This video of a tiny chick embryo took first place in the 2011 Nikon Small World in Motion competition. Researcher Anne Franz cut away a small portion of the eggshell and then injected ink into the yolk sac. In the video, the arteries and vascular system show clearly as the ink flows through. The yolk sac provides nourishment in the early stages of development in most mammals, fish and birds. As an embryo grows, much of the yolk sac is absorbed into the body and nutrients are provided directly by the mother.