What is the significance of the two deformed babies that come from beneath the ghost of Christmas presents skirts

In stave 4 of A Christmas Carol, Charles Dickens brings the Ghost of Christmas Present, who shows him many scenes of Christmas.  Scrooge notices something moving under the Ghost’s robes, and when he opens it, two ragged and deformed children are huddled inside. The Ghost tells him the boy is Ignorance and the girl is Want, symbolizing the dire effects when society discounts the needs of the poor.  However, the ghost tells him that Ignorance holds a greater doom as it continues the insidious cycle of poverty. When he asks if there is no refuge, the ghost mocks him with his earlier words when asked for donations, if there were no prisons or workhouses.  Scrooge’s transformation is based on opening his heart beyond his miserly desire for money to care for poor and destitute of society.

The second spirit to visit Scrooge, the Ghost of Christmas Present, closely resembles a Santa Claus figure. It is he who shows Scrooge the pitiful sight of Tiny Tim and the shocking level of squalor in which the Cratchit family lives. Scrooge is so enclosed in his money-obsessed, miserly little bubble that he has no understanding of the world outside. The Ghost is going to open his eyes and show him a side of life which he's steadfastly ignored for so long.
As well as scenes of appalling poverty and deprivation, the Ghost also shows Scrooge that other people actually enjoy the holidays, people such as his nephew, Fred, laughing heartily at old Ebenezer's condemnation of Christmas as so much humbug. Scrooge even joins in the frivolity, though no one can see him.
But it's the utter destitution in which so many Victorians live that is the main focus of the Ghost of Christmas Present's message. Out from under his flowing green gown emerge two ragged, emaciated children, a boy and a girl. The girl represents Want, the boy Ignorance. Ignorance and Want are among the evils of humankind. Want leads to hunger, disease and death, and ignorance leads to the perpetuation of want.
This is a particularly pertinent lesson for Scrooge as he's always shown such complete indifference to the sufferings of the destitute. It is the willful ignorance of Scrooge and others like him which is directly responsible for the heartbreaking condition of poor, starving children such as those beneath the Ghost of Christmas Present's robe.