TIIH METAMORPHOSIS OF /.Y.S7-XT.S 



175 



. GRADUAL METAMORPHOSIS 



(Paurometaboloiis* Development ) 



In several orders of insects there exists a type of development that 

 is characterized by the fact that the young resemble the adult in the 

 general form of the body and in manner of life. There is a gradual 

 growth of the body and of the wing rudiments and genital appendages. 



Fig. 194. Nymph of Mcln- 

 n>plns, first instar (After 

 Emerton) 



Fig. 196. Nymph of Melano- 

 plus, third instar (After Emer- 

 ton) 



Fig. 198. Xymph of Mclano- 

 plus, fifth instar (After Emer- 

 ton). 



Fig. 195. Nymph of Mela- 

 noplus, second instar 

 (After Emerton). 



Fig. 197. Nymph of Mclano- 

 plus, fourth instar (After 

 Emerton). 



Fig. 199. Melanyplvs, 



adult. 



But the changes in form take place gradually and are not very great 

 between any two successive instars except that at the last ecdysis 

 there takes place a greater change, especially in the wings, than at 

 any of the preceding ecdyses. This type of metamorphosis is desig- 

 nated as gradual metamorphosis or pawrometabolous development. 



The characteristic features of paurometabolous development are 

 correlated with the fact that the mode of life of the young and of the 



fc Paurometabolous: f>anros (iravpos), little; H/C/I '>.>/< 



i . 



