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