X - Studies on the embryology of the African migratory locust, <i>Locusta migratoria migratorioides</i> R. and F. - I - The early development, with a new theory of multi-phased gastrulation among insects

Abstract

Abstract Notwithstanding the large amount of work done on insect embryology, certain outstanding problems are still productive of much divergence of opinion. The process of gastrulation, the origin of the mid-gut epithelium, and, in short, the general problem as to how far the germ-layer theory is applicable to insects, are matters of dispute to-day. Further, the claim of Wiesmann (1926) to have found the labral and the preantennary coelom sacs in Carausius (Dixippus) morosus (Orthoptera, Phasmidae) has lent a new interest to the problem of head segmentation among Arthropods in general and insects in particular.