found swarming 

 literally by the million at a depth of 6 to 8 feet in a stiff clay subsoil. 



AS FOOD AND CLOTHING AND AS USED IN THE ARTS. 



In this role insects play an important part. Insects as food and 

 their products as clothing are well known to all. The great silk indus- 

 try of the world is derived wholly from insects and almost entirely 

 from a single species — tlie silkworm of commerce. 



As food, insects have formed articles of diet for certain savage peoples 

 since the beginning of the human race. Hope, in 1842, catalogued 46 

 species of insects used as food, and Wallace, in 1854, showed that 

 insects of six different orders were used as food by the Indians of the 

 Amazon. Semicivilized peoples to-day use certain insects as food, as 

 witness the consumption of Corixa eggs by the Mexicans, and a book 

 has been written under the caption Why Not Bat Insects'? for the pur- 

 pose of showing that many possibilities in the way of dietetics are 

 being ignored to-day. M. de Fontvielle, in addressing the Societe 

 d'Insectologie, in 1883, expressed regret that the attempts made to 

 popularize the use of insects as food have made so little progress, and 



