FORMATION OF BONE- CORPUSCLES. 461 



cases, we still succeed in finding cartilage-corpuscles, in 

 which the capsular cavity has (without the occurrence 

 of calcification) become diminished in consequence of 

 the deposition of new capsular matter, so as to assume 

 the form of a bone cavity (lacuna) which it generall}' 

 assumes only after ossification whilst the old cellular 

 element (the cartilage -cell with its nucleus) still remains 

 in it. After this still without the occurrence of any 

 calcification the boundary disappears which originally 

 existed between the capsules of the cartilage-cells and 

 the basis-substance, and we find jagged elements* (the 

 future bone-cells) in an apparently entirely homogeneous 

 substance in other words, a tissue still soft, though in 

 structure like bone (osteoid tissue, Fig. 133, 0). Usually 

 this process is concealed by means of the early calcifi- 

 cation of the cartilage and only certain processes, for 

 example, rickets, give us the opportunity of seeing the 

 osteoid transformation take place in just the same man- 

 ner in those parts of the cartilage also which are begin- 

 ning to calcify. 



But the old limits of the .capsule still represent the real 

 district which is under the sway of the bone-corpuscule, 

 and, as I pointed out to you at the commencement of my 

 lectures (p. 41) with an especial reference to this point, 

 in pathological conditions this district comes again not only 

 in force but also into view. Within these limits we see 

 the bone-corpuscle accomplish its peculiar destinies. If, 

 for example, the bone is by any cause impelled to enter 



* The cartilage-cells (and the same holds good of the marrow -cells) during ossi- 

 fication throw out processes (become jagged) in the same way that connective-tis- 

 sue corpuscles, which are also originally round, do, both physiologically and patho- 

 logically. These processes 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 membrane and into the vessels of the uterus, or like the pac- 

 chionian granulations (glands) of the pia mater of the brain into (and occasionally 

 through) the calrarium. From a MS. Note by the Author. 



