48 ELEMENTS OF HISTOLOGY. [Ch*p.vi* 



replaced by bone, being the precursor of the formation 

 of bone, as in the embryo (see below), and at the 

 growing ends of tubular bones. 



58. The multiplication of the cartilage cells has 

 been observed during life by Schleicher and Flemming. 

 It takes place after the mode of karyokinesis. The 

 lacunas of the cartilage are not isolated cavities, but 

 are connected with one another by fine channels (Fig. 

 SOe), so that the ground substance is easily permeable 

 by the current of nutritive fluid. These channels and 

 lacunae make one intercommunicating system, and are 

 connected with the lymphatics of the perichondrium 

 (Budge). Formed matter like pigment granules, red 

 and white blood corpuscles, and pus corpuscles may 

 also find its way into the channels and lacunae of the 

 cartilage from the perichondrium. 



At the borders of articular cartilage, where it is 

 joined to the synovial membrane and the articulation- 

 capsule, the cartilage cells are more or less branched, 

 and pass insensibly into the branched connective tissue 

 cells of the membrane. In foetal hyaline cartilage 

 many of the cells are spindle-shaped or branched. 



59. In the cartilage separating the bone of the 

 apophyses from the end of the diaphysis of tubular 

 bones, there is a peculiar hyaline cartilage, known as 

 the intermediary or ossifying. Its cells are arranged in 

 characteristic vertical rows, owing to the continued 

 division of the cells in a transverse direction. 



Cartilages, or parts of cartilages, in which the cells 

 are very closely placed, owing to the absence, or im- 

 perfect deposit and formation, of ground substance, 

 are called parenchymatous. 



60. (2) Fibro-cartilage, or connective tissue 

 cartilage, occurs as the intervertebral discs, as the 

 interarticular cartilages, sesamoid cartilages, and as 

 that forming the margin of a fossa glenoidalis. It is 

 fibrous connective tissue arranged in bundles, and these 



