S44< AFFECTION OF INSECTS FOR THEIR YOUNG. 



occupy that of another insect, or find a convenient abode 

 within the body of that on which they feed. But upon the 

 maternal affection of another large hymenopterous tribe, 

 chiefly belonging to the Linnean genus Sphex, whose 

 young in like manner feed on other insects, is imposed 

 the arduous task not merely of collecting a supply of 

 food, but of inclosing it along with their eggs in cells or 

 burrows often of considerable depth, and dug with great 

 labour in sand or the solid earth. 



The general economy of these insects is similar. Having 

 first dug a cylindrical cavity of the requisite dimensions, 

 and deposited an egg at the bottom, they inclose along with 

 it one or more caterpillars, spiders, or other insects, each 

 particular species for the most part selecting a distinct 

 kind, as a provision for the young one when hatched, 

 and sufficiently abundant to nourish it until it becomes a 

 pupa. Many thus furnish several cells. This process, 

 however, is varied by different species, some of whose 

 operations are worthy of a more detailed description. 



One of the most early histories of the procedure of an 

 insect of this kind (probably Ammophila vulgaris^ Kirby) 

 is left us by the excellent Ray, who observed it along 

 with his friend Willughby. On the 22d of June 1667, 

 he tells us, they noticed this insect dragging a green ca- 

 terpillar thrice as big as itself, which after thus convey- 

 ing about fifteen feet, it deposited at the entrance of a 

 hole previously dug in the sand. Then removing a pel- 

 let of earth from its mouth, it descended into the cavity, 

 and, presently returning, dragged along with it the ca- 

 terpillar. After staying awhile it again ascended, then 

 rolled pieces of earth into the hole, at intervals scratch- 



