Index Entry
Gestation Lag:
"We know there is a great variety in the time spans of gestation lags between the moment of egg fertilization and the birth of the independently conceived babies of the different zoological species. But almost no variation occurs within any one species’ gestation rate-- for instance, human babies take nine months. In the same way there is a great range of time lags between invention and industrial production among the different technical arts, but almost no difference within a given art "
