STAGE | FORELIMB | HINDLIMB |
---|---|---|
Day 18 | Bud has formed with no defined shape as yet | Thickening of the hindlimb has occurred with a small protrusion as the beginnings of a bud |
Day 19-21 | Paddle like structure with the regions of the future digital rays beginning to form. | Elongation of the bud has occurred with no distinct structure |
Day 22-23 | Digital rays more pronounced and the interdigital tissue has begun to regress | The bud has formed into a flattened arrow-head like structure with the beginnings of the digital condensations. The pointed edge of the paddle appears to be the presumptive 4th digit |
Day 23-24 | Interdigital webbing has regressed. Epitrichial claws are present and fingers are open but not clenched. The distinct protrusion of the future elbow joint is beginning to form | The digital rays have begun to form and a distinct separation of the hindlimb digits begins. The interdigital webbing is reduced and an asymmetrical shape has started to form |
Day 25 | A well-defined forelimb with claws present with digits in a clenched position. The future elbow joint has become more pronounced | The interdigital webbing has regressed and all four digits are distinct. The 4th digit has become more pronounced and has an asymmetrical shape. |