PLANT-EATING INSECTS AND MYRIAPODS 209 



in which mankind engages. The abodes of these Ants underlie 

 heaps of earth thrown up from below, and in some cases attain- 

 ing a circumference of 40 yards. From this home as a centre 

 regular paths are made in various directions, so as to make 

 desirable foraging spots readily accessible. These ant -roads 

 may be more or less underground, and extend for considerable 

 distances with a directness rivalling the public ways of the ancient 

 Romans. M'Cook took the measurements of such a road con- 

 structed by the North American species Atta fervens. The 

 total length was more than 600 feet, of which the first 448 were 

 excavated below the surface at an average depth of 18 inches, 

 while in some parts it was four times as much as this. Worker- 

 ants busily swarm along these roads and ascend the trees or 

 shrubs of which they are the goal, cutting from these small 

 round pieces of leaf. The bits of foliage are carried back to 

 the nest, and there made into a sort of mushroom bed, upon 

 which a kind of fungus (Rozites gongylophora] is raised. This, 

 however, is not simply left to itself, but is kept free from unde- 

 sirable moulds, &c., and its way of growth is modified in some 

 mysterious manner, so as to make it produce little white nodules, 

 which constitute the main food-supply of the Ants. 



BEETLES (COLEOPTERA) 



A very large number of species belonging to this enormous 

 order, which includes the insects popularly called Beetles, feed 

 upon vegetable matter. The structure of the mouth-parts has 

 already been alluded to (p. 107). Only a few examples can be 

 mentioned here, but further details will be given later on when 

 insect pests are considered. The Common Cockchafer (Melo- 

 lontha vulgaris) has earned an unenviable notoriety on account 

 of its devastations, especially in some parts of the Continent 

 (Holland, Germany, France, &c.), where, during what are known 

 as "chafer years", it appears in millions. Its favourite food 

 consists of the leaves and buds of many fruit- and forest-trees, 

 and its destructive larva, which lives as an underground grub 

 for three or four years, attacks the roots of all sorts of crops. 

 The Cockchafer is one of a group containing some 4000 known 

 species, all apparently of similar habits. The Sacred Scarab 

 (Scarabczus sacer) (fig. 443) is a dung -eating member of an 

 allied and larger (5000 species) group. The following inter- 



VOL. II. 46 



