Question

relate antonio naturally melancholy disposition ,which is emphasized in the opening scene, to his stoic acceptance of misfortune when he has to forfeit the bond

Answer 1

As the play opens in Venice, Antonio is seen worried for something, yet no one knows why. He was worried for his ships that had gone for trade. He is teased by Salerio and Solanio to be "in love" however he does not respond to them. When Bassanio comes to him and shares his love for Portia, he listens to him and does not mention his grievance.

Despite knowing that his ships might bring him misfortune, he does not refuse Bassanio for the loan but asks him to get one on his credit. He even signs the bond with Shylock for Bassanio's love for Portia.

When he writes to Bassanio in Belmont about the trial to be held, he does not ask for return of money but only wishes to meet his best friend for one last time. 

These two scenes show that Antonio is a person who cares for human relationships more than money or life. He is happy in loss and when death is close to him when he has his dear friend, Bassanio by his side. He is a person of great character.