59 



in a small depression formed in the skin (Fig. 5). Its canal is nearly 

 as large as the central canal, which lies almost at the ventral edge of 

 the cord. The central canal is nowhere obliterated, and at this point is 





s c 



Fig. 5. C. S. Spinal cord and surrounding tissues, showing the outgrowth from 

 the cord penetrating to the exterior. 



smallest. This outgrowth from the cord extends through some fourteen 

 sections, and its canal comes to lie in the most dorsal part of the 

 right side of the cord. Connecting it and the central canal is a broad 

 band of darker stained tissue. 



The central canal now rapidly elongates along the path of this 

 band of tissue, and the cord begins to assume its normal shape. Two 

 secondary canals appear soon after, one in the roof-plate and one on 

 the left, but they disappear very quickly, the central canal continues 

 to elongate, and cord and canal appear almost normal except for a 

 slight asymmetry. After about fifty sections, a small canal appears 

 in the right dorsal horn, but it causes very slight swelling of the 



