in Lambs and Young Sheep. 
517 
feel that there may yet be a closer relationship than at first 
appears in all that pertains to their essential character. Both 
are evidently the results of disturbance of nutrition, being essen- 
tially dependent for their existence on causes purely dietetic, 
while both may be counteracted by supplying an appropriate 
food supply. It may be thought that the gross lesions in the 
case of the one affection, viz. that where the stability of the 
bones of the limbs is chiefly at fault, must point to conditions 
essentially different from those which operate where the changes 
seem primarily and chiefly located in the great nerve centres. 
This apparent difference in the character and relation of 
symptoms to textural changes may, however, be capable of a 
not unsatisfactory explanation. 
If we regard both affections as only manifestations of a par- 
ticular perturbation in the nutrition and development of bone 
elements, it is possible to show that the diagnostic symptoms 
of both are capable of being linked to this one unnatural 
condition. 
In referring to the anatomical characters of enzootic lamb- 
paralysis, " Rickets," attention was directed to the state of the 
component segments of the vertebral chain. Here it was noted 
that many cases exhibited an unnatural growth or development 
of the individual pieces of the bony canal. The floor of the 
canal, in which rests the spinal cord, it was observed, was liable 
to exhibit an uneven and undulating surface from peculiarities 
in the growth of the separate bones. The swelling, from ap- 
pearing in each separate piece at their ends or extremities, was 
consequently most marked at the junction of the several seg- 
ments. Wherever this irregularity existed, the consequent 
intrusion on the cavity of the spinal canal is explanation suffi- 
cient of disturbed or destroyed nervous power through pressure 
on the contained cord. Such changes in the growth of the 
bones forming the vertebral chain are well known to accompany 
the same disturbance in bone development in the limbs. Or 
the same fact is better put by saying that disturbance in bone 
growth, in the same variety of animals, may, when occurring at 
one particular age, exhibit its results in the central skeleton — the 
head and spinal column — while at a different period of life the 
same disturbance is shown in changes chiefly confined to the 
bones of the limbs. 
Viewed in this light, both these affections come to be regarded 
as merely types or modifications of that general disturbance of 
bone nutrition and development included under the term 
" RicketsJ" This general state of ill-health has not usually been 
considered as congenital in any animal. Still, viewed in a 
large sense, particularly as to the influences which seem to 
