What's the significance of Calphuria's dream?

Calphuria has nightmares about her husband's impending death. Caesar can't even sleep because she keeps calling his demise in her sleep. Here Caesar narrates her dream to DEclus before they go to the senate,

"Calpurnia here, my wife, stays me at home;

She dreamt tonight she saw my statue,

Which like a fountain with an hundred spouts,

Did run pure blood, and many lusty Romans

Came smiling and did bathe their hands in it.

And these does she apply for warnings and portents

And evils imminent, and on her knee

Hath begg'd that I will stay at home today."

This of course is a major case of foreshadowing. She sees the "lusty Romans" come to bathe in his blood. They are the conspirators who will take Caesar's life. The statue represents Caesar who will soon bleed at the hands of the conspirators. Calpurnia represents the fear and the superstitious beliefs of the Elizabethan audiences. They really believed in dreams being the harbinger of coming events.