VI 
CONTENTS. 
X. The Structure , Bionomics , and Forest Importance of Myelophilus minor. 
Hart. By Walter Ritchie, B.Sc., B.Sc. (Agr.). ; Fullerton Scholar, 
University of Aberdeen ; Research Scholar, University of Edinburgh. 
(With Two Plates), . . . . . . .213 
XL On Knots, with a Census of the Amphicheirals with Tivelve Crossings. 
By Mary Gertrude Haseman. (With One Plate), . . . 235 
PART II. (1918-19.) 
XII. The Development of the Heart in Man. By Professor 1). Waterston, 
M.D., Bute Medical School, University of St Andrews. (With 
Eighteen Text-figures and Sixteen Plate-figures), . . . 257 
XIII. The Formation, Rupture, and Closure of Ovarian Follicles in Ferrets 
and Ferret- Polecat Hybrids, and some Associated Phenomena. By 
Professor Arthur Robinson, University of Edinburgh. (With Ten 
Plates), . . . . . .... 303 
XIV. The Anatomy and Affinity of certain Rare and Primitive Ferns. By 
John M‘Lean Thompson, M.A., D.Sc., Lecturer in Botany, Glasgow 
University. (With Seven Plates and Thirty Figures in the Text), . 363 
XV. The Correlation between Relatives on the Supposition of Mendelian 
Inheritance. By R. A. Fisher, B.A. (With Four Figures in Text) . 399 
XVI. The Prostate Glands of the Earthworms of the Family Megascolecidse. 
By J. Stephenson, D.Sc., M.B., Lieut. -Col. Indian Medical Service; 
Professor of Zoology, Government College, Lahore ; and Haru Ram, 
M.Sc., Professor of Zoology, Hindu University, Benares, late Demon- 
strator of Zoology, Government College, Lahore. (With One Plate), . 435 
XVII. The Calciferous Glands of Earthworms. By J. Stephenson, D.Sc., 
M.B., Lieut. -Col. Indian Medical Service, Professor of Zoology, 
Government College, Lahore; and Baini Prashad, D.Sc., Assistant 
Director of Fisheries, Bengal and Bihar and Orissa, late Assistant 
Professor of Zoology, Government College, Lahore. (With One Plate 
and One Text-figure), ....... 455 
XVIII. The Morphology of the Prosencephalon of Spinax as a Type of 
Elasmobranch Fore-brain. By J. Stuart Thomson, M.Sc., Ph.D., 
Lecturer and Senior Demonstrator in Zoology in the Victoria Uni- 
versity of Manchester. (With Two Plates and Three Text-figures), . 487 
