68 



SCIENCE 



[N. S. Vol. LI. No. 1307 



(3) Determination of specific require- 

 mentg. 

 C. Field interpretation of laboratory re- 

 sults. (In the case of temperature 

 this will probably mean remeasure- 

 ments unless recording instruments 

 have been used.) 



IV. Studies of plants and animals at the edges of 



their ranges. Determination of the environ- 

 ment at the edge of the ranges of plants 

 and animals should help to give, for the dif- 

 ferent environmental factors, the limits 

 within which individual species of plants 

 and animals can grow. 



V. Ecological differentiation in plants and ani- 



mals, structural and functional. 



(0) Ecological differentiation in single spe- 



cies. 

 (6) Growth forms and regional distribution. 

 Frequency of occurrence and abund- 

 ance, correlated vrith environmental 

 factors. 



VI. Migration of plant and animals. 



(1) Wind. 



(2) Animals. 



(3) Water. 



(4) Free movement of organisms. 



(5) Landslides and avalanches. 



(6) Movement of environment. 



VII. Relation of present plant and animal life to 



past floras and faunas. 



(1) In unglaciated regions. 



(2) In glaciated regions. 



(3) Post-glacial changes. 



VIII. Origin and composition of organic soUs. 



Includes forest soils, humus, peat, muck, 

 etc. 



IX. Studies of soil organisms. Bacteria, nema- 



todes, fungi and other organisms. 



SPECIAL PROBLEMS 



X. Relation of osmotic pressure to elongation. 



XI. Relation of temperature to root absorption. 



XII. Seasonal rhythm in organism, e. g.: 



(1) Resting period. 



(2) Photosynthesis of evergreens in 



winter. 



XIII. Relation of mycorrhiza to root hair devel- 



opment. (Part of general problem of 

 symbiosis.) 



XIV. Composition of light under forest canopies. 



Is this diffused light or light of different 

 compositionf 



XV. Effect of shade on chlorophyll content. 



XVI. Water requirement of forest trees. 



XVII. Nutrition of forest trees. Influence of vari- 



ous kinds of soils. 



XVIII. Minimum requirement of solar energy for 

 tree seedling growth or leaf development. 



XIX. Factors controlling the natural pruning of 



forest trees. 



XX. Factors controlling the non-periodic shedding 



of the leaves of forest trees. 



XXI. Study of seed bed in forests under natural 



conditions, in relation to germination and 

 establishment; comparison of seed bed in 

 forests with nursery seed beds. 



XXII. Sensitiveness of roots of different species 



to: (ffl) lack of oxygen, (&) soil acidity, 

 and (c) soil alkalinity. 



XXIII. Studies of fungi in forest soUs. 



(1) With relation to rendering nutrients 

 (chiefly nitrogen) available to 



(2) With relation to soil reaction (acid- 



ity or alkalinity). 



(3) Influence on ventilation. 



(4) Effect on plant roots. 



XXIV. Selective absorption of roots in soil. 



(1) Under different soil moisture con- 



ditions. 



(2) Under different atmospheric con- 

 ditions. 



XXV. Pull exerted by roots in withdrawing water 



from soils under different moisture con- 

 ditions. Influence of atmospheric con- 

 ditions Barrington Moore, 

 Chairman Committee on Cooperation 



THE CANADIAN BRANCH OF THE 



AMERICAN PHYTOPATHO- 



LOGICAL SOCIETY 



The first annual meeting of the Canadian 

 Branch of the American Phytopathological Society 

 was held at the Ontario Agricultural College 

 Guelph, Ontario, December 11 and 12. 



Canadian phytopathologdsts were well repre^ 

 sented at this meeting. Among those taking ac- 

 tive part in the proceedings were: Dr. A. H. E, 

 BuUer, University of Manitoba; Dr. J. H. Faull 

 Toronto University; Mr. P. A. Murphy, Dominion 

 Laboratory of Plant Pathology, Charlottetown, P, 

 E. I.; Mr. W. H. Rankin, St. Catharines; Mr. W, 

 P. Fraser, Saskatoon, Sask. ; R. J. Blair, Forest 

 Products Laboratories, Montreal; Mr. F. L. Dray 

 ton. Central Experimental Farm, Ottawa; Pro 

 fessor L. Caesar, Professor J. E. Howitt and Dr. R, 

 E. Stone, Ontario Agricultural College. 



