480 OFFICIAL JOURNEYS. 
Section A (MATHEMATICS AND PHysICcs). 
Sir Ricoarp Pacet—Nature of Speech. 
Prof. A. 8. Eppineton—Interior of Stars. 
Sir Witt1am Brace—Crystal Structure. 
Section C (Grotoey). (See below.) 
Prof. J. A. Attan—Local Geology. 
Prof. P. G. H. Boswett—The Trend of Recent Work on the Petrology of 
Sedimentary Rocks. 
Prof. W. A. Parxs—Searching for Dinosaurs in Alberta. 
Dr. J. W. Mettor—Ceramics and the Clay Industries. 
Prof. W. A. Bone—The Coking Constituents of Coal. 
Sections K anp M (Botany AND AGRICULTURE). 
Prof. C. H. OStTENFELD—Means of Migration of Plants. 
Prof. E. C. JErrery—Polyploidy and Allied Phenomena in Relation to 
the Origin of Species. 
Sir Ropert Greic—Economic Trend of Animal Husbandry. 
Dr. A. W. Bortawick—Forest and Climate. 
Prof. W. W. Watts, F.R.S., President, opened the session of Section C in the 
Geological Department. The first communication was a description of the general 
geology of the province by Prof. J. A. Allan. In the short time at his disposal Prof. 
Allan carried his audience over a wide area by means of diagrams and sketches. He 
thus indicated the possibilities of the province in regard to mineral wealth and, at 
the same time, some of the problems confronting the geologist in that part of Canada. 
Prof. P.G. H. Boswell followed with his paper on V’he Trend of Recent Work on the 
Petrology of Sedimentary Rocks.. The following is an abstract :— 
The history of investigations on the petrography of sedimentary rocks shows that 
the phases passed through included the following: (a) The simple description of 
adventitious minerals in recent sands and gravels; (b) accounts of those of more 
ancient rocks ; (c) the description of lateral variation or constancy in mineral assem- 
blages of strata, deductions regarding source, drainage, etc., being made; (d) the 
utilisation of peculiarities of petrography for establishing relative age or for correla- 
tion over limited areas. Some light was obtained on the relative stability of various 
minerals in sedimentary rocks, but much work still remains to be accomplished. 
Descriptions of lithic and textural characters accompanied the more special work 
outlined above. 
Certain principles seem to have emerged from the detailed study of the complete 
series of British formations, aided by examination of numerous extra-British deposits. 
Amongst these principles are :— 
1. Sediments derived from crystalline rocks display greater variety in their con- 
stituent minerals (both in species and varietal characters) than those derived from 
pre-existing sediments. 
2. The variety of minerals in any one sediment (except as in 3 below) varies 
inversely as the distance from the source. Simplification and, in part, sorting are more 
effective as transport increases. ' 
3. The proportion of heavy minerals varies with the mechanical composition of 
the deposit. Sediments of coarse grade even near to their source may show but few 
heavy detrital minerals. 
4. Colour-bandings due to minerals (pay-streaks) indicate the action of wind and 
water currents and are therefore marginal features. 
5. The erosion of a rock-succession results in a reversal of the order of the 
characteristic constituents in the sediments produced. 
6. A general tendency exists for progressive mineralogical simplification and 
increasing uniformity with decreasing age in a series of beds laid down in a marine 
basin. More variety occurs in marginal deposits and less in those occupying the middle 
of the basin. 
