3 
L 906-7.] Excessive Meat Diet and the Osseous System. 
is the marked general softness of the whole osseous system, this condition 
being present in every meat-fed subject. The long bones of the flesh-fed 
rats are distinctly softer and more pliable than those of the bread-and-milk- 
fed animals ; a similar condition is observed in the ribs, short bones, and 
cranial bones of the meat-fed rats. This soft condition is present in the 
bones at birth, and becomes accentuated as age advances. A second 
striking appearance in the meat-fed animals is the darker colour of the 
long bones, more especially of the ribs, this being due to increased 
vascularity. This condition is present, in a greater or less degree, in all 
the meat-fed subjects which died or were killed after the second week of 
life. In some cases nothing further was observed in the bones of the flesh- 
fed rats killed even as late as three months after birth, but in the majority 
of cases a third feature shows itself. During the second month various 
curvatures of the spine and long bones occur. These consist in marked 
scoliosis and lordosis, with bending of the ribs at their angles, while curving 
of the bones of the limbs is present in a less degree. This condition of the 
bones is usually associated with an enlargement of the costo-chondral 
junction. In a small percentage of cases (about 15 per cent.) an additional 
feature is the presence of small white nodules in the bony ribs, these 
nodules standing out as pale bead-like prominences in the substance of the 
dark bone of the rib. On section these nodules are composed chiefly of 
cartilage (see fig. 7). In the more pronounced cases the skeletal changes 
generally are similar to those seen in advanced cases of rickets in the 
human subject. Microscopically, however, this similarity is not borne out. 
Microscopic Appearances. 
Owing to the uniformity of the bony changes throughout the whole 
series of meat-fed animals, it was unnecessary to make a histological 
examination of each subject. Sections were accordingly made from forty 
out of the hundred meat-fed rats and from an equal number of control 
bread-and-milk-fed animals. In this examination special attention was 
directed to the following points : — 
{a) Long bones . — The state of their development, by intra-in embranous 
and intra-cartilaginous ossification. 
(b) The histological appearances of the cranial bones. 
(c) Ribs . — The minute structure of the nodules present in the bony ribs. 
(a) Long Bones . — The ossification of the long bones of meat-fed rats is 
delayed and imperfect, the defect involving both the endochondral and 
periosteal bone formation. The epiphyses are for the most part normal ; 
