Movie S3.

PIV of a shrinking toroidal droplet, observed from the side, with an initial aspect ratio ξ≈1.2. We note that a0 is measured as the half distance across the cross-section of the torus along the horizontal. The inner liquid is a solution of 0.1 wt% PEG 8,000 in water containing tracer particles at a volume fraction of 0.001. The outer liquid is a 60,000 cSt silicone oil. The evolution is in real time.