Cytochemical Studies on the Embryonic Development of Drosophila melanogaster

In the egg of Drosophila the distribution of sulphydryl and ribonucleic acid compounds has no apparent connexion with the dorso-ventral organization, contrary to the situation found in the amphibian egg. Histochemical evidence suggests that the nucleic acid metabolism of the Drosophila egg may be similar to that of the chick embryo. During embryogenesis the contraction of the germ band can be considered as an important morphogenetic stage which marks the beginning of the histo-differentiation of all larval structures.