NO. lO THE CIRCULATORY SYSTEM IN BONE — FOOTE 1 7 



TANGENTIAL SECTION OF A HUMAN INFERIOR MAXILLA, 

 SHOWING THE CIRCULATION 



Pl. s, Fig. 47 



The section is taken from the bone just in front of and below the 

 left central incisor tooth. The type of bone is first. Entering canals 

 with and without lamellae are present. The circulation is a branch- 

 ing plexiform type having a slanting direction from above downward 

 and forward. The meshes are long and irregular in shape. Vascular 

 expansions are numerous. 



TANGENTIAL SECTION OF THE INFRA-SPINOUS FOSSA OF A 

 HUMAN SCAPULA, SHOWING THE CIRCULATION 



Pl. 6, Fig. 48 



The type of bone is first with here and there an Haversian system. 

 A few entering canals with enclosing lamellae are seen in the section. 

 The circulation is a branching and plexiform type, the former pre- 

 dominating. Vascular expansions are prominent. The one in the 

 center of the drawing suggests a distributing center. 



TANGENTIAL SECTION OF THE SUPRA-SPINOUS FOSSA OF THE SAME 

 SCAPULA, SHOWING THE CIRCULATION 



Pl. 6, Fig. 49 



The type of bone is first. A few entering canals with and without 

 surrounding lamellae are present. The circulation is branching in 

 type with a few vascular expansions. It takes an oblique direction 

 from above downwards and toward the vertebral border, 



CROSS AND TANGENTIAL SECTIONS OF THE 9TH RIB OF ADULT 

 MAN, MALE WHITE 



CROSS SECTION SHOWING THE STRUCTURE 

 Pl. 6, Fig. 50 

 This is a third type bone composed of Haversian systems of a late 

 degree of differentiation. The systems extend lengthwise of the rib 

 and enclose a cancellous center. 



TANGENTIAL SECTION OF THE INNER WALL OF THE SAME RIB, 



SHOWING THE CIRCULATION 



Pl. 6, Fig. 51 



The section is taken from the posterior third of the bone. The 



circulation is an elongated plexus. In the center of the section is a 



vascular expansion which suggests a center of distribution for the 



blood vessels. 



