CARTILAGE. 101 



detached from the wall of the cavity ; the nucleus varies in 

 distinctness, and is sometimes homogeneous and sometimes 

 granular. Cells are frequently observed in the costal or laryngeal 

 cartilages, containing deep yellow-coloured drops (of oil), sur- 

 rounded by dark rings, more or less strongly refracting light. 

 Similar drops are often found free in the cavity of the car- 

 tilage, external to the shrivelled remains of the cell. 



The cells, and the cavities of the cartilage in which they are 

 lodged, are separated by a variable amount of the matrix ; they, 

 moreover, sometimes lie detached and separate at regular dis- 

 tances, whilst at others they are united together into groups of 

 few or many cells ; and these again may be separated from one 

 another by wide intervening spaces or by a few solitary cells. 

 Two or more cells lying in close proximity to one another are 

 frequently seen to occupy the same cavity. The form of the 

 cartilage cavities is spheroidal, ellipsoidal, or elongated and 

 fusiform, or somewhat flattened and lenticular ; the two latter 

 forms occurring closely compressed together, near the free sur- 

 faces that play over one another in joints, or in many of those 

 cartilages whose surfaces are invested by perichondrium, and the 

 cells then lie with their long diameter parallel to the surface; 

 whilst in the more centrally situated portions of these cartilages 

 are the larger cavities of the first-named varieties, and between 

 these and the most external, various transitional forms. At 

 points where cartilage and bone tissue are in immediate appo- 

 sition the cartilage cells are frequently found to be arranged 

 with great regularity in longitudinal rows in the direction from 

 the bones towards the free surface of the extremity invested 

 with cartilage. The cells in these longitudinal rows will be 

 subsequently considered in treating of the subject of ossification. 

 The cartilage cavities occasionally present a stellate form. State- 

 ments to this effect may be found in the writings of Leydig,* 

 where he is describing the skull of the Chimsera and various 

 Plagiostomatous fishes. Stellate cells have also been found by 

 Kolliker-f- (in softer parts ?) in the tracheal cartilages of oxen. 



The matrix of hyaline cartilage, when in a perfectly fresh con- 



* Miiller's Archiv, 1851, p. 241. 

 t Gewebelehre, 1867, p. 69. 



