It would appear that the growth of an insect embryo has never been measured, and, indeed, with the exception of Ranzi's (1929, 1930) work on Sepia, all the available information on embryonic growth pertains to vertebrates. The object of the present study was to obtain measures of the growth of the locust embryo. Such data, together with other relevant physical data on changes in the developing egg, are needed to provide a basis for further studies on the energetics of growth and development. It is also important to know whether the principles of vertebrate embryonic growth may be usefully applied to the insect embryo.
The eggs used were those of Locusta migratoria migratorioides (R. & F.). They are laid in pods, 22–81 eggs per pod according to Roonwal (1936a), are among the largest of insect eggs (6–8 mm. length), and are highly telolecithal.