ORIGIN AND FATE OF OSTEOCLASTS 325 



Hence it appears that the degree of multinuclearity is an 

 index of the number of osteoblasts and bone cells entering into 

 the composition of the osteoclasts. Also, in general, the larger 

 an osteoclast, the more numerous its nuclei and the more exten- 

 sive its history in relation to bone resorption (compare figs. 1, 

 21, and 22). 



Fig. A The encapsulated bone cell, b.c, is half ingested by an osteoclast, 

 ocl., which lies on a spicule of bone, mix. Only a portion of the entire osteoclast 

 appears in this section. Photograph. X 650. 



OCl. . 



lb 



b . m 



Fig. B A stage in osteoclastic phagocytosis similar to that of fig. A. The 

 bone cell is half within and half without the osteoclast. Photograph. X 650. 



My observations agree with those of Maximow ('10) in that 

 nuclear division either by mitosis or amitosis has never been 

 observed in these older stages. Shrunken and folded nuclei 

 do appear, especially in cells which show other evidences of 

 degeneration, but convincing stages of amitosis have not been 

 found by me. In much of the material used mitoses were not 

 uncommon in the near-by germinative layer of the epithelium, 

 so the preparations would seem to be favorable for demon- 

 strating nuclear division did it occur. 



