49. Observations on Ants, Bees, and Wasps. Part 9.—Journal of the Linnean Society, 1881.
50. On the Limits of Vision among some of the lower Animals.—Journal of the Linnean Society, 1881.
51. Observations on Ants, Bees, and Wasps. Part 10.—Journal of the Linnean Society, 1882.
CONTENTS.
| CHAPTER I. | |
| THE CLASSIFICATION OF INSECTS. | |
| Introduction.—Stages in the Life of an Insect.—Classification ofInsects.—Characters derived from the Wings; from the parts ofthe Mouth; from the Metamorphoses.—The Classes of Insects:Hymenoptera, Strepsiptera, Coleoptera, Euplexoptera, Orthoptera,Thysanoptera, Neuroptera, Trichoptera, Diptera, Aphaniptera,Heteroptera, Homoptera, Lepidoptera | page [1-26] |
| CHAPTER II. | |
| THE INFLUENCE OF EXTERNAL CONDITIONS ON THE FORM ANDSTRUCTURE OF LARVÆ. | |
| Larvæ depend partly on the group to which they belong.—Wood-eatingLarvæ.—Larvæ of Lamellicorns.—Larvæ depend also in part onmode of life.—Larvæ of Hymenoptera, of Sirex; of Tenthredo; ofIchneumons; of Bees.—Rudimentary legs of Bee Embryo.—Beetles,Weevils, Scolytus, Crioceris, Sitaris, Metamorphoses of Pteromalidæ.Platygaster, Polynema.—Influence of external conditions.—Developmentaland adaptive Metamorphoses | page [27-41] |
| CHAPTER III. | |
| THE NATURE OF METAMORPHOSES. | |
| The life history of an Insect must be considered as a whole.—Vaguenessof the term Larva.—Some larvæ much more advanced than others.—Organsdevelope in different order, in different groups.—Suppressedstages.—Apod condition of Phryganea; of Aphis; ofChrysopa.—Libellulidæ.—Donacia.—Spiders.—Myriapods.—Apodstage of Homomorphous Insects once probably longer than now.—Suppressionof embryonic stages.—Metamorphoses of Hydroida,Crustacea, Isopods, and Amphipods.—Echinoderms.—Variationsin development induced by the influence of external conditions. | page [41-62] |
| CHAPTER IV | |
| THE ORIGIN OF METAMORPHOSES. | |
| Origin of Metamorphoses.—Views of Messrs. Kirby and Spence.—Natureof the question.—Young animals often more similar thanmature.—Views of Darwin, Herbert Spencer, Johannes Müller,Fritz Müller, and Agassiz.—Effect of size of egg.—Insects leave theegg in a more or less developed condition.—Consideration of pupalcondition.—Quiescence of pupa.—Period of quiescence at eachmoult.—Changes not so abrupt as generally supposed.—Change inmouth-parts.—Difficulty in reference to Darwinian theory.—Mouth-partsof Campodea and Collembola, as intermediate between themandibulate and haustellate types.—Change in mouth-parts as connectedwith pupal conditions.—Origin of wings.—Use of wingsunder water.—Connection of metamorphoses with alternation ofgenerations.—Parthenogenetic larvæ of Cecidomyia.—In alternationof generations one form always agamic.—Dimorphism and Dieidism.—Summaryand Conclusions | page [62-81] |
| CHAPTER V | |
| THE ORIGIN OF INSECTS. | |
| The Origin of Insects.—Mistaken views of Darwinian theory.—Naturalselection a vera causa.—Application of Darwin’s views to Insects.—Similarityof young Crustacea as compared with mature forms;ditto in Insects.—Type of Insecta.—Two principal types of larvæ:Hexapod and Apod.—Conclusions to be drawn from them.—Campodeathe modern representative of the Insect-stock.—Campodea,perhaps derived from Tardigrade.—Vermiform or Apod type oflarva.—Views of Fritz Müller, Brauer, and Packard.—Representsa still earlier ancestor.—Modern representatives.—Notommata,Albertia, Lindia.—Earlier forms difficult to trace.—Lowest formsof animal life.—Yolk-segmentation.—Embryology and Evolution.—Lightthrown by the evolution of the individual on that of thespecies | page [82-108] |