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SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE 



vol. 35 



Structure. — The external circumferential lamellae are fragmentary. The 

 central ring is composed of large, small, and irregularly shaped Haversian sys- 

 tems, most of which show T marked degrees of senility. Some are black and 

 partly gone and others have entirely disappeared, leaving spaces. The internal 

 circumferential lamellae are fragmentary, appearing only here and there. 



Type III, C, senile. 



LEFT FEMUR OF A WHITE MALE. NO. 162, MED. DEPT. NORTHWESTERN UNIV. 



Pl. 30, Fig. 384, Syn. Tab. X 



Antero-posterior diameter of bone, 25 mm. ; lateral, 29 mm. 



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



The medullary canal is full. Medullary index, 35%. 



Structure. — The external circumferential lamellae are fragmentary. 



The centra] ring is composed of Haversian systems of various shapes and 

 sizes with round and oval lacunae and bushy and straight canaliculi, many of 

 which are senile. 



The internal circumferential lamellae with long, narrow lacunae and straight 

 canaliculi surround the medullary canal. 

 Type III, C, senile. 



RIGHT FEMUR OF A WHITE MALE. NO. 244, CR. MED. COLL. 



Pl. 30, Fig. 385. Syn. Tab. X 



Antero-posterior diameter of bone, 35 mm. ; lateral, 30 mm. 

 Antero-posterior diameter of medullary canal, 17 mm. ; lateral, 15 mm. 

 The medullary canal is full. Medullary index, 32%. 



Structure. — Slight remains of the lamellar horseshoe are found on both 

 sides of the posterior ridge. 



The external circumferential lamellae are fragmentary. 



The central ring constitutes most all of the section, and is composed of 

 Haversian systems with many senile changes. 



The internal circumferential lamellae form a narrow fragmentary ring 

 around the medullary canal. 



Type III, C, senile. 



RIGHT FEMUR OF AN EAST INDIAN. NO. 223, CR. MED. COLL. 



Pl. 30, Fig. 386. Syn. Tab. X 



Antero-posterior diameter of bone, 29 mm.; lateral, 24 mm. 

 Antero-posterior diameter of medullary canal, 16 mm.; lateral, 12 mm. 

 The medullary canal is full. Medullary index, 38%. 



