130 MR. youatt’s veterinary lectures. 
The Lateral Farrows .—Running parallel with the mesian 
furrow is another on each side, and on both surfaces. It is very 
distinct on the superior surface of the chord, and may be satis¬ 
factorily traced on the inferior one. 
It is sometimes peculiarly interesting to observe the slow pro¬ 
gress of the most important discoveries. Sir Charles Bell, to 
whom we are indebted for almost all we know of this portion of 
the nervous system, was long in detecting these subdivisions; 
indeed, in the early editions of his admirable system of anatomy, 
he speaks of a distinction, convenient for the purpose of illus¬ 
tration, but which has no structural existence. He says that 
“ the two lateral portions are divided into an anterior (inferior) 
and posterior (superior) portion, so that this prolongation has 
four distinct portions.’’ He has since discovered (and it is the 
key-stone to our knowledge of the structure and function of the 
spinal chord) that there are six distinct portions. Observe this 
transverse section of the spinal marrow. Can you not trace 
three distinct chords on each side—a central one superiorly and 
inferiorly, and a lateral one ? 
The Central Canal .—The perfect distinction or separation be¬ 
tween the central columns, superiorly and inferiorly, is a most 
important thing. There is a cavity interposed between them—a 
central canal along the whole course of the spinal marrow. I 
must claim the discovery of this for a veterinary surgeon. Mr. 
Sewell, the assistant professor of the Veterinary College, so long 
ago as the year 1808, in a letter to the Royal Society, describes 
this canal running from the fourth ventricle through the whole 
length of the spinal marrow, containing a limpid colourless fluid, 
and lined by an arachnoid membrane. How near did this gen¬ 
tleman approach to one of the most interesting discoveries in 
physiology that was ever made ! An error with regard to the 
commencement of the canal possibly prevented the discovery of 
the true structure of the spinal chord from becoming the proud 
boast of a veterinarian. I will not enter into the disputed ques¬ 
tion who was the actual discoverer of these six columns ;—let 
the honour be awarded, if due, to M. Bellingeri, of Turin ; but 
the conclusion, the all-important physiological and pathological 
deduction, from this structure of the spinal chord, I will claim 
for an English physiologist, the veterinary students’ patron and 
friend. Respect and gratitude give me a double interest in his 
well-earned fame ; although I now see him, with some others of 
his brethren, and to the exclusion of the only legitimate claim¬ 
ants—veterinary practitioners—sustaining the strangely ano¬ 
malous character of a medical examiner of veterinary pupils; and 
for which, in truth, even he is, and can be, no more qualified 
