Glass Menagerie---Glass a metaphor

Through out the play I was trying to piece together the significance of the glass menagerie which is the title of the play. It is also repeated several times throughout the play by characters and also in the stage directions where music called the "Glass Menagerie" is sometimes played. I could not figure it out until in the stage directions there is a description of Laura as being fragile and possessing a different kind of beauty. It really made me see how Laura who takes care of these glass animals is also a fragile girl. Since she is so shy because of being crippled she becomes a very different girl that goes unnoticed and has a gentle temperment. She is always worrying about her glass menagerie breaking when in reality she herself is worrying about herself breaking. Amanda the mother is also on the precipice of the breaking point when she has erractic behaviour about her past and present circumstances. It becomes apparent that this family is on thin ice with their relationship with each other and also in how they deal with the problems they are faced with.