i68 INSECT TRANSFORMATION 



any winged forms, but also because they exhibit a combination 

 of primitive characters which marks them out as probably 

 representing offshoots of the ancestral stock of the whole class 

 of insects as they might be imagined to have existed before 



f 



FIG. 96. ROCK-JUMPER (PctroblUS), FEMALE, VENTRAL VIEW. 



mp, maxillary palp ; Ip, labial palp ; s, stylets ; o, ovi- 

 positor ; c, cercus ; mf, median tail-process (truncated). 

 X 3. From Comstock, " Introduction to Entomology ". 



the development of wings. This small, but highly interesting 

 assemblage of orders is known therefore as the Apterygota, 

 and is sharply distinguished in classificatory systems from the 

 winged groups. 



As a typical example of the Apterygota we may take a specie 



