Fic; 10 BoiK' niatiix luns vertically down left margin. Ruffled border 

 adjoins Collagen denuded of bone salt seen cut in longitudinal section (hori- 

 zontal arrows) and, possibly, transversely (vertical arrow). A pinosome (P) is 

 indicated. In original electron micrograph collagen cross-banding is discern- 

 ible at arrows, but it is difficult to make out in positive print. (X 40,000.) 



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