  We study the morphology of a fluid membrane in spherical confinement. When
the area of the membrane is slightly larger than the area of the outer
container, a single axisymmetric invagination is observed. For higher area,
self-contact occurs: the invagination breaks symmetry and deforms into an
ellipsoid-like shape connected to its outer part via a small slit. For even
higher areas, a second invagination forms inside the original invagination. The
folding patterns observed could constitute basic building blocks in the
morphogenesis of biological tissues and organelles.
