Stephanie Linn, Graduate Student, Department of Cell & Developmental Biology, University of Michigan Medical School
Not unlike the way branches of a tree fan out to capture sunlight, the blood vessels of a fertilized chick egg branch over the yolk to absorb nutrients for the growing chick. These vessels have been filled with black ink to illustrate their intricate web. The flecks of white ("snow") are small pieces of eggshell that fell onto the yolk as the egg was opened.