Plates 7, 8, 9, 10, 11

(Alternate and compare the two sides of Plates 7, 9, 10, and 11 by masking the opposite side.)

Plate 7: A study of the mechanism of action of m. frontalis in an old man (see his photographic portrait, Plate 3).

On the right, a moderate degree of electrical excitation of m. frontalis; fundamental lines (elevation and curvature of the eyebrow) and secondary lines (frontal folds, rounded and concentric with the arch of the eyebrow): attention.

On the left, a relaxed face.

Plate 8: Showing how the secondary expressive lines of attention join and are continuous at the midline during contraction of the right m. frontalis.

Plate 9: A study of m. frontalis in maximum contraction.

On the right maximal excitation of m. frontalis: profound attention.

On the left, a relaxed face.

Plate 10: Showing the expressive lines of m. frontalis in a young girl (see her portrait, Plate 5).

On the left, electrization of m. frontalis, with development of the fundamental line (elevation and curvature of the eyebrow, without frontal folds): attention.

On the right, spontaneous lowering of the eyebrow, due to very bright light.

Plate 11: Showing the secondary lines (frontal ridges, which are both irregular and numerous) produced by strong electrical excitation of m. frontalis, in a woman aged 41 years whose skin was tanned by the sun.

On the right the electrization of m. frontalis; elevation and curvature of the eyebrow; frontal ridges are irregular and numerous: attention. On the left, a relaxed face.