These Pictures you see were from my project "The New Way To Watch An Embryo Grow" project started in 2009. After 7 attempts I finally got one to hatch and at the same time watching it grow without candling. More of the story Click HERE- https://www.backyardchickens.com/t/...id-it-huge-thanks-to-everyone/80#post_9532401 Day 1- 6 to 10 h - First kidney-like cells (pronephros) begin to form. 8 h -Appearance of primitive streak. 10 h -Yolk sac (embryonic membrane) begins. Functions include: a) blood formation; b) yolk digestion; c) yolk absorption; d) food provision after hatching. Mesoderm appears; embryo oriented at 90° angle to egg's long axis; mesonephros begins. 18 h -Primitive gut begins; primordial germ cells appear in germinal crescent. 20 h -Vertebral column begins. 21 h -Appearance of neural groove, nervous system. 22 h -Appearance of first pair of somites (block-like segments) and head. 23 to 24 h -Blood islands, vitelline (yolk sac) circulation, blood, heart,blood vessels begin (2 to 4 somites). Video- Day 2- 25 h -Appearance of eye; vertebral column visible; embryo begins to turn on left side (6 somites). 28 h -Ear begins (7 somites). 30 h -Amnion (embryonic membrane around embryo) begins. Primary function is to protect embryo against shock and sticking; also responsible for some albumen absorption. Chorion (embryonic membrane that fuses with allantois) begins; heartbeat begins (10 somites). 38 h -Cranial flexure and torsion evident; heartbeat moves blood (16 to 17 somites). 42 h -Thyroid begins. 48 h -Anterior pituitary and pineal glands begin to develop. Video- Day 3- 50 h -Embryo turns on left side; allantois (embryonic membrane that fuses with chorion) begins. Functions of chorioallantois are: a) respiration; b) albumen absorption; c) absorption of calcium from shell; d) storage of kidney excretions. 60 h -Nasal pits, pharynx, lungs, anterior limb buds begin. 62 h -Posterior limb buds begin. 72 h -Middle and outer ear, trachea begin; amnion completes growth around embryo. Video- Day 4- Tongue and esophagus begin; embryo separates from yolk sac; allantois grows through amnion; contractions occur in amnion wall; adrenal development begins; pronephros (nonfunctional kidney) disappears; metanephros (definitive or final kidney) begins; proventriculus, gizzard, ceca, large intestine begin. Pigment visible in eye (dark eye Video- Day 5- Reproductive system and differentiation of sex appear; thymus, bursa of Fabricius, duodenal loop begin; chorion and allantois begin to fuse; mesonephros begins to function; first cartilage present. Video- Day 6- Beak appears; voluntary movement begins; chorioallantois (chorion fused with allantois) lies against shell near large end of egg. Video- http://www.youtube.com/watch?v=L9jQ4M3l-0Q&feature=channel&list=UL Day 7- Digits appear; comb growth begins; egg tooth begins; melanin produced; absorption of mineral from shell begins. Chorioallantois is attached to inner shell membrane and growth around the inner surface is progressing. Video- http://www.youtube.com/watch?v=LsQV7kjzg5Y&feature=channel&list=UL Day 8- Father tracts appear; parathyroid begins; bone calcification begins. Video- http://www.youtube.com/watch?v=fwrSALWikFk&feature=BFa&list=UL1ILb4RtGXRg Day 9- Growth of chorioallantois about 80% complete (still open at small end); mouth opening appears. Video- http://www.youtube.com/watch?v=ojtqd0j_tdo&feature=channel&list=UL Day 10- Beak begins to harden; digits completely separated. Video- http://www.youtube.com/watch?v=1ILb4RtGXRg&feature=channel&list=UL Day 11- - Abdominal walls established; loops of intestine begin to protrude into the yolk sac; down feathers visible; comb and wattles visible; claws and scales appear on toes; mesonephros reaches maximum level of function, then begins to degenerate; metanephros begins to function. Video- http://www.youtube.com/watch?v=zR3HGddfCTo&feature=channel&list=UL Day 12- Chorioallantois completes enclosure of egg contents; embryo water content begins to decrease. Video- http://www.youtube.com/watch?v=c7F2_z1bmR4&feature=channel&list=UL Day 13- - Cartilaginous skeleton is relatively complete; embryo heat production and oxygen consumption begin to increase rapidly. Video- http://www.youtube.com/watch?v=YTjBh_NF2PU&feature=channel&list=UL Day 14- Embryo begins to turn head toward large end of egg; long bone ossification becomes rapid. Turning of egg no longer essential. Video- http://www.youtube.com/watch?v=-Fh_tlEYaL0&feature=channel&list=UL Day 15- Intestinal loops easily seen in yolk sac; contraction of amnion ceases. Video- http://www.youtube.com/watch?v=41aMhmmVD_o&feature=channel&list=UL Day 16- Beak, claws, and scales relatively cornified; albumen is practically gone and yolk increasingly important as food source; down feathers cover body; intestinal loops begin to retract into body. Video- http://www.youtube.com/watch?v=Ljk9IfkZ6Kc&feature=channel&list=UL Day 17- Amniotic fluid decreases; embryo positioning head toward large end, toward right wing with beak toward air cell; definitive feathers begin. Video- http://www.youtube.com/watch?v=P0j61aXdGaU&feature=channel&list=UL Day 18- Video- http://www.youtube.com/watch?v=KXijRBWvlF4&feature=channel&list=UL Blood volume decreases, total blood hemoglobin decreases. Embryo should be in proper position to hatch: embryo's long axis the same as long axis of egg; head in large end of egg; head to right and under right wing; beak pointed toward air cell; feet toward head. Day 19: Intestinal loop retraction complete; yolk sac begins to enter body cavity; amniotic fluid (swallowed by embryo) disappears; beak may pierce air cell and lungs begin to function (pulmonary respiration). Day 20: Yolk sac completely drawn into body; air cell pierced, followed by functioning of pulmonary respiration; embryo makes sounds; chorioallantoic circulation, respiration, and absorption decrease; embryo may pip shell. Day 21: Hatching process: chorioallantoic circulation ceases; embryo breaks shell over air cell with egg tooth; embryo slowly rotates in egg counterclockwise, chipping and breaking shell as it does; embryo kicks and attempts to straighten neck, pushes shell open; kicks free of shell, rests, straightens, dries. >Day 21: Some embryos are unable to hatch but survive beyond the normal hatching time.