Does the Form-relationship of the Larva coincide with that of the Imago? p. [432].
Family groups, [432]. Families frequently completely congruent, [435]. Exception offered by the Nymphalidæ, [435]. In transitional families the larvæ also show intermediate forms, [441]. Genera; almost completely congruent; the Nymphalideous genera can be based on the structure of the larvæ, [444]. So also can certain sub-genera, as Vanessa, [445]. Incongruence in Pterogon, [450]. Species; incongruence very common; S. Ocellatus and Populi, [451]. Species of Deilephila show a nearer form-relationship as imagines than as larvæ, [454]. Systemy not only the expression of morphological relationship, [455]. Varieties; incongruence the rule; seasonal dimorphism; climatic varieties; dimorphism of caterpillars; local varieties of caterpillars, [456]. Result of the investigation, [458]. Causes of incongruence, [460]. A phyletic vital force does not explain the phenomena, [461]. This force is superfluous, [464].
III.
Incongruences in other Orders of Insects, p. [481].
Hymenoptera. The imagines only possess ordinal characters, [481]. Double incongruence: different distance and different group-formation, [483]. Diptera, [488]. The larvæ form two types depending on different modes of life, [489]. The similarity of the grub-like larvæ of Diptera and Hymenoptera depends upon convergence, [494]. These data again furnish strong arguments against a phyletic vital force, [496]. The tribe Aphaniptera, [498]. Results furnished by the form-relationship of Diptera and Hymenoptera, [499]. Difference between typical and non-typical parts transient, [501].
IV.
Summary and Conclusion, p. [502].
First form of incongruence, [503]. Second form of incongruence, [506]. General conclusion as to the elimination of a phyletic vital force, [511]. Parallelism with the transformation of systems of organs, [513].
Appendix I., p. [520].
Additional notes on the Ontogeny, Phylogeny, &c., of Caterpillars. Ontogeny of Noctua larvæ, [520]. Additional descriptions of Sphinx-larvæ, [521]. Retention of the subdorsal line by ocellated larvæ, [529]. Phytophagic variability, [531]. Sexual variation in larvæ, [534].