Answer: A bone can develop inside the pain of the some male cats, but it is not always present. When it does develop, it is not formed until well after puberty. It results from the fibrous partition between two columns of spongy tissue in the pains becoming slowly converted into bone, i.e. ossified. The bone is only about ¼ inch (1/2cm) long and is shaped like a long tampering cone with its apex near the tip of the penis. If it has any purpose, it must be to help support the pains during mating.
A similar bone in the penis of the dog is much better developed and always present. Both are examples of the bones which can from soft tissues unconnected to the res of the skeleton; a further example is the two small bones which developed in the heart of cattle.
