TABLE 2 

 Areas of cross-sectio7is of the spinal cord in an 11 mm. humaii embryo, showing the 

 absolute and relative amounts of gray matter, of white matter, and of ependyma with 

 canal 



TABLE 3 



Areas of cross-sections of the spinal cord in a 17 mm. human embryo, shoiving the 

 absolute and relative amounts of gray matter, of white matter, and of ependyma with 

 canal 



58 



