148 OF THE BIOPLASM OF BONE. 



This is the part of the tissue which was first formed. 

 Soon each mass of bioplasm becomes surrounded by 

 a ring of such globules, some of which coalesce, but. 

 converging lines of matrix are always left here and 

 there uncalcified, and these are traversed by currents 

 of fluid holding various substances in solution, which 

 flow to and from the masses of bioplasm. The con- 

 tinual flowing of the fluid prevents the precipitation 

 of calcareous material in these channels, and, pro- 

 bably, gradually dissolves the matrix, so that little 

 canals are formed at short intervals in the calcifying 

 cartilaginous tissue. More calcareous matter is de- 

 posited nearer and still nearer to the bioplasm in the 

 centre of the space, and at its outer part the bioplasm 

 continues to produce more new cartilage matrix, 

 which in its turn becomes impregnated with cal- 

 careous salts. The little canals are at the same time 

 increasing in length, although the distance from the 

 centre of the bioplasm to the spot in the cartilage 

 matrix where the canal began to be formed always 

 remains the same. As the deposition proceeds, the 

 bioplasm becomes smaller, and the space in which it 

 lies is gradually encroached upon until in the fully 

 formed bone it remains as a very small mass lying in 

 a little cavity (lacuna) which communicates with 

 neighbouring lacunae by the little canals (caiialiculi), 

 the formation of which has been described. This 

 view concerning the formation of lacunae and canali- 

 culi is very different from that generally taught, for 

 most authorities look upon the lacunae as cells, the 

 canaliculi as processes from them, and the osseous 

 tissue as an intercellular substance. 



2O 9. Of the bioplasm of bone. If the growing 

 bone of any animal be examined, after having been 

 properly prepared with carmine fluid, the masses of 

 bioplasm will be demonstrated without difficulty, in 

 the lacunal spaces. The fact of the presence of soft 

 matter in the lacunae of fully formed bone has how- 



