Graphic showing the appearance on candling of the unabsorbed yolk and blood vessels

and absorbed yolk and vessels as a 'hollow' void appears

source: https://www.backyardchickens.com/t/491013/goose-incubation-hatching-guide-completed
and absorbed yolk and vessels as a 'hollow' void appears
source: https://www.backyardchickens.com/t/491013/goose-incubation-hatching-guide-completed