NO. 3 COMPAEATIVE HISTOLOGY OF FEMUR FOOTE 155 



LEFT FEMUR OF A NEGRO. NO. 87, MED. DEPT. TULANE UNIV. 



Pl. 22, Pig. 309. Syn. Tab. VIII 



Antero-posterior diameter of bone, 27.5 mm. ; lateral, 30 mm. 



Antero-posterior diameter of medullary canal, 17 mm.; lateral, 17 mm. 



The medullary canal is full. Medullary index, 54%. 



Structure. — The external circumferential lamellae are fragmentary. The 

 central ring is composed of large, small, and irregular Haversian systems, which 

 show marked senile changes. The internal lamelliE form a fragmentary ring- 

 around the medullary canal. 



Type III, C, senUe. 



RIGHT FEMUR OF A NEGRO. NO. 7, MED. DEPT. TULANE UNIV. 



Pl. 22, Fig. 310. Stn. Tab. VIII 



Antero-posterior diameter of bone, 27 mm. ; lateral, 30 mm. 



Antero-posterior diameter of medullary canal, 19 mm.; lateral, 18 mm. 



The medullary canal is full. Medullary index, 74%. 



Structure. — The external lamelte are fragmentary. The central ring is 

 composed of Haversian systems with few senile changes. The internal lamellae 

 form a narrow ring around the medullary canal. 



Type III, C, senile. 



LEFT FEMUR OF A NEGRO. NO. 4, MED. DEPT. TULANE UNIV. 



Pl. 22, Fig. 311. Stn. Tab. VIII 



Antero-posterior diameter of bone, 30 mm. ; lateral, 23 mm. 



Antero-posterior diameter of medullary canal, 21 mm.; lateral, 13 mm. 



The medullary canal is full. Medullary index, 65%. 



Structure. — The external circumferential lamellae form a narrow enclosing 

 ring, excepting in the posterior ridge where it is absent. The central ring forms 

 most of the section and is composed of regular, well developed Haversian sys- 

 tems, excepting in the inner wall where the systems are much elongated. 



The internal circumferential lamellae are fragmentary. 



Type III, C. 



LEFT FEMUR OF A NEGRO. NO. 84, MED. DEPT. TULANE UNIV. 



Pl. 22, Fig. 312. Stn. Tab. VIII 



Antero-posterior diameter of bone, 24 mm.; lateral, 25 mm. 

 Antero-posterior diameter of medullary canal, 15 mm.; lateral, 13 mm. 

 The medullary canal is full. Medullary index, 48%. 



