HARD PARTS OF THE GRASSHOPPER. 237 



g. After two or three moults the posterior end of the 

 body lengthens to form the long hind-body of the adult, 

 while the rounded anterior portion becomes the carapace 

 of the adult. The mandibles develop cutting blades upon 

 their basal joints, and the two pairs of maxillae make their 

 appearance as small buds on the ventral surface of the 

 body. 



li. After one or two more moults, the second antenna 

 becomes uniramous, as shown in Fig. 128, e. The 

 blade (f) of the mandible becomes fully developed, and 

 the two terminal branches of the nauplius mandible dis- 

 appear. The two pairs of maxilla? (g, h) assume their 

 adult form, and the thoracic appendages (,./, &) and the 

 free somites of the thorax and abdomen appear, in succes- 

 sion, from in front backwards. The larva changes grad- 

 ually, through a number of moults, until the adult form is 

 reached. 



XXIII. THE HARD PARTS OF THE GRASS- 

 HOPPER. 



(Acridium Americanum.) 



THE following description was written from the above 

 species, which should if possible be procured for labora- 

 tory work, as its large size makes it an especially good 

 type for elementary work. Any other grasshopper may, 

 however, be used, or even a cricket, or a cockroach. 

 Fresh specimens, or those which have been preserved in 

 alcohol, will answer for examination. If the alcoholic 

 specimens are stiff and brittle they may be softened by 

 placing them in warm water for a few hours. 



Examine a fresh or a preserved specimen, and notice the 



