OSSIFICA TIOy—R I X ES OF EPIPII } ".S'^.S 3 



rate epiphyses, as is the case at the upper end of the femur. Epiphyses, though of 

 no morphological value, seem to follow certain rules, thus: — 



1. Those epi])hyses which appear last are the first to unite with the shaft. 



Exception. — The distal epiphysis of the fibula is visible three years before the 

 jiroximal, l)ut fuses Avith the shaft much earlier than it. It should be rememl)ered 

 that the proximal end of the fibula in man and many other mannnals is vestigial. 



Fro. 1. — Tm: Tibi.a and Fibula in section to show the Epiphyses. 



CENTRE OF OSSIFICATION OF EPIPHYSIS 

 EPIPHYSIAL LINE 



i 



SHAFT OF FIBULA 



SHAFT OF TIBIA IN SECTION 



EPIPHYSIS OF TIBIA 



EPIPHYSIS OF FIBULA 



2. The epiphvsis towards which the nutrient arterv is directed unites first witli 

 the shaft. 



3. \\'hen a bone has only one t-jiiphysis, the nutrient artery is directed towards 

 the extremity which has no epiphysis. 



4. The centres of ossification appear earliest for those ei^iphyscs which bear the 

 largest relative proportion to the shafts of the bones to which they belong. 



5. When an eiiiphysis ossifies from more than one centre, the various nuclei 

 coalesce before the shaft and ei)iphysis consolidate. 



On section, the shaft of a fcjetal long bone is found occupied with red marrow 

 lodged in bony cells which do not ])resent any definite arrangement. In an adult, 

 the central jjortion of the shaft of a long bone is filled with fat. or marrow, heM 



