I30 



GEORGE FRED SUTHERLAND. 



have begun to pull apart, stretching out the connecting cyto- 

 plasm (Fig, ii). In general they extend toward the opposite 



RBC 



Fig. 9. Sagittal section close to the edge of the central canal, showing a row of 

 cells, not quite at the end, extending across the central canal. Other sections of 

 the series show that the end of the cord is still open, cc, central canal; r^c, red blood 

 corpuscles; Ic, leucocyte. (920 diameters.) 



wall of the central canal, thus narrowing the opening at the end. 

 Some sections show pseudopod-like cytoplasmic extensions of 

 the cells into the central canal as if closing were to be produced 



MIT 



HTC 



Fig. 10. Sagittal section through the new spinal cord six days after the opera- 

 tion, hv, blood vessel; mit, mitotic figures; nlc, notocord; ct, connective tissue. 

 (330 diameters.) 



