714 
but, being of small size, it eseaped the notice 
of the observer. 
This explanation is likewise contirmed by the 
occurrence of cases (rare, it is true) in which 
the brain existed, but the spinal cord was 
wanting. A very able narrative of a case of this 
kind has lately been published by Dr. Lonsdale 
of Edinburgh. “ The anterior and middle 
lobes of the brain appeared to be properly 
developed, and occupied their usual positions 
in the cranial cavity ; whilst the posterior lobes 
were much smaller, and were partially squeezed 
through a large abnormal opening or deficiency 
in the occipital bone. e cerebellum and 
that part of the occipital bone in which it is 
normally lodged, were wanting. There was not 
the slightest vestige of medulla oblongata or 
spinal cord, and the posterior arches of the 
vertebre did not exist.’* The fcetus had 
reached its full term, and its body and limbs 
‘were well formed. 
An interesting feature which had been well 
observed in this case, although probably not 
peculiar to it, but hitherto overloo ed, was the 
relation of the nerves in the cranial and spinal 
cavities. All the nerves of the medulla oblon- 
gata, and the first, second, and third cervical 
nerves, hung as loose threads in the cranial 
cavity or in the upper part of the spinal canal, 
and presented a looped arrangement, seeming to 
denote that such is their normal disposition in 
the nervous centre. 
Partial deficiencies of the spinal cord, al- 
though also rare, are more frequent than the 
total absence of the organ. ese occur in 
connection with other defects of developement. 
Thus, in spina bifida much of the cord is defi- 
cient, either throughout its entire extent or in 
those parts where the vertebral wall is defective. 
In such cases it is probable that the deficiency 
is attributable to the destructive influence of the 
dropsical effusion rather than to an original de- 
fect of the organ. In cases in which the upper 
or the lower extremities have not been deve- 
loped, the usual cervical or lumbar swelling is 
imperfectly developed, owing to the absence or 
atrophy of the fibres which would have formed 
the nerves to those limbs. 
Excessive congenital developement of the 
spinal cord occurs only in those monstrosities 
which arise from the junction or fusion of the 
spinal columns of two embryos. 
The diseased states of the spinal cord may be 
enumerated as follows :—hypertrophy, atrophy, 
induration, sofiening, suppuration, deposits of 
tubercle or of other morbid products. 
In abi the cord is enlarged and 
looks full and plump, without any alteration of 
its consistence or of its intimate structure. It 
is not improbable that the elementary fibres as 
well as the vesicles of grey matter may be en- 
larged in such cases, and that the increased 
dimensions of the whole organ must be attri- 
buted to this cause, and not to the deposition 
of any new material in it. I have not, however, 
had any opportunity of ascertaining this point 
by microscopic examination. 
* Edin. Med. and Surg. Journal. 
NERVOUS SYSTEM. (Nervous Centres. AsNnonmat Anatomy.) 
Atrophy occurs in the cord lly as the 
result of some local re a tumour 
developed in connection with some one of the — 
membranes or external to them. In a case of © 
this kind which I lately examined, the tumour — 
consisted of a mass of scrofulous matter situate — 
between the vertebra and the dura mater in the — 
upper part of the dorsal region. That part of - 
the cord which was pressed upon by the tumour 
was wasted to one-half its natural size, whilst 
below it the cord exhibited its natural size. 
Atrophy of the cord occurs as part of that 
general rene of the nervous centres which 
accompanies advanced life, or a state of general — 
cachexy. In persons long bedridden the cord 
is found in a wasted state; and in cases of @x- 
tensive hysterical paralysis, in which exercise of 
the enfeebled limbs has been neglected, the 
cord will participate in the wasting of the nerve 
which supply the affected \. ‘8 
Induration of the cord is not of unfrequent 
occurrence, and appears to be the result of 
some abnormal nutrition analogous to if not 
identical with chronic inflammation— inflam- 
mation modified, perhaps, in the nature of 
event by some peculiar state of the blood. e 
hardness occurs generally in patches, involvin 
more or less of the thickness of the cord, an 
affecting the peripheral of the body, in pro 
rtion as it involves the immediate points 
implantation of the roots of the nerves, or those 
roots themselves. It is generally accompanier 
by some discolouration of a light brownish hue 
as if the first changes which gave rise to it wer 
attended with extravasation of the colouri 
matter of the blood. : 
Sometimes, however, induration seems to re 
sult from the changes which accompany 
phy of the cord, as if from an imperfect 
ply of the fluids necessary for perfect nutritio 
Softening of the cord is found in two stat 
which are probably essentially different in the 
intrinsic nature and origin. One is that of F 
softening ; the other is that of white or colourle 
softening. In the former the tissue of 
spinal cord is much softer than it ought to 
and is readily disintegrated by a m 
water directed upon it; its colour is due to 
full injection of the bloodvessels whie 
verse it, or to some extravasated blood. 
latter the nervous matter is reduced to a 
semifluid mass, like thick cream, withot 
least appearance of injected vessels. 
former the nerve fibres are more or less bri 
down and softened; in the latter there is lit 
no breaking down of the fibres, but theya 
tenuated and have lost the distinctive ¢ 
of the white substance and central axis to a gt 
or less degree. Red softening ob 
rca in its origin, but white softenin, 
dicates a deficient supply of blood, and _ 
resembles the gangrene which occurs in ex! 
soft parts. A 
The anatomist should be to di 
guish the white softening, which is the pro 
of a morbid process during life, from © 
which occurs death as the result of deee 
position, or which may be produced by vi 
compression of a part of the cord in ope 
& 
