Chapter IV: Part III: The Metamorphoses of Insects

_a._ The nymph as distinguished from the larval stage 593

_b._ Stages or stadia of metamorphosis 594

_c._ Ametabolous and metabolous stages 594

THE LARVA 599

_a._ The Campodea-form type of larva 600

_b._ The eruciform type of larva 602

_c._ Growth and increase in size of the larva 608

_d._ The process of moulting 609

The number of moults in insects of different orders 615
Reproduction of lost limbs 619
Formation of the cocoon 619
Sanitary conditions observed by the honey-bee larva, and
admission of air within the cocoon 623

THE PUPA STATE 625

_a._ The pupa considered in reference to its adaptation to its
surroundings and its relation to phylogeny 631

_b._ Mode of escape of the pupa from its cocoon 632

_c._ The cremaster 636

Mode of formation of the cremaster and suspension of the
chrysalis in butterflies 637

FORMATION OF THE PUPA AND IMAGO IN THE HOLOMETABOLOUS INSECTS (THE
DIPTERA EXCEPTED) 640

_a._ The Lepidoptera 642

The changes in the head and mouth-parts 646
The change in the internal organs 647
The wings 654
Development of the feet and of the cephalic appendages 654
Embryonic cells and the phagocytes 655
Formation of the femur and of the tibia; transformation of
the tarsus 656
The antennæ 657
Maxillæ and labial palpi 658
Process of pupation 660

_b._ The Hymenoptera 661

Ocular or oculo-cephalic buds 665
The antennal buds 665
The buds of the buccal appendages 665
The buds of the ovipositor 665

DEVELOPMENT OF THE IMAGO IN THE DIPTERA 666

_a._ Development of the outer body-form 668

Formation of the imago in Corethra 668
Formation of the imago in Culex 670
Formation of the imago in Chironomus 671
Formation of the imago in Muscidæ 673

_b._ Development of the internal organs of the imago 678

The hypodermis 678
The muscles 680
The digestive canal 681
The tracheal system 683
The nervous system 684
The fat-body 685
Definitive fate of the leucocytes 685
The post-embryonic changes and imaginal buds in the
Pupipara (Melophagus) 686

_c._ General summary 687

HYPERMETAMORPHISM 688

SUMMARY OF THE FACTS AND SUGGESTIONS AS TO THE CAUSES OF
METAMORPHISM 705

Theoretical conclusions; causes of metamorphosis 708

TEXT-BOOK OF ENTOMOLOGY