A cleavage time-lapse in warm brightfield: a zygote divides into 2, 4, 8 blastomeres, packs into a solid morula, then hollows into a blastula ringed around a fluid blastocoel before an early-gastrula fold invaginates — dark cleavage furrows where cells meet, a bright refractive membrane, all inside a circular field of view. Drag to rotate, scroll to run time, press to rewind to the zygote.