DEVELOPMENT OF HYALINE CARTILAGE. 113 



unsatisfactory on account of its attributing a double and con- 

 sequently fundamentally distinct mode of origin to one and 

 the same substance that, namely, which yields the chondrin ; 

 and it is unlikely, therefore, to be correct. If, however, 

 we adopt the view of Fiirstenberg, which may be directly 

 proved in the case of many cartilages, it is easy to show that 

 in those cases where the lamination of the matrix is not com- 

 pletely accomplished, a portion of the original cell boundaries 

 vanishes after the action of reagents, just as in most car- 

 tilages before the action of reagents they are likewise indis- 

 tinguishable. It still, however, remains a question whether 

 we shall represent the generations of capsules, of which the 

 matrix of cartilage is composed, as new formations proceeding 

 from the surface of mother and daughter cells, or as meta- 

 morphosed superficial layers of the cell protoplasm. The latter 

 view is held by Max Schultze, Briicke, and Heidenhain; 

 the two latter investigators, however, remark upon the diffi- 

 culty of disproving the opposite view, and Heidenhain refers 

 to cases where minute cells are surrounded by strong laminated 

 capsules. It remains to be investigated whether isolated 

 cells can undergo complete chondrogenous metamorphosis, and 

 whether it can thus be explained how it happens that the 

 matrix is frequently to be observed destitute of cells for a 

 considerable extent. 



According to Harting's researches on the cartilages of the 

 ribs, the cartilage cavities increase in size throughout the 

 period of foetal life, and also after birth. The number of 

 cartilage cavities in the newly born child is three or four times 

 greater than in the foetus, whilst in adults it is scarcely half 

 as great as in the new-born child. In adults the cells are 

 arranged more in groups than in newly born children, and in 

 these more than in the foetus. 



As regards the growth of permanent cartilage in length and 

 thickness, but little is positively known. It is impossible to 

 admit that isolated cell formation in the interior of a large car- 

 tilaginous mass can cause an increase in its volume. 



The result would, however, be different if the process of 

 division were frequently repeated at the surface, or between 

 two definite cleavage planes throughout the entire mass of the 



