I.] METAMORPHOSES OF INSECTS. 5 



this point of view, the Insecta have been divided 

 into two series the Mandibulata and Haustellata, or 

 mandibulate and suctorial groups, between which, 

 as I have elsewhere shown, 1 the Collembola (Podura, 

 Smynthurus, &c.) occupy an intermediate position. 

 These two series are : 



MANDIBULATA. HAUSTELLATA. 



Hymenoptera. Lepidoptera. 



Strepsiptera. Diptera. 



Coleoptera. Aphaniptera. 



Euplexoptera. Hemiptera. 



Orthoptera. Homoptera. 

 Trichoptera ? 

 Thysanoptera ? 



Again and this is the most important from my 

 present point of view insects have sometimes been 

 divided into two other series, according to the nature 

 of their metamorphoses : "Heteromorpha," to use the 

 terminology of Prof. Westwood, 2 ' or those in which 

 there is no resemblance between the parent and the 

 offspring; and Homomorpha, or those in which the 

 larva resembles the imago, except in the absence of 

 wings. In the former the larva is generally worm- 

 like, of a soft and fleshy consistence, and furnished 

 with a mouth, and often with six short legs attached 

 in pairs to the three segments succeeding the head. 

 In the Homomorpha, including the Orthoptera, 

 Hemiptera, Homoptera, and certain Neuroptera, the 

 body, legs, and antennae are nearly similar in their 

 form to those of the perfect insect, but the wings 

 are wanting." 



1 Linnean Journal, vol. xi. 



2 Introduction to the Modern Classification of Insects, p. 17. 



