In the opening of Act 1, Scene 2, Caesar addresses his wife Calpurnia as follows:
Stand you directly in Antonio's way,
When he doth run his course.
Then Caesar addresses his friend and faithful follower Marc Antony:
Forget not, in your speed, Antonio,
To touch Calpurnia, for our elders say,
The barren, touched in this holy chase,
Shake off their sterile curse.
Caesar is less concerned about Calpurnia than about himself. He assumes he is about to become a king, and as a king he naturally wants an heir to continue his dynasty. It is a common belief that if a runner touches a woman who is having trouble conceiving a child, she will be able to become pregnant.
This little exchange in Act 1, Scene 2 helps to characterize Caesar as a man with high ambitions, as well as a man who already possesses a great deal of authority in Rome. It also characterizes Marc Antony as an athlete and a devoted follower. He replies:
I shall remember.
When Caesar says “Do this,” it is perform'd.
Shakespeare apparently also wanted to introduce Caesar's wife Calpurnia, who will have an important role in a later scene. She will try to persuade her egotistical husband to stay at home on the Ides of March because she has had terrible nightmares in which she has seen Caesar assassinated. By introducing Calpurnia so naturally in Act 1, Scene 2, Shakespeare could spare himself the necessity of introducing her to the audience in Act 2, Scene 2, when she is pleading with Caesar to stay at home.
Alas, my lord,
Your wisdom is consumed in confidence.
Do not go forth today. Call it my fear
That keeps you in the house and not your own.
We'll send Mark Antony to the Senate-house,
And he shall say you are not well today.
Let me, upon my knee, prevail in this.