V.] METAMORPHOSES OF INSECTS. 91 



have generally been classed with the maggots of Flies, 

 Weevils, &c., rather than with the more active form 

 of larva just adverted to. This seems to me, as I 

 have already pointed out, 1 to be a mistake. The 

 caterpillar type differs, no doubt, in its general ap- 

 pearance, owing to its greater clumsiness, but still 

 essentially agrees with that already described. 



No Dipterous larva, so far as I know, belongs truly 

 to this type ; in fact, the early stages of the pupa 

 in the Diptera seem in some respects to correspond 

 to the larvae of other Insect orders. The Develop- 

 ment of the Diptera is, however, as Weissman 2 has 

 shown, very abnormal in other respects. 



Thus, then, we find in many of the principal 

 groups of insects that, greatly as they differ from 

 one another in their mature condition, when they 

 leave the egg they more nearly resemble the typical 

 insect type ; consisting of a head ; a three-segmented 

 thorax, with three pairs of legs ; and a many- 

 jointed abdomen, often with anal appendages. Now, 

 is there any mature animal which answers to this 

 description ? We need not have been surprised if 

 this type, through which it would appear that 

 insects must have passed so many ages since (for 

 winged Neuroptera have been found in the carboni- 

 ferous strata) had long ago become extinct. Yet it 

 is not so. The interesting genus Campodea (PI. 3, 

 Fig. 5) still lives ; it inhabits damp earth, and 

 closely resembles the larva of Chloeon (PI. 2, Fig. i\ 

 constituting, indeed, a type which, as shown in PI. 4, 



1 Linnean Transactions, vol. xxiv. p. 65. 



2 Sieboid und Kolliker's Zeitschr. f. Wiss. Zool., 1864. 



