Abstract
In homebred and satisfactory grown 222 beagles (108 males and 114 females), X-ray photographs were taken periodically over a period from one day to 14 months of age to study growth of the bones of the pectoral limb. The appearance of the epiphyseal and diaphyseal ossification centers, the process of formation of proper shapes, fusing of epiphysis to diaphysis, and closure of the epiphyseal line were examined by referring to the assessing standards of bone age of Ohwada and Sutow. An increase in bone length and body weight was measured at the same time. In all the bones, except the carpal bones, of the pectoral limb, the diaphyseal ossification center appeared at one day of age. It appeared in the carpal bones by 2 months of age. The epiphyseal ossification center appeared in those bones at different times. It was seen earliest, or at one week of age, in the caput humeri and last, or at 2 months of age, at the cranio-distal end of the scapula and at the distal end of the ulna. Closure of the epiphyseal line occurred earliest, or at 6 months of age, at the cranio-distal end of the scapula and latest, or at 14 months of age, in the caput humeri. It took place in almost all the main long bones at 10-12 months of age. Bones grew rapidly in length up to 5 months of age and Slowly thereafter. They ceased increasing in length at about 10 months of age. The bones of the pectoral limb as a whole reached an adult state at 14 months of age.
