464 ME. J. 1. CLAEKE ON THE OBEY SEBSIANCE OF THE SPINAL COED. 
Figs. 18, 19, 20 & 21, Plate XXIII. Sections through the remaining portion of the 
conus medullaris. i-.no >.011 path the 
Fig. 19 . The gelatmous substance, g, is continuous across the 
^ poster-ior columns, A ; D, opake portion of the caput cornu . N, bundles 
Fin 20 Xhr^prsterior^whTte columns (A, A) are wanting in the midcUe line, and 
rises to the sui-face in a straight transverse layer, covered only hy pia mater, , 
D are the dark bundles which in the precedmg figraes formed t e opa -e poi- 
tim of the caput cornu; similar-, but less numerous, bundles are scattered 
through the rest of the grey substance anteriorly . .p ^ T ■ 
V. 91 The slal canal has extended backwar-ds and sideways m the forrn of T. 
its lateral extension is through the gelatinous substance, whic t us 
continuous with the space previously surroundmg the 
nart corresponding to the opake portion of the caput coinu ( ) 
c.r, .b. i. .< a. w. ■— 
are covered and permeated by a quantity of pia mate , , . 
to consist of little or nothing else; this pia mater rs continuous rnth 
4-1, a on' Ti' tlip anterior grey substance, forminj^ a 
that surrounding the cord, m . F, the anteiioi ^ ) 
network between longitudinal bundles of fibres. 
Fio- 22, Plate XXIV. Transverse section of the conus meduUan 's-.^jieters ■— 
nail- of coccygeal nerves ; drawn from a preparation magnified 60 chameteis . 
pan ot coccygeal ’ ™ „„.„,o.lateral columns. From the grey sub- 
A A nosterior columns; ,13, 15 , anteio laieicii , 
Lt' a ......b... -b 
the white, especially the antero-lateral, columns (B, » 
meshes a multitude of longitudinal bundles. Fioni i - 
anterior cor-nua, considerable offsets of the grey Jl, 
others proceeding from ar-e 
“iLrbrdW longitudinal fibres ; one of these is partially cucircW 
TyTc^ several other loW— bundles are seen amongst the fibres ot 
Fig. 23, Plate ^IV. Transverse section thrmrgh the 
Uctrmnp- F anterior o-rey substance : the uhole ot the > 
Lr:iCe“fl -:i dkiL . here very large), is pierced 
“de of longitudinal bundles of fibres of " ^ - 
(represented by the dark masses), and is interspersed with 
