372 SECTIONAL TRANSACTIONS.- -K. 



2. Professor Lloyd Williams. — Alternation of Generations 



in the Laminariacece. 



3. Mrs. Eleanor M. Reid. — The History of the West Euro- 



pean Pliocene Flora as Deciphered by the Study of 



Fossil Seeds. 



Afternoon. 



4. Prof. R. Chodat. — Some Aspects of Plant Ecology and 



Biology in Paragiuv}£. 



5. Prof. F. J. Lewis and Miss Gwynneth M. Tuttle. — 



On the Phenomena attending Seasonal Conversion of 

 Reserve Food Materials in the Leaves of Picea 

 canadensis. 



6. Miss Gwynneth M. Tuttle. — On the Nature of Reserve 



Food Materials in the Tissues of some Plants of 

 Northern Alberta. 



Wednesday, August 25. 



v. Joint Discussion with Sections C and D on Mendelism and 

 Paleontology : The Factorial Interpretation of Gradual 

 Changes, especially when New Characters appear late 

 in the Individual Life-cycle. 



(See programme of Section C, p. 354.) 



8. Lr. E. A. Newell Arber. — The Leaves of the Irids and 



the Phyllode Theory. 



Afternoon. 



9. Dr. Harold Wager. Geotropism of Foliage Leaves; 



Geotropic and Nastic Growth; Localisation and 

 Diff.erentiation of Geotropic Stimulus. Are Leaves 

 dia-geotropic ? 



10. Prof. J. Small and Miss W. Eea. — Further Evidence for 



the Differentiation in Hydrion Concentration in stem 

 and root as the explanation of Positive and Negative 

 Geotropism, with evidence for Carbon-Dinxide Balance 

 as the cau.'ie of that Differentiation. 



11, Miss K. B. Blackburn. — A7iomalies in Microspore 



Formation in ' Rosa ' and its possible connection with 

 Hybridity in the Genus, including a description of 

 normal ineiosis in three species for comparison with 

 ahnormnl features found i)i ten forms, including two 

 hybrid.^. 



Excursion. 



A short Botanical Expedition took place to visit local plants 

 of considerable interest. 



