And sometimes stimulation applied to these holographic areas could produce certain effects not reproducible by applying the same stimulation to acupoints located in the same areas. This indicated that the holographic area itself could independently produce different effects, although located in a same region as the acupoints. So we may propose the existence of a health record of the body, from certain developmental stages, retained in the living cells, and the existence of an adjusting mechanism capable of affecting the entire body by stimulating a very limited area.

The regular acupoints, extra acupoints, and holographic points and reflecting areas can be considered as independent "in-formation-inducing units," and through them the adjusting impulse can be transmitted from the local point or area to the rest of the body. Scientific investigators may study the mechanism of this phenomenon if they are interested, but clinicians need only learn and master the acupoints and areas for clinical practice, without necessarily knowing the underlying reasons.

For the convenience of the reader, the proportional unit of the thumb width (Fig. 2-4) should be mentioned first.

The unit of length used since ancient times for locating acupoints is called a "cun," which is equal to the width of the interphalangeal joint of the thumb. There-fore, the exact length of a cun varies from person to person. For convenience in clinical practice, the width of the physician's interphalangeal thumb joint may be used as a cun, if his physique is similar to that of his patient. One cun can be further divided into 10 fractions, and one-tenth of a cun is called one "fen."