THE SKELETON AND ITS JOINTS 351 
to be undoubted instances of myelitis, but the osseous 
changes are not sufficiently discussed. In many cases it 
would seem, therefore, that there is some change in the 
nervous system, but there may be some examples without 
this and with predominant osseous lesions. We are in- 
clined to think that these two groups differ quaUtatively, 
and we look upon the confusion as demanding for its ulti- 
mate solution the use of exact nomenclature, especially the 
exclusion of ''cage paralysis" as a diagnostic term. The 
only division we can understand at the present time 
depends upon the gross changes in the bones, those with 
and those without definite irregularities in contour due 
to periosteal overgrowth. Certain of the former may 
show no unevennesses at all, the deformity being due to 
softness of the skeleton. The other group has shafts of 
irregular thickness, swellings around the joints and much 
beading of the middle of the ribs. 
Whether or not there be true paralysis is difficult to 
settle, but in our cases we have decided always in the 
negative because of the ability of the monkeys to grasp 
firmly with the hind digits. The animals tend to lie in one 
position, determined probably by comfort, the result 
being that they develop sores at the points of contact with 
their cage floor, and deformities of the skeleton (see 
Fig. 45). These deforaiities are especially well exhibited 
by the chest, the vertebrae and the pelvis and are referable 
to the almost constant squatting of the animal ; the long 
bones may be bowed but not as much as in rickets, nor is 
the epiphyseal junction so knobby as in that disease. 
The foregoing description is based chiefly upon obser- 
vations on monkeys but may be closely paralleled in 
carnivores and rodents. These latter, however, lie rather 
than sit during the development of the disease, so that 
thoracic and pelvic deformity is relatively less than in 
monkeys. Death is due to enteritis, anemia, shock from 
fractures and respiratory inflammation. 
