which we call the chest. They are joined in front to the breast- bone. It is worth noticing that the vertebras increase in size and solidity downwards. The bones at the base of the column are very thick, solid, and strong.
It is a curious fact, too, that the vertebral column of a child contains thirty-three distinct bones; but there are only twenty-six bones in the vertebral column of anadult. The explanation is this; as the child advances into adult life the four lowermost vertebras grow together and form one piece, corresponding to the tail of the lower animals-in fact, a sort of rudimentary tail; and at the same time the five next above these also become weldedinto one piece to form the sacrum. The sacrum and the great haunch or hip-bones form a sort of bony basin-the pelvis-at the base of the column.
Lesson 04
The Woody Stems of Plants
