QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 189 



By the growth of those processes the calcified parts of the 

 cartilage-matrix are gradually absorbed, in which proceed- 

 ings the osteoclasts play an important part. 



"The cartilage-cells themselves do not become transformed 

 into cells of the marrow. 



" (c) Exactly the same takes place at the ossification-margin 

 of the diaphysis, for here the elongated vascular processes, 

 which gradually penetrate from the diaphysal extremity into 

 the cartilaginous epiphysis, are also offsprings of the perios- 

 teal processes. Those vascular processes are always and 

 everywhere sharply defined from the cartilage. Osteoclasts 

 are generally not to be met with at the terminal points of the 

 vascular processes, but they occur in great numbers near the 

 ossification-margin ; so that they play certainly a part in the 

 absorption of calcified cartilage-matrix, but not in the 

 dehiscence of the cartilage-cavities. 



" 3. Growth of bones in length. — By the well - known 

 method of feeding very young animals with madder, KoUiker 

 arrived in agreement with Oilier and Humphry to the follow- 

 ing conclusions as regards the growth of bones in length. 



" [a) In long tubular bones with epiphyses on both ex- 

 tremities, that extremity of the diaphysis grows quicker whose 

 epiphysis remains longer separated. 



" [b) Short tubular bones, with only one epiphysis, grow 

 quickest at the diaphysis touching that epiphysis (calcaneus, 

 metatarsi, metacarpi, phalanges). 



" (c) All free edges and apophyses of any bone show a 

 very marked growth (crista ossia ilii tuber ischii, processus 

 spinosi et transversi, processus xyphoideus sterni, processus 

 styloideus ulnse). 



" {d) The same holds good with certain extremities of 

 long bones, which are provided with a considerable layer of 

 cartilage — e. g. the ribs. 



" (e) Short bones, with and without epiphyses, grow pretty 

 equally on all cartilaginous surfaces, which are in contact 

 with other bones (vertebral diaphyses, tarsus, carpus, 

 sternum). 



" (/) All epiphyses which touch an articulation grow most 

 at the extremity touching the articulation. 



" {g) Those parts of bones that are covered with cartilage 

 and are not in contact Avith other bones show a considerable 

 growth. (The edges of the vertebral epiphyses, the lateral 

 parts of all epiphyses.) 



" {h) The thickness of the cartilage, whose cells are in the 

 act of proliferation, stands generally in relation to the energy 



VOL. XIV. NEW SER. N 



