... time before these separate pieces are united to form one bone. 71. When the process of ossification is completed, there is still a constant change in the bones. They increase in bulk, and become ... arranged as to form an instrument designed for action. The action of an organ is called its function, or use. Example. The liver is an organ, and the secretion of the bile from the blood is one of ... direction. In this experiment, the acid has removed the earthy matter, (carbonate and phosphate of lime,) yet the form of the bone is unchanged. 69. The bones are formed from the blood, and are...