STAGE 54 Age +/- 26 d.; length 58-65 mm.

Ext. Crit.: *All our fingers indicated*; edge of hand slightly scalloped between fingers; melanophores appearing on forelimb. *Length of hindlimb without foor nearly twice its breadth; all five toes indicated, the 2^nd only very slightly*.

Int. Crit.: *Dorsal column extending throughout trunk levels and over short distance into postscral levels of spinal cord*. Ventro-lateral lobe of saccus endolymphaticus extending from diencephalon down to 1^st spinal nerve. *Chondrification completed in 1^st and 2^nd pairs and caudalwards down to 10^th pair of vertebral arches; chondrification of ventral perichordal tube reaching down to 6^th vertebra*; perichondral ossification as well as destruction and calcification of cartilage starting in vertebral arches. Shallow acetabulum formed and iliac process well defined. *Chondrification of hind limb proceeded up to tibiale and fibulare, metatarsalia procartilaginous*. Some muscles of hindlimb with indication of both origin and insertion. *First signs of atrophy in pronephros*.

Up to 7 revolutions in outer and inner spiral of intestinal helix.