In Act I Scene ii of Julius Caesar, how are Antony and Brutus contrasted as each appears for the first time?

In Act I, Scene II Antony is depicted as a young, vibrant,
athletic man due to his participating in the Feast of Lupercal race.  Antony seems
carefree, but at the same time, quite loyal to Caesar.  Caesar asks him to whip
Calphurnia as he races and Antony obediently replies, "I shall remember.  When Caesar
says, 'do this,' it is performed" (lines 12-13).

Brutus is
introduced as a more serious, troubled, introspective character.  In the same scene,
when Cassius approaches him, Brutus makes a direct reference to Antony mentioning how
they are so different, "I am not gamesome.  I do lack some part of the quick spirit that
is in Antony.  Let me not hinder, Cassius, your desires.  I'll leave you" (lines
30-33).  Brutus shows a lack of interest in the festivities, preferring to stay off to
the side by himself rather than celebrating with the crowd.  Brutus shows a lack of
support for Caesar, when Cassius asks him if he wants Caesar to become King and he
responds, "I would not, Cassius, yet I love him well" (line
84).

To sum it up, Antony is athletic, carefree, and loyal
to Caesar, while Brutus is more sedentary, serious, and skeptical of
Caesar.