This is the story of the first hour of an animal’s life, whether it is a man, dog, fish or worm. Each begins life as a single cell. In order to observe animal mitosis under the microscope we have chosen the egg sac of the ascaris, a parasitic worm. Ascarus is a good subject for this study because the chromosomes are large and the number of chromosomes in this species is only four. The female ascaris lays her eggs in small sacs. We can observe some of the eggs as they begin their development, just after fertilization. Although the adult worm is very different from a human, the first hours of both are quite similar and make a good study on the initial stages of animal mitosis.