As the life-conditions and feedinghabits of the larva and imago become constantly more divergent, the appearance of the wing-rudiments would be postponed to the pre-imaginal instar, and that instar would become predominantly passive.
It may eat roots or refuse, while the imago lives on leaves and flowers.
They are as follows: Institutum Societatis Jesu (7 vols., Avignon, 1830-1838); Orlandini, Historia Societatis Jesu (Antwerp, 1620); Imago primi saeculi Societatis Jesu (Antwerp, 1640); Nieremberg, Vida de San Ignacio de Loyola (9 vols., fol., Madrid, 1645-1736); Genelli, Life of St Ignatius of Loyola (London, 1872); Backer, Bibliotheque des ecrivains de la Compagnie de Jesus (7 vols., Paris, 1853-1861); Cretineau Joly, Histoire de la Compagnie de Jesus (6 vols., Paris, 1844); Guettee, Histoire des Jesuites (3 vols., Paris, 1858-1859); Wolff, Allgemeine Geschichte der Jesuiten (4 vols., Zurich, 1789-1792); Gioberti, Il Gesuita moderno (Lausanne, 1846); F.
Fragmentary as the records are, they show that the Exopterygota preceded the Endopterygota in the evolution of the class, and that among the Endopterygota those orders in which the greatest difference exists between imago and larva - the Lepidoptera, Diptera and Hymenoptera - were the latest to take their rise.
Cervin, Imago virtutum Roberti card.
The larva may be aquatic, or subterranean, or a burrower in wood, while the imago is aerial.
That on geography is particularly good, and is interesting as having been read by Columbus, who lighted on it in Petrus de Alliaco's Imago Mundi, and was strongly influenced by its reasoning.
Moreover, in many insects with imperfect metamorphosis the change from larva or (as the later stage of the larva is called in these cases) nymph to imago is about as great as the corresponding change in the Holometabola, as the student will recognize if he recalls the histories of Ephemeridae, Odonata and male Coccidae.
A common result of metamorphosis is that the larva and imago differ markedly in their habitat and mode of feeding.
If we admit that the larva has, in the phylogeny of insects, gradually diverged from the imago, and if we recollect that in the ontogeny the larva has always to become the imago (and of course still does so) notwithstanding the increased difficulty of the transformation, we cannot but recognize that a period of helplessness in which the transformation may take place is to be expected.