1905.] 



Cord of the Macaque Monkey. 



99 



□ I 



nm. 



I i i i 







I'l' 



1 1 1 1 



1 ' 

































- 

















- 





c -s 













- 

















- 



- 















- 





A 



^ / 



— 





























JP^ 







Vtj^ — 











— i 1 1 — pi 



] L_ » ' 





, 1 ,r I.I 









2 -4 1 



1 Lumbar 



1 -2 



H 



■8 2 

 W 



V 



■8 3 1 -2 | -4 



■6 | -8 4 I '2 



in 



8 |5 



W 



•4 -6 -|3 



ICoayR 



TBl 



CnART II. — Curves showing the Areas of the Cross-sections of the Cord, of the Grey 

 Substance, and of the Dorsal and the Ventrolateral Columns of the White Substance 

 (Tables I, II, IV, V). 



The ordinates denote section area in square millimetres, the abscissa? the length of the 

 cord in centimetres measured from the uppermost section in the first lumbar region. The 

 numbers (I, II, III, etc.) mark approximately the cephalic end of the region of each pair 

 of spinal nerves. 



Total area of the cross-section of the cord C, thick continuous line. 



Section area of the grey substance G, dotted lin 4 ). 



Section area of the dorsal white columns P, broken line. 



Section area of the ventro-lateral white columns ... A, line and dot. 



The section area of the dorsal columns (P) (Chart II, Table IV), is 



2 - 81 sq. mm. in the upper portion of the first lumbar region, and increases 

 gradually from this to the fourth lumbar, where it reaches its maximum, 



3 - 6 sq. mm. 



The maximum thus occurs in the region of the same lumbar nerve as the 

 maximum section areas of the cord and of the white substance ; but it 

 differs in position to these, being found in the upper instead of the lower 

 portion of the fourth lumbar region. It occurs at some distance, therefore, 

 from the maximum section area of the grey substance (v. L., lower). 



The larger areas of the dorsal columns extend through the fourth and the 

 upper portion of the fifth lumbar region. The section area in the middle 

 portion of the latter region is much the same as that in the first lumbar. 



