150 VIRCHOW'S VIEWS ON THE 



impregnated with calcareous matter, while the " gra- 

 nular cell" corresponding to the primordial utricle of 

 the vegetable cell, remains within unaltered. He 

 thinks that the caualiculi extend through the matrix 

 by " resorption." 



Virchow says bone contains, "in an apparently 

 altogether homogeneoiis basis-substance, peculiar 

 stellate lone cells disti-ibutcd in a very regular man- 

 ner." According to this view it is maintaiaed that 

 the matrix is formed as a true intercellular substance, 

 while from the "cells" it is supposed that processes 

 grow out, and that these gradually make their way 

 through the matrix and anastomose with correspond- 

 ing processes from neighbouring cells. The " lacuna" 

 is said to be occupied by a " cell " with " stellate 

 processes" which pass into the canaliculi. Virchow 

 expresses himself very clearly as to the manner in 

 which the supposed processes are formed from cells : — • 

 " The cartilage cells (and the same holds good of the 

 marrow cells) during ossification throw out processes 

 (become jagged) in the same way that connective 

 tissue corpuscles, which are also originally round, do, 

 both physiologically and pathologically. These pro- 

 cesses, which in the case of the cartilage cells are 

 generally formed after, but in that of the marrow 

 cells frequently before, calcification has taken place, 

 bore their way into the intercellular substance, like 

 the villi of the chorion do into the mucous memhrane 

 and into the vessels of the utems, or like the Pac- 

 chionian granulations (glands) of pia mater of the 

 brain into (and occasionally throngh) the calvarium." 

 Again, " the cells which thus result from the 

 proliferation of the periosteal corpuscles are con- 

 verted into bone corpuscles exactly in the way I 

 described when speaking of the marrow. In the 

 neighbourhood of the surface of the bone the inter- 

 cellular substance grows dense and becomes almost 

 cartilaginous, the cells throiv out processes, hecome 



