460 IIoMi-i N.\i rKi>Srrn\- CtU'KSi:. 



Outdoor obscn'atio)is. — ^As soon as the pupils arc interested in this 

 question of insect music they will naturally observe for themselves. Let 

 them find a black cricket musician ; note where he lives, how he acts 

 when disturbed, whether he sings most during the day or in the evening, 

 whether there is more cricket music early or late in the season. On the 

 vines and shrubs may be found a slender, white cricket, called the snowy 

 tree cricket; this sings only late in the afternoon and night (see "Ways 

 of the Six- Footed," p. 25). 



LESSON XVL 



HOW^ THE CRICKETS AND GRASSHOPPERS LISTEN TO MUSIC. 



Purpose. — To teach that the hearing organs in insects are not in the 

 head, as with us, and not invariably situated alike. 



There should be a little talk to bring out the fact that there would 

 be very little use of an insect making music unless others could hear it. 

 Take a short-horned grasshopper and lift its wings to see the disc-shaped 

 ears on the abdomen very close to the thorax where the wings are fastened 

 (see " Comstock's Manual," p. 58, fig. 70). Take a black cricket and 

 looking at it through a lens, note the white spot on the front legs near 

 the elbow ; this is the ear (see " Ways of the Six-Footed," p. 24, fig. 12). 

 The ears of the katydid and long-horned grasshopper are placed in the 

 front elbows, like those of the cricket (see " Comstock's Alanual," p. 

 112, fig. 125). 



THE POTATO BEETLE. 

 LESSON XVIL 



Preliminary Work. — The study of the potato beetle naturally follows and be- 

 longs to gardening. The larva should be brought into the schoolroom and placed 

 in a breeding cage, similar to that made for the crickets except, of course, its food 

 must be a potato vine. Other plants may be put in the cage to prove that these 

 insects will only touch the potato. Note how they eat and how many leaves one 

 larva eats during its life time, and how the larvae go down to the earth to change 

 to pupae; in fact, all their habits are interesting, because we must know all about 

 this enemy in order to learn its tactics, so that we may conquer it. The nature- 

 study lesson suggested should be quite incidental to the interest in this insect 

 as a foe. 



Purpose. — To acquaint the pupils with the form of beetles and in 

 particular with the life habits of the potato beetle. 



Material. — One or more potato beetles. These may be found in Octo- 

 ber on or in the earth of a neglected potato patch. 



Obserz'ations on its form. — The legs are not fitted for jumping 

 because the hind ones are not much longer than the front ones ; they 



