HENDRY, ON THE NERVE-CELLS IN THE OX. 43 
present a more homogeneous structure, and, as a further dis- 
tinction, the blood-vessels may frequently be traced in con- 
nection with others containing altered blood-corpuscles, their 
nature being thus placed beyond all doubt. 
My present object is not so much to enter fully into the 
histology of the cord as to endeavour to awaken new interest 
in the subject, and to offer certain suggestions with respect 
to manipulation, by which the investigation may be rendered 
more easy and satisfactory. 
I would, in the first place, recommend the experimenter to 
obtain a foot or two in length of the cord of the ox, to cut 
this up into pieces two or three inches long, and then to 
place these in a wide-mouthed quart stoppered bottle contain- 
ing a solution of chromic acid, of a moderate yellow colour. 
Other portions may be preserved in spirits of wine. After a 
few days the investigation may be commenced, it bemg by no 
means necessary to wait for some months, as is usually stated 
to be requisite, before sections can be made. These should 
be made with a sharp razor, with which the larger portions 
are to be cut into lengths of about + inch. On the surfaces 
thus exposed, the arrangement of parts in the interior of the 
cord will be seen. Its substance consists of a white external 
and a gray or cineritious internal substance, disposed in the 
form of two crescentic masses, one on either side and placed 
back to back, united by a transverse band or commissure. 
Of the horns, or cornua as they are termed, of each crescent, 
the anterior are short and thick, whilst the posterior are 
longer, slenderer, and more divergent. Besides this, the cord 
will now be seen to be partially divided into two halves by an 
anterior and posterior median fissure, the former not so deep 
but wider than the latter, and both occupied by a vascular 
membrane or tissue. 
Tt will be found convenient to have the following articles 
and reagents at hand, and in readiness for immediate use. 
One or two pair of surgeon’s forceps, several common 
sewing needles, a razor, several glass slides, box of round, 
thin, glass covers, three or four watch-glasses, one or two wine- 
glasses, two or three glass rods, blotting-paper m slips of 
one inch square, one or two cloths, basin of water for clean- 
ing slides, &c., lancet or two, and a pair of sharp scissors— 
also— 
1. A solution of moderately dilute caustic soda, in a watch- 
glass. 
2. Dilute acetic acid, in a wine-glass. 
3, Water, in a wine-glass. 
4, Creosote and naphtha solution, in watch-glass. 
