Ouroboros
An ouroboros is an ancient symbolism of infinity. Its image is a snake eating its tail, representing the unending cycle of life and death. The novel itself is essentially a large-scale representation of this cycle with Ursula being born into the same life over and over again with no end.
Snow
There is a heavy snowstorm in 1910 when Ursula is born. The heavy snow and the difficult birth symbolize a difficult life and a fate more complicated than what anyone could imagine. When dying Ursula is enveloped in darkness and sees the heavy snow, indicating her rebirth. The snow could be seen as a form of passage between one life and the following one.
Dogs
Living through to the Second World War in one of her lifetimes, Ursula lives in an apartment complex with several interesting, almost whimsical characters. This apartment complex is a whole world in itself and there is an extensive description of characters and their lives. All of them, Ursula included, go to hide in the basement during the bombing. In the first lifetime of this sort, Ursula dies when a bomb falls. In the following one, she sees a dog outside and runs after it, but dies when one of the walls falls. Towards the end, the dog finally manages to save her, playing the part of the guardian angel sent to her rescue.
Death
Death is a constant motif in the novel. Death is a part of Ursula's infinite cycle, at times coming abruptly, at other times by choice. It is an ending and a beginning in one, and with each death, she gets closer to realizing her purpose.