152 T. H. BAST 



also attribute a possible function to the bone cell in the following 

 statement: ''Apparently bone cells do not divide, and if they 

 produce matrix, thus becoming more widely separated from each 

 other, it is only to a slight extent and in young bones; they are 

 therefore quite inactive." 



As early as 1873, Z. G. Strelzoff showed that under certain 

 conditions slight interstitial growth may take place. Jean Haour 

 expressed the view that osteoblasts are not the active bone 

 formers, that they together with the fibroblasts produce a hya- 

 line matrix; but that the engulfed bone cells are concerned with 

 the bone formation. He claims that many of these bone cells 

 degenerate and hberate phosphoric acid which has a special 

 afhnity for calcium. Haour states that Gardner has shown that 

 certain highly refractive granules in bone cells liquefy and that 

 this liquid is directly concerned n the process of ossification. 



In 1901 Fujinami in his paper on 'Tissue changes in healing 

 of Bone Fractures' writes, "In sparrows I saw at times a nucleus 

 in the middle of an elongated spicule of ossific ground-substance, 

 both sides of which were closely lined by osteoblasts. The 

 nucleus, whose shape very nearly resembled that of the spicule, 

 showed a rim of finely granular protoplasm, which, without a 

 sharp boundry, graduallj^ passed over in all directions, especially 

 in the long axis, into the ground substance." He also found 

 in his stained preparations that the osteoblasts were differen- 

 tiated very sharply from the spicule on which they were lying. 

 He implies in this description that the bone cell rather than the 

 osteoblast is the active bone former. 



That the bone cell is not entirely inactive is certainly brought 

 out by many of these observations. Its exact relation to bone 

 formation however, is differently expressed by the observers. 

 Haour attributes bone formation to the degenerating cell. Gard- 

 ner attributes it to the granules in the cell. According to 

 Fujinami the peripheral protoplasm gradual y passes over into 

 bone. 



Many of the observations presented in this article affirm the 

 position that the bone cells are actively concerned in bone 

 formation. What the exact relationship between matrix and 

 bone cells is I am unable to say at the present time. 



