602 FUNCTIONS OF THE C EREBRO - SPIN AL NERVOUS SYSTEM, 



FIG. 210. 



markably fine and delicate fibres, interlace so as to form with each other an 

 intricate plexus; and from this, straight and distinct bundles enter the pos- 



terior cornua along their whole breadth, 

 crossing the " subatantia gelatinosa " 

 both obliquely and at right angles. 

 Having thus entered the vesicular sub- 

 stance of the Cord, some of the fibres 

 become connected with multipolar 

 ganglionic cells; others, after travers- 

 ing it, emerge from it again, into either 

 the posterior columns, or the posterior 

 portion of the lateral columns ; others 

 pass towards the transverse commis- 

 sure, through which they seem to make 

 their way to the posterior and lateral 

 columns of the opposite side ; and 

 others, again, form a fine network, 

 which extends towards the anterior 

 cornua. Of the fibres of a third set 

 (Fig. 210, c, c, c), a part seem to be- 

 come directly continuous with the fibres 

 of the posterior columns ; the larger 

 proportion of them, however, cross 

 these columns obliquely upwards, and 

 enter the gray substance at different 

 points ; after passing into which, they 

 can no longer be clearly followed, al- 

 though some of them appear to form 

 loops and then return to the white col- 

 umns. The fasciculi of fibres which 

 constitute the anterior roots [Figs. 207, 

 211, b, b, b; Fig. 210, A, A], on the 

 other hand, traverse the anterior col- 

 umns of the Cord nearly horizontally, 

 and in straight and distinct bundles, 

 which do not interlace with each other 

 until they reach the anterior cornua of 

 the gray substance ; on entering this, 

 they break up into smaller bundles 

 and separate fibres, which diverge in 



Longitudinal S,,t in,, through Cervical en- j ous (1 j rections . many uriite W itll 



largement of Spinal Cord 01 Cat: AC, anterior . < .. .. 



white columns; A c', portion, showing the ar- the large multipolar gaiiglionic cells 

 raiigcnicnt of the longitudinal fibres; r c, pos- of the anterior horns of the gray sub- 



torior white columns : .;, K ray substance between gt auoe ; $01116 passing Ollt again ill'to the 

 them (tin- vesicles omittfil, to avoid obscuring . , r . ' i i , i 



- 



nerves; 



. , . i i , i 



o.o.. anterior, and others into the lateral 



es; r, posterior roots, consisting of th'ree columns of the same side ; others again 



kinds, the first, a, crossing the posterior columns p ass towards the anterior part of the 



horizontally, and then passing obliquely down- comm j ssure ; n w hi c h they cross OVCr 

 wards, amiss the gray substance, into the an- . . , 



columns; the second, i,, traversing the to the opposite side, entering its an- 



posterior columns horizontally, and then losing tcrior and lateral columns; a CODSlder- 



themselves in the gray substance; the thlrd.c, ab^ number plunge into the central 



lor the nis! ii:irt hrc-oniing continuous with the i /> .1 ,,] _p 



longitudinal fibres of the posterior column J.V11, Bubatanoe ) the gray cor.ni, and of 



or almost all, ultimately entering the gray sub- these some become longitudinal, pass- 



stain.. ing equally upwards and downwards, 



