The =ribs= number fourteen or fifteen pairs, of which seven are sternal
and seven or eight asternal usually. They are in general strongly curved
in the improved breeds, so that there is a fairly distinct angle, except
toward the end of the series. The backward slope of the posterior ribs
is slight. The first rib is prismatic, has a large sternal end, and a
very short cartilage. The width is greatest in the third to the sixth,
and the length in the sixth and seventh usually. The tuberosity fuses
with the head on the last five or six. The second to the fifth form
diarthrodial joints with their cartilages, which are wide and
plate-like.