398 



INFLAMMA TION. 



medullary tissue freely supplied with blood-vessels of considera- 

 ble caliber, venous and capillary chiefly ; but the production of 

 bone from this vascularized tissue is extremely scanty and with- 

 out uniformity. (See Fig. 167.) 



At the peripheral portions of the shaft-bones we find, between 

 the thin cortical bone-tissue and the fibrous portion of the perios- 

 teum, a broad layer of medullary tissue, which is sometimes 

 arranged in patches. The blood supply of this medullary tissue 

 is so great as to give the appearance of a hemorrhage to the 



MS 



MossENGCoN.Y, 



FIG. 167. RACHITIS. RIB OF A CHILD, IN TRANVERSE 

 SECTION. CHROMIC ACID SPECIMEN. 



C, cartilage corpuscles, arranged in territories ; MS, medullary space, sprung from carti- 

 lage tissue ; M, medullary tissue with very large blood-vessels, BV, and a scanty new forma- 

 tion of bone-tissue, B. Magnified 200 diameters. 



naked eye. The bone generally remains in the stage of cancel- 

 lous structure, with large, irregular medullary spaces. 



The flat skull-bones, being developed from fibrous connective 

 tissue, exhibit similar features the so-called craniotabes. In 

 some places medullary tissue is formed, leading to a reproduction 

 of fibrous connective tissue, instead of bone j or already formed 

 bone, through the intermediate medullary stage, passes into a 



