in Lambs and Young Sheep. 
511 
form the canal in which the cord is lodged. Here, with an 
averase amount of care in conducting: an examination of the 
cord and vertebral canal, it will, in the great majority of cases, 
be clearly enough made out that any changes observed in the 
cord are more probablv the result of pressure, proceeding from 
change of form in the bonv canal in which it is lod";ed. 
When making this examination, it is better to carry out a 
longitudinal section of the bony column through the canal, than 
to lift the roof simply from the cavity, by dividing the arches. 
After making this longitudinal section, examination w^ill dis- 
close the fact that the cord exhibits regular portions, more or 
less constricted, these constrictions being opposite to the 
points of union or articulation of the segments of the spinal 
column. The bulging of these at the intervertebral cartilaginous 
discs by w^hich they are connected, and more so the bulging and 
increase in bulk at the ends of the bodies of the individual 
segments, close behind the epiphysial cartilages, are the cause 
of the production of an uneven floor in the canal ; this nar- 
rowing results in pressure and constriction of the contained 
cord, with an increase of fluid in the cavities of the investing 
membranes. This swelling of the individual extremities of the 
separate portions of the vertebral chain is dependent on the im- 
perfect bone-development incident to a state of general mal- 
nutrition. In these very voung creatures the local evidences of 
the general disturbance are chieflv confined to the bone-elements 
constituting the spinal column ; in older ones the lesions exhibit 
themselves more in the passive organs of support, the bones of 
the limbs. 
Si/mptoms. — The chief as well as the diagnostic indications 
of the affection are those associated with, or proceeding from, 
disturbed motorial power. In many instances where the 
disease appears as a virulent enzootic, numbers of lambs, 
although of full size and carried the full time, are never able to 
rise from their birth. With the greater number, however, the 
evidence of defective movement of the posterior parts most 
distinctly exhibits itself when the lambs have reached a few 
weeks old, while a certain proportion may appear well enough 
for a much longer period. In cases where this affection is 
known to exist, a little careful watching will soon detect the 
affected. On any little excitement or attempts to gambol, the 
animal will stagger or fall over ; while in making an effort to 
run, the hind limbs cannot be brought forward in conformity 
with the other parts, or with the will of the sufferer. From the 
lelt difficulty to execute movement, all sufferers from this impair- 
ment of power are disposed to rest much, only rising, or making 
attempts to do so, in response to the calls of appetite. When 
