28 Practical Zoology. 



bottom. Why this number? What new fact in regard to the 

 relation of the bottom of a cell to the cells on the opposite side of 

 the comb ? Why should the bottom of a cell be of this form and 

 not flat ? Why this relation to the cells on the other side ? 



THE ANT-LION. 



Field Study of the Larva. In dry, sandy places look for 

 conical depressions, as evenly made as if rimmed out by a 

 mechanic. Many of these pits may be found near each other, in 

 the neighborhood of ants' nests. Drop a few grains of sand into 

 the center of the pit, looking closely meanwhile, for the protruding 

 jaws at the bottom of the pit. 



Quickly scoop up the whole pit, aiming to go an inch deeper 

 than its greatest depth. This can be done very well with the 

 hand, though a garden trowel is best. A tin cup or dipper would 

 serve very well. Sift the sand thus scooped up through the fingers 

 or over the edge of the hand, and look closely for the dull gray 

 larva of the ant-lion (Fig. 16). It has an oval body, and a pair 

 of long, hooked jaws. Place the larva on sand held in the hand, 

 cup, or can, and see how it buries itself. 



Home Study of the Ant-lion Larva. Take several larvae home. 

 Place each on sand in a separate tumbler or can. Two or three 

 inches deep will be enough. Watch again how the larva buries 

 itself. Watch patiently to find how it digs the pit. Drop an ant, 

 a crippled fly, or almost any small insect into the pit and see 

 what the larva does. How does it eat ? How much of its victim 

 does it consume ? For the appearance of the adult ant-lion see 

 Fig. 15, in the descriptive text. 



REVIEW OF INSECTS. 



Take any insect not yet studied, and examine it thoroughly. 

 Write a full description, and make drawings of it. Which of the 

 insects previously studied is this most like ? To what order, then, 

 does it probably belong? 



