10 Microscope Slides. 1(f). Chicken, 24 hour, t.s. with neural groove, notochord, germ layers 2(f). Chicken, 36 hour, t.s. with neural tube 3(g). Chicken, 48 hour, l.s. with differentiation of mesoderm and ectoderm 4(f). Chicken, 3 day, t.s. through body showing amnion and serosa 5(f). Chicken, 3 day, t.s. of head with primordium of brain, eyes and heart 6(g). Chicken, 3-4 day, horizontal section of entire specimen shows primordia of organs 7(f). Chicken, 4-5 day, t.s. region of head with brain, gill arches 8(f). Chicken, 4-5 day, t.s. region of heart 9(g). Chicken, 8 day, sagittal l.s. through entire specimen showing embryonic organs 10(f). Chicken, feather development, sec. through wings.