CONTENTS 
PAGE 
Campbell, Douglas Houghton.— The Gametophyte and IJmbryo of Botrychium 
obliquum, Miihl. With Plate VIII and eleven Figures in the Text .... 141 : 
Blackburn, Kathleen B., and Harrison, J. W. Heslop— The Status of the British 
Rose Forms as determined by their Cytological Behaviour. With Plates iX and X and 
five Figures in the Text . . 1 59 ■ 
Smith, T. O., and Butler, O.— Relation of Potassium to Growth in Plants . . . 189 . 
Jeffrey, Edward Charles, and Torrey, Ray Ethan.— Transitional Herbaceous 
Dicotyledons. With Plates XI-XI 1 1 and five Figures in the Text .... 227 
Holmes, M. G. — A Contribution to the Study of Water-conductivity in Sycamore Wood. 
With thirteen Figures in the Text . . . . 251 
Seifriz, William. — Observations on some Physical Properties of Protoplasm by Aid of 
Microdissection. With one Figure in the Text 269 j 
NOTES. 
Sahni, B. — Note on the Presence of a ‘ Tent-pole ’ in the Seed of Cephalotaxus pedun- 
culata With two Figures in the Text 297 
Welsford, E. J. — Division of the Nuclei in Synchytrium endobioticum, Perc. |' 
With one Figure in the Text 298 
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