THE OSSEOUS SYSTEM. 355 



menccment of ossification in the matrix, but without any 

 primary formation of calcareous particles; and secondly, upon 

 the continually increasing deposition of earthy matter in it, and 

 in the thickened cell-walls, owing to which, the new bone- 

 substance, to the naked eve becomes more and more white, and 

 under the microscope appears more and more dark and 

 transparent; it now, also, becomes more homogeneous, and the 

 abrupt limits of the bone-cells gradually less and less defined, 

 till at last they appear, not as cellular organisms lodged in the 

 matrix, but to be confused with it, being recognisable only 

 from their peculiar stellate cavities, — the so-termed bone- cor- 

 puscles, or lacuna and canaliculi. 



With the knowledge thus obtained of the formation of the 

 lacuna in rachitic bone, the endeavour to arrive at an insight 

 into the same process in normal bone, is no longer attended 

 with as much difficulty as before, when the inquirer was involved 

 in a maze of hypotheses of the most various kinds, and all 

 without any certain foundation. The investigation of the con- 

 ditions attending the development of bone, both in man and 

 other animals, must nevertheless still be regarded as trouble- 

 some, and frequently little worth the pains bestowed upon it. 

 It is, perhaps, certainly manifest {old. 'Mik. Anat./ tab. iii, 

 fig. 6), that the bone-cells, a little beyond the limit of ossi- 

 fication, become thickened, and, still presenting the remains 

 of their cavity and the nucleus, beset with calcareous particles; 

 and although such encrusted cells mav even be isolated, vet the 

 mode in which the changes are effected further on, is not, 

 beyond a short distance, I must affirm, to be seen with anything 

 like the distinctness that it is in rachitic bone, because, more 

 internally, the newly-formed medulla with its vessels, and the 

 calcareous particles, render almost everything indistinct; and 

 it is not till we get to the homogeneous and more transparent 

 osseous tissue beyond, that distinct, but almost perfectly- 

 formed lacunas come into view. Nevertheless, from all that we 

 see, there cannot be the least doubt, but that the processes 

 are essentially the same as in rachitis, only, that in the healthy 

 bone the ossification of the thickened walls of the cartilage-cells, 

 presents two stages, instead of only one, as in the former case, 

 inasmuch as they first appear granular from the deposition of 

 the calcareous particles, and afterwards homogeneous. More- 



