Querbandhechtling. Bewegung und Teilung der Blastodermzellen. Entwicklungsablauf von der Blastula bis zur Epibolie, Verschluß des Blastoporus und Entstehung der Kupfferschen Blase. Keimblätterbildung und Segmentierung des Keimstreifs. Mit Zeitraffung.

The film informs on the process during the so-called epiboly in boned fish in the course of which on the one hand the cells colonize the ovum surface, but in which also on the other hand the emergence of the blastodermic layer takes place. Attention is focused hereby on a few phases of this stage of development: 1. separation and movement of the various cell types, 2. closure of the blastopore and emergence of the Kupffer bladder, 3. formation of the blastodermic layer and segmentation of the germ band.