List of Plates Facing Page E. Percival. Plates 1–7 16 Patricia M. Ralph.         Plates 8–9 28 L. E. Richdale.         Plate 10 48 E. J. Searle.         Plates 11–13 64 C. O. Hutton.         Plates 14–15 48 B. B. Given.         Plates 16–20 164 L. E. Richdale.         Plate 21 and Graph 180 C. C. Anderson and J. H. Sorensen.         Plates 22–23 184 K. B. Cumderland.         Plates 24–25 188 J. E. Holloway.         Plates 26–29 206 R. Speight.         Plates 30–34 248 J. Marwick.         Plates 35–37 270 E. Amy Hodgson.         Plate 38 286 Marion L. Fyfe.         Plate 39 290 W. B. Benham.         Plate 40 294 B. B. Given.         Plate 41 298 Frederick Chapman 302 Frances R. Nurse.         Plates 42–44 312 Lucy B. Moore.         Plates 45–49 336 Elizabeth J. Batham.         Plates 50–54 368 Valerie Todd.         Plates 55–58 400 E. Fairburn.         Plate 59 408 C. A. Fleming.         Plates 60–62 416