Bee eggs and young larvae. The milky substance is a glandular secretion from the heads of adult bees that is fed to larvae.
Older drone larvae in the comb. Worker bees have started sealing the cells with wax in preparation for pupation.
Eggs and young worker larvae in the brood nest, interspersed with cells filled with "bee bread"- a mix of honey and pollen that serves as food for older larvae.