This migration is usually accompanied by a more or less complete metamorphosis.
A propensity necessary for understanding the dynamics of labor market changes is the migration propensity.
Hirschsprung's disease occurs early in fetal development when, for unknown reasons, there is either failure of nerve cell development, failure of nerve cell migration, or arrest in nerve cell development in a segment of bowel.
The birds are currently beginning their large migration to the south.
The result of migration is that races of widely different origin and habit have had to adapt themselves to similar conditions.