NO. 10 THE CIRCULATORY SYSTEM IN BONE — FOOTE I3 



TANGENTIAL SECTION OF THE FEMUR OF MAN, A WHITE MALE, 

 SHOWING CIRCULATION 



Pl. 4, Fig. 33 



The type of bone is first and third. Numerous entering vascular 

 canals with and without enclosing lamellae are present. The circula- 

 tion is a dense branching and plexiform distribution of blood vessels 

 with small meshes of various shapes. Vascular expansions are 

 numerous and large. The lacunae of the bone substance are round, 

 oval, and long and narrow with the canaliculi which belongs to each 

 degree of differentiation. The density of the circulation varies in 

 different bones of the same structural type and also in bones of 

 different type combinations. 



TANGENTIAL SECTION OF THE FEMUR OF MAN, A WHITE MALE, 

 SHOWING THE CIRCULATION 



Pl. 4, Fig. 34 



The type of bone is first and third. The type of circulation is 

 branching, changing to plexiform. Entering canals, for the most 

 part without enclosing lamellae, are few in number in this section. 

 The circulation shown in the drawing is situated in the external 

 lamellae which encloses the internal third type differentiation. It is 

 a large branch dividing into many small ones which, by uniting, form 

 a plexiform distribution. 



TANGENTIAL SECTION OF THE FEMUR OF MAN, A WHITE MALE, 

 AGE 50, WHO DIED OF PULMONARY TUBERCULOSIS 



Pl. 4, Fig. 35 



The type of bone is third. The type of circulation is essentially 

 branching although a coarsely plexiform arrangement can be distin- 

 guished. Entering canals with and without enclosing lamellae are 

 seen in the bone substance. The blood vessels are irregular in size 

 and shape and show varicose enlargements very frequently. Whether 

 or not this varicose condition and irregularity in the circulation in 

 bone are indices of similar changes in the general circulation cannot 

 be told ; but they may be thought of in connection with the pathologi- 

 cal condition present in this individual. 



