i8 



INSECT TRANSFORMATION 



Behind the thorax with its legs and wings, extends the 

 elongate abdomen or hind-body of the grasshopper. In this 

 region ten segments may be readily distinguished, most of 

 them simple in construction, destitute of limbs, and closely 

 similar to one another, the exoskeleton consisting of a strongly- 

 arched tergum above and a flattened sternum beneath. On 

 either side of the first abdominal segment is a specialized, thin, 

 tense, circular area of cuticle the tympanum or drum of an 

 organ of hearing (Fig. 9 t). The sternum of this segment is 

 imperfectly developed on account of the backward extension 

 of the thoracic metasternum while the tenth segment carries a 

 pair of short but definite limbs, the cerci or tail-feelers (Fig. 9 c) . 

 Behind this, small dorsal and ventral sclerites surround the 



ep pr 



Sp.8 



FIG. 9. SIDE-VIEW OF A LOCUST WITH WINGS AND LEGS REMOVED. 



ep, crown ; /, irons ; cl, clypeus ; la, labrum ; ge, cheek ; pr, pronotum ; i-io 

 abdominal terga ; sp.i, ii, thoracic spiracles (the first exposed by removal of corner 

 of pronotum) ; t, ear-drum ; sp.2, 8, second and eighth abdominal spiracles ; c, cercus ; 

 op, ovipositor. Natural size. 



vent or intestinal anus ; these may be regarded as the exoskele- 

 ton of a terminal tail-segment. In the female grasshopper 

 there are three pairs of hard processes, one pair belonging to 

 the eighth and two pairs to the ninth abdominal segment ; 

 these form the egg-laying organ or ovipositor, and their strong, 

 sharp tips extend backwards beyond the rest of the abdomen 

 (Fig. 9 op). 



Close examination of the grasshopper's exoskeleton reveals 

 the presence of a series of paired openings (Fig. 9 sp) on the 

 sides of many of the segments. These are the spiracles or 

 stigmata, by means of which the insect's breathing organs are 

 in connexion with the atmosphere. The foremost of them are 

 seen on the thin cuticle between the pronotum and the meso- 



