104 



£QUlNE ANATOMY. 



reaching the surface ; the smaller look upward and outward, 

 reaching the surface. The two horns are connected by a trans- 

 verse band, called the commissure, which shows in its middle the 

 central canal of the cord. 



FissiLres. 



Running the whole length of the cord above and below are two 

 fissures ; the superior longitudinal is narrower and more shallow 

 than the inferior, which is separated from the gray commissu7'e 

 by a white band, the white coiiiniissure. 



Fig. 



SECTION OF THE SPINAL CORD OF THE HORSE AT THE LUMBAR REGION; IvfAGNIFIED TWO 



DIAMETERS. 



I, Superior median fi;siue; 2, Inferior median fissure; 3, 3, Superior collateral fissures; 4, 4, 

 Inferior ditto; 5, Gray commissure; 6, White commissure; 7, 7, Superioi gray cornua; 

 8, 8, Inferior gray cornua; 9, Central canal. 



Columns. 



The supe7ior column lies between the superior fissure and su- 

 perior or sensory nerve roots. 



The inferior, between the inferior fissure and the inferior or 

 motor roots. 



The lateral Mqs between the two. 



Memb7'anes. 



Dura mater, outer, is not adherent to bony canal. 



Arachnoid, as in brain. 



Pia mater, passes into fissures and on sides has festoons at- 



