THE SKELETON AND ITS JOINTS 353 
piiik or blood red areas of marrow. These strands may 
contain calcareous matter and are probably the remains of 
the cancellated tissue. Despite all this activity at the 
ends of the long bones there is not the extreme promi- 
nence of articulations so characteristic of rickets. 
Gelatinous or cartilaginous islands may be seen in the 
deep red shaft marrow. 
Fractures may be found and around them may form a 
blood clot or loose fibrous tissue entirely devoid of bone 
salts. If a break has existed for some time a very pro- 
nounced fibrous overgrowth from the periosteum is apt 
to occur, indeed an excessive fibrosis may exist, but this is 
ineffective for healing of the fracture or splinting of the 
shaft. Certain cases, notably in Carnivora, seem to have 
especial activity in and around joints so that when the 
member is dissected one gets the impression of osteoar- 
thritis. In such cases the synovia may be fibrotic and the 
articular surfaces dry. The pelvic deformities are simi- 
lar to those in the human being — lateral contraction with 
bending in of the superior rami of the pubis with the pro- 
duction of a beak, to which the name "duckbill" has 
been given. The anterior curvature of the lumbar spine 
makes an acute angle at the upper end of the sacrum. 
Histological examination of a number of our cases of 
osteomalacia and rickets have failed to show any lesion 
different from those known for the human being and for 
domesticated animals. It is noteworthy that not all bones 
of a given case will show the changes to the same degree 
even though grossly they may seem comparably affected. 
So too there is no certain relation between the degree of 
deformity as shown by the body as a whole and the 
advancement of osteoporosis as seen under the micro- 
scope. These observations are in accord with those of 
Brooks and Blair. Just why this is cannot be stated, but 
as the cause of these two bone diseases may not always 
be the same, variations in gross and minute anatomy are 
not remarkable. 
