The merchant of Venice

He thinks that Bassanio suffers from a lack of depth in his personality. 

Bassanio says that Gratiano is too rude,too bold of voice and too wild.Bassanio says that  it is nothing new in front of his friends but for people who do not know him they migth misunderstand him and bassanio fears that because of gratiano he will also appear bad in the eyes of the people.