1. 1 \ i i or 





''...Ions insects, it i- CUStomary l<> (ISC tin- term n\ml>li durin:/ tin- 



\ ;il between egg and im.: 

 .! rare abnormality. ;i holbmetaboloufl lar 



pair> nt" true external wini: pad-. Thi- < ondil i>n ha- been reported in 



>. L'ictula tihiccH. A, imago emerging from nymphal skin; B, the cast skin; C, 

 imago. Natural size. 



,d specimens of the meal worm, Tenebrio molitor (by Heymons), six 

 larva.* of the museum beetle, Anthrenus verbasci (A. Busck) and one 

 pyrochroid larva, Dendroides canadensis (P. B. Powell). In these larva,' 



B 



210. Eggs of various insects. A, butterfly, Polygonia interrogation^: B, house 



(', chalcid, Bruchopha^n.\ funchris; D, butterfly, Papilio trot, 

 ncura trifolii; F, hemipteron, Triphleps insidiosus; G, hemipteron, Podisus 

 maciil: . fly, Drosophila ampclophila. Greatly magnified. 



all coleopterous it is comparatively an easy step from the internal 

 Wing-rudiment to an external win^-pad. as Dr. W. A. Riley has pointed 

 out. He regards tin- phenomenon not as an instance of atavism a 

 barking-back to a period when the larva bore win^s but as an example 



