160 INSECT TRANSFORMATION 



genera, such as Ceratocombus, in which the forewings, though 

 relatively long are imperfectly developed, and others, Micro- 

 physa for example, in which these organs are normal in the 

 male but abbreviated or rudimentary in the female. It is 

 suggestive to recognize a tendency towards the wingless 



FIG. QI. 



a, Bed-bug (Cimex lectularius) , female, x 5. b, vestigial wing, x 20. c, egg; d, young in 

 first stage ; e, cast cuticle of first instar ; /, second instar just after moult ; g, second instar after 

 feeding, x 25. After Marlatt, U.S. Dept. Agric. Entom. Bull. 4. 



condition, in the allies of those insects wherein complete 

 winglessness accompanies the parasitic mode of life. 



In the opening pages of this chapter reference was made to 

 the occurrence of wingless insects among the orders which 

 undergo the hidden process of wing-growth and pass through a 

 marked transformation in the course of their life-history. 



