THE CELL DOCTRINE. 93 



ligamentum nuchse, and likewise formed from nuclei 

 (frontispiece, Fig. 14), but in part also of the remains 

 of nerves and vessels, which were active at an earlier 

 period of life* 



So, also, with hyaline cartilage. According to Beale, 

 the intercellular substance of cartilage results from 

 the cojiversion of the so-called cartilage-corpuscles or 

 cells into formed material, and here also the germinal 

 matter is directly continuous with the matrix, no 

 proper cell-wall intervening. 



Cartilage is not to be considered as a distinct class 

 of tissue from epithelium, nor can the latter, in all 

 cases, be distinguished from cartilage by the exist- 

 ence of separate cells, since in many forms of epi- 

 thelium, at an e&v\y period of existence, the formed 

 material corresponding to the masses of germinal 

 matter is continuous throughout, and presents no 

 indication of division into cells.f A " cell," or "ele- 

 mentary part," then, of fully formed tendon or carti- 

 lage, would consist of a portion of germinal matter, 

 with a proportion of formed material about it, ex- 

 tending to a line midwa}' between that mass of ger- 

 minal matter and the masses immediately adjacent, 

 of which the cartilage or tendon is composed ; and 

 such a line would correspond to the outer part of 

 the surface of an epithelial cell.:}: In very young car- 

 tilages, as in very young epithelium, the cells consist 



* Beale, On the Structure and Growth of the Tissues, and on 

 Life. London, 1865, pp. 95, 96, and 101. 



f Beale, Protoplasm ; or. Life, Force, and Matter. London, 

 1870, p. 51. 



% Beale, Protoplasm, pp. 51-2. 



