Sentence:  [Describing scoliosis.] The integuments over the abdomen are folded or wrinkled, the left breast is seldom fully developed, the ribs lose their natural shape, those of the left side becoming straighter, while, on the right side, they are so much curved, as to admit of their being easily grasped by the hand; they are closer together on the left side, and frequently rest upon the <WSD>spine</WSD> of the ilium, thus giving the right side a fuller and more rounded appearance than is natural. 
Meaning of the word marked with <WSD> tags:  Something resembling a backbone, such as a ridge, or a long, central structure from which other structures radiate.