32 



Development of the Limbs, Body-wall and Back in Man 



SUMMARY OF THE EAELY DEVELOPMENT OF THE BACK, LIMBS AND 



BODY-WALL. 



In an embryo of two weeks, XII, Figs. 1 and IG, fourteen myotomes 

 are present, three occipital and eleven spinal (8c, 3t). In an embryo of 



Fig. 37. Photograph of a section through the leg region of Embryo XXIL 



four weeks, II, Figs. 6, 20, 21 and A, thirty-eight myotomes have been 

 counted, three occipital and thirty-five spinal (8c, 12t, 51, 5s and 5c). 

 At this stage the formation of myotomes ceases. Soon hereafter the 



