xii FIBRO-CARTILAGE 551 



way. But it is possible that the chondrigenous material 

 may be, as it were, secreted by and thrown out between 

 the cells, as the constituents of the bile are thrown out 

 between the hepatic cells, or at all events manufactured 

 in some way by the agency of the cells, without the 

 substance of the cells being actually transformed into it. 

 Thus the capsule of each cell may be such a secretion, 

 which then fuses into the adjacent matrix. Our know- 

 ledge will not at present permit us to form a definite 

 judgment on this point. One thing, however, seems 

 certain, viz. that the cells are in some way concerned in 

 the matter ; the matrix is unable to increase itself in the 

 entire absence of cells. 



Fia. 178. — Section of White Fibro-Cartilaqe. (Hardy.) 



The embryonic cells, which give rise to cartilage, are 

 not distinguishable by any means we at present possess 

 in any respect of importance from those which give rise 

 to epidermis. 



Nevertheless, the common form must disguise a different 

 molecular machinery, inasmuch as the two, when set 

 going by the conditions of temperature, supply of oxygen 

 and nutriment to which they are exposed in the living 

 economy, work out, as their ultimate products, tissues 

 which differ so widely as cartilage and epidermis. 



The embryonic cartilage cells, like the embryonic epi- 

 dermic cells, are living organisms in which certain 



